BGS logo and link to BGS website homepage

Full listing of The BGS Rock Classification Scheme

Agate - A type of chert consisting of translucent cryptocrystalline quartz. This is a variegated chalcedony, commonly mixed or alternating with opal and characterised by banded colours. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Agglomerate - A type of pyroclastic-rock. In the Rock Classification Scheme, it is a pyroclastic-rock in which more than 75% of the pyroclastic fragments exceed 64 mm in size. Agglomerate and pyroclastic-breccia are separated according to the relative proportion of blocks (angular fragments exceeding 64 mm) and bombs (rounded fragments exceeding 64 mm): if bombs dominate over blocks the rock is agglomerate. It is the consolidated equivalent of bomb-tephra or block-bomb-tephra. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Agglomerate, basaltic Agglomerate, rhyolitic Agglomerate, trachytic Aggregate - A type of artificial deposit. In the building industry, aggregate is a range of mineral substances, for example sand, gravel, crushed rock, stone, slag and other minerals which, when cemented, forms concrete, mortar, mastic, and plaster. Uncemented, it can be used as a bulk material in road-making and ballast. British Geological Survey Research Report RR/99/04, appendix 1. Alcrete - One of the hydroxides and oxides of alumina. It is an indurated deposit consisting predominantly of an accumulation of aluminium sesquioxides. British Geological Survey Research Report RR/99/03, section 13.6. Alkali-feldspar-granite - A type of granitic-rock. In the Rock Classification Scheme, it is a granitic rock in which plagioclase comprises less than 10% of the total feldspar. The mineral mode plots in field 2 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Alkali-feldspar-microgranite - A type of microgranitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of alkali-feldspar-granite. British Geological Survey Research Report RR/99/06, section 5.1. Alkali-feldspar-microsyenite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of alkali-feldspar-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Alkali-feldspar-rhyolite - A type of rhyolitic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 2 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. It is the fine-grained equivalent of alkali-feldspar-granite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Alkali-feldspar-syenite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 6 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Alkali-feldspar-trachyte - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 6 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Amphibolite - A type of metamorphic rock with unknown protolith based on modal composition. In the Rock Classification Scheme, it is one composed largely of hornblende and plagioclase. This mineralogy reflects amphibolite facies conditions. Note that para-amphibolite indicates a rock that is thought to have a sedimentary protolith, and ortho-amphibolite indicates a rock that is thought to have an igneous protolith. British Geological Survey Research Report RR/99/02, section 6.2. Amphibolite, foliated Amphibolite, quartz-xenolithic Amphibolite, schistose Analcime-gabbro - A foid-gabbro in which the dominant feldspathoid mineral is analcime. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Analcime-gabbro, hornblende Analcime-microgabbro - A foid-microgabbro in which the dominant feldspathoid mineral is analcime. It is the medium-grained equivalent of analcime-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Analcime-microgabbro, olivine Andesite (TAS) - A type of andesitic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of andesite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Andesite - A type of andesitic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in fields 9 and 10 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Andesite and basalt may be separated chemically using SiO2 content: if wt% SiO2 is greater than 52% the rock is andesite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19, 21. Andesite, augite Andesite, feldspar-phyric Andesite, foliated Andesite, garnet-bearing Andesite, garnet-rich Andesite, glassy Andesite, hypersthene Andesite, lava Andesite, porphyritic Andesite, pyroxene Andesite, pyroxene, feldspar-phyric Andesite, pyroxene-plagioclase-phyric Andesite, tholeiitic Andesitic-rock (TAS) Andesitic-rock - A type of mafite. In the Rock Classification Scheme, this class includes andesite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Andesitic-rock, foliated Anhydrite-stone - A type of non-carbonate salt that is composed of particles of the sulphate mineral anhydrite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Ankerite-boundstone - A dolomite-boundstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-framestone - A dolomite-framestone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-grainstone - A dolomite-grainstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-gravel - A type of ankerite-sediment. In the Rock Classification Scheme, it is one in which over 25% of clasts are larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.2, table 6 and fig. 7. See also: silicate-gravel. Ankerite-microsparstone - A dolomite-microsparstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-microstone - A dolomite-microstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-mud - A type of ankerite-sediment. In the Rock Classification Scheme, it is one in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.2, table 6 and fig. 7. See also: silicate-mud. Ankerite-mudstone - A dolomite-mudstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-packstone - A dolomite-packstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-pseudosparstone - A dolomite-pseudosparstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-sand - A type of ankerite-sediment. In the Rock Classification Scheme, it is one in which clasts are predominantly 32 µm to 2 mm, with less than 75% of the clasts smaller than 32 µm and less than 25% larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.2, table 6 and fig. 7. See also: silicate-sand. Ankerite-sediment - In the Rock Classification Scheme, this is a dolomite-sediment where it is known that the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-sparstone - A dolomite-sparstone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankerite-wackestone - A dolomite-wackestone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Ankeritestone - In the Rock Classification Scheme, this is a dolostone where it is known that ankerite forms more than 50% of the carbonate component. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Anorthosite - A type of anorthositic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Diorite, gabbro and anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is less than 10% the rock is anorthosite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Anorthositic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes anorthosite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Anthracite - A type of coal. It is a member of the pure humic coal series. The members of the pure humic coal series can be ranked in order as peat (the unlithified form), lignite, bituminous-coal, and anthracite (the lithified forms) based on increasing carbon content and decreasing volatile content. Anthracite is a hard black coal with a semi-metallic lustre and semiconchoidal fracture. It ignites with difficulty and burns without smoke. British Geological Survey Research Report RR/99/03, section 6.1, table 16 and fig. 10. Apatite-magnetite-rock Aragonite-boundstone - A lime-boundstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-framestone - A lime-framestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-grainstone - A lime-grainstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-gravel - A type of lime-gravel in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Aragonite-limestone - A limestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-microsparstone - A lime-microsparstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-microstone - A lime-microstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-mud - A type of lime-mud in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Aragonite-mudstone - A lime-mudstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-packstone - A lime-packstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-pseudosparstone - A lime-pseudosparstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-sand - A type of lime-sand in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Aragonite-sediment - A type of lime-sediment in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Aragonite-sparstone - A lime-sparstone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Aragonite-wackestone - A lime-wackestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Arenite - A type of silicate-sandstone. In the Rock Classification Scheme, arenites have 0 - 15% matrix. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. Argillaceous rock Argillaceous rock, dolomitic Artificial deposit - A type of artificially modified ground. British Geological Survey Research Report RR/99/04, section 3. Artificially modified ground - A type of superficial deposit (natural and/or artificial). British Geological Survey Research Report RR/99/04, section 3. Asbestos waste - A type of artificial deposit. It is waste material derived from asbestos products or their manufacture. British Geological Survey Research Report RR/99/04, appendix 1. Ash - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments is less than 64 mm. Lapilli-tephra, lapilli-ash, and ash are separated according to the relative proportion of lapilli-grade (2 - 64 mm) and ash-grade (<2 mm) fragments: if less than 25% of the fragments are lapilli the sediment is ash. It is the unconsolidated equivalent of tuff. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Ash fill (industrial) - A type of artificial deposit. It is a general term for powdery residue left after combustion of any substance. British Geological Survey Research Report RR/99/04, appendix 1. See also: ash. Ash, crystal Ash, lithic Ash, vitric Ash-breccia - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment which contains more than 25% of each of the main pyroclastic fragment size divisions: blocks and bombs (>64 mm), lapilli (2 - 64 mm), and ash (<2 mm). It is the unconsolidated equivalent of tuff-breccia. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Augite-andesite, metalava Ballast - A type of artificial deposit. It is coarse stone mixed with sand etc., used to form the bed of a railway or the substratum of a road. British Geological Survey Research Report RR/99/04, appendix 1. Banded-bright-coal - A type of bituminous-coal, classified according to brightness. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Banded-coal - A type of bituminous-coal, classified according to brightness. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Banded-dull-coal - A type of bituminous-coal, classified according to brightness. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Barite-stone - A type of non-carbonate salt that is composed of particles of the sulphate mineral barite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Baryte (vein) - A type of vein rock. Basalt (TAS) - A type of basaltic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of basalt (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Basalt - A type of basaltic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in fields 9 and 10 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Andesite and basalt may be separated chemically using SiO2 content: if wt% SiO2 is less than 52% the rock is basalt. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Basalt, alkali - A type of basalt (TAS). In the Rock Classification Scheme, the root name basalt (TAS) may be divided into alkali basalt and subalkali basalt according to the state of silica saturation. If the analysis contains normative nepheline the rock may be called an alkali basalt. British Geological Survey Research Report RR/99/06, section 5.2. Basalt, clinopyroxene-olivine-macrophyric Basalt, clinopyroxene-olivine-microphyric Basalt, clinopyroxene-olivine-phyric Basalt, clinopyroxene-olivine-plagioclase-macrophyric Basalt, clinopyroxene-olivine-plagioclase-phyric Basalt, feldspar-phyric Basalt, foliated Basalt, glassy Basalt, hornfelsed Basalt, lava-pillowed Basalt, macrophyric Basalt, microporphyritic Basalt, olivine-clinopyroxene-microphyric Basalt, olivine-clinopyroxene-plagioclase-macrophyric Basalt, olivine-clinopyroxene-plagioclase-phyric Basalt, olivine-macrophyric Basalt, olivine-microphyric Basalt, olivine-phyric Basalt, olivine-plagioclase-macrophyric Basalt, olivine-plagioclase-microphyric Basalt, olivine-plagioclase-phyric Basalt, plagioclase-macrophyric Basalt, plagioclase-microphyric Basalt, plagioclase-olivine-clinopyroxene-macrophyric Basalt, porphyritic Basalt, pyroxene-phyric Basalt, schistose Basalt, subalkali - A type of basalt (TAS). In the Rock Classification Scheme, the root name basalt (TAS) may be divided into alkali basalt and subalkali basalt according to the state of silica saturation. If the analysis contains no normative nepheline the rock may be called a subalkali basalt. British Geological Survey Research Report RR/99/06, section 5.2. Basalt, tholeiitic - A subgroup of subalkali basalt. Tholeiitic describes a variety of basalt which is saturated or slightly oversaturated in silica with respect to alkalis so that hypersthene appears in the CIPW norm and hypersthene or pigeonite amongst the modal pyroxenes. Olivine may be present in widely varying amounts, or absent. The term is also used for a suite of rocks showing marked iron-enrichment on AFM diagrams. British Geological Survey Research Report RR/99/06, section 8.4. Basalt, variolitic Basaltic-andesite - A type of andesitic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of basaltic-andesite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Basaltic-andesite, porphyritic Basaltic-rock - A type of mafite. In the Rock Classification Scheme, this class includes basalt and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Basaltic-rock, hornfelsed Basaltic-rock, macroporphyritic (unclassed) Basaltic-rock, microporphyritic (unclassed) Basaltic-rock, olivine-clinopyroxene-macrophyric Basaltic-rock, plagioclase-macrophyric Basaltic-rock, plagioclase-microphyric Basaltic-rock, plagioclase-olivine-clinopyroxene-macrophyric Basaltic-rock, plagioclase-olivine-clinopyroxene-phyric Basaltic-rock, plagioclase-olivine-microphyric Basaltic-rock, plagioclase-phyric Basaltic-trachyandesite - A type of trachytic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of basaltic-trachyandesite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Basanite (TAS) - A type of tephritic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of basanite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Basanite - A type of tephritic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 14 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Basanite and tephrite are distinguished by the amount of olivine in the CIPW norm: if normative olivine exceeds 10% the rock is basanite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Basanite, analcime Basanite, biotite Basanite, nepheline Basanitic-foidite - A type of foiditic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 15b of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Basanitic-foidite and tephritic-foidite are distinguished by the amount of olivine in the CIPW norm: if normative olivine exceeds 10% the rock is basanitic-foidite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Bauxite - One of the hydroxides and oxides of alumina. It consists predominantly of hydrated aluminium oxides with iron oxides and other impurities. British Geological Survey Research Report RR/99/03, section 9.2. Bauxite-clay Benmoreite - A sodic trachyandesite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Bioclastic sand deposit - A type of biological sediment. It consists of sand composed of broken and fragmental remains of organisms including shells, coral and lithothamnium algae. British Geological Survey Research Report RR/99/04, appendix 2. Biological deposit - A type of natural superficial deposit. The term describes a deposit directly formed and characterised by living organisms which secrete either silica or carbonate to form a skeleton or shell. British Geological Survey Research Report RR/99/04, appendix 2. Biological rock - A type of biological deposit. In the Rock Classification Scheme, it is the consolidated equivalent of biological sediment. Biological sediment - A type of biological deposit. In the Rock Classification Scheme, it is the unconsolidated equivalent of biological rock. Bituminous deposit Bituminous-coal - A type of coal. It is a member of the pure humic coal series. The members of the pure humic coal series can be ranked in order as peat (the unlithified form), lignite, bituminous-coal, and anthracite (the lithified forms) based on increasing carbon content and decreasing volatile content. Bituminous-coal is a black, hard and bright coal which typically breaks into rectangular lumps. The bituminous coals can be subdivided in two ways. The first scheme is based on lithotypes which are macroscopically recognisable bands of coal seams. This scheme can be used for describing individual specimens or discrete horizons within a coal seam. Using this scheme, bituminous-coal can be subdivided into vitrain, clarain, fusain, and durain. The second scheme describes the brightness of the coal, and should be used in the field to describe megascopically distinct layers of coal seams. Using this scheme, bituminous-coal can be subdivided into bright-coal, banded-bright-coal, banded-coal, banded-dull-coal, and dull-coal. British Geological Survey Research Report RR/99/03, section 6.1, table 16 and fig. 10. Black-lignite - A type of lignite. It is dark brown to black with a silky lustre, and much harder than brown-lignite. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Blast-furnace slag - A type of artifical deposit. It is semi-fused or fused waste material produced in the metal industry. British Geological Survey Research Report RR/99/04, appendix 1. Blastomylonite - A type of mylonitic-rock. Blastomylonites are formed where extensive recrystallisation and mineral growth accompanied deformation, resulting, for example, in ribbon textures in quartzose rocks. British Geological Survey Research Report RR/99/02, section 7.3. Block-bomb-tephra - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments exceeds 64 mm. Block-tephra, bomb-block-tephra, block-bomb-tephra, and bomb-tephra are separated according to the relative proportion of blocks (angular fragments exceeding 64 mm) and bombs (rounded fragments exceeding 64 mm): if between 25% and 50% of all pyroclastic fragments bigger than 64 mm are blocks the sediment is block-bomb-tephra. It is the unconsolidated equivalent of agglomerate. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Block-tephra - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments exceeds 64 mm. Block-tephra, bomb-block-tephra, block-bomb-tephra, and bomb-tephra are separated according to the relative proportion of blocks (angular fragments exceeding 64 mm) and bombs (rounded fragments exceeding 64 mm): if more than 75% of all pyroclastic fragments bigger than 64 mm are blocks the sediment is block-tephra. It is the unconsolidated equivalent of pyroclastic-breccia. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Bog iron-ore - A type of manganiferous/ferruginous deposit. It is a porous, earthy form of limonite (impure hydrous ferric oxide). British Geological Survey Research Report RR/99/04, section 4 and tables 5, 17. Boghead-cannel-coal - A type of sapropelic-coal. It is a transitional stage between cannel-coal and boghead-coal in which miospores dominate over alginite. British Geological Survey Research Report RR/99/03, section 6.2 and fig. 10. Boghead-coal - A type of sapropelic-coal. It is similar to cannel-coal but browner and rich in alginite with very few miospores. It appears unstratified on macroscopic examination. Microscopic examination shows that boghead-coal consists of alginite and very finely dispersed inertinite and vitrinite. The proportion of alginite can vary widely. Boghead-coal is sometimes referred to as torbanite. This term is not recommended for usage. British Geological Survey Research Report RR/99/03, section 6.2 and fig. 10. Bomb-block-tephra - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments exceeds 64 mm. Block-tephra, bomb-block-tephra, block-bomb-tephra, and bomb-tephra are separated according to the relative proportion of blocks (angular fragments exceeding 64 mm) and bombs (rounded fragments exceeding 64 mm): if between 50% and 75% of all pyroclastic fragments bigger than 64 mm are blocks the sediment is bomb-block-tephra. It is the unconsolidated equivalent of pyroclastic-breccia. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Bomb-tephra - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments exceeds 64 mm. Block-tephra, bomb-block-tephra, block-bomb-tephra, and bomb-tephra are separated according to the relative proportion of blocks (angular fragments exceeding 64 mm) and bombs (rounded fragments exceeding 64 mm): if less than 25% of all pyroclastic fragments bigger than 64 mm are blocks the sediment is bomb-tephra. It is the unconsolidated equivalent of agglomerate. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Bone-coal - A type of impure-coal with clay disseminated throughout the organic-matter. It can be recognised by its dull appearance and grey streak. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Boninite - A type of high-Mg rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of boninite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 22. Borax-stone - A type of non-carbonate salt that is composed of particles of the borate mineral borax. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Boulders [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). Boulders, clayey [Unlithified Deposits Coding Scheme] Boulders, clayey, cobbly, gravelly [Unlithified Deposits Coding Scheme] Boulders, clayey, gravelly [Unlithified Deposits Coding Scheme] Boulders, clayey, peaty [Unlithified Deposits Coding Scheme] Boulders, clayey, sandy [Unlithified Deposits Coding Scheme] Boulders, clayey, sandy, gravelly [Unlithified Deposits Coding Scheme] Boulders, cobbly [Unlithified Deposits Coding Scheme] Boulders, cobbly, clayey [Unlithified Deposits Coding Scheme] Boulders, cobbly, gravelly [Unlithified Deposits Coding Scheme] Boulders, cobbly, gravelly, clayey [Unlithified Deposits Coding Scheme] Boulders, cobbly, peaty [Unlithified Deposits Coding Scheme] Boulders, cobbly, sandy [Unlithified Deposits Coding Scheme] Boulders, granite [Unlithified Deposits Coding Scheme - Extended] Boulders, gravelly [Unlithified Deposits Coding Scheme] Boulders, gravelly, cobbly [Unlithified Deposits Coding Scheme] Boulders, gravelly, peaty [Unlithified Deposits Coding Scheme] Boulders, gravelly, sandy [Unlithified Deposits Coding Scheme] Boulders, gravelly, silty [Unlithified Deposits Coding Scheme] Boulders, peaty [Unlithified Deposits Coding Scheme] Boulders, sandy [Unlithified Deposits Coding Scheme] Boulders, sandy, clayey [Unlithified Deposits Coding Scheme] Boulders, sandy, gravelly [Unlithified Deposits Coding Scheme] Boulders, sandy, peaty [Unlithified Deposits Coding Scheme] Boulders, silty [Unlithified Deposits Coding Scheme] Boulders, silty, peaty [Unlithified Deposits Coding Scheme] Boulders, silty, sandy [Unlithified Deposits Coding Scheme] Breccia - A type of silicate-conglomerate. In the Rock Classification Scheme, this term may be used for conglomerates made of sharply angular clasts. British Geological Survey Research Report RR/99/03, section 2.1 and fig. 2. Synonym: angular silicate-conglomerate. Breccia, hornfelsed Breccia, quartzite Breccia, slide Breccia, trachyandesitic Breccia, trachydacitic Brick - A type of artifical deposit. It consists of clay kneaded, moulded, and baked (fired) or sun-dried, usually as small, rectangular blocks. British Geological Survey Research Report RR/99/04, appendix 1. Bright-coal - A type of bituminous-coal, classified according to brightness. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Brown-lignite - A type of lignite. It is brown with a dull or earthy lustre. Many are banded with a fibrous structure. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Building rubble - A type of artificial deposit. It is waste material derived from construction, usually consisting of brick, concrete, stone and plasterboard with minor amounts of wood and metal. It may be partly organic in content. British Geological Survey Research Report RR/99/04, appendix 1. Calcarenite - A type of limestone. The term may be used as a synonym for sand-grade limestone. British Geological Survey Research Report RR/99/03, section 3.1. Calcilutite - A type of limestone. The term may be used as a synonym for mud-grade limestone. British Geological Survey Research Report RR/99/03, section 3.1. Calciocarbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a chemical classification is necessary because the rock is too fine grained for an accurate mode to be determined, or if the carbonate minerals are complex Ca-Mg-Fe solid solutions. The definition of calciocarbonatite is as shown in British Geological Survey Research Report RR/99/06, section 6.1 and figs. 25, 26. See also: calcite-carbonatite. Calcite-boundstone - A lime-boundstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-carbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a modal classification is possible. In a calcite-carbonatite more than 90% of the carbonate is calcite. British Geological Survey Research Report RR/99/06, section 6.1 and fig. 25. See also: calciocarbonatite. Calcite-framestone - A lime-framestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-grainstone - A lime-grainstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-gravel - A type of lime-gravel in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Calcite-limestone - A limestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-microsparstone - A lime-microsparstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-microstone - A lime-microstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-mud - A type of lime-mud in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Calcite-mudstone - A lime-mudstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-packstone - A lime-packstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-pseudosparstone - A lime-pseudosparstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-sand - A type of lime-sand in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Calcite-sediment - A type of lime-sediment in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and table 2. Calcite-sparstone - A lime-sparstone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcite-wackestone - A lime-wackestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Calcrete - A type of duricrust. It is a conglomerate consisting of surficial sand and gravel cemented into a hard mass by calcium carbonate. British Geological Survey Research Report RR/99/03, section 13.6; RR/99/04, appendix 2. Synonym: caliche. Calcsilicate-rock - A type of metasedimentary rock composed largely of calcsilicate and/or carbonate minerals. In the Rock Classification Scheme, it is one in which the modal calcsilicate mineral content exceeds the modal abundance of carbonate minerals. British Geological Survey Research Report RR/99/02, section 3.2 and fig. 7. Calcsilicate-rock, gneissose Calcsilicate-rock, granofelsic Calcsilicate-rock, mylonitic Calcsilicate-rock, schistose Camptonite - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which plagioclase is the dominant feldspar, feldspar dominates over feldspathoids, and the predominant mafic minerals are amphibole, Ti-rich augite, olivine, and biotite. British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Cannel-boghead-coal - A type of sapropelic-coal. It is a transitional stage between cannel-coal and boghead-coal in which alginite dominates over miospores. British Geological Survey Research Report RR/99/03, section 6.2 and fig. 10. Cannel-coal - A type of sapropelic-coal. It is a dull black, has a waxy lustre, is homogeneous, has concoidal fracture, and is rich in miospores with very little alginite. Macroscopic examination shows no stratification. Microscopic examination shows that compared with humic coals the macerals are more intimately mixed and at the same time are finer and more uniformly grained. Moreover cannel-coal frequently shows a uniform microstratification and is more homogeneous in structure than humic coals. Siderite is commonly abundant in cannel-coal. There is a continuous range of transitional stages between cannel-coal and boghead-coal with both alginite and miospores present. Intermediate types can be called boghead-cannel-coal and cannel-boghead-coal. British Geological Survey Research Report RR/99/03, section 6.2 and fig. 10. Cannel-metamudstone Cannel-mudstone - A type of sedimentary-rock rich in organic matter. Sapropelite and cannel-mudstone are both derived from the unlithified fine organic mud termed sapropel. These sapropels contain more inorganic matter and plant matter than the sapropels that form sapropelic coals. Inorganic sedimentary rocks rich in sapropel are classified according to their type of organic matter. Sapropelite is rich in alginite, whereas cannel-mudstone is rich in miospores. In the Rock Classification Scheme, it is recommended that total organic content (TOC) for cannel-mudstone should be between 8% and 50%. British Geological Survey Research Report RR/99/03, section 6.3, table 18 and fig. 10. Carbonate sediment and sedimentary rock - In the Rock Classification Scheme, carbonate sediments and rocks are defined as rocks in which the carbonate component forms more than 50% of the sediment or rock. For a rock to be termed a carbonate sedimentary rock, the 50% carbonate criterion should not include any carbonate cement in an originally non-carbonate rock. The class is divided into lime-sediment and limestone, dolomite-sediment, dolostone and magnesite-stone, and Na carbonate sedimentary rock, defined on the basis of the carbonate composition. British Geological Survey Research Report RR/99/03, section 3. Carbonate-rock Carbonate-rock, mylonitic Carbonatite - A type of exotic crystalline igneous rock. In the Rock Classification Scheme, it is defined as an igneous rock that contains more than 50% modal primary carbonate. It is known to occur in extrusive, shallow and deep-seated environments. British Geological Survey Research Report RR/99/06, section 6.1 and figs. 25, 26. Cardboard - A type of artifical deposit. It consists of thick paper or paste board. British Geological Survey Research Report RR/99/04, appendix 1. Carnallite-stone - A type of non-carbonate salt that is composed of particles of the chloride mineral carnallite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Cataclasite - A type of cataclastic-rock. In the Rock Classification Scheme, it is one in which fragments significantly coarser than the matrix comprise 10 - 50% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.2 and table 4. Cataclastic-rock - A type of unfoliated mechanically broken rock with primary cohesion. These rocks are formed at higher confining pressures than those without cohesion. The nature of the rocks depends on factors such as confining pressure, original lithology, amount and duration of movement, and the availability of fluids. Cataclastic rocks exhibit grain size reduction by fragmentation of grains during deformation. In the Rock Classification Scheme, they are classified as protocataclasite, cataclasite, and ultracataclasite on the relative proportions of fragments and matrix. British Geological Survey Research Report RR/99/02, section 7.2 and table 4. Cementstone (historical use only) Ceramic waste - A type of artifical deposit. It consists of waste material from the pottery and ceramic industries, commonly comprising partly fired and fired clay products. British Geological Survey Research Report RR/99/04, appendix 1. Chalk - A friable and porous limestone. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Chalk, argillaceous Chalk, clay-rich Chalk, marly Chalk, marly, glauconitic Chalk, sandy Chalk, shelly, marly Chalk, silty Chemical deposit (natural superficial) - A type of natural superficial deposit. It consists of sediments formed primarily by precipitation from solution or colloidal suspension or by the deposition of insoluble precipitates. British Geological Survey Research Report RR/99/04, appendix 2 and tables 5, 17. Chemical waste - A type of artifical deposit. It consists of waste material and by-products derived from the chemical industry and chemical processes. British Geological Survey Research Report RR/99/04, appendix 1. Chert - A type of siliceous rock. It usually has a porosity of less than 10%. Chert is dense, very hard, and has a vitreous lustre. It can be further classified as opaline-chert and quartzose-chert according to the type of silica. It may not be possible to accurately use this classification without X-ray analysis. In addition, the root names jasper, flint, and agate are available to describe distinctive types. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. China clay waste - A type of artifical deposit. It consists of kaolin and waste materials derived from the extraction of kaolin from granitic rocks. British Geological Survey Research Report RR/99/04, appendix 1. Chromitite - A type of rock of restricted mineralogy. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock in which chromite exceeds 90% of the mineral mode. British Geological Survey Research Report RR/99/06, section 8.2. Clarain - A type of bituminous-coal, classified according to lithotype. It consists of bright to semi-bright bands of finely laminated coal. Clarain generally exhibits an overall silky lustre, and commonly contains fine vitrain bands alternating with a duller attrital groundmass. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Clay Clay (brick/tile) waste - A type of artifical deposit. It consists of generally clayey material usually containing at least 20% by weight of clay particles (less than 1/16 mm in size). British Geological Survey Research Report RR/99/04, appendix 1. Clay [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). Clay, bouldery [Unlithified Deposits Coding Scheme] Clay, bouldery, cobbly [Unlithified Deposits Coding Scheme] Clay, bouldery, peaty [Unlithified Deposits Coding Scheme] Clay, calcareous [Unlithified Deposits Coding Scheme - Extended] Clay, calcareous, sandy [Unlithified Deposits Coding Scheme - Extended] Clay, cobbly [Unlithified Deposits Coding Scheme] Clay, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, cobbly, gravelly [Unlithified Deposits Coding Scheme] Clay, cobbly, gravelly, sandy [Unlithified Deposits Coding Scheme] Clay, cobbly, peaty [Unlithified Deposits Coding Scheme] Clay, cobbly, sandy [Unlithified Deposits Coding Scheme] Clay, cobbly, sandy, gravelly [Unlithified Deposits Coding Scheme] Clay, glauconitic Clay, gravelly Clay, gravelly [Unlithified Deposits Coding Scheme] Clay, gravelly cobbly peaty [Unlithified Deposits Coding Scheme] Clay, gravelly, bouldery [Unlithified Deposits Coding Scheme] Clay, gravelly, bouldery, sandy [Unlithified Deposits Coding Scheme] Clay, gravelly, bouldery, sandy, silty [Unlithified Deposits Coding Scheme] Clay, gravelly, bouldery, silty [Unlithified Deposits Coding Scheme] Clay, gravelly, bouldery, silty, sandy [Unlithified Deposits Coding Scheme] Clay, gravelly, cobbly [Unlithified Deposits Coding Scheme] Clay, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, gravelly, cobbly, sandy [Unlithified Deposits Coding Scheme] Clay, gravelly, peaty [Unlithified Deposits Coding Scheme] Clay, gravelly, peaty, sandy [Unlithified Deposits Coding Scheme] Clay, gravelly, peaty, sandy, silty [Unlithified Deposits Coding Scheme] Clay, gravelly, peaty, silty [Unlithified Deposits Coding Scheme] Clay, gravelly, sandy [Unlithified Deposits Coding Scheme] Clay, gravelly, sandy, bouldery [Unlithified Deposits Coding Scheme] Clay, gravelly, sandy, cobbly [Unlithified Deposits Coding Scheme] Clay, gravelly, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, gravelly, sandy, shelly [Unlithified Deposits Coding Scheme - Extended] Clay, gravelly, sandy, silty [Unlithified Deposits Coding Scheme] Clay, gravelly, shelly [Unlithified Deposits Coding Scheme - Extended] Clay, gravelly, silty [Unlithified Deposits Coding Scheme] Clay, gravelly, silty, peaty [Unlithified Deposits Coding Scheme] Clay, gravelly, silty, sandy [Unlithified Deposits Coding Scheme] Clay, laminated Clay, organic Clay, peaty [Unlithified Deposits Coding Scheme] Clay, peaty, cobbly [Unlithified Deposits Coding Scheme] Clay, peaty, gravelly [Unlithified Deposits Coding Scheme] Clay, peaty, gravelly, cobbly [Unlithified Deposits Coding Scheme] Clay, peaty, sandy [Unlithified Deposits Coding Scheme] Clay, peaty, sandy, gravelly [Unlithified Deposits Coding Scheme] Clay, peaty, sandy, silty [Unlithified Deposits Coding Scheme] Clay, peaty, sandy, silty, gravelly [Unlithified Deposits Coding Scheme] Clay, peaty, silty [Unlithified Deposits Coding Scheme] Clay, peaty, silty, sandy [Unlithified Deposits Coding Scheme] Clay, peaty, silty, sandy, gravelly [Unlithified Deposits Coding Scheme] Clay, pebbly Clay, sandy Clay, sandy [Unlithified Deposits Coding Scheme] Clay, sandy, bouldery [Unlithified Deposits Coding Scheme] Clay, sandy, bouldery, gravelly [Unlithified Deposits Coding Scheme] Clay, sandy, calcareous [Unlithified Deposits Coding Scheme - Extended] Clay, sandy, cobbly [Unlithified Deposits Coding Scheme] Clay, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, sandy, cobbly, gravelly [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, bouldery [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, cobbly [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, peaty [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, peaty, silty [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, shelly [Unlithified Deposits Coding Scheme - Extended] Clay, sandy, gravelly, silty [Unlithified Deposits Coding Scheme] Clay, sandy, gravelly, silty, peaty [Unlithified Deposits Coding Scheme] Clay, sandy, peaty [Unlithified Deposits Coding Scheme] Clay, sandy, peaty, gravelly [Unlithified Deposits Coding Scheme] Clay, sandy, peaty, silty [Unlithified Deposits Coding Scheme] Clay, sandy, peaty, silty, gravelly [Unlithified Deposits Coding Scheme] Clay, sandy, shelly [Unlithified Deposits Coding Scheme - Extended] Clay, sandy, silty [Unlithified Deposits Coding Scheme] Clay, sandy, silty, gravelly [Unlithified Deposits Coding Scheme] Clay, sandy, silty, gravelly, bouldery [Unlithified Deposits Coding Scheme] Clay, sandy, silty, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, sandy, silty, gravelly, peaty [Unlithified Deposits Coding Scheme] Clay, sandy, silty, peaty [Unlithified Deposits Coding Scheme] Clay, shell Clay, shelly [Unlithified Deposits Coding Scheme - Extended] Clay, shelly, sandy [Unlithified Deposits Coding Scheme - Extended] Clay, silty Clay, silty [Unlithified Deposits Coding Scheme] Clay, silty, bouldery [Unlithified Deposits Coding Scheme] Clay, silty, cobbly [Unlithified Deposits Coding Scheme] Clay, silty, gravelly [Unlithified Deposits Coding Scheme] Clay, silty, gravelly, peaty [Unlithified Deposits Coding Scheme] Clay, silty, gravelly, sandy [Unlithified Deposits Coding Scheme] Clay, silty, gravelly, sandy, peaty [Unlithified Deposits Coding Scheme] Clay, silty, peaty [Unlithified Deposits Coding Scheme] Clay, silty, peaty, gravelly [Unlithified Deposits Coding Scheme] Clay, silty, peaty, sandy [Unlithified Deposits Coding Scheme] Clay, silty, peaty, sandy, gravelly [Unlithified Deposits Coding Scheme] Clay, silty, sandy [Unlithified Deposits Coding Scheme] Clay, silty, sandy, bouldery [Unlithified Deposits Coding Scheme] Clay, silty, sandy, cobbly [Unlithified Deposits Coding Scheme] Clay, silty, sandy, gravelly [Unlithified Deposits Coding Scheme] Clay, silty, sandy, gravelly, bouldery [Unlithified Deposits Coding Scheme] Clay, silty, sandy, gravelly, cobbly [Unlithified Deposits Coding Scheme] Clay, silty, sandy, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Clay, silty, sandy, gravelly, peaty [Unlithified Deposits Coding Scheme] Clay, silty, sandy, peaty [Unlithified Deposits Coding Scheme] Clay-ironstone Claystone - A type of mudstone. British Geological Survey Research Report RR/99/03, fig. 13. See: silicate-claystone. Claystone, seat-earth Clinker - A type of artifical deposit. It consists of semi-fused or fused hard foundry slag which is the stony residue from burnt coal. British Geological Survey Research Report RR/99/04, appendix 1. Clinopyroxene-micronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of clinopyroxene-norite. British Geological Survey Research Report RR/99/06, section 5.1. Clinopyroxene-norite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with pyroxene 5 - 45% clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Clinopyroxenite - A type of pyroxenite (s.s.) in which the pyroxene is entirely or almost entirely clinopyroxene. In the Rock Classification Scheme, it is a pyroxenite with olivine <10%, clinopyroxene >90% and orthopyroxene <10% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Coal - A type of sedimentary-rock rich in organic matter. British Geological Survey Research Report RR/99/03, section 6. Coal shale Coarse-grained normal crystalline rock - In the Rock Classification Scheme, a crystalline rock is coarse-grained if its average crystal size is greater than 2 mm. This group corresponds to the plutonic division of the IUGS scheme. British Geological Survey Research Report RR/99/06, section 1.3 and figs. 1, 3 and 9. Coarse-sand [Unlithified Deposits Coding Scheme - Extended] Cobble Cobbles [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). Cobbles, bouldery [Unlithified Deposits Coding Scheme] Cobbles, bouldery, clayey [Unlithified Deposits Coding Scheme] Cobbles, bouldery, clayey, sandy [Unlithified Deposits Coding Scheme] Cobbles, bouldery, gravelly [Unlithified Deposits Coding Scheme] Cobbles, bouldery, gravelly, sandy [Unlithified Deposits Coding Scheme] Cobbles, bouldery, peaty [Unlithified Deposits Coding Scheme] Cobbles, bouldery, sandy, gravelly [Unlithified Deposits Coding Scheme] Cobbles, bouldery, sandy, silty [Unlithified Deposits Coding Scheme] Cobbles, clayey [Unlithified Deposits Coding Scheme] Cobbles, clayey, gravelly [Unlithified Deposits Coding Scheme] Cobbles, clayey, peaty [Unlithified Deposits Coding Scheme] Cobbles, clayey, sandy [Unlithified Deposits Coding Scheme] Cobbles, clayey, sandy, gravelly [Unlithified Deposits Coding Scheme] Cobbles, clayey, silty [Unlithified Deposits Coding Scheme] Cobbles, clayey, silty, gravelly [Unlithified Deposits Coding Scheme] Cobbles, clayey, silty, gravelly, sandy [Unlithified Deposits Coding Scheme] Cobbles, gravelly [Unlithified Deposits Coding Scheme] Cobbles, gravelly, bouldery [Unlithified Deposits Coding Scheme] Cobbles, gravelly, clayey [Unlithified Deposits Coding Scheme] Cobbles, gravelly, clayey, sandy [Unlithified Deposits Coding Scheme] Cobbles, gravelly, peaty [Unlithified Deposits Coding Scheme] Cobbles, gravelly, sandy [Unlithified Deposits Coding Scheme] Cobbles, gravelly, sandy, bouldery [Unlithified Deposits Coding Scheme] Cobbles, gravelly, sandy, clayey [Unlithified Deposits Coding Scheme] Cobbles, gravelly, sandy, silty [Unlithified Deposits Coding Scheme] Cobbles, gravelly, silty, sandy [Unlithified Deposits Coding Scheme] Cobbles, peaty [Unlithified Deposits Coding Scheme] Cobbles, sandy [Unlithified Deposits Coding Scheme] Cobbles, sandy, clayey [Unlithified Deposits Coding Scheme] Cobbles, sandy, gravelly [Unlithified Deposits Coding Scheme] Cobbles, sandy, peaty [Unlithified Deposits Coding Scheme] Cobbles, sandy, silty [Unlithified Deposits Coding Scheme] Cobbles, silty [Unlithified Deposits Coding Scheme] Cobbles, silty, gravelly [Unlithified Deposits Coding Scheme] Cobbles, silty, gravelly, sandy [Unlithified Deposits Coding Scheme] Cobbles, silty, peaty [Unlithified Deposits Coding Scheme] Cobbles, silty, sandy [Unlithified Deposits Coding Scheme] Cobbles, silty, sandy, gravelly, peaty [Unlithified Deposits Coding Scheme] Cobbles, silty, sandy, peaty [Unlithified Deposits Coding Scheme] Colemanite-stone - A type of non-carbonate salt that is composed of particles of the borate mineral colemanite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Colliery waste - A type of artifical deposit. It consists of heterolithic waste material produced from the mining of coal or associated ironstone and fireclay. It is commonly a mixture of mudstone, siltstone, sandstone, carbonaceous shale and coal, with minor amounts of ironstone. It may contain secondary minerals such as pyrite and sulphur. British Geological Survey Research Report RR/99/04, appendix 1. Synonyms: spoil, tip, bing (Scotland). Concrete - A type of artificial deposit. It is a construction material composed of cement, aggregate and water. The proportions vary according to the particular application. When mixed, it hardens to form a rock-like material. A Dictionary of Geology and Earth Sciences, 4th Ed. (2013), Oxford University Press. Conglomerate - A rudaceous sedimentary rock based on grain size or crystal size. See: silicate-conglomerate. Conglomerate, angular, pebble-grade Conglomerate, hornfelsed Conglomerate, mud-flake Contact metamorphic rock - Contact metamorphism results from the temperature perturbation associated with the emplacement of magma into the crust. The extent of the thermal perturbation will be determined by both the crustal level at which the magma was emplaced and the volume of the magma body; contact metamorphism will merge into regional metamorphism when a large body of magma is emplaced at greater depths. In many cases, contact metamorphism is not accompanied by recognisable tectonic effects, with the result that new mineral assemblages develop granoblastic textures. The amount of recrystallisation and the associated metamorphic mineral assemblages are largely a product of a combination of the heat energy available, nature and volume of fluid flow, lithology of the country rock and the distance from the heat source. A gabbroic magma is hotter than a granite magma and so would be expected to produce greater recrystallisation with higher temperature minerals. With increasing recrystallisation granoblastic textures progressively develop so that pre-existing features in the rock are destroyed, ultimately resulting in hard, fine- to medium-grained rocks lacking parting surfaces. Preexisting features such as schistose or gneissose textures may be recognised by lithological heterogeneities. British Geological Survey Research Report RR/99/02, section 9.6. Copper (vein) - A type of vein rock. Crystalline igneous rock - Rock comprised essentially of interlocking crystals and/or glass. In the Rock Classification Scheme, this class includes normal crystalline igneous rock, and exotic crystalline igneous rock. British Geological Survey Research Report RR/99/06, section 1.3 and fig. 1. Cumulate-rock - A type of rock of restricted mineralogy. Cumulate is a term used for igneous rocks formed by crystal settling in a magma chamber, i.e. it is a genetic term. Some of the physical processes involved in producing cumulates result in sub-monomineralic layers. British Geological Survey Research Report RR/99/06, section 8.2. Dacite (TAS) - A type of dacitic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of dacite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Dacite - A type of dacitic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in fields 4 and 5 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Dacite, garnet-bearing Dacite, glassy Dacite, lava Dacite, lava, porphyritic Dacite, porphyritic Dacite, porphyritic (TAS) Dacitic-rock (TAS) Dacitic-rock - A type of felsite. In the Rock Classification Scheme, this class includes dacite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Deposit, mussel Diamictite - A type of siliciclastic sediment and sedimentary rock. Sedimentary rocks that are poorly sorted and contain a wide range of clast sizes can be given this root name. The strict descriptive definition relates to range of particle size and not to relative abundance of any or all size classes. These rock types therefore traverse the boundary of siliciclastic rudaceous, arenaceous and argillaceous sedimentary rocks. This is the consolidated equivalent of diamicton. British Geological Survey Research Report RR/99/03, section 2 and figs. 2, 3 and 5. Diamicton - A type of siliciclastic sediment and sedimentary rock. Sediments that are poorly sorted and contain a wide range of clast sizes can be given this root name. The strict descriptive definition relates to range of particle size and not to relative abundance of any or all size classes. These sediment types therefore traverse the boundary of siliciclastic rudaceous, arenaceous and argillaceous sediments. This is the unconsolidated equivalent of diamictite. British Geological Survey Research Report RR/99/03, section 2 and figs. 2, 3 and 5. Diamicton, chalk-rich Diamicton, pedogenically-altered Diamicton, sandy Diatom-rich sediment - A type of biological sediment. Diatomaceous-ooze - A type of siliceous-ooze which is predominantly composed of diatoms. It is the unlithified equivalent of diatomite. British Geological Survey Research Report RR/99/03, section 8.1 and fig. 12. Diatomite - A type of siliceous rock which is predominantly composed of diatoms. It is the lithified equivalent of diatomaceous-ooze. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Diorite - A type of dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Diorite, gabbro and anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is greater than 10% and An (the anorthite content of plagioclase) is less than 50% the rock is diorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Diorite, appinitic Diorite, augite Diorite, foliated Diorite, gneissose Diorite, hornblende Diorite, hornblende-bearing-biotite-rich Diorite, hornblende-biotite Diorite, olivine Diorite, pyroxene Diorite, pyroxene-biotite Diorite, pyroxene-mica Diorite, sheared Dioritic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes diorite, monzodiorite, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Dioritic-rock, appinitic Dioritic-rock, gneissose Dolerite, clinopyroxene-olivine-macrophyric Dolerite, clinopyroxene-olivine-microphyric Dolerite, clinopyroxene-olivine-phyric Dolerite, feldspar-phyric Dolerite, foliated Dolerite, hypersthene-bearing Dolerite, olivine-clinopyroxene-plagioclase Dolerite, olivine-clinopyroxene-plagioclase-phyric Dolerite, olivine-microphyric Dolerite, olivine-phyric Dolerite, olivine-plagioclase-phyric Dolerite. Synonym: microgabbro Doleritic-rock, plagioclase-macrophyric Doleritic-rock, plagioclase-microphyric Doleritic-rock, plagioclase-phyric Dolomite-boundstone - A type of dolostone, classified on the basis of its biogenic texture. It is a dolostone in which the original components were bound and encrusted together by the action of plants and animals in the position of growth. British Geological Survey Research Report RR/99/03, section 3.2, table 7 and fig. 7. Dolomite-carbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a modal classification is possible. In a dolomite-carbonatite more than 90% of the carbonate is dolomite. British Geological Survey Research Report RR/99/06, section 6.1 and fig. 25. See also: magnesiocarbonatite. Dolomite-framestone - A type of dolostone, classified on the basis of its biogenic texture. It is a type of reef rock consisting of a rigid framework of colonies, shells or skeletons. Internal cavities are filled with fine sediment. British Geological Survey Research Report RR/99/03, section 3.2, table 7 and fig. 7. Dolomite-grainstone - A type of dolostone, classified on the basis of its depositional texture. It is a grain-supported dolostone with little matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.2, table 7 and fig. 7. Dolomite-gravel - A type of dolomite-sediment. In the Rock Classification Scheme, it is one in which over 25% of clasts are larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.2, table 6 and fig. 7. See also: silicate-gravel. Dolomite-microsparstone - A type of dolostone, classified on the basis of its diagenetic texture. It is similar to dolomite-sparstone but with 4 - 32 µm crystal size. Crystals are resolvable under an optical microscope. British Geological Survey Research Report RR/99/03, section 3.2, table 8 and fig. 7. Dolomite-microstone - A type of dolostone, classified on the basis of its diagenetic texture. It is similar to dolomite-sparstone but with crystals smaller than 4 µm. Crystals are not resolvable under an optical microscope. British Geological Survey Research Report RR/99/03, section 3.2, table 8 and fig. 7. Dolomite-mud - A type of dolomite-sediment. In the Rock Classification Scheme, it is one in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.2, table 6 and fig. 7. See also: silicate-mud. Dolomite-mudstone - A type of dolostone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported dolostone composed of greater than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.2, table 7 and fig. 7. Dolomite-packstone - A type of dolostone, classified on the basis of its depositional texture. It is a grain-supported dolostone with intergranular spaces filled by matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.2, table 7 and fig. 7. Dolomite-pseudosparstone - A type of dolostone, classified on the basis of its diagenetic texture. It is a dolostone composed almost totally of a divergent radial fibrous calcite cement in which grains or in-situ biogenic material do not constitute a framework. British Geological Survey Research Report RR/99/03, section 3.2, table 8 and fig. 7. Dolomite-sand - A type of dolomite-sediment. In the Rock Classification Scheme, it is one in which clasts are predominantly 32 µm to 2 mm, with less than 75% of the clasts smaller than 32 µm and less than 25% larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.2, table 6 and fig. 7. See also: silicate-sand. Dolomite-sediment - In the Rock Classification Scheme, all dolomite sediments are given this group name. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Dolomite-sediment, dolostone and magnesite-stone - In the Rock Classification Scheme, these are defined as carbonate sediments and sedimentary rocks which are dominantly (> 50%) composed of a magnesium carbonate in the form of dolomite (CaMg(CO3)2), ankerite (Ca3 (Mg2Fe) (CO3)6) or magnesite (MgCO3. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Dolomite-sparstone - A type of dolostone, classified on the basis of its diagenetic texture. It is a dolostone composed of obliterative sparry crystals, with a crystal size larger than 32 µm. British Geological Survey Research Report RR/99/03, section 3.2, table 8 and fig. 7. Dolomite-wackestone - A type of dolostone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported dolostone composed of less than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.2, table 7 and fig. 7. Dolostone - In the Rock Classification Scheme, sedimentary rocks which are composed dominantly of dolomite or ankerite are given this group name. The textural classification of dolostones follows that for limestone. The classification of dolostones composed dominantly of one constituent similarly follows that for limestone. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Dolostone, ferruginous Dolostone, mudmound Dolostone, sandy Domestic/garden refuse - A type of artifical deposit. It consists of undifferentiated organic and inorganic waste. British Geological Survey Research Report RR/99/04, appendix 1. Dull-coal - A type of bituminous-coal, classified according to brightness. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Dunite - A type of peridotite. In the Rock Classification Scheme, it is a peridotite with olivine >90%, pyroxene <10% and hornblende <10% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Dunite, chromite Dunite, chromite-bearing Durain - A type of bituminous-coal, classified according to lithotype. It consists of dark grey to black bands with a dull to slightly greasy lustre. The material is relatively hard compared to other lithotypes, and tends to break into large blocky fragments. Durain may be confused with impure coal which is also dull and hard, but it can be distinguished by its lower density. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Duricrust - A type of residual deposit. It is a general term for a hard crust on the surface of, or layer in, the upper horizons of a soil in a semiarid climate. It is an indurated product of surface and near-surface processes formed by cementation or replacement of bedrock, weathering deposits, unconsolidated sediments, soil or other materials produced by low-temperature physiochemical processes. British Geological Survey Research Report RR/99/03, section 13.6; RR/99/04, appendix 2. Eclogite - A type of metamorphic rock with unknown protolith based on modal composition. In the Rock Classification Scheme, it is defined as a rock composed of more than 70% garnet and jadeitic clinopyroxene (omphacite). Eclogites do not contain plagioclase. They may contain other anhydrous minerals such as quartz, kyanite, orthopyroxene and rutile, together forming no more than 30% of the rock. Eclogites result from metamorphism of basaltic or gabbroic igneous rocks under very low P.H20 producing anhydrous mineral assemblages. They define a unique eclogite facies metamorphism, typically reflecting very high pressures although their local occurrence within amphibolite facies rocks suggests they may be formed over a significant range of pressure. British Geological Survey Research Report RR/99/02, section 6.2. Effluent - A type of artifical deposit. It consists of waste liquid flowing from a sewage tank or industrial process etc. British Geological Survey Research Report RR/99/04, appendix 1. Exotic crystalline igneous rock - These are the chemically and/or mineralogically exotic crystalline igneous rocks. In the Rock Classification Scheme, this class includes carbonatite, melilitic rock, kalsilitic rock, kimberlite, lamproite, leucitic rock, and lamprophyre. Rocks in these groups have sufficiently unusual mineral and chemical compositions that they are not classified using the modal (QAPF and ultramafic diagrams) or chemical (e.g. TAS) methods by which normal crystalline igneous rocks are classified. Although they comprise only a tiny proportion of all crystalline igneous rocks, the unusual characteristics and distinctive field settings of the exotic igneous rocks means they have attracted a large amount of attention from geologists. British Geological Survey Research Report RR/99/06, section 1.3 and fig. 1. Fault-breccia - A type of mechanically broken rock without primary cohesion. In the Rock Classification Scheme, a fault-breccia is not foliated, and contains angular to rounded fragments that comprise more than 30% of the rock which are significantly coarser than the matrix, and are composed of mechanically broken rock fragments and/or mineral grains. British Geological Survey Research Report RR/99/02, section 7.1 and table 3. Fault-breccia, igneous Fault-gouge - A type of mechanically broken rock without primary cohesion. In the Rock Classification Scheme, a fault-gouge may be strongly foliated, and comprises less than 30% fragments lying in fine-grained, commonly clayey matrix. British Geological Survey Research Report RR/99/02, section 7.1 and table 3. Fayalite-hedenbergite-rock, magnetite-rich Feldspar-porphyry Feldspathic-arenite - A type of arenite. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Feldspathic-wacke - A type of wacke. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Felsic-rock Felsite - A type of fine-grained normal crystalline rock. It is a general term used for light-coloured aphanitic rocks. In the Rock Classification Scheme, the class includes rhyolitic-rock, dacitic-rock, and trachytic-rock. British Geological Survey Research Report RR/99/06, section 5.2 and fig. 17. Felsite, albite Felsite, albitised Felsite, appinitic Felsite, appinitic-foliated Felsite, foliated Felsite, foliated-porphyritic Felsite, porphyritic Felsite, porphyritic-brecciated Felsite, quartz-albite-phyric Felsite, quartz-phyric Felsite, riebeckite Felsite, sheared Fenite - A type of metasomatic-rock. Fenites are desilicated crustal rocks formed by reaction with Na- and K-rich fluids expelled during the emplacement of carbonatite or undersaturated alkaline magmas. British Geological Survey Research Report RR/99/02, section 8. Ferricrete - A type of duricrust. It is a conglomerate consisting of surficial sand and gravel cemented into a hard mass by iron oxide derived from the oxidation of percolating solutions of iron salts. British Geological Survey Research Report RR/99/03, section 13.6; RR/99/04, appendix 2. Synonyms: iron laterite, iron pan. Ferroan-carbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a modal classification is possible. In a ferroan-carbonatite, the main carbonate mineral is ferroan dolomite, ankerite or siderite. These can be distinguished from other carbonates by stain tests. British Geological Survey Research Report RR/99/06, section 6.1 and fig. 25. See also: ferrocarbonatite. Ferrocarbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a chemical classification is necessary because the rock is too fine grained for an accurate mode to be determined, or if the carbonate minerals are complex Ca-Mg-Fe solid solutions. The definition of ferrocarbonatite is as shown in British Geological Survey Research Report RR/99/06, section 6.1 and figs. 25, 26. See also: ferroan-carbonatite. Fill - A type of artifical deposit. It is a general term for material used to infill a void or cavity in the earth's surface or sub-surface. Constructional fill (made ground) is material placed above the natural earth surface. British Geological Survey Research Report RR/99/04, appendix 1. Fine-grained normal crystalline rock - In the Rock Classification Scheme, a crystalline rock is fine-grained if its average crystal size is less than 0.25 mm. This classification is used for fine-grained, very fine-grained, and glassy crystalline igneous rocks. The class includes felsite, mafite, glassy-igneous-rock, and porphyry. This group corresponds to the volcanic division of the IUGS scheme. British Geological Survey Research Report RR/99/06, section 1.3 and figs. 1, 3. Fine-grained-crystalline-rocks [exotic] Fine-sand [Unlithified Deposits Coding Scheme - Extended] Fines (silts and clays) - A type of artificial deposit. In the Rock Classification Scheme, this refers to sediment grains less than 1/16 mm in size. British Geological Survey Research Report RR/99/04, table 8a. Flint - A nodular form of grey/black chert. The term is restricted to the nodules of chert present in Cretaceous chalk. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Foid-bearing-alkali-feldspar-microsyenite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-alkali-feldspar-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-alkali-feldspar-syenite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 6' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-alkali-feldspar-trachyte - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 6' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Foid-bearing-anorthosite - A type of anorthositic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-bearing-diorite, foid-bearing-gabbro and foid-bearing-anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is less than 10% the rock is foid-bearing-anorthosite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-diorite - A type of dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-bearing-diorite, foid-bearing-gabbro and foid-bearing-anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is greater than 10% and An (the anorthite content of plagioclase) is less than 50% the rock is foid-bearing-diorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-gabbro - A type of gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-bearing-diorite, foid-bearing-gabbro and foid-bearing-anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is greater than 10% and An (the anorthite content of plagioclase) is greater than 50% the rock is foid-bearing-gabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-latite - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 8' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Foid-bearing-micro-anorthosite - A type of micro-anorthositic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-anorthosite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-microdiorite - A type of microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-diorite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-microdioritic-rock Foid-bearing-microgabbro - A type of microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-micromonzodiorite - A type of microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-micromonzogabbro - A type of microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-micromonzonite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-monzonite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-microsyenite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-bearing-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-bearing-monzodiorite - A type of dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 9' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-bearing-monzodiorite and foid-bearing-monzogabbro are separated according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is less than 50% the rock is foid-bearing-monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-monzogabbro - A type of gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 9' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-bearing-monzodiorite and foid-bearing-monzogabbro are separated according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is greater than 50% the rock is foid-bearing-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-monzonite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 8' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-syenite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 7' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-bearing-trachyte - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 7' of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Foid-diorite - A type of foid-dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 14 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-diorite and foid-gabbro are distinguished according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is less than 50% the rock is foid-diorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-dioritic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes nepheline-diorite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Foid-gabbro - A type of foid-gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 14 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-diorite and foid-gabbro are distinguished according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is greater than 50% the rock is foid-gabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-gabbroic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes analcime-gabbro, nepheline-monzogabbro and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Foid-microdiorite - A type of foid-microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-diorite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-microdioritic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-dioritic-rock. The class includes foid-microdiorite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Foid-microgabbro - A type of foid-microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Foid-microgabbroic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-gabbroic-rock. The class includes analcime-microgabbro, nepheline-micromonzogabbro and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Foid-micromonzodiorite - A type of foid-microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-micromonzogabbro - A type of foid-microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1. Foid-micromonzosyenite - A type of foid-microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-monzosyenite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-microsyenite - A type of foid-microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Foid-microsyenitic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foid-syenitic-rock. The class includes nepheline-microsyenite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Foid-monzodiorite - A type of foid-dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 13 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-monzodiorite and foid-monzogabbro are distinguished according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is less than 50% the rock is foid-monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-monzogabbro - A type of foid-gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 13 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Foid-monzodiorite and foid-monzogabbro are distinguished according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is greater than 50% the rock is foid-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-monzosyenite - A type of foid-syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 12 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-syenite - A type of foid-syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 11 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foid-syenitic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes nepheline-syenite, nepheline-monzosyenite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Foidite (TAS) - A type of foiditic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of foidite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Foidite - A type of foiditic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 15 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Foiditic-rock - A type of mafite. In the Rock Classification Scheme, this class includes foidite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Foidolite - A type of foidolitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 15 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. This field contains rocks in which the light-coloured minerals are almost entirely feldspathoids. The fine-grained equivalent is foidite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Foidolitic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes leucitolite and nephelinolite. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Foliated mechanically broken rock with primary cohesion - British Geological Survey Research Report RR/99/02, section 7.3. Foundry ash - A type of artifical deposit. It consists of the residue left after the combustion of any substance, but commonly coal in metallic blast furnaces. British Geological Survey Research Report RR/99/04, appendix 1. Foundry sand - A type of artifical deposit. It may be impregnated with organic materials produced in the metal and glass industries. British Geological Survey Research Report RR/99/04, appendix 1. Foundry slag - A type of artifical deposit. It consists of semi-fused or fused waste material produced in the metal and glass industries. British Geological Survey Research Report RR/99/04, appendix 1. Fragmental igneous rock and sediment - Includes those rocks constituted of mixtures of fragments of rocks, crystals and glass. British Geological Survey Research Report RR/99/06, section 1.3 and fig. 1. Fusain - A type of bituminous-coal, classified according to lithotype. It is a black, soft, friable coal which closely resembles charcoal. It easily disintegrates into a black, fibrous powder. A hard form of fusain that has been impregnated with mineral matter can be found in some coals. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Gabbro (s.s.) - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 90% (<5% orthopyroxene) and olivine < 5% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Gabbro - A type of gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Diorite, gabbro and anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is greater than 10% and An (the anorthite content of plagioclase) is greater than 50% the rock is gabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Gabbro, biotite Gabbro, biotite-bearing Gabbro, biotite-bytownite Gabbro, biotite-rich Gabbro, bytownite Gabbro, feldspar-phyric Gabbro, fluxioned Gabbro, foliated Gabbro, gneissose Gabbro, hypersthene-bearing Gabbro, migmatitic Gabbro, olivine-glomerocrystic Gabbro, pegmatitic Gabbro, sheared Gabbro, xenolithic Gabbroic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes gabbro, monzogabbro, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Gabbroic-rock, appinitic Gabbroic-rock, contaminated Gabbroic-rock, hornfelsed Gabbroic-rock, magnetic Gabbronorite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 90% (>5% clino- and orthopyroxene) and olivine <5% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Ganister - A type of quartz-arenite. It is a hard, fine-grained, quartz-arenite, cemented with silica and possessing a splintery fracture. Traces of roots may be visible. It is associated with coal seams. British Geological Survey Research Report RR/99/03, section 13.6. See also: seat-earth. Garden waste - A type of artifical deposit. It consists of predominantly organic waste including woody materials, grass and soil. British Geological Survey Research Report RR/99/04, appendix 1. Gaylussite - A type of Na carbonate sedimentary rock. Gaylussite (Na2CO3.CaCO3.5H2O) is characterised by monoclinic flattened wedge-shaped crystals. British Geological Survey Research Report RR/99/03, section 3.3. Glassy-igneous-rock - A type of fine-grained normal crystalline rock. British Geological Survey Research Report RR/99/06. Glassy-meta-igneous-rock Gneiss - A type of metamorphic rock with unknown protolith based on textural attributes. In the Rock Classification Scheme, it is defined as a medium- to coarse-grained inhomogeneous rock, commonly with a well-developed preferred orientation of constituent minerals, and characterised by a coarse foliation or layering that is more widely spaced, irregular or discontinuous than that in a schist. Adjacent layers generally exhibit contrasting texture, grain size, and mineralogy. However, there is a continuum between schists and gneisses, with factors such as the spacing of the foliation and the degree of contrast between adjacent layers contributing to the assignment of a rock to either category. Gneiss is distinguished from schist where some layers are over 5 mm thick. Gneisses generally occur in areas of middle to upper amphibolite or granulite facies metamorphism and can encompass a wide range of lithologies. Note that orthogneiss indicates a rock that is thought to have an igneous protolith, and paragneiss indicates a rock that is thought to have a sedimentary protolith. British Geological Survey Research Report RR/99/02, sections 3.3, 6.1 and fig. 1. Gneiss, hornblende-biotite Gneiss, k-feldspar-augen Gneiss, mafic Gneiss, micaceous Gneiss, microcline-plagioclase Gneiss, microcline-porphyroblastic Gneiss, nebulitic Gneiss, plagioclase Gneiss, protomylonitic Gneiss, pyroxene-bearing Gneiss, quartzofeldspathic Gneiss, re-metamorphosed Gossan - A type of duricrust. It is a near-surface, iron oxide-rich zone overlying a sulphide-bearing ore deposit, caused by the oxidation and leaching of sulphides. British Geological Survey Research Report RR/99/04, appendix 2. Granite - A type of granitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 3 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Granite may be subdivided into syenogranite and monzogranite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Granite, alkali Granite, biotite Granite, biotite-phyric Granite, charnockitic Granite, foliated Granite, foliated-biotite Granite, foliated-muscovite-biotite Granite, gneissose Granite, gneissose-augen Granite, granophyric Granite, granophyric-hornfelsed Granite, granophyric-porphyritic Granite, muscovite-biotite Granite, pegmatitic Granite, pegmatitic-muscovite-biotite Granite, porphyritic Granite, sheared Granite, xenolithic Granitic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes granite, granodiorite, tonalite, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Granitic-rock, foliated Granitic-rock, gneissose Granitic-rock, nebulose Granodiorite - A type of granitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 4 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Granodiorite, biotite Granodiorite, foliated Granodiorite, gneissose Granodiorite, hornblende Granodiorite, hornblende-biotite Granodiorite, hyperstene Granodiorite, k-feldspar-megacrystic-hornblende Granodiorite, porphyritic Granodiorite, tonalitic Granofels - A type of metamorphic rock with unknown protolith based on textural attributes. It lacks any obvious foliation and layering and is commonly characterised by a granoblastic texture. A granofels can occur at any metamorphic grade with a range of lithologies. Note that orthogranofels indicates a rock that is thought to have an igneous protolith, and paragranofels indicates a rock that is thought to have a sedimentary protolith. British Geological Survey Research Report RR/99/02, sections 3.3, 6.1 and fig. 1. Granofels, pyroxene Gravel Gravel (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: G Gravel [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). Gravel, bouldery [Unlithified Deposits Coding Scheme] Gravel, bouldery, clayey [Unlithified Deposits Coding Scheme] Gravel, bouldery, peaty [Unlithified Deposits Coding Scheme] Gravel, clayey Gravel, clayey [Unlithified Deposits Coding Scheme] Gravel, clayey sandy cobbly peaty [Unlithified Deposits Coding Scheme] Gravel, clayey, bouldery [Unlithified Deposits Coding Scheme] Gravel, clayey, cobbly [Unlithified Deposits Coding Scheme] Gravel, clayey, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, clayey, peaty [Unlithified Deposits Coding Scheme] Gravel, clayey, sandy [Unlithified Deposits Coding Scheme] Gravel, clayey, sandy, cobbly [Unlithified Deposits Coding Scheme] Gravel, clayey, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, clayey, sandy, peaty [Unlithified Deposits Coding Scheme] Gravel, clayey, sandy, silty [Unlithified Deposits Coding Scheme] Gravel, clayey, shelly [Unlithified Deposits Coding Scheme - Extended] Gravel, clayey, silty [Unlithified Deposits Coding Scheme] Gravel, clayey, silty, bouldery [Unlithified Deposits Coding Scheme] Gravel, clayey, silty, cobbly [Unlithified Deposits Coding Scheme] Gravel, clayey, silty, peaty [Unlithified Deposits Coding Scheme] Gravel, clayey, silty, sandy [Unlithified Deposits Coding Scheme] Gravel, clayey, silty, sandy, bouldery [Unlithified Deposits Coding Scheme] Gravel, clayey, silty, sandy, peaty [Unlithified Deposits Coding Scheme] Gravel, cobbly [Unlithified Deposits Coding Scheme] Gravel, cobbly sandy clayey bouldery [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, clayey [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, clayey, sandy [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, sandy [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, sandy, clayey [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, sandy, silty [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, silty [Unlithified Deposits Coding Scheme] Gravel, cobbly, bouldery, silty, sandy [Unlithified Deposits Coding Scheme] Gravel, cobbly, clayey [Unlithified Deposits Coding Scheme] Gravel, cobbly, clayey, sandy [Unlithified Deposits Coding Scheme] Gravel, cobbly, peaty [Unlithified Deposits Coding Scheme] Gravel, cobbly, sandy [Unlithified Deposits Coding Scheme] Gravel, cobbly, sandy, clayey [Unlithified Deposits Coding Scheme] Gravel, cobbly, sandy, silty [Unlithified Deposits Coding Scheme] Gravel, cobbly, silty [Unlithified Deposits Coding Scheme] Gravel, cobbly, silty, sandy [Unlithified Deposits Coding Scheme] Gravel, flinty Gravel, flinty [Unlithified Deposits Coding Scheme - Extended] Gravel, limestone-rich [Unlithified Deposits Coding Scheme - Extended] Gravel, muddy Gravel, muddy (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: mG Gravel, muddy sandy (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: msG Gravel, peaty [Unlithified Deposits Coding Scheme] Gravel, peaty, clayey [Unlithified Deposits Coding Scheme] Gravel, peaty, clayey, sandy, silty [Unlithified Deposits Coding Scheme] Gravel, peaty, clayey, silty [Unlithified Deposits Coding Scheme] Gravel, peaty, clayey, silty, sandy [Unlithified Deposits Coding Scheme] Gravel, peaty, sandy [Unlithified Deposits Coding Scheme] Gravel, peaty, sandy, clayey [Unlithified Deposits Coding Scheme] Gravel, peaty, sandy, silty, clayey [Unlithified Deposits Coding Scheme] Gravel, peaty, silty [Unlithified Deposits Coding Scheme] Gravel, peaty, silty, sandy, clayey [Unlithified Deposits Coding Scheme] Gravel, sandy Gravel, sandy (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: sG Gravel, sandy (unknown/industrial) Gravel, sandy [Unlithified Deposits Coding Scheme] Gravel, sandy cobbly clayey bouldery [Unlithified Deposits Coding Scheme] Gravel, sandy, bouldery [Unlithified Deposits Coding Scheme] Gravel, sandy, clayey Gravel, sandy, clayey [Unlithified Deposits Coding Scheme] Gravel, sandy, clayey, bouldery [Unlithified Deposits Coding Scheme] Gravel, sandy, clayey, cobbly [Unlithified Deposits Coding Scheme] Gravel, sandy, clayey, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, sandy, clayey, silty [Unlithified Deposits Coding Scheme] Gravel, sandy, cobbly [Unlithified Deposits Coding Scheme] Gravel, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, sandy, cobbly, clayey [Unlithified Deposits Coding Scheme] Gravel, sandy, cobbly, silty [Unlithified Deposits Coding Scheme] Gravel, sandy, peaty [Unlithified Deposits Coding Scheme] Gravel, sandy, peaty, clayey [Unlithified Deposits Coding Scheme] Gravel, sandy, peaty, silty, clayey [Unlithified Deposits Coding Scheme] Gravel, sandy, shelly [Unlithified Deposits Coding Scheme - Extended] Gravel, sandy, silty [Unlithified Deposits Coding Scheme] Gravel, sandy, silty, clayey [Unlithified Deposits Coding Scheme] Gravel, sandy, silty, cobbly [Unlithified Deposits Coding Scheme] Gravel, sandy, silty, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, shelly [Unlithified Deposits Coding Scheme - Extended] Gravel, shelly, clayey [Unlithified Deposits Coding Scheme - Extended] Gravel, silty Gravel, silty [Unlithified Deposits Coding Scheme] Gravel, silty, bouldery [Unlithified Deposits Coding Scheme] Gravel, silty, clayey [Unlithified Deposits Coding Scheme] Gravel, silty, clayey, peaty [Unlithified Deposits Coding Scheme] Gravel, silty, clayey, sandy [Unlithified Deposits Coding Scheme] Gravel, silty, cobbly [Unlithified Deposits Coding Scheme] Gravel, silty, cobbly, sandy [Unlithified Deposits Coding Scheme] Gravel, silty, peaty [Unlithified Deposits Coding Scheme] Gravel, silty, peaty, clayey [Unlithified Deposits Coding Scheme] Gravel, silty, peaty, sandy [Unlithified Deposits Coding Scheme] Gravel, silty, sandy [Unlithified Deposits Coding Scheme] Gravel, silty, sandy, cobbly [Unlithified Deposits Coding Scheme] Gravel, silty, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Gravel, silty, sandy, peaty [Unlithified Deposits Coding Scheme] Gravel, silty, sandy, peaty, clayey [Unlithified Deposits Coding Scheme] Gravel, silty, shelly [Unlithified Deposits Coding Scheme - Extended] Greisen - A type of metasomatic-rock. It is a granitic-rock altered through interaction with Li-rich and F-rich, and/or B-rich, hydrothermal fluids. British Geological Survey Research Report RR/99/02, section 8. Group-1-kimberlite - A type of kimberlite. Group-1-kimberlite corresponds to archetypal rocks from Kimberley, South Africa that formerly were termed basaltic kimberlites. These are volatile-rich (dominantly CO2), potassic, ultrabasic rocks which commonly exhibit a distinctive inequigranular texture resulting from the presence of macrocrysts (and in some instances megacrysts) set in a fine-grained matrix. British Geological Survey Research Report RR/99/06, section 6.4. Group-2-kimberlite - A type of kimberlite. Group-2-kimberlite corresponds to micaceous or lamprophyric kimberlites. They are characterised by the presence of macrocrysts, phenocrysts and groundmass micas, which vary from phlogopite to tetraferriphlogopite. British Geological Survey Research Report RR/99/06, section 6.4. Guano - A type of phosphorite. It is a phosphate-rich deposit formed from the excrement of birds or bats. British Geological Survey Research Report RR/99/03, section 4.2 and fig. 8. Gypsum-grainstone - A type of gypsum-stone, classified on the basis of its depositional texture. It is a grain-supported gypsum-stone with little matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-gravel - A type of gypsum-sediment that is composed of gravel-sized (> 2 mm) particles. British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-metamudstone Gypsum-metastone Gypsum-mudstone - A type of gypsum-stone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported gypsum-stone composed of greater than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-packstone - A type of gypsum-stone, classified on the basis of its depositional texture. It is a grain-supported gypsum-stone with intergranular spaces filled by matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-sand - A type of gypsum-sediment that is composed of sand-sized (32 µm - 2 mm) particles. British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-sediment - A type of non-carbonate salt-sediment that is composed of particles of the sulphate mineral gypsum. It is the unlithified equivalent of gypsum-stone. British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-stone - A type of non-carbonate salt that is composed of particles of the sulphate mineral gypsum. It is the lithified equivalent of gypsum-sediment. The textural classification of gypsum-stones follows that for limestone. British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Gypsum-wackestone - A type of gypsum-stone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported gypsum-stone composed of less than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Halite-stone - A type of non-carbonate salt that is composed of particles of the chloride mineral halite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Harzburgite - A type of pyroxene-peridotite. In the Rock Classification Scheme, it is a pyroxene-peridotite with olivine 40 - 90%, orthopyroxene 5 - 60% and clinopyroxene <5% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Hawaiite - A sodic trachybasalt. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Hawaiite, aphyric Hawaiite, basaltic Hawaiite, basaltic, feldspar-phyric Hawaiite, feldspar-phyric Hawaiite, olivine-basaltic Hawaiite, olivine-phyric Hematite (vein) - A type of vein rock. Herbicide - A type of artifical deposit. It is a substance toxic to plants and used to kill unwanted vegetation. British Geological Survey Research Report RR/99/04, appendix 1. Hornblende-andesite, lava Hornblende-gabbro - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene <10% and hornblende 5 - 90% of plagioclase + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Hornblende-microgabbro - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of hornblende-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Hornblende-microperidotite - A type of microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of hornblende-peridotite. British Geological Survey Research Report RR/99/06, section 5.1. Hornblende-micropyroxenite Hornblende-peridotite - A type of peridotite. In the Rock Classification Scheme, it is a peridotite with olivine 40 - 90%, pyroxene <5% and hornblende 5 - 40% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Hornblende-pyroxenite - A type of pyroxenite. In the Rock Classification Scheme, it is a pyroxenite with olivine <5%, pyroxene 47 - 90%, hornblende 5 - 50% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Hornblende-rock - A type of meta-ultramafic-rock in which the dominant mineral is hornblende. British Geological Survey Research Report RR/99/02, section 5.2. Hornblende-trachyte Hornblendite (s.s.) - A type of hornblende-rich (>90%) hornblendite. In the Rock Classification Scheme, it is a hornblendite with olivine <10%, pyroxene <10% and hornblende >90% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Hornblendite - A type of ultramafic-rock. In the Rock Classification Scheme, it is a coarse-grained ultramafic rock with less than 40% olivine, and hornblende dominant over pyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 15, 16. Hornfels - A type of contact metamorphic rock. Hornfels is a variant of granofels. The term is applied to a hard fine- to medium-grained rock of unknown protolith and modal composition which lacks parting planes and has recrystallised as a result of contact metamorphism. British Geological Survey Research Report RR/99/02, section 6.1. Hyaloclastite - This describes rocks or sediments composed entirely of shattered, angular, glassy fragments created by quenching of lavas during subaqueous or subglacial extrusion. British Geological Survey Research Report RR/99/06, section 4.2. Hyaloclastite, basaltic Hybrid metasedimentary rock Hybrid metasedimentary rocks Hybrid sediment - In the Rock Classification Scheme, these are sediments which comprise more than one primary compositional component, with no component forming more than 50%. British Geological Survey Research Report RR/99/03, section 11. Hybrid sediment and sedimentary rock - British Geological Survey Research Report RR/99/03, section 11. Hybrid sedimentary rock - In the Rock Classification Scheme, these are sedimentary rocks which comprise more than one primary compositional component, with no component forming more than 50%. British Geological Survey Research Report RR/99/03, section 11. Hydrothermal-rock - A rock whose characteristics are the result of the actions of hot aqueous solutions. Many mineral assemblages are possible. British Geological Survey Research Report RR/99/02, section 8. Hydroxides and oxides of alumina - British Geological Survey Research Report RR/99/03, section 9.2. Hydroxides and oxides of alumina and iron - Their classification is based upon the state of hydration of the silicate minerals. British Geological Survey Research Report RR/99/03, section 9.2. Hydroxides and oxides of iron - British Geological Survey Research Report RR/99/03, section 9.2. Igneous rock and sediment - In the Rock Classification Scheme, this high level class includes fragmental igneous rock and sediment, and crystalline igneous rock. British Geological Survey Research Report RR/99/06, fig. 1. Igneous-rock of inferred intermediate composition, coarse-crystalline Igneous-rock of inferred intermediate composition, fine-crystalline Igneous-rock, mafic Ignimbrite Illite-clay - A type of monomineralic aluminium-silicate sediment in which the aluminium-silicate mineral is illite. It is the unlithified equivalent of illite-claystone. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Illite-claystone - A type of monomineralic aluminium-silicate sedimentary rock in which the aluminium-silicate mineral is illite. It is the lithified equivalent of illite-clay. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Ilmenitite - A type of rock of restricted mineralogy. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock in which ilmenite exceeds 90% of the mineral mode. British Geological Survey Research Report RR/99/06, section 8.2. Impact metamorphic rock - A type of metamorphic rock. Impure-coal - A type of coal. It is a lithified end-member of the impure humic coal series. The impure humic coal series can be subdivided into muddy-peat / sandy-peat (the unlithified form) and impure-coal (the lithified form). British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Industrial waste - A type of artifical deposit. It consists of waste products from industrial processes. British Geological Survey Research Report RR/99/04, appendix 1. Intrusion-breccia - An intrusive fragmental igneous rock. British Geological Survey Research Report RR/99/06, section 8.2. Iron (vein) - A type of vein rock. Iron-boundstone - A type of ironstone, classified on the basis of its biogenic texture. It is an ironstone in which the original components were bound and encrusted together by the action of plants and animals in the position of growth. British Geological Survey Research Report RR/99/03, section 5.2, table 14 and fig. 9. Iron-grainstone - A type of ironstone, classified on the basis of its depositional texture. It is a grain-supported ironstone with little matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 5.2, table 14 and fig. 9. Iron-gravel - A type of iron-sediment. In the Rock Classification Scheme, it is one in which over 25% of clasts are larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 5.1, table 13 and fig. 9. See also: silicate-gravel. Iron-mud - A type of iron-sediment. In the Rock Classification Scheme, it is one in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 5.1, table 13 and fig. 9. See also: silicate-mud. Iron-mudstone - A type of ironstone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported ironstone composed of greater than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 5.2, table 14 and fig. 9. Iron-packstone - A type of ironstone, classified on the basis of its depositional texture. It is a grain-supported ironstone with intergranular spaces filled by matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 5.2, table 14 and fig. 9. Iron-sand - A type of iron-sediment. In the Rock Classification Scheme, it is one in which clasts are predominantly 32 µm to 2 mm, with less than 75% of the clasts smaller than 32 µm and less than 25% larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 5.1, table 13 and fig. 9. See also: silicate-sand. Iron-sediment - In the Rock Classification Scheme, all iron-sediments are given this group name. This is the unlithified equivalent of ironstone. British Geological Survey Research Report RR/99/03, section 5.1 and fig. 9. Iron-sediment and ironstone - In the Rock Classification Scheme, these are defined as those sediments and sedimentary rocks which have more than 50% iron-bearing minerals (ironstones should have greater than 15% wt. iron). British Geological Survey Research Report RR/99/03, section 5 and fig. 9. Iron-wackestone - A type of ironstone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported ironstone composed of less than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 5.2, table 14 and fig. 9. Ironstone - In the Rock Classification Scheme, all lithified iron-rich sedimentary rocks are given this group name. This is the lithified equivalent of iron-sediment. The textural classification of ironstones follows that for limestone. The classification of ironstones composed dominantly of one constituent similarly follows that for limestone. British Geological Survey Research Report RR/99/03, section 5.2 and fig. 9. Ironstone nodular Ironstone, carbonaceous Ironstone, manganiferous Ironstone, shelly Ironstone, siliceous Jasper - A type of chert whose red colour is due to the presence of haematite. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Kainite-stone - A type of non-carbonate salt that is composed of particles of the sulphate mineral kainite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Kalsilitic rock - A type of exotic crystalline igneous rock. In the Rock Classification Scheme, it is defined as a rock that contains more than 10% modal kalsilite. Kalsilite is a very rare mineral, and its presence is sufficiently important to merit defining rocks with notable kalsilite as a separate group. In the present scheme a threshold value of 10% modal kalsilite has been adopted, the same as the threshold for melilitic rock and leucitic rock. Kalsilite behaves metastably and only rarely survives slow cooling, so virtually all rocks containing kalsilite are fine- or very fine-grained lavas. Coarse-grained rocks containing kalsilite (e.g. kalsilite-bearing syenite and kalsilite-bearing-biotite pyroxenite) have been reported from Russia; however they are extremely rare. British Geological Survey Research Report RR/99/06, section 6.3. Kalsilitite - A type of kalsilitic rock. Kalsilitite is the general name for fine-grained kalsilitic rocks. At present, only one true kalsilitic rock is known, namely olivine-pyroxene kalsilitite, known formerly as mafurite, from Uganda. No coarse-grained rocks containing more than 10% modal kalsilite have been found so far, but if such a rock is found, it should be called a kalsilitolite following the convention used in melilitic rock. British Geological Survey Research Report RR/99/06, section 6.3. Kalsilitite, olivine-pyroxene - A type of kalsilitite. British Geological Survey Research Report RR/99/06, figs. 29, 30. Synonym: mafurite. Kalsilitolite - A type of kalsilitic rock. No coarse-grained rocks containing more than 10% modal kalsilite have been found so far, but if such a rock is found, it should be called a kalsilitolite following the convention used in melilitic rock. British Geological Survey Research Report RR/99/06, section 6.3. Kalsilitolite, olivine-pyroxene - This would be a type of kalsilitolite. Kaolinite-clay - A type of monomineralic aluminium-silicate sediment in which the aluminium-silicate mineral is kaolinite. It is the unlithified equivalent of kaolinite-claystone. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Kaolinite-claystone - A type of monomineralic aluminium-silicate sedimentary rock in which the aluminium-silicate mineral is kaolinite. It is the lithified equivalent of kaolinite-clay. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Synonym: china clay. Kernite-stone - A type of non-carbonate salt that is composed of particles of the borate mineral kernite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Kersantite - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which plagioclase is the dominant feldspar, and the predominant mafic minerals are biotite and diopsidic augite (with/without olivine). British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Kieserite-stone - A type of non-carbonate salt that is composed of particles of the sulphate mineral kierserite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Kimberlite - A type of exotic crystalline igneous rock. Kimberlites are currently divided into two groups. Group-1-kimberlite corresponds to archetypal rocks from Kimberley, South Africa that formerly were termed basaltic kimberlites. Group-2-kimberlite corresponds to micaceous or lamprophyric kimberlites. Recent studies have demonstrated that these two groups are mineralogically different and petrogenetically separate rock types. British Geological Survey Research Report RR/99/06, section 6.4. Komatiite - A type of picritic-rock. Its definition is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 22. Lamalginite - A type of sapropelite. It is one in which algal matter occurs in very thin laminae cryptically interbedded with mineral matter. British Geological Survey Research Report RR/99/03, section 6.3 and fig. 10. Lamproite, diopside-leucite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: cedricite. Lamproite, diopside-leucite-phlogopite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: wyomingite. Lamproite, diopside-leucite-richterite-madupitic - A type of lamproite. The term madupitic indicates that the rock contains poikilitic groundmass phlogopite, as opposed to a phlogopite lamproite in which the phlogopite occurs as phenocrysts. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: wolgidite. Lamproite, diopside-madupitic - A type of lamproite. The term madupitic indicates that the rock contains poikilitic groundmass phlogopite, as opposed to a phlogopite lamproite in which the phlogopite occurs as phenocrysts. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: madupite. Lamproite, diopside-sanidine-phlogopite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: orendite. Lamproite, enstatite-sanidine-phlogopite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: cancalite. Lamproite, hyalo-enstatite-phlogopite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: fortunite. Lamproite, hyalo-olivine-diopside-phlogopite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: verite. Lamproite, leucite-phlogopite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: fitzroyite. Lamproite, leucite-richterite - A type of lamproite. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: mamilite. Lamproite, olivine-diopside-richterite Lamproite, olivine-diopside-richterite-madupitic - A type of lamproite. The term madupitic indicates that the rock contains poikilitic groundmass phlogopite, as opposed to a phlogopite lamproite in which the phlogopite occurs as phenocrysts. British Geological Survey Research Report RR/99/06, section 6.5. Synonym: jumillite. Lamproite - A type of exotic crystalline igneous rock. There is no universally accepted definition for lamproites, however they occur characteristically as lavas, pipes and dykes. Some lamproites have a fragmental origin (i.e. they are volcaniclastic). In the Rock Classification Scheme they are classified on the predominance of phlogopite, richterite, olivine, diopside, sanidine and leucite. British Geological Survey Research Report RR/99/06, section 6.5. Lamprophyre, biotite Lamprophyre, foliated Lamprophyre, foliated-biotite Lamprophyre, hornblende Lamprophyre - A type of exotic crystalline igneous rock. Lamprophyres are mesocratic to melanocratic igneous rocks, usually hypabyssal, with a panidiomorphic texture and abundant mafic phenocrysts of dark mica (biotite or Fe-phlogopite) and/or amphibole, with or without pyroxene, with or without olivine, and sometimes melilite, set in a matrix of the same minerals. Any feldspar, usually alkali feldspar, is restricted to the groundmass. British Geological Survey Research Report RR/99/06, section 6.7. Lapilli-ash - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments is less than 64 mm. Lapilli-tephra, lapilli-ash, and ash are separated according to the relative proportion of lapilli-grade (2 - 64 mm) and ash-grade (<2 mm) fragments: if between 25% and 75% of the fragments are lapilli the sediment is lapilli-ash. It is the unconsolidated equivalent of lapilli-tuff. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Lapilli-tephra - A type of pyroclastic-sediment. In the Rock Classification Scheme, it is a pyroclastic-sediment in which the average size of more than 75% of the pyroclastic fragments is less than 64 mm. Lapilli-tephra, lapilli-ash, and ash are separated according to the relative proportion of lapilli-grade (2 - 64 mm) and ash-grade (<2 mm) fragments: if more than 75% of the fragments are lapilli the sediment is lapilli-tephra. It is the unconsolidated equivalent of lapillistone. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Lapilli-tuff - A type of pyroclastic-rock. In the Rock Classification Scheme, it is a pyroclastic-rock in which the average size of more than 75% of the pyroclastic fragments is less than 64 mm. Lapillistone, lapilli-tuff, and tuff are separated according to the relative proportion of lapilli-grade (2 - 64 mm) and ash-grade (<2 mm) fragments: if between 25% and 75% of the fragments are lapilli the rock is lapilli-tuff. It is the consolidated equivalent of lapilli-ash. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Lapilli-tuff, andesitic Lapilli-tuff, basaltic Lapilli-tuff, dacitic Lapilli-tuff, felsitic Lapilli-tuff, rhyolitic Lapilli-tuff, rhyolitic, garnet-bearing Lapillistone - A type of pyroclastic-rock. In the Rock Classification Scheme, it is a pyroclastic-rock in which the average size of more than 75% of the pyroclastic fragments is less than 64 mm. Lapillistone, lapilli-tuff, and tuff are separated according to the relative proportion of lapilli-grade (2 - 64 mm) and ash-grade (<2 mm) fragments: if more than 75% of the fragments are lapilli the rock is lapillistone. It is the consolidated equivalent of lapilli-tephra. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Latite (TAS) - A potassic trachyandesite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Latite - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 8 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Lava Lava, andesitic Lava, augite-andesite Lava, basalt Lava, basaltic Lava, basaltic-trachyandesite Lava, calcareous-basalt Lava, dacitic Lava, felsic Lava, mafic Lava, rhyolite Lava, rhyolitic Lava, trachyandesite Lava, trachydacitic Lava, trachyte Lava, trachytic Lead (vein) - A type of vein rock. Lead-zinc (vein) - A type of vein rock. Leucitic rock - A type of exotic crystalline igneous rock. In all known leucitic rocks the leucite occurs as phenocrysts and should be readily identifiable in hand-specimen. In the Rock Classification Scheme, this class includes tephritic-leucitite, phonolitic-leucitite, and leucitite, corresponding to the three sub-fields of field 15 on the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, sections 5.2, 6.6. Leucitite - A foidite in which leucite is the only, or virtually the only, feldspathoid mineral. British Geological Survey Research Report RR/99/06, sections 5.2, 6.6. Leucitolite - A foidolite in which the dominant feldspathoid mineral is leucite. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Leucodiorite Leucogabbro Leucogranite Leucogranite, foliated Leucogranite, foliated-pegmatitic Leucogranite, granophyric Leucogranite, lithium-rich Leucogranite, pegmatitic Leucogranodiorite Leucomicrodiorite Leucomicrogranite Leucomicrogranite, foliated Leucomicrogranite, foliated-pegmatitc Leucomicrogranite, granophyric Leucomicrogranite, lithium-rich Leucomicrogranite, pegmatitic Leucomicrogranodiorite Leucomicromonzogranite Leucomicromonzonite Leucomicrosyenite Leucomicrotonalite Leucomicrotonalite, pegmatitic Leucomonzogranite Leucosyenite Leucotonalite Leucotonalite, pegmatitic Lherzolite - A type of pyroxene-peridotite. In the Rock Classification Scheme, it is a pyroxene-peridotite with olivine 40 - 90%, orthopyroxene 5 - 55% and clinopyroxene 5 - 55% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Lignite - A type of coal. It is a member of the pure humic coal series. The members of the pure humic coal series can be ranked in order as peat (the unlithified form), lignite, bituminous-coal, and anthracite (the lithified forms) based on increasing carbon content and decreasing volatile content. Lignite is a consolidated, dull, soft brown to black coal with many readily discernible plant fragments set in a finer-grained organic matrix. It tends to crack and fall apart on drying. Lignite may be further classified into brown-lignite and black-lignite. British Geological Survey Research Report RR/99/03, section 6.1, table 16 and fig. 10. Lime-boundstone - A type of limestone, classified on the basis of its biogenic texture. It is a limestone in which the original components were bound and encrusted together by the action of plants and animals in the position of growth (e.g. reef limestones). British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-framestone - A type of limestone, classified on the basis of its biogenic texture. It is a type of reef rock consisting of a rigid framework of colonies, shells or skeletons. Internal cavities are filled with fine sediment. British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-grainstone - A type of limestone, classified on the basis of its depositional texture. It is a grain-supported limestone with little matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-gravel - A type of lime-sediment. In the Rock Classification Scheme, it is a lime-sediment in which over 25% of clasts are larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.1, table 2 and fig. 6. See also: silicate-gravel. Lime-microsparstone - A type of limestone, classified on the basis of its diagenetic texture. It is similar to lime-sparstone but with 4 - 32 µm crystal size. Crystals are resolvable under an optical microscope. British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-microstone - A type of limestone, classified on the basis of its diagenetic texture. It is similar to lime-sparstone but with crystals smaller than 4 µm. Crystals are not resolvable under an optical microscope. British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-mud - A type of lime-sediment. In the Rock Classification Scheme, it is a lime-sediment in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.1, table 2 and fig. 6. See also: silicate-mud. Lime-mudstone - A type of limestone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported limestone composed of greater than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-packstone - A type of limestone, classified on the basis of its depositional texture. It is a grain-supported limestone with intergranular spaces filled by matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-pseudosparstone - A type of limestone, classified on the basis of its diagenetic texture. It is a limestone composed almost totally of a divergent radial fibrous calcite cement in which grains or in-situ biogenic material do not constitute a framework. The calcite pseudospar occurs as in-situ botryoidal masses commonly found in the core of algal mounds and probably formed from early diagenetic alteration of aragonite masses. The diagenetic process does not cause any alteration to the depositional or biological texture. British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-sand - A type of lime-sediment. In the Rock Classification Scheme, it is a lime-sediment in which clasts are predominantly 32 µm to 2 mm, with less than 75% of the clasts smaller than 32 µm and less than 25% larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 3.1, table 2 and fig. 6. See also: silicate-sand. Lime-sediment - In the Rock Classification Scheme, these are carbonate sediments in which the dominant carbonate mineral is calcium carbonate in the form of calcite, aragonite and/or vaterite (vaterite is a metastable hexagonal form of calcium carbonate. It is exceptionally rare and it is unlikely that it would ever occur as the main mineral). British Geological Survey Research Report RR/99/03, section 3 and fig. 6. Lime-sediment and limestone - British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Lime-sparstone - A type of limestone, classified on the basis of its diagenetic texture. It is a limestone composed of obliterative sparry calcite crystals, typically in inequant, blocky mosaics, with a crystal size larger than 32 µm. British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Lime-wackestone - A type of limestone, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported limestone composed of less than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 3.1, table 3 and fig. 6. Limestone - In the Rock Classification Scheme, these are carbonate sedimentary rocks in which the dominant carbonate mineral is calcium carbonate in the form of calcite, aragonite and/or vaterite (vaterite is a metastable hexagonal form of calcium carbonate. It is exceptionally rare and it is unlikely that it would ever occur as the main mineral). Two classification schemes are available to give root names to limestones: the first scheme is based on texture; the second scheme is designed to classify limestones composed dominantly of one constituent. Textural classification includes use of depositional (i.e. matrix-supported versus grain-supported), biogenic, and diagenetic textures. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Limestone, clayey Limestone, clayey sandy Limestone, dolomitic Limestone, ferruginous Limestone, gravelly Limestone, hornfelsed Limestone, micritic Limestone, mudmound Limestone, mylonitic Limestone, nodular (cornstone) Limestone, sandy Limestone, sandy silty Limestone, shelly Limestone, siliceous Limestone, silt-grade Limestone, silty Limestone, silty sandy Lithic-arenite - A type of arenite. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Lithic-wacke - A type of wacke. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Lithomarge - One of the hydroxides and oxides of alumina. It consists essentially of hydrated silicates of alumina or kaolinite minerals. British Geological Survey Research Report RR/99/03, section 9.2. Mafic-rock Mafic-rock, gneissose Mafic-rock, hornfelsed Mafite - A type of fine-grained normal crystalline rock. It is a general term used for dark-coloured aphanitic rocks. In the Rock Classification Scheme, the class includes andesitic-rock, basaltic-rock, phonolitic-rock, tephritic-rock and foiditic-rock. British Geological Survey Research Report RR/99/06, section 5.2 and fig. 17. Mafite, chlorite-actinolite Magmatic-breccia Magnesiocarbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a chemical classification is necessary because the rock is too fine grained for an accurate mode to be determined, or if the carbonate minerals are complex Ca-Mg-Fe solid solutions. The definition of magnesiocarbonatite is as shown in British Geological Survey Research Report RR/99/06, section 6.1 and figs. 25, 26. See also: dolomite-carbonatite. Magnesitestone - Sedimentary rocks composed of magnesite are very rare and the few known examples are formed as primary precipitates. Unlithified equivalents are not known. All rocks composed of magnesite are given the group name magnesite-stone. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Magnetite, cumulate Magnetite-garnet-hypersthene-rock Magnetite-garnet-hypersthene-rock, schistose Magnetitite - A type of rock of restricted mineralogy. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock in which magnetite exceeds 90% of the mineral mode. British Geological Survey Research Report RR/99/06, section 8.2. Manganiferous/ferruginous deposit - A type of chemical deposit (natural superficial). It consists of deposits formed in a variety of environments, comprising mixtures of hydrated ferric and manganese oxides and other oxides. British Geological Survey Research Report RR/99/04, appendix 2 and tables 5, 17. Marble - A type of metamorphic rock with unknown protolith based on modal composition. In the Rock Classification Scheme, it is one composed largely of calcsilicate and/or carbonate minerals, but where the relative proportions of either mineral group are unknown. British Geological Survey Research Report RR/99/02, section 6.2. Marine sediment - A type of natural superficial deposit. This class holds the sediment classification used on BGS offshore sea-bed sediment maps. The general subdivision adopted by BGS is the Folk (1954) triangular diagram. British Geological Survey Research Report RR/99/04, section 4 and table 8c; Folk 1954 Journal of Geology Vol. 62 pp 344-359. Mechanically broken and reconstituted rock - This part of the Rock Classification Scheme covers principally fault and shear zone rocks. The class includes mechanically broken rock without primary cohesion, unfoliated mechanically broken rock with primary cohesion, and foliated mechanically broken rock with primary cohesion. British Geological Survey Research Report RR/99/02, section 7 and fig. 1. Mechanically broken rock without primary cohesion - In the Rock Classification Scheme, this class is subdivided into fault-breccia, and fault-gouge, according to the proportion of visible fragments within a finer-grained matrix. The abundance and size of the fragments depends on the original character of the rock and also the rate and duration of movement. The resulting rocks range from coarse breccias with limited disruption of the original rock to fine gouge where the rock is largely reduced to paste. Any cohesion is the result of secondary cementation. Such rocks invariably form at low confining pressures. British Geological Survey Research Report RR/99/02, section 7.1. Medium-grained normal crystalline rock - In the Rock Classification Scheme, a crystalline rock is medium-grained if its average crystal size is in the range 0.25 - 2 mm. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 3. Medium-sand [Unlithified Deposits Coding Scheme - Extended] Meimechite - A type of picritic-rock. Its definition is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 22. Meladiorite Meladiorite, hornblende Melagabbro Melagabbro, hornblende Melagabbroic-rock Melagabbroic-rock, hornblende Melagranite Melagranite, biotite Melagranite, foliated-biotite Melagranite, pegmatitic-biotite Melagranodiorite Melametatroctolite Melamicrodiorite Melamicrodiorite, foliated Melamicrodiorite, hornblende Melamicrogabbro Melamicrogabbro, olivine Melamicrogabbroic-rock Melamicrogranite Melamicrogranite, biotite Melamicrogranite, foliated-biotite Melamicrogranite, pegmatitic-biotite Melamicrogranodiorite Melamicrosyenite Melamonzonite Melamonzonite, olivine Melasyenite Melatroctolite Melilite-bearing-ultramafic-volcanic-rock - British Geological Survey Research Report RR/99/06, fig. 28. Melilitic rock - A type of exotic crystalline igneous rock. In the Rock Classification Scheme, it is defined as a rock that contains more than 10% modal melilite. Although light-coloured, melilite is classified as a mafic mineral belonging to group M. Melilitic rocks are divided into ultramafic-melilitic-rock, and non-ultramafic-melilitic-rock. British Geological Survey Research Report RR/99/06, section 6.2 and figs. 27, 28. Melilitite - A type of ultramafic-melilitic-rock. Melilitite is the general name for fine-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28b. Melilitite, kalsilite-leucite-olivine - A type of melilitite. British Geological Survey Research Report RR/99/06, figs. 29, 30. Synonym: katungite. Melilitite, kalsilite-phlogopite - A type of melilitite. British Geological Survey Research Report RR/99/06, figs. 29, 30. Synonym: coppaelite. Melilitite, kalsilite-phlogopite-olivine-leucite - A type of melilitite. British Geological Survey Research Report RR/99/06, figs. 29, 30. Synonym: venanzite. Melilitolite - A type of ultramafic-melilitic-rock. Melilitolite is the general name for coarse-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28a. Meta-agate Meta-agglomerate Meta-agglomerate, basaltic Meta-agglomerate, rhyolitic Meta-agglomerate, trachytic Meta-alcrete Meta-alkali-feldspar-granite Meta-alkali-feldspar-rhyolite Meta-alkali-feldspar-syenite Meta-alkali-feldspar-trachyte Meta-analcime-gabbro Meta-analcime-gabbro, hornblende Meta-andesite Meta-andesite (TAS) Meta-andesite, augite Meta-andesite, foliated Meta-andesite, garnet-bearing Meta-andesite, garnet-rich Meta-andesite, glassy Meta-andesite, hypersthene Meta-andesite, porphyritic Meta-andesite, pyroxene Meta-andesite, pyroxene-plagioclase-phyric Meta-andesitic-rock Meta-anhydrite-stone Meta-ankerite-boundstone Meta-ankerite-framestone Meta-ankerite-grainstone Meta-ankerite-microsparstone Meta-ankerite-microstone Meta-ankerite-mudstone Meta-ankerite-packstone Meta-ankerite-pseudosparstone Meta-ankerite-sparstone Meta-ankerite-wackestone Meta-ankeritestone Meta-anorthosite Meta-anorthositic-rock Meta-anthracite Meta-aragonite-boundstone Meta-aragonite-framestone Meta-aragonite-grainstone Meta-aragonite-limestone Meta-aragonite-microsparstone Meta-aragonite-microstone Meta-aragonite-mudstone Meta-aragonite-packstone Meta-aragonite-pseudosparstone Meta-aragonite-sparstone Meta-aragonite-wackestone Meta-arenite Meta-arenite, coarse Meta-basaltic-trachyandesite Meta-fusain Meta-group-1-kimberlite Meta-group-2-kimberlite Meta-igneous rock - In the Rock Classification Scheme, a rock is classified within this category if it is considered to be a metamorphic rock derived from an igneous protolith, either because of its lithological characteristics (i.e. preservation of igneous textures and in some cases composition or mineralogy) or its lithological associations. The class includes meta-igneous rock based on protolith name, meta-igneous rock based on modal composition, and meta-igneous rock based on textural attributes. British Geological Survey Research Report RR/99/02, section 5 and fig. 1. Meta-igneous rock based on modal composition - In the Rock Classification Scheme, a meta-igneous rock is classified within this category if it cannot be classified according to protolith name. The class includes metafelsic-rock, metamafic-rock, and meta-ultramafic-rock. They are distinguished on the relative proportions of quartz, feldspar, and mafic minerals. Muscovite, carbonate and other generally pale-toned minerals are considered neutral and not used in the modal classification. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8. Meta-igneous rock based on protolith name - In the Rock Classification Scheme, a meta-igneous rock is classified within this category if its igneous protolith is clearly recognisable. British Geological Survey Research Report RR/99/02, section 5.1 and fig. 1. See also: igneous rock and sediment. Meta-igneous rock based on textural attributes - In the Rock Classification Scheme, a meta-igneous rock is classified within this category if neither the exact nature of the protolith nor the modal composition is known. This class includes orthoschist, orthogneiss, and orthogranofels. British Geological Survey Research Report RR/99/02, section 5.3 and fig. 1. Meta-igneous-rock of inferred intermediate composition, coarse-crystalline Meta-ignimbrite Meta-illite-claystone Meta-impure-coal Meta-iron-boundstone Meta-iron-grainstone Meta-iron-microoncolite Meta-iron-mudstone Meta-iron-oncolite Meta-iron-packstone Meta-iron-peloidite Meta-iron-pisolite Meta-iron-wackestone Meta-ironstone Meta-ironstone, carbonaceous Meta-ironstone, ooidal Meta-ironstone, shelly Meta-ironstone, siliceous Meta-microoncoid-aragonite-limestone Meta-non-carbonate salt Meta-non-ultramafic melilitic-rock Meta-oilshale Meta-olivine-basalt Meta-olivine-clinopyroxene-norite Meta-olivine-gabbro Meta-olivine-gabbro, Fe-rich Meta-olivine-gabbro, porphyritic Meta-olivine-gabbronorite Meta-olivine-melilitite Meta-olivine-melilitolite Meta-olivine-norite Meta-olivine-orthopyroxene-gabbro Meta-olivine-pyroxene-melilitolite Meta-oncoid-ankeritestone - Synonym: meta-ankerite-oncolite. Meta-oncoid-aragonite-limestone Meta-oncoid-calcite-limestone Meta-oncoid-limestone - Synonym: metalime-oncolite. Meta-ooid-ankeritestone - Synonym: meta-ankerite-oolite. Meta-ooid-aragonite-limestone Meta-ooid-calcite-limestone Meta-ooid-limestone Meta-oolitic ironstone or ferruginous meta-oolite Meta-opaline-chert Meta-opaline-porcellanite Meta-orthopyroxene-gabbro Meta-ultramafic melilitic rocks Meta-ultramafic-rock - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are meta-igneous rocks containing 90% or more mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1 and 8. Meta-ultramafitite Metabanded-bright-coal Metabanded-coal Metabanded-dull coal Metabarite-stone Metabasalt Metabasalt (TAS) Metabasalt, alkali Metabasalt, clinopyroxene-olivine-macrophyric Metabasalt, clinopyroxene-olivine-microphyric Metabasalt, clinopyroxene-olivine-phyric Metabasalt, clinopyroxene-olivine-plagioclase-macrophyric Metabasalt, clinopyroxene-olivine-plagioclase-phyric Metabasalt, feldspar-phyric Metabasalt, foliated Metabasalt, glassy Metabasalt, hornfelsed Metabasalt, olivine-clinopyroxene-plagioclase-macrophyric Metabasalt, olivine-clinopyroxene-plagioclase-phyric Metabasalt, olivine-microphyric Metabasalt, olivine-phyric Metabasalt, olivine-plagioclase-macrophyric Metabasalt, olivine-plagioclase-microphyric Metabasalt, olivine-plagioclase-phyric Metabasalt, phyllitic Metabasalt, plagioclase-macrophyric Metabasalt, plagioclase-microphyric Metabasalt, porphyritic Metabasalt, pyroxene-phyric Metabasalt, schistose Metabasalt, subalkali Metabasaltic-andesite Metabasaltic-rock Metabasaltic-rock, hornfelsed Metabasaltic-rock, macroporphyritic (unclassed) Metabasaltic-rock, microporphyritic (unclassed) Metabasaltic-rock, plagioclase-macrophyric Metabasaltic-rock, plagioclase-microphyric Metabasaltic-rock, plagioclase-phyric Metabasanite Metabasanite (TAS) Metabasanite, analcime Metabasanite, biotite Metabasanite, nepheline Metabasanitic-foidite Metabauxite Metabenmoreite Metabituminous-coal Metablack-lignite Metaboghead-cannel coal Metaboghead-coal Metabone-coal Metaboninite Metaborax-stone Metabreccia Metabreccia, trachyandesitic Metabright-coal Metabrown-lignite Metacalcilutite Metacalciocarbonatite Metacalcite-boundstone Metacalcite-carbonatite Metacalcite-framestone Metacalcite-grainstone Metacalcite-limestone Metacalcite-microsparstone Metacalcite-microstone Metacalcite-mudstone Metacalcite-packstone Metacalcite-pseudosparstone Metacalcite-sparstone Metacalcite-wackestone Metacannel-boghead-coal Metacannel-coal Metacarbonate-rock - A type of metasedimentary rock composed largely of calcsilicate and/or carbonate minerals. In the Rock Classification Scheme, it is one in which the modal carbonate mineral content exceeds the modal abundance of calcsilicate minerals. British Geological Survey Research Report RR/99/02, section 3.2 and fig. 7. Metacarbonate-rock, mylonitic Metacarbonatite Metacarnalite-stone Metachalk Metachert Metachromitite Metaclarain Metaclinopyroxene-norite Metacoal Metacoal shale Metacolemanite-stone Metaconglomerate Metaconglomerate, hornfelsed Metaconglomerate, schistose Metaconglomerate, sheared Metadacite Metadacite (TAS) Metadacitic-rock Metadiamictite Metadiatomite Metadiorite Metadiorite, augite Metadiorite, foliated Metadiorite, gneissose Metadiorite, hornblende Metadiorite, olivine Metadiorite, pyroxene Metadiorite, pyroxene-biotite Metadiorite, pyroxene-mica Metadiorite, sheared Metadioritic-rock Metadioritic-rock, gneissose Metadolerite Metadolerite, feldspar-phyric Metadolerite, foliated Metadolerite, hypersthene-bearing Metadolomite-boundstone Metadolomite-carbonatite Metadolomite-framestone Metadolomite-grainstone Metadolomite-microsparstone Metadolomite-microstone Metadolomite-mudstone Metadolomite-packstone Metadolomite-pseudosparstone Metadolomite-sparstone Metadolomite-wackestone Metadolostone Metadolostone and metamagnesite-stone Metadolostone, sandy Metadull-coal Metadunite Metadurain Metafeldspar-porphyry Metafeldspathic-arenite Metafeldspathic-wacke Metafelsic-rock - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are coarse-grained meta-igneous rocks containing 65% or more felsic minerals and 35% or less mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8 and 9. Metafelsite - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are fine-grained meta-igneous rocks containing 65% or more felsic minerals and 35% or less mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8 and 9. Metafelsite, foliated Metafelsite, foliated-porphyritic Metafelsite, porphyritic Metafelsite, sheared Metaferricrete (iron laterite/iron pan) Metaferroan-carbonatite Metaferrocarbonatite Metaflint Metafoid-bearing-alkali-feldspar-syenite Metafoid-bearing-alkali-feldspar-trachyte Metafoid-bearing-anorthosite Metafoid-bearing-diorite Metafoid-bearing-gabbro Metafoid-bearing-latite Metafoid-bearing-monzodiorite Metafoid-bearing-monzogabbro Metafoid-bearing-monzonite Metafoid-bearing-syenite Metafoid-bearing-trachyte Metafoid-diorite Metafoid-dioritic-rock Metafoid-gabbro Metafoid-gabbroic-rock Metafoid-monzodiorite Metafoid-monzogabbro Metafoid-monzosyenite Metafoid-syenite Metafoid-syenitic-rock Metafoidite Metafoidite (TAS) Metafoiditic-rock Metafoidolite Metafoidolitic-rock Metagabbro Metagabbro (s.s.) Metagabbro, biotite-bytownite Metagabbro, bytownite Metagabbro, feldspar-phyric Metagabbro, fluxioned Metagabbro, foliated Metagabbro, gneissose Metagabbro, hypersthene-bearing Metagabbro, migmatitic Metagabbro, pegmatitic Metagabbro, sheared Metagabbro, xenolithic Metagabbroic-rock Metagabbroic-rock, appinitic Metagabbroic-rock, hornfelsed Metagabbroic-rock, magnetic Metagabbronorite Metagaylussite Metagranite Metagranite, biotite Metagranite, biotite-phyric Metagranite, foliated Metagranite, foliated-biotite Metagranite, foliated-muscovite-biotite Metagranite, gneissose Metagranite, gneissose-augen Metagranite, granophyric Metagranite, granophyric-porphyritic Metagranite, muscovite-biotite Metagranite, pegmatitic Metagranite, pegmatitic-muscovite-biotite Metagranite, porphyritic Metagranite, sheared Metagranite, xenolithic Metagranitic-rock Metagranitic-rock, foliated Metagranitic-rock, gneissose Metagranodiorite Metagranodiorite, biotite Metagranodiorite, foliated Metagranodiorite, gneissose Metagranodiorite, hornblende Metagranodiorite, hornblende-biotite Metagranodiorite, hypersthene Metagranodiorite, k-feldspar-megacrystic-hornblende Metagranodiorite, porphyritic Metagypsum-grainstone Metagypsum-packstone Metagypsum-wackestone Metahalite-stone Metaharzburgite Metahawaiite Metahawaiite, feldspar-phyric Metahawaiite, olivine-phyric Metahornblende-gabbro Metahornblendite Metahyaloclastite Metahydroxides and oxides of alumina Metahydroxides and oxides of alumina and iron Metailmenitite Metajasper Metakainite-stone Metakalsilitic-rock Metakalsilitite Metakalsilitolite Metakaolinite-claystone Metakernite-stone Metakersantite Metakieserite-stone Metakimberlite Metakomatiite Metalamalginite Metalamproite Metalamprophyre Metalamprophyre, biotite Metalamprophyre, foliated Metalamprophyre, foliated-biotite Metalamprophyre, hornblende Metalapilli-tuff Metalapilli-tuff, andesitic Metalapilli-tuff, dacitic Metalapilli-tuff, rhyolitic Metalapillistone Metalatite Metalatite (TAS) Metalava Metalava, andesite Metalava, basalt Metalava, basaltic Metalava, basaltic-trachyandesite Metalava, calcareous-basalt Metalava, calcareous-basaltic Metalava, dacite Metalava, felsic Metalava, hornblende-andesite Metalava, mafic Metalava, rhyolite Metalava, trachyandesite Metalava, trachydacite Metalava, trachyte Metaleucitic rock Metaleucitite Metaleucitolite Metaleucodiorite Metaleucogranite Metaleucogranite, foliated Metaleucogranite, foliated-pegmatitic Metaleucogranite, granophyric Metaleucogranite, lithium-rich Metaleucogranite, pegmatitic Metaleucogranodiorite Metaleucomonzogranite Metaleucosyenite Metaleucotonalite Metaleucotonalite, pegmatitic Metalignite Metalime-boundstone Metalime-framestone Metalime-grainstone Metalime-microsparstone Metalime-microstone Metalime-mudstone Metalime-packstone Metalime-pseudosparstone Metalime-sparstone Metalime-wackestone Metalimestone Metalimestone, dolomitic Metalimestone, ferruginous Metalimestone, gravelly Metalimestone, micritic Metalimestone, mylonitic Metalimestone, nodular (cornstone) Metalimestone, ooidal Metalimestone, sandy Metalithic-arenite Metalithic-wacke Metalithomarge Metamafic-rock - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are coarse-grained meta-igneous rocks containing 35 - 90% mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8 and 9. Metamafic-rock, gneissose Metamafic-rock, hornfelsed Metamafite - A class within meta-igneous rock based on modal composition. In the Rock Classification Scheme, these are fine-grained meta-igneous rocks containing 35 - 90% mafic minerals. British Geological Survey Research Report RR/99/02, section 5.2 and figs. 1, 8 and 9. Metamafite, chlorite-actinolite Metamagnesiocarbonatite Metamagnesite-stone Metamagnetitite Metameimechite Metameladiorite Metameladiorite, hornblende Metamelagabbro Metamelagabbroic-rock Metamelagranite Metamelagranite, biotite Metamelagranite, foliated-biotite Metamelagranite, pegmatitic-biotite Metamelagranodiorite Metamelamonzonite Metamelamonzonite, olivine Metamelasyenite Metamelilitic-rock Metamelilitite Metamelilitolite Metamicro-oncoid-calcite-limestone Metamicrogabbro Metamicrogabbro, feldspar-phyric Metamicrogabbro, foliated Metamicrogabbro, hypersthene-bearing Metamicrogabbroic-rock Metamicrogabbroic-rock, hornfelsed Metamicrogranite Metamicrogranite, aplitic Metamicrogranitic-rock Metamicrooncoid-ankeritestone - Synonym: meta-ankerite-micro-oncolite. Metamicrooncoid-dolostone Metamicrooncoid-limestone Metamicrooncoid-phosphorite Metamineral-type-claystone (specified mineral) Metaminette Metamonchiquite Metamonchiquite, nepheline Metamonzodiorite Metamonzodiorite, olivine Metamonzogabbro Metamonzogranite Metamonzogranite, biotite Metamonzogranite, porphyritic Metamonzonite Metamonzonite, foliated Metamonzonite, olivine Metamorphic carbonate sedimentary rock Metamorphic rock - In the Rock Classification Scheme, this high level class includes metasedimentary rock, metavolcaniclastic rock, meta-igneous rock, metamorphic rock with unknown protolith, mechanically broken and reconstituted rock, metasomatic-rock and hydrothermal-rock. Metamorphism encompasses all the solid state changes that occur between the upper and lower limits of metamorphism. Major changes in bulk composition are referred to as metasomatism. British Geological Survey Research Report RR/99/02, section 1 and fig. 1. Metamorphic rock with unknown protolith - In the Rock Classification Scheme, a rock is classified within this category if the nature of the protolith is not known. The class includes metamorphic rock with unknown protolith based on textural attributes, and metamorphic rock with unknown protolith based on modal composition. British Geological Survey Research Report RR/99/02, section 6 and fig. 1. Metamorphic rock with unknown protolith based on modal composition - In the Rock Classification Scheme, a metamorphic rock is classified within this category if the nature of the protolith is not known but a modal composition is available. British Geological Survey Research Report RR/99/02, section 6.2 and fig. 1. Metamorphic rock with unknown protolith based on textural attributes - In the Rock Classification Scheme, a metamorphic rock is classified within this category if neither the nature of the protolith nor the modal composition is known. This class includes slate, schist, gneiss, and granofels. British Geological Survey Research Report RR/99/02, section 6.1 and fig. 1. Metamorphosed coarse-grained normal crystalline rock Metamorphosed crystalline igneous rock Metamorphosed exotic crystalline igneous rock Metamorphosed fine-grained normal crystalline rock Metamorphosed fragmental igneous rock Metamorphosed medium-grained normal crystalline rock Metamorphosed normal crystalline igneous rock Metamorphosed pyroclastic rock Metamorphosed rock of restricted mineralogy Metamorphosed volcaniclastic igneous rock Metamudstone Metamudstone rich in organic matter Metamudstone, bituminous Metamudstone, calcareous Metamudstone, carbonaceous Metamudstone, ferruginous Metamudstone, friable, calcareous Metamudstone, glauconitic Metamudstone, kaolinite-rich (tonstein) Metamudstone, manganiferous Metamudstone, micaceous Metamudstone, non-marine, shelly Metamudstone, pebbly Metamudstone, phospha-pebbly Metamudstone, phosphate-nodular Metamudstone, phosphatic Metamudstone, sandy Metamudstone, shelly Metamudstone, siliceous, organic Metamudstone, silty Metamugearite Metamugearite, feldspar-phyric Metanatrocarbonatite Metanatron Metanepheline-melagabbro, hornblende Metanepheline-monzogabbro Metanepheline-syenite Metanephelinite Metanephelinolite Metanorite Metanorite, quartz-biotite Metaobsidian Metaoncoid-dolostone Metaoncoid-phosphorite Metaooid-dolostone Metaooid-phosphorite Metaorthopyroxene-gabbro, hypersthene Metaorthopyroxenite Metapegmatite Metapegmatite, biotite Metapegmatite, brecciated-feldspar-quartz Metapegmatite, feldspar-quartz Metapegmatite, foliated Metapegmatite, foliated-feldspar-quartz Metapegmatite, migmatitic Metapegmatite, sheared Metapeloid-ankeritestone - Synonym: meta-ankerite-peloidite. Metapeloid-aragonite-limestone Metapeloid-calcite-limestone Metapeloid-dolostone Metapeloid-limestone Metapeloid-phosphorite Metaperidotite Metaphono-tephrite Metaphonolite Metaphonolite (TAS) Metaphonolitic-basanite Metaphonolitic-foidite Metaphonolitic-rock Metaphonolitic-tephrite Metaphosphate-boundstone Metaphosphate-grainstone Metaphosphate-mudstone Metaphosphate-packstone Metaphosphate-wackestone Metaphosphorite Metaphosphorite, nodular Metaphosphorite, pebble-grade Metapicrite Metapicritic-rock Metapicrobasalt Metapisoid-ankeritestone - Synonym: Meta-ankerite-pisolite. Metapisoid-aragonite-limestone Metapisoid-calcite-limestone Metapisoid-dolostone Metapisoid-limestone Metapisoid-phosphorite Metapitchstone Metapitchstone, porphyritic-rhyolitic Metapolyhalite-stone Metaporcellanite Metaporphyry Metaporphyry, biotite-feldspar Metapotassic-trachybasalt Metapyrite-rock Metapyroclastic-breccia Metapyroclastic-rock Metapyroclastic-rock, basaltic Metapyroxene-hornblende-clinopyroxene-norite Metapyroxene-hornblende-gabbro Metapyroxene-hornblende-gabbronorite Metapyroxene-hornblende-norite Metapyroxene-hornblende-orthopyroxene-gabbro Metapyroxene-melilitolite Metapyroxene-olivine-melilitolite Metapyroxene-peridotite Metapyroxenite Metapyroxenite (s.s.) Metapépérite Metaquartz-alkali-feldspar-syenite Metaquartz-alkali-feldspar-trachyte Metaquartz-anorthosite Metaquartz-arenite Metaquartz-diorite Metaquartz-feldspar-porphyry Metaquartz-gabbro Metaquartz-gabbro, biotite Metaquartz-garnet-magnetite-rock Metaquartz-latite Metaquartz-monzodiorite Metaquartz-monzogabbro Metaquartz-monzonite Metaquartz-norite Metaquartz-porphyry Metaquartz-rich-coarse-grained-crystalline-rock Metaquartz-rich-granitic-rock Metaquartz-rich-medium-grained-crystalline-rock Metaquartz-syenite Metaquartz-trachyte Metaquartz-wacke Metaquartzolite Metaquartzose-porcellanite Metaradiolarite Metarhyolite Metarhyolite (TAS) Metarhyolite, comenditic Metarhyolite, pantelleritic Metarhyolite, porphyritic Metarhyolitic-rock Metarhyolitic-rock, biotite-phyric Metarudite (psephite) Metasandstone Metasandstone, calcareous Metasandstone, carbonaceous Metasandstone, carbonaceous, argillaceous Metasandstone, ferruginous Metasandstone, hornfelsed Metasandstone, micaceous Metasandstone, muddy Metasandstone, pebbly Metasandstone, phosphate-nodular Metasandstone, shelly Metasandstone, silty Metasannaite Metasapropelic-coal Metasapropelic-lignite Metasapropelite Metasedimentary rock - In the Rock Classification Scheme, a rock is classified within this category if it is known to be a metamorphic rock derived from a sedimentary protolith, either because of its lithological characteristics or its lithological associations. The class includes metasedimentary rock based on protolith name, metasedimentary rock based on modal composition, and metasedimentary rock based on textural attributes. British Geological Survey Research Report RR/99/02, section 3 and fig. 1. Metasedimentary rock based on grain size or crystal size Metasedimentary rock based on modal composition - In the Rock Classification Scheme, a metasedimentary rock is classified within this category if it cannot be classified according to protolith name. British Geological Survey Research Report RR/99/02, section 3.2 and figs. 1, 5-7. Metasedimentary rock based on protolith name - In the Rock Classification Scheme, a metasedimentary rock is classified within this category if its sedimentary protolith is clearly recognisable. British Geological Survey Research Report RR/99/02, section 3.1 and fig. 1. See also: sedimentary rock and sediment. Metasedimentary rock based on textural attributes - In the Rock Classification Scheme, a metasedimentary rock is classified within this category if neither the exact nature of the protolith nor the modal composition is known. This class includes paraschist, paragneiss, and paragranofels. British Geological Survey Research Report RR/99/02, section 3.3 and fig. 1. Metasedimentary rock composed largely of calcsilicate and/or carbonate minerals - A class within metasedimentary rock based on modal composition. In the Rock Classification Scheme, these are metamorphic rocks containing more than 50% calcsilicate and/or carbonate minerals. This class includes calcsilicate-rock, and metacarbonate-rock. British Geological Survey Research Report RR/99/02, section 3.2 and figs. 6, 7. Metasedimentary rock composed largely of quartz, feldspar and mica - A class within metasedimentary rock based on modal composition. In the Rock Classification Scheme, this class includes quartzite, psammite, semipelite, and pelite. British Geological Survey Research Report RR/99/02, section 3.2 and figs. 5, 6. Metasedimentary rock composed of non-carbonate salts Metasedimentary rock rich in organic matter Metasedimentary rock rich in sapropel Metashell-limestone Metashoshonite Metasiderite-mudstone Metasilicate-claystone Metasilicate-conglomerate Metasilicate-conglomerate, calcite-cemented (calcrete) Metasilicate-mudstone Metasilicate-mudstone, dolomitic Metasilicate-mudstone, ferruginous Metasilicate-mudstone, fissile Metasilicate-sandstone Metasilicate-sandstone, calcite-cemented Metasilicate-sandstone, coarse Metasilicate-sandstone, dolomitic Metasilicate-siltstone Metasilicate-siltstone, dolomitic Metasiliceous rock Metasiltstone Metasiltstone, calcareous Metasiltstone, carbonaceous Metasiltstone, ferruginous Metasiltstone, hornfelsed Metasiltstone, micaceous Metasiltstone, pebbly Metasiltstone, phosphate-nodular Metasiltstone, shelly Metasinter Metasmectite-claystone Metasomatic-rock - A heterogeneous group of metamorphic rocks where metamorphism has involved a significant change in the chemistry of the protolith. Rocks commonly classified as metasomatic include fenite, greisen, rodingites, and skarn. British Geological Survey Research Report RR/99/02, section 8. Metaspessartite Metaspiculite Metasubfeldspathic-arenite Metasublithic-arenite Metasyenite Metasyenite, mafic Metasyenitic-rock Metasyenogranite Metasylvite-stone Metatelaginite Metatephri-phonolite Metatephrite Metatephrite (TAS) Metatephritic-foidite Metatephritic-phonolite Metatephritic-rock Metathermonatrite Metatonalite Metatonalite, foliated Metatonalite, pegmatitic Metatonalite, porphyritic Metatrachyandesite Metatrachyandesite, feldspar-macroporphyritic Metatrachybasalt Metatrachydacite Metatrachyte Metatrachyte (TAS) Metatrachyte, biotite Metatrachyte, comenditic Metatrachyte, pantelleritic Metatrachytic-rock Metatroctolite Metatroctolite, bytownite Metatuff Metatuff, andesitic Metatuff, basalt Metatuff, basaltic Metatuff, basaltic-trachyandesitic Metatuff, calcareous-basaltic Metatuff, dacitic Metatuff, felsic Metatuff, mafic Metatuff, rhyolitic Metatuff, trachyandesitic Metatuff, trachytic Metatuff-breccia Metatuffaceous-breccia Metatuffaceous-conglomerate Metatuffaceous-mudstone Metatuffaceous-sandstone Metatuffaceous-sedimentary-rock Metatuffisite Metatuffite Metatuffite, felsic Metaulexite-stone Metaultramafic-rock, foliated Metavitrain Metavogesite Metavolcaniclastic rock - In the Rock Classification Scheme, a rock is classified within this category if it is known to be a metamorphic rock derived from a volcaniclastic protolith. British Geological Survey Research Report RR/99/02, section 4 and fig. 1. Metavolcaniclastic-breccia - A type of metavolcaniclastic rock. In the Rock Classification Scheme, it has a primary grain size bigger than 2 mm. British Geological Survey Research Report RR/99/02, section 4 and table 2. See also: volcaniclastic-breccia, breccia. Metavolcaniclastic-breccia, basaltic Metavolcaniclastic-conglomerate - A type of metavolcaniclastic rock. In the Rock Classification Scheme, it has a primary grain size bigger than 2 mm. British Geological Survey Research Report RR/99/02, section 4 and table 2. See also: volcaniclastic-conglomerate, conglomerate. Metavolcaniclastic-mudstone - A type of metavolcaniclastic rock. In the Rock Classification Scheme, it has a primary grain size smaller than 0.032 mm. British Geological Survey Research Report RR/99/02, section 4 and table 2. See also: volcaniclastic-mudstone, mudstone. Metavolcaniclastic-sandstone - A type of metavolcaniclastic rock. In the Rock Classification Scheme, it has a primary grain size 0.032 - 2 mm. British Geological Survey Research Report RR/99/02, section 4 and table 2. See also: volcaniclastic-sandstone, sandstone. Metavolcaniclastic-sandstone, andesitic Metavolcaniclastic-sandstone, basaltic Metavolcaniclastic-sandstone, dacitic Metavolcaniclastic-sandstone, rhyolitic Metavolcaniclastic-sedimentary-rock Metawacke Micro-anorthosite - A type of micro-anorthositic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of anorthosite. British Geological Survey Research Report RR/99/06, section 5.1. Micro-anorthositic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of anorthositic-rock. The class includes micro-anorthosite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Micro-ilmenitite Micro-orthopyroxenite - A type of micropyroxenite (s.s.). In the Rock Classification Scheme, it is the medium-grained equivalent of orthopyroxenite. British Geological Survey Research Report RR/99/06, section 5.1. Micro-ultramafic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of ultramafic-rock. The class includes microperidotite, micropyroxenite, and microhornblendite. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Microclinopyroxenite - A type of micropyroxenite (s.s.). In the Rock Classification Scheme, it is the medium-grained equivalent of clinopyroxenite. British Geological Survey Research Report RR/99/06, section 5.1. Microcrystalline-igneous-rock [exotic] Microdiorite - A type of microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of diorite. British Geological Survey Research Report RR/99/06, section 5.1. Microdiorite, feldspar-phyric Microdiorite, foliated Microdiorite, foliated-hornfelsed Microdiorite, foliated-hornfelsed-porphyritic Microdiorite, foliated-porphyritic Microdiorite, gneissose Microdiorite, hornblende Microdiorite, hornblende-phyric Microdiorite, olivine Microdiorite, porphyritic Microdiorite, pyroxene Microdiorite, pyroxene-bearing Microdiorite, pyroxene-mica Microdiorite, sheared Microdioritic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of dioritic-rock. The class includes microdiorite, micromonzodiorite, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Microdioritic-rock, foliated Microdunite - A type of microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of dunite. British Geological Survey Research Report RR/99/06, section 5.1. Microfoidolite - A type of microfoidolitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foidolite. British Geological Survey Research Report RR/99/06, section 5.1. Microfoidolitic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of foidolitic-rock. The class includes micronephelinolite. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Microgabbro (s.s.) - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of gabbro (s.s.). British Geological Survey Research Report RR/99/06, section 5.1. Synonym: dolerite. Microgabbro - A type of microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Microgabbro, biotite-bytownite Microgabbro, bytownite Microgabbro, feldspar-phyric Microgabbro, fluxioned Microgabbro, foliated Microgabbro, glassy Microgabbro, olivine-clinopyroxene-macrophyric Microgabbro, olivine-macrophyric Microgabbro, pegmatitic Microgabbro, plagioclase-microphyric Microgabbro, plagioclase-olivine-clinopyroxene-macrophyric Microgabbro, plagioclase-olivine-microphyric Microgabbro, plagioclase-phyric Microgabbro, porphyritic Microgabbro, sheared Microgabbro, tholeiitic Microgabbro, variolitic Microgabbro, xenolithic Microgabbroic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of gabbroic-rock. The class includes microgabbro, micromonzogabbro, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Microgabbroic-rock, hornfelsed Microgabbroic-rock, magnetic Microgabbronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of gabbronorite. British Geological Survey Research Report RR/99/06, section 5.1. Microgranite - A type of microgranitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of granite. Microgranite may be subdivided into microsyenogranite and micromonzogranite. British Geological Survey Research Report RR/99/06, section 5.1. Microgranite, aplitic Microgranite, aplitic-foliated Microgranite, aplitic-porphyritic Microgranite, biotite-phyric Microgranite, feldspar-phyric Microgranite, foliated Microgranite, foliated-biotite Microgranite, foliated-muscovite-biotite Microgranite, gneissose Microgranite, gneissose-augen Microgranite, granophyric Microgranite, granophyric-hornfelsed Microgranite, pegmatitic Microgranite, pegmatitic-muscovite-biotite Microgranite, porphyritic Microgranite, porphyritic-foliated Microgranite, sheared Microgranite, xenolithic Microgranitic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of granitic-rock. The class includes microgranite, microgranodiorite, microtonalite, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Microgranitic-rock, foliated Microgranitic-rock, gneissose Microgranodiorite - A type of microgranitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of granodiorite. British Geological Survey Research Report RR/99/06, section 5.1. Microgranodiorite, biotite Microgranodiorite, feldspar-phyric Microgranodiorite, foliated Microgranodiorite, foliated-feldspar-phyric Microgranodiorite, foliated-porphyritic Microgranodiorite, gneissose Microgranodiorite, hornblende Microgranodiorite, hornblende-biotite Microgranodiorite, k-feldspar-megacrystic-hornblende Microgranodiorite, plagioclase-phyric Microgranodiorite, porphyritic Microgranodiorite, sheared Microharzburgite - A type of pyroxene-microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of harzburgite. British Geological Survey Research Report RR/99/06, section 5.1. Microhornblendite (s.s.) - A type of microhornblendite. In the Rock Classification Scheme, it is the medium-grained equivalent of hornblendite (s.s.). British Geological Survey Research Report RR/99/06, section 5.1. Microhornblendite - A type of micro-ultramafic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of hornblendite. British Geological Survey Research Report RR/99/06, section 5.1. Microkalsilitic-rock Microkalsilitolite Microleucitic-rock Microleucitolite Microlherzolite - A type of pyroxene-microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of lherzolite. British Geological Survey Research Report RR/99/06, section 5.1. Micromagnetitite Micromelilitic-rock Micromelilitolite Micromonzodiorite - A type of microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1. Micromonzodiorite, olivine Micromonzogabbro - A type of microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1. Micromonzogranite - A type of microgranite. In the Rock Classification Scheme, it is the medium-grained equivalent of monzogranite. British Geological Survey Research Report RR/99/06, section 5.1. Micromonzogranite, porphyritic Micromonzonite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of monzonite. British Geological Survey Research Report RR/99/06, section 5.1. Micromonzonite, foliated Micromonzonite, olivine Micronephelinolite - A microfoidolite in which the dominant feldspathoid mineral is nepheline. It is the medium-grained equivalent of nephelinolite. British Geological Survey Research Report RR/99/06, section 5.1. Micronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of norite. British Geological Survey Research Report RR/99/06, section 5.1. Micronorite, quartz-biotite Microoncoid-ankeritestone - A microoncoid-dolostone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Synonym: ankerite-micro-oncolite. Microoncoid-aragonite-limestone - A microoncoid-limestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Microoncoid-calcite-limestone - A microoncoid-limestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Microoncoid-dolostone - A type of dolostone composed dominantly of microoncoids. British Geological Survey Research Report RR/99/03, section 3.2, table 9 and fig. 7. Microoncoid-ironstone - A type of ironstone composed dominantly of microoncoids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonym: iron-microoncolite. Microoncoid-limestone - A type of limestone composed dominantly of microoncoids. British Geological Survey Research Report RR/99/03, section 3.1, table 4 and fig. 6. Microoncoid-phosphorite - A type of phosphorite composed dominantly of microoncoids. British Geological Survey Research Report RR/99/03, section 4.2, table 12 and fig. 8. Microperidotite - A type of micro-ultramafic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of peridotite. British Geological Survey Research Report RR/99/06, section 5.1. Micropyroxene-rock - A type of meta-ultramafic-rock in which the dominant mineral is pyroxene. British Geological Survey Research Report RR/99/02, section 5.2. Micropyroxenite (s.s.) - A type of micropyroxenite. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxenite (s.s.). British Geological Survey Research Report RR/99/06, section 5.1. Micropyroxenite - A type of micro-ultramafic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxenite. British Geological Survey Research Report RR/99/06, section 5.1. Microquartzolite - A type of quartz-rich-medium-grained-crystalline-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartzolite. British Geological Survey Research Report RR/99/06, section 5.1. Microsyenite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of syenite. British Geological Survey Research Report RR/99/06, section 5.1. Microsyenitic-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of syenitic-rock. The class includes microsyenite, micromonzonite, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Microsyenogranite - A type of microgranite. In the Rock Classification Scheme, it is the medium-grained equivalent of syenogranite. British Geological Survey Research Report RR/99/06, section 5.1. Microtonalite - A type of microgranitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of tonalite. British Geological Survey Research Report RR/99/06, section 5.1. Microtonalite, foliated Microtonalite, pegmatitic Microtonalite, porphyritic Microtroctolite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of troctolite. British Geological Survey Research Report RR/99/06, section 5.1. Microtroctolite, bytownite Microwebsterite - A type of micropyroxenite (s.s.). In the Rock Classification Scheme, it is the medium-grained equivalent of websterite. British Geological Survey Research Report RR/99/06, section 5.1. Microwehrlite - A type of pyroxene-microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of wehrlite. British Geological Survey Research Report RR/99/06, section 5.1. Migmatitic rock - A megascopically composite rock consisting of two or more petrographically different parts, one of which is the country rock in a more or less metamorphic stage, the other is of pegmatitic, aplitic, granitic or generally plutonic appearance. Migmatitic rocks contain leucosomes, mesosomes and melanosomes. Leucosomes are defined as being of variable scale and comprising the leucocratic, quartzofeldspathic or feldspathic fraction of the rock. Mesosome is the part of the rock having the appearance of an ordinary metamorphic rock, that is schist or gneiss, and is generally of intermediate colour between the leucosome and melanosome. The melanosome is the melanocratic, mafic-rich fraction of the migmatitic rock, complementary to the leucosome. The neosome comprises both the leucosome and the melanosome. Most migmatitic rocks occur in middle to upper amphibolite facies and granulite facies terrains. They may be produced by partial melting, injection or solid state diffusion processes. British Geological Survey Research Report RR/99/02, section 9.3. Mine dumps (tailings) - A type of artifical deposit. It consists of the inferior part of ore or mineral or surrounding rock, usually deposited close to the mine. British Geological Survey Research Report RR/99/04, appendix 1. See also: mineral fill. Mineral fill - A type of artifical deposit. It is a general term for the waste products of mining and surface mineral workings. British Geological Survey Research Report RR/99/04, appendix 1. See also: mine dumps (tailings) Mineral-type-clay (specified mineral) - A type of monomineralic aluminium-silicate sediment. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Mineral-type-claystone (specified mineral) - A type of monomineralic aluminium-silicate sedimentary rock. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Minette - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which orthoclase is the dominant feldspar, and the predominant mafic minerals are biotite and diopsidic augite (with/without olivine). British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Miscellaneous hydroxide, oxide and silicate metasedimentary rock Miscellaneous hydroxide, oxide and silicate sediment and sedimentary rock - In the Rock Classification Scheme, these are subdivided into two main groups: monomineralic aluminium-silicate, and hydroxides and oxides of alumina and iron. British Geological Survey Research Report RR/99/03, section 9. Monchiquite - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which feldspar is absent, and the predominant mafic minerals are amphibole, Ti-rich augite, olivine, and biotite. British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Monchiquite, nepheline Monomineralic aluminium-silicate - These sediments and rocks take the form of clays and claystones. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Monomineralic aluminium-silicate metasedimentary rock Monomineralic aluminium-silicate sediment - These sediments take the form of clays. This is the unlithified equivalent of monomineralic aluminium-silicate sedimentary rock. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Monomineralic aluminium-silicate sedimentary rock - These rocks take the form of claystones. This is the lithified equivalent of monomineralic aluminium-silicate sediment. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Monomineralic meta-aluminium-silicates Monzodiorite - A type of dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 9 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Monzodiorite and monzogabbro are separated according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is less than 50% the rock is monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Monzodiorite, olivine Monzogabbro - A type of gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 9 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Monzodiorite and monzogabbro are separated according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is greater than 50% the rock is monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Monzogranite - A type of granite. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 3b of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Monzogranite, biotite Monzogranite, porphyritic Monzonite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 8 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Monzonite, charnockitic Monzonite, foliated Monzonite, olivine Monzonitic-rock Mud Mud (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: M Mud [Unlithified Deposits Coding Scheme - Extended] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme - Extended is an extension to the Unlithified Deposits Coding Scheme, for deposit types not defined in the original scheme. Mud, calcareous Mud, gravelly Mud, gravelly (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: gM Mud, gravelly sandy Mud, organic Mud, sandy (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: sM Mud, sandy [Unlithified Deposits Coding Scheme - Extended] Mud, shell Mud, slightly gravelly (Sea bed sediment, based on Folk) - A type of marine sediment. Symbol: (g)M Mud, slightly gravelly sandy (Sea bed sediment, based on Folk) - A type of marine sediment. Symbol: (g)sM Mud, slightly sandy (Sea bed sediment, based on Folk) - A type of marine sediment. Symbol: (s)M Muddy-peat - A type of peat. It is an unlithified end-member of the impure humic coal series. The impure humic coal series can be subdivided into muddy-peat / sandy-peat (the unlithified form) and impure-coal (the lithified form). Muddy-peat and sandy-peat are distinguished on the basis of their mineral content. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Mudstone - An argillaceous sedimentary rock based on grain size or crystal size. British Geological Survey Research Report RR/99/03, fig. 13. See: silicate-mudstone. Mudstone rich in organic matter Mudstone, bituminous Mudstone, burrow-mottled Mudstone, calcareous Mudstone, carbonaceous Mudstone, dolomitic Mudstone, ferruginous Mudstone, friable, calcareous Mudstone, glauconitic Mudstone, hemipelagic, laminated Mudstone, hornfelsed Mudstone, manganiferous Mudstone, marine, shelly Mudstone, micaceous Mudstone, non-marine, shelly Mudstone, pebbly Mudstone, phospha-pebbly Mudstone, phosphate-nodular Mudstone, phosphatic Mudstone, sandy Mudstone, seat-earth Mudstone, shelly Mudstone, siliceous Mudstone, siliceous, organic Mudstone, silty Mudstone, slaty Mudstone, slumped Mudstone, slumped and foliated Mugearite - A sodic basaltic-trachyandesite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Mugearite, feldspar-phyric Mylonite - A type of mylonitic-rock. In the Rock Classification Scheme, it is one in which porphyroclasts comprise 10 - 50% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.3 and table 5. Mylonite, hornfelsed Mylonite, quartzose Mylonitic-rock - A type of foliated mechanically broken rock with primary cohesion. Mylonitic rocks represent the products of dominantly ductile deformation. They generally occur within restricted zones related to faults, thrusts or shear zones. These foliated rocks develop as a result of grain size reduction by a combination of breakage and plastic strain of grains. Plastic deformation increases the aspect ratio of affected minerals producing textures such as quartz ribbons and a foliated fine-grained matrix. Other minerals, for example feldspar and garnet, may resist ductile deformation or fracture in a brittle manner and remain significantly larger than the foliated matrix. These are commonly lens shaped and termed porphyroclasts. As mylonitisation proceeds, the porphyroclasts are progressively wrapped by and then become isolated within the foliated matrix. They also become smaller, either by fracturing or by marginal erosion. Porphyroclasts may develop asymmetrical tails which can indicate the sense of shearing (dextral or sinistral) within the mylonitic rocks. Mylonitic rocks are classified into protomylonite, mylonite, and ultramylonite based on the percentage of visible porphyroclasts within the streaky, platy, fine-grained matrix. British Geological Survey Research Report RR/99/02, section 7.3 and table 5. Na carbonate sedimentary rock - In the Rock Classification Scheme, these are carbonate sedimentary rocks in which the dominant carbonate mineral is sodium carbonate. The Na carbonate sedimentary rocks are primary precipitates and do not have an unlithified equivalent. They are classified as gaylussite, natron, thermonatrite and trona. British Geological Survey Research Report RR/99/03, section 3.3. Na/Mg carbonate metasedimentary rock Natrocarbonatite - A type of carbonatite. In the Rock Classification Scheme, this term may be used when a modal classification is possible. A natrocarbonatite is composed essentially of sodium, potassium and calcium carbonate minerals. British Geological Survey Research Report RR/99/06, section 6.1 and fig. 25. Natron - A type of Na carbonate sedimentary rock. Natron (Na2CO3.10H2O) is usually in solution, but also forms monoclinic crystals and efflorescent crusts. British Geological Survey Research Report RR/99/03, section 3.3. Natural fill Natural superficial deposit - A type of superficial deposit (natural and/or artificial). British Geological Survey Research Report RR/99/04, section 4. Nepheline-diorite - A foid-diorite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Nepheline-melagabbro, hornblende Nepheline-micromonzogabbro - A foid-micromonzogabbro in which the dominant feldspathoid mineral is nepheline. It is the medium-grained equivalent of nepheline-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1. Nepheline-microsyenite - A foid-microsyenite in which the dominant feldspathoid mineral is nepheline. It is the medium-grained equivalent of nepheline-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Nepheline-monzogabbro - A foid-monzogabbro in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Nepheline-monzosyenite - A foid-monzosyenite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Nepheline-syenite - A foid-syenite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Nephelinite - A foidite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.2. Nephelinolite - A foidolite in which the dominant feldspathoid mineral is nepheline. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Non-carbonate salt - British Geological Survey Research Report RR/99/03, section 7 and fig. 11. Non-carbonate salt-metarock Non-carbonate salt-rock - This is the lithified equivalent of non-carbonate salt-sediment. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Non-carbonate salt-sediment - The root name includes reference to the grain size and the composition. This is the unlithified equivalent of non-carbonate salt-rock. British Geological Survey Research Report RR/99/03, section 7.2 and fig. 11. Non-clastic siliceous metasedimentary rock Non-clastic siliceous sediment - In the Rock Classification Scheme, these are sediments which are composed of more than 50% silica of biogenic or chemical origin. This is the unlithified equivalent of siliceous rock. British Geological Survey Research Report RR/99/03, section 8.1 and fig. 12. Non-clastic siliceous sediment and sedimentary rock - In the Rock Classification Scheme, these are rocks and sediments which are composed of more than 50% silica of biogenic or chemical origin. The classification is based upon the stage of the mineralogical transformation of silica, the type of silica and, if recognisable, the type of biogenic matter. British Geological Survey Research Report RR/99/03, section 8 and fig. 12. Non-ultramafic-melilitic-rock - A type of melilitic rock. In the Rock Classification Scheme, ultramafic-melilitic-rock and non-ultramafic-melilitic-rock are distinguished using colour index M: non-ultramafic-melilitic-rock has M less than 90%. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 27. Non-ultramafic-micromelilitic-rocks Norite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with 10 - 90% plagioclase, <5% olivine and 5 - 90% pyroxene (<5% clinopyroxene) of plagioclase + olivine + pyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Norite, quartz Norite, quartz-biotite Normal crystalline igneous rock - These are the chemically and/or mineralogically normal crystalline igneous rocks. In the Rock Classification Scheme, this class includes coarse-grained normal crystalline rock, medium-grained normal crystalline rock, and fine-grained normal crystalline rock. These comprise the vast majority of all crystalline igneous rocks. British Geological Survey Research Report RR/99/06, section 1.3 and fig. 1. Obsidian - A type of glassy-igneous-rock. It is a glassy, fresh, igneous rock. The term has no compositional inference. British Geological Survey Research Report RR/99/06, section 8.3. Oil shale waste - A type of artifical deposit. It consists of waste products from the mining of dark grey or black shale containing organic substances that yield liquid hydrocarbons on distillation. British Geological Survey Research Report RR/99/04, appendix 1. Oilshale Olivine-basalt Olivine-chromite-rock Olivine-chromite-rock, cumulate Olivine-clinopyroxene-micronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-clinopyroxene-norite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-clinopyroxene-norite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, olivine >5% and pyroxene 5 - 90% (orthopyroxene > clinopyroxene) of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Olivine-clinopyroxenite - A type of olivine-pyroxenite. In the Rock Classification Scheme, it is an olivine-pyroxenite with olivine 5 - 40%, pyroxene 55 - 90% (<5% orthopyroxene) and hornblende <5% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Olivine-gabbro - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% and olivine 5 - 85% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Olivine-gabbro, Fe-rich Olivine-gabbro, porphyritic Olivine-gabbronorite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 5 - 85%, pyroxene 5 - 85% (both clino- and orthopyroxene >5%) and olivine 5 - 85% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Olivine-hawaiite Olivine-hornblende-micropyroxenite Olivine-hornblende-pyroxenite - A type of pyroxenite. In the Rock Classification Scheme, it is a pyroxenite with pyroxene 30 - 90%, olivine 5 - 40% and hornblende 5 - 47% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Olivine-hornblendite - A type of hornblendite. In the Rock Classification Scheme, it is a hornblendite with pyroxene <5%, olivine 5 - 40% and hornblende 55 - 90% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Olivine-melilitite - A type of ultramafic-melilitic-rock. Melilitite is the general name for fine-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28b. Olivine-melilitolite - A type of ultramafic-melilitic-rock. Melilitolite is the general name for coarse-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. Olivine-melilitolite replaces the special varietal term kugdite. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28a. Olivine-micro-orthopyroxenite - A type of olivine-micropyroxenite. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-orthopyroxenite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-microclinopyroxenite - A type of olivine-micropyroxenite. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-clinopyroxenite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-microgabbro - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-microgabbro, Fe-rich Olivine-microgabbronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-gabbronorite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-microhornblendite - A type of microhornblendite. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-hornblendite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-micromelilitolite Olivine-micronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-norite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-micropyroxenite - A type of micropyroxenite. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-pyroxenite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-microwebsterite - A type of olivine-micropyroxenite. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-websterite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-norite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<5% clinopyroxene) and olivine >85% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Olivine-orthopyroxene-gabbro - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<45% orthopyroxene) and olivine 5 - 85% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Olivine-orthopyroxene-microgabbro - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-orthopyroxene-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-orthopyroxenite - A type of olivine-pyroxenite. In the Rock Classification Scheme, it is an olivine-pyroxenite with olivine 5 - 40%, pyroxene 55 - 90% (<5% clinopyroxene) and hornblende <5% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Olivine-pyroxene metakalsilitite Olivine-pyroxene metakalsilitolite Olivine-pyroxene-hornblendite - A type of hornblendite. In the Rock Classification Scheme, it is a hornblendite with hornblende 30 - 90%, olivine 5 - 40% and pyroxene 5 - 47% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Olivine-pyroxene-melilitolite - A type of ultramafic-melilitic-rock. Melilitolite is the general name for coarse-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. Olivine-pyroxene-melilitolite replaces the special varietal term olivine uncompahgrite. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28a. Olivine-pyroxene-microhornblendite - A type of microhornblendite. In the Rock Classification Scheme, it is the medium-grained equivalent of olivine-pyroxene-hornblendite. British Geological Survey Research Report RR/99/06, section 5.1. Olivine-pyroxene-micromelilitolite Olivine-pyroxenite - A type of pyroxenite. In the Rock Classification Scheme, it is a pyroxenite with olivine 5 - 40%, pyroxene 55 - 90% and hornblende <5% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Olivine-websterite - A type of olivine-pyroxenite. In the Rock Classification Scheme, it is an olivine-pyroxenite with olivine 5 - 40%, orthopyroxene 5 - 90% and clinopyroxene 5 - 90% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Oncoid-ankeritestone - An oncoid-dolostone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Synonym: ankerite-oncolite. Oncoid-aragonite-limestone - An oncoid-limestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Oncoid-calcite-limestone - An oncoid-limestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Oncoid-dolostone - A type of dolostone composed dominantly of oncoids. British Geological Survey Research Report RR/99/03, section 3.2, table 9 and fig. 7. Oncoid-ironstone - A type of ironstone composed dominantly of oncoids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonym: iron-oncolite. Oncoid-limestone - A type of limestone composed dominantly of oncoids. British Geological Survey Research Report RR/99/03, section 3.1, table 4 and fig. 6. Synonym: lime-oncolite. Oncoid-phosphorite - A type of phosphorite composed dominantly of oncoids. British Geological Survey Research Report RR/99/03, section 4.2, table 12 and fig. 8. Ooid-ankeritestone - An ooid-dolostone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Synonym: ankerite-oolite. Ooid-aragonite-limestone - An ooid-limestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Ooid-calcite-limestone - An ooid-limestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Ooid-dolostone - A type of dolostone composed dominantly of ooids. British Geological Survey Research Report RR/99/03, section 3.2, table 9 and fig. 7. Ooid-ironstone - A type of ironstone composed dominantly of ooids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonyms: ooidal ironstone; ironstone, ooidal. Ooid-limestone - A type of limestone composed dominantly of ooids. British Geological Survey Research Report RR/99/03, section 3.1, table 4 and fig. 6. Synonyms: ooidal limestone; limestone, ooidal. Ooid-phosphorite - A type of phosphorite composed dominantly of ooids. British Geological Survey Research Report RR/99/03, section 4.2, table 12 and fig. 8. Opaline-chert - A type of chert in which the silica includes amorphous silica (opal-A), opal CT, low-cristobalite and tridymite. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Opaline-porcellanite - A type of porcellanite in which the silica includes amorphous silica (opal-A), opal CT, low-cristobalite and tridymite. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Organic waste - A type of artifical deposit. It consists of waste materials containing carbon compounds, such as wood, plant materials, coal. British Geological Survey Research Report RR/99/04, appendix 1. Organic-rich sediment and sedimentary rock - In the Rock Classification Scheme, these are defined as those sediments and sedimentary rocks where the organic content is sufficiently high to have a noticeable effect on the lithology. A definition based on a greater than 50% volumetric abundance of organic matter is not possible because historically the definitions of sediments and sedimentary rocks rich in organic-matter have been based on their quality as fossil fuels. British Geological Survey Research Report RR/99/03, section 6 and fig. 10. Ortho-amphibolite - A type of metamafic-rock. In the Rock Classification Scheme, it is one composed largely of hornblende and feldspar. This mineralogy reflects amphibolite facies conditions. Note the ortho- prefix indicates a rock that is thought to have an igneous protolith, in contrast with para-amphibolite which has a sedimentary protolith, and amphibolite where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, section 5.2. Orthogneiss - A type of meta-igneous rock based on textural attributes. In the Rock Classification Scheme, it is defined as a medium- to coarse-grained inhomogeneous rock, commonly with a well-developed preferred orientation of constituent minerals, and characterised by a coarse foliation or layering that is more widely spaced, irregular or discontinuous than that in a schist. Adjacent layers generally exhibit contrasting texture, grain size, and mineralogy. However, there is a continuum between schists and gneisses, with factors such as the spacing of the foliation and the degree of contrast between adjacent layers contributing to the assignment of a rock to either category. Gneiss is distinguished from schist where some layers are over 5 mm thick. Gneisses generally occur in areas of middle to upper amphibolite or granulite facies metamorphism and can encompass a wide range of lithologies. Note the ortho- prefix indicates a rock that is thought to have an igneous protolith, in contrast with paragneiss which has a sedimentary protolith, and gneiss where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, sections 3.3, 5.3 and fig. 1. Orthogneiss, alkali-feldspar Orthogneiss, felsic Orthogneiss, hornblende-bearing Orthogneiss, mafic Orthogneiss, mylonitic Orthogranofels - A type of meta-igneous rock based on textural attributes. It lacks any obvious foliation and layering and is commonly characterised by a granoblastic texture. A granofels can occur at any metamorphic grade with a range of lithologies. Note the ortho- prefix indicates a rock that is thought to have an igneous protolith, in contrast with paragranofels which has a sedimentary protolith, and granofels where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, sections 3.3, 5.3 and fig. 1. Orthopyroxene-gabbro - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<45% orthopyroxene) and olivine <5% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Orthopyroxene-gabbro, hypersthene Orthopyroxene-microgabbro - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of orthopyroxene-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Orthopyroxene-microgabbro, hypersthene Orthopyroxenite - A type of pyroxenite (s.s.) in which the pyroxene is entirely or almost entirely orthopyroxene. In the Rock Classification Scheme, it is a pyroxenite with olivine <10%, orthopyroxene >90% and clinopyroxene <10% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Orthoschist - A type of meta-igneous rock based on textural attributes. In the Rock Classification Scheme, it is defined as a medium-grained strongly foliated rock that can be readily split into flakes or slabs due to the well-developed preferred orientation of the majority of the minerals present, particularly those of platy or prismatic habit. Schists occur characteristically in areas of medium-grade metamorphism and can encompass a wide range of lithologies. Note the ortho- prefix indicates a rock that is thought to have an igneous protolith, in contrast with paraschist which has a sedimentary protolith, and schist where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, sections 3.3, 5.3 and fig. 1. Palaeosoil Paper - A type of artifical deposit. It is a substance made from compacted interlaced fibres of rags, wood, or straw. British Geological Survey Research Report RR/99/04, appendix 1. Para-amphibolite - A type of calcsilicate-rock. In the Rock Classification Scheme, it is one composed largely of hornblende and plagioclase. This mineralogy reflects amphibolite facies conditions. Note the para- prefix indicates a rock that is thought to have a sedimentary protolith, in contrast with ortho-amphibolite which has an igneous protolith, and amphibolite where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, section 3.2. Paragneiss - A type of metasedimentary rock based on textural attributes. In the Rock Classification Scheme, it is defined as a medium- to coarse-grained inhomogeneous rock, commonly with a well-developed preferred orientation of constituent minerals, and characterised by a coarse foliation or layering that is more widely spaced, irregular or discontinuous than that in a schist. Adjacent layers generally exhibit contrasting texture, grain size, and mineralogy. However, there is a continuum between schists and gneisses, with factors such as the spacing of the foliation and the degree of contrast between adjacent layers contributing to the assignment of a rock to either category. Gneiss is distinguished from schist where some layers are over 5 mm thick. Gneisses generally occur in areas of middle to upper amphibolite or granulite facies metamorphism and can encompass a wide range of lithologies. Note the para- prefix indicates a rock that is thought to have a sedimentary protolith, in contrast with orthogneiss which has an igneous protolith, and gneiss where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, section 3.3. Paragranofels - A type of metasedimentary rock based on textural attributes. It lacks any obvious foliation and layering and is commonly characterised by a granoblastic texture. A granofels can occur at any metamorphic grade with a range of lithologies. Note the para- prefix indicates a rock that is thought to have a sedimentary protolith, in contrast with orthogranofels which has an igneous protolith, and granofels where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, section 3.3. Paraschist - A type of metasedimentary rock based on textural attributes. In the Rock Classification Scheme, it is defined as a medium-grained strongly foliated rock that can be readily split into flakes or slabs due to the well-developed preferred orientation of the majority of the minerals present, particularly those of platy or prismatic habit. Schists occur characteristically in areas of medium-grade metamorphism and can encompass a wide range of lithologies. Note the para- prefix indicates a rock that is thought to have a sedimentary protolith, in contrast with orthoschist which has an igneous protolith, and schist where the nature of the protolith is not defined. British Geological Survey Research Report RR/99/02, section 3.3. Paraschist, albite-chlorite Peat - A type of sediment rich in organic matter. It is the unlithified end-member of the pure humic coal series. The members of the pure humic coal series can be ranked in order as peat (the unlithified form), lignite, bituminous-coal, and anthracite (the lithified forms) based on increasing carbon content and decreasing volatile content. Peat is an unconsolidated deposit of semi-carbonised plant remains, with individual plant remains commonly seen with the unaided eye. Peat has a yellowish brown to brownish black colour, is generally of a fibrous consistency and can be plastic or friable. In its natural state it can be cut and has a very high moisture content (> 75%, generally > 90%). It can be distinguished from lignite by the fact that the greater part of its moisture content can be squeezed out by pressure (e.g. in the hand). British Geological Survey Research Report RR/99/03, section 6.1, table 16 and fig. 10. Peat [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). See also: peat. Peat, bouldery [Unlithified Deposits Coding Scheme] Peat, clayey [Unlithified Deposits Coding Scheme] Peat, clayey, gravelly [Unlithified Deposits Coding Scheme] Peat, clayey, gravelly, sandy [Unlithified Deposits Coding Scheme] Peat, clayey, gravelly, silty, sandy [Unlithified Deposits Coding Scheme] Peat, clayey, sandy [Unlithified Deposits Coding Scheme] Peat, clayey, sandy, gravelly [Unlithified Deposits Coding Scheme] Peat, clayey, sandy, silty [Unlithified Deposits Coding Scheme] Peat, clayey, silty [Unlithified Deposits Coding Scheme] Peat, clayey, silty, sandy [Unlithified Deposits Coding Scheme] Peat, cobbly [Unlithified Deposits Coding Scheme] Peat, gravelly [Unlithified Deposits Coding Scheme] Peat, gravelly, clayey [Unlithified Deposits Coding Scheme] Peat, gravelly, clayey, sandy [Unlithified Deposits Coding Scheme] Peat, gravelly, clayey, silty [Unlithified Deposits Coding Scheme] Peat, gravelly, sandy [Unlithified Deposits Coding Scheme] Peat, gravelly, sandy, clayey, silty [Unlithified Deposits Coding Scheme] Peat, gravelly, sandy, silty [Unlithified Deposits Coding Scheme] Peat, gravelly, sandy, silty, clayey [Unlithified Deposits Coding Scheme] Peat, gravelly, silty, clayey [Unlithified Deposits Coding Scheme] Peat, sandy [Unlithified Deposits Coding Scheme] Peat, sandy, clayey [Unlithified Deposits Coding Scheme] Peat, sandy, clayey, silty [Unlithified Deposits Coding Scheme] Peat, sandy, gravelly [Unlithified Deposits Coding Scheme] Peat, sandy, silty [Unlithified Deposits Coding Scheme] Peat, sandy, silty, clayey [Unlithified Deposits Coding Scheme] Peat, silty [Unlithified Deposits Coding Scheme] Peat, silty, clayey [Unlithified Deposits Coding Scheme] Peat, silty, clayey, sandy [Unlithified Deposits Coding Scheme] Peat, silty, gravelly [Unlithified Deposits Coding Scheme] Peat, silty, gravelly, clayey [Unlithified Deposits Coding Scheme] Peat, silty, gravelly, sandy [Unlithified Deposits Coding Scheme] Peat, silty, sandy [Unlithified Deposits Coding Scheme] Peat, silty, sandy, clayey [Unlithified Deposits Coding Scheme] Peat, silty, sandy, gravelly [Unlithified Deposits Coding Scheme] Pegmatite - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, the term pegmatite is used for veins comprised of coarse or very coarse crystals. The term is used with qualifiers to describe component minerals in increasing abundance, for example biotite-quartz-feldspar pegmatite. British Geological Survey Research Report RR/99/06, section 8.1. Pegmatite, biotite Pegmatite, brecciated-feldspar-quartz Pegmatite, feldspar-quartz Pegmatite, foliated Pegmatite, foliated-feldspar-quartz Pegmatite, migmatitic Pegmatite, sheared Pelite - A type of metasedimentary rock composed largely of quartz, feldspar and mica. In the Rock Classification Scheme, it is one with mica component >40%, and quartz + feldspar <60% of quartz + feldspar + mica. The mica component includes all minerals other than quartz and feldspar, with the exception of calcsilicate and carbonate minerals. British Geological Survey Research Report RR/99/02, section 3.2, table 1 and fig. 5. Pelite, banded Pelite, calcareous Pelite, gneissose Pelite, gneissose migmatitic Pelite, gneissose-banded Pelite, gneissose-muscovite-rich Pelite, graphitic Pelite, hornfelsed Pelite, magnetic Pelite, migmatitic Pelite, muscovite-rich Pelite, phyllitic Pelite, phyllitic graphitic Pelite, phyllitic magnetic Pelite, schistose Pelite, schistose banded Pelite, schistose graphitic Pelite, slaty Peloid-ankeritestone - A peloid-dolostone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Synonym: ankerite-peloidite. Peloid-aragonite-limestone - A peloid-limestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Peloid-calcite-limestone - A peloid-limestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Peloid-dolostone - A type of dolostone composed dominantly of peloids. British Geological Survey Research Report RR/99/03, section 3.2, table 9 and fig. 7. Peloid-ironstone - A type of ironstone composed dominantly of peloids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonym: iron-peloidite. Peloid-limestone - A type of limestone composed dominantly of peloids. British Geological Survey Research Report RR/99/03, section 3.1, table 4 and fig. 6. Peloid-phosphorite - A type of phosphorite composed dominantly of peloids. British Geological Survey Research Report RR/99/03, section 4.2, table 12 and fig. 8. Peridotite - A type of ultramafic-rock. In the Rock Classification Scheme, it is a coarse-grained ultramafic rock with more than 40% olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 15, 16. Peridotite, feldspathic Peridotite, garnet Peridotite, garnet-bearing Pesticide - A type of artifical deposit. It is a substance used for killing pests, especially insects. British Geological Survey Research Report RR/99/04, appendix 1. Phono-tephrite - A type of tephritic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of phono-tephrite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Phonolite (TAS) - A type of phonolitic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of phonolite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Phonolite - A type of phonolitic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 11 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Phonolitic-basanite - A type of tephritic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 13 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Phonolitic-basanite and phonolitic-tephrite are distinguished by the amount of olivine in the CIPW norm: if normative olivine exceeds 10% the rock is phonolitic-basanite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Phonolitic-foidite - A type of foiditic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 15a of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Phonolitic-leucitite - A type of leucitite. In the Rock Classification Scheme, this rock plots in field 15a on the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram; foids constitute 60 to 90% of light-coloured constituents; alkali feldspar is dominant over plagioclase. British Geological Survey Research Report RR/99/06, sections 5.2, 6.6. Phonolitic-rock - A type of mafite. In the Rock Classification Scheme, this class includes phonolite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Phonolitic-tephrite - A type of tephritic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 13 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Phonolitic-basanite and phonolitic-tephrite are distinguished by the amount of olivine in the CIPW norm: if normative olivine is less than 10% the rock is phonolitic-tephrite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Phosphate sediment and phosphorite - In the Rock Classification Scheme, these are defined as those sediments and sedimentary rocks which have more than 50% phosphate minerals. These may be phosphates of calcium, aluminium or iron (equivalent to about 18 to 21% wt P2O5 depending on the nature of the phosphate minerals present). British Geological Survey Research Report RR/99/03, section 4 and fig. 8. Phosphate-boundstone - A type of phosphorite, classified on the basis of its biogenic texture. It is a phosphorite in which the original components were bound and encrusted together by the action of plants and animals in the position of growth. British Geological Survey Research Report RR/99/03, section 4.2, table 11 and fig. 8. Phosphate-grainstone - A type of phosphorite, classified on the basis of its depositional texture. It is a grain-supported phosphorite with little matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 4.2, table 11 and fig. 8. Phosphate-gravel - A type of phosphate-sediment. In the Rock Classification Scheme, it is one in which over 25% of clasts are larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 4.1, table 10 and fig. 8. See also: silicate-gravel. Phosphate-mud - A type of phosphate-sediment. In the Rock Classification Scheme, it is one in which over 75% of the clasts are smaller than 32 µm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 4.1, table 10 and fig. 8. See also: silicate-mud. Phosphate-mudstone - A type of phosphorite, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported phosphorite composed of greater than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 4.2, table 11 and fig. 8. Phosphate-packstone - A type of phosphorite, classified on the basis of its depositional texture. It is a grain-supported phosphorite with intergranular spaces filled by matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 4.2, table 11 and fig. 8. Phosphate-sand - A type of phosphate-sediment. In the Rock Classification Scheme, it is one in which clasts are predominantly 32 µm to 2 mm, with less than 75% of the clasts smaller than 32 µm and less than 25% larger than 2 mm. The grain size classes are defined in the same way as the siliciclastic sediments. British Geological Survey Research Report RR/99/03, section 4.1, table 10 and fig. 8. See also: silicate-sand. Phosphate-sediment - In the Rock Classification Scheme, all phosphate-sediments are given this group name. This is the unlithified equivalent of phosphorite. British Geological Survey Research Report RR/99/03, section 4.1 and fig. 8. Phosphate-wackestone - A type of phosphorite, classified on the basis of its depositional texture. In the Rock Classification Scheme, it is a matrix-supported phosphorite composed of less than 75% matrix (mud-grade material smaller than 32 µm). British Geological Survey Research Report RR/99/03, section 4.2, table 11 and fig. 8. Phosphorite - In the Rock Classification Scheme, all lithified phosphate-rich sedimentary rocks are given this group name. This is the lithified equivalent of phosphate-sediment. The textural classification of phosphorites follows that for limestone. The classification of phosphorites composed dominantly of one constituent similarly follows that for limestone. British Geological Survey Research Report RR/99/03, section 4.2 and fig. 8. Phosphorite, nodular Phosphorite, pebble-grade Phyllonite - A type of mylonitic-rock. They are defined as mylonitic rocks of phyllitic appearance and hence are dominated by platy minerals. British Geological Survey Research Report RR/99/02, section 7.3. Picrite - A type of picritic-rock. Its definition is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 22. Picritic-rock - A type of mafite. Picritic rocks are high-Mg fine-grained crystalline rocks. They are classified using an extension of the total alkali silica (TAS) classification. In the Rock Classification Scheme, this class includes picrite, komatiite, and meimechite. British Geological Survey Research Report RR/99/06, section 5.2 and fig. 17b. Picrobasalt - A type of mafite. Its definition is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20, 22. Pisoid-ankeritestone - A pisoid-dolostone in which the carbonate is composed dominantly of ankerite. British Geological Survey Research Report RR/99/03, section 3.2 and fig. 7. Synonym: ankerite-pisolite. Pisoid-aragonite-limestone - A pisoid-limestone in which the carbonate is composed dominantly of aragonite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Pisoid-calcite-limestone - A pisoid-limestone in which the carbonate is composed dominantly of calcite. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Pisoid-dolostone - A type of dolostone composed dominantly of pisoids. British Geological Survey Research Report RR/99/03, section 3.2, table 9 and fig. 7. Pisoid-ironstone - A type of ironstone composed dominantly of pisoids. British Geological Survey Research Report RR/99/03, section 5.2, table 15 and fig. 9. Synonym: iron-pisolite. Pisoid-limestone - A type of limestone composed dominantly of pisoids. British Geological Survey Research Report RR/99/03, section 3.1, table 4 and fig. 6. Pisoid-phosphorite - A type of phosphorite composed dominantly of pisoids. British Geological Survey Research Report RR/99/03, section 4.2, table 12 and fig. 8. Pitchstone - A type of glassy-igneous-rock. It is a glassy, altered (hydrated/devitrified), igneous rock. The term has no compositional inference. British Geological Survey Research Report RR/99/06, section 8.3. Pitchstone, andesitic Pitchstone, porphyritic-rhyolitic Plasterboard - A type of artifical deposit. It consists of board with a core of plaster for walls. British Geological Survey Research Report RR/99/04, appendix 1. Polyhalite-stone - A type of non-carbonate salt that is composed of particles of the sulphate mineral polyhalite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Porcellanite - A type of siliceous rock. It usually has a porosity of 15 to 30%. Porcellanites have the texture, lustre and conchoidal fracture of porcelain. They can be further classified as opaline-porcellanite and quartzose-porcellanite according to the type of silica. It may not be possible to accurately use this classification without X-ray analysis. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Porphyry - A type of fine-grained normal crystalline rock. It is a rock containing phenocrysts and with an aphanitic groundmass of indeterminate origin. British Geological Survey Research Report RR/99/06, section 8.3. Porphyry, biotite-feldspar Potassic-trachybasalt - A potassic trachybasalt. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Protocataclasite - A type of cataclastic-rock. In the Rock Classification Scheme, it is one in which fragments significantly coarser than the matrix comprise more than 50% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.2 and table 4. Protomylonite - A type of mylonitic-rock. In the Rock Classification Scheme, it is one in which porphyroclasts comprise more than 50% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.3 and table 5. Psammite - A type of metasedimentary rock composed largely of quartz, feldspar and mica. In the Rock Classification Scheme, it is one with mica component <20%, and quartz + feldspar 80 - 100% of quartz + feldspar + mica. The mica component includes all minerals other than quartz and feldspar, with the exception of calcsilicate and carbonate minerals. British Geological Survey Research Report RR/99/02, section 3.2, table 1 and fig. 5. Psammite, banded Psammite, calcareous Psammite, dolomitic Psammite, epidotic Psammite, feldspathic Psammite, feldspathic-gneissose Psammite, feldspathic-gneissose-migmatitic Psammite, feldspathic-migmatitic Psammite, flaggy Psammite, foliated-gritty Psammite, gneissose Psammite, gneissose banded Psammite, gneissose micaceous Psammite, gneissose migmatitic Psammite, granofelsic Psammite, gritty Psammite, gritty calcareous Psammite, hornfelsed Psammite, hornfelsed micaceous Psammite, laminated Psammite, micaceous Psammite, micaceous pebbly Psammite, micaceous-flaggy Psammite, migmatitic Psammite, migmatitic micaceous Psammite, mylonitic Psammite, pebbly Psammite, pebbly migmatitic Psammite, quartzose Psammite, quartzose gneissose migmatitic Psammite, schistose Psammite, schistose banded Psammite, schistose, magnetite-bearing Pseudoleucite-syenite - A foid-syenite in which the dominant feldspathoid mineral is pseudoleucite. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Pseudotachylite - A particular variety of cataclasite in which fragments occur in a glassy groundmass produced by frictional melting. It may be injected as veinlets into adjoining cataclasite. British Geological Survey Research Report RR/99/02, section 7.4. Pulverised fuel ash (PFA) - A type of artifical deposit. It consists of pulverised (fine grade) ash waste from the burning of coal, usually in coal-fired power stations. It is commonly used as an inert fill material, or for the production of breeze blocks. British Geological Survey Research Report RR/99/04, appendix 1. Pyrite (vein) - A type of vein rock. Pyrite-rock Pyroclastic rock and sediment - A type of volcaniclastic igneous rock and sediment. In the Rock Classification Scheme, pyroclastic rocks and sediments contain more than 75% by volume pyroclastic fragments. The class includes pyroclastic-rock, and pyroclastic-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and figs. 1, 4. Pyroclastic-breccia - A type of pyroclastic-rock. In the Rock Classification Scheme, it is a pyroclastic-rock in which more than 75% of the pyroclastic fragments exceed 64 mm in size. Agglomerate and pyroclastic-breccia are separated according to the relative proportion of blocks (angular fragments exceeding 64 mm) and bombs (rounded fragments exceeding 64 mm): if blocks dominate over bombs the rock is pyroclastic-breccia. It is the consolidated equivalent of block-tephra or bomb-block-tephra. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Pyroclastic-breccia, basaltic Pyroclastic-breccia, trachytic Pyroclastic-rock - In the Rock Classification Scheme, pyroclastic-rock contains more than 75% by volume pyroclastic fragments. It is the consolidated equivalent of pyroclastic-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Pyroclastic-rock, basaltic Pyroclastic-rock, rhyolitic Pyroclastic-sediment - In the Rock Classification Scheme, pyroclastic-sediment contains more than 75% by volume pyroclastic fragments. It is the unconsolidated equivalent of pyroclastic-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Synonym: tephra. Pyroxene-hornblende-clinopyroxene-micronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblende-clinopyroxene-norite. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-hornblende-clinopyroxene-norite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<45% clinopyroxene) and hornblende 5 - 85% of plagioclase + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Pyroxene-hornblende-gabbro - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<5% orthopyroxene) and hornblende 5 - 85% of plagioclase + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Pyroxene-hornblende-gabbronorite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (ortho- and clinopyroxene both >5%) and hornblende 5 - 85% of plagioclase + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Pyroxene-hornblende-microgabbro - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblende-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-hornblende-microgabbronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblende-gabbronorite. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-hornblende-micronorite - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblende-norite. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-hornblende-microperidotite - A type of microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblende-peridotite. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-hornblende-norite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<5% clinopyroxene) and hornblende 5 - 85% of plagioclase + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Pyroxene-hornblende-orthopyroxene-gabbro - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene 5 - 85% (<45% orthopyroxene) and hornblende 5 - 85% of plagioclase + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Pyroxene-hornblende-orthopyroxene-microgabbro - A type of microgabbro. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblende-orthopyroxene-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-hornblende-peridotite - A type of peridotite. In the Rock Classification Scheme, it is a peridotite with olivine 40 - 90%, pyroxene 5 - 55% and hornblende 5 - 55% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Pyroxene-hornblendite - A type of hornblendite. In the Rock Classification Scheme, it is a hornblendite with olivine <5%, hornblende 47 - 90% and pyroxene 5 - 50% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Pyroxene-melilitolite - A type of ultramafic-melilitic-rock. Melilitolite is the general name for coarse-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. Pyroxene-melilitolite replaces the special varietal term uncompahgrite. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28a. Pyroxene-microhornblendite - A type of microhornblendite. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-hornblendite. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-micromelilitolite Pyroxene-microperidotite - A type of microperidotite. In the Rock Classification Scheme, it is the medium-grained equivalent of pyroxene-peridotite. British Geological Survey Research Report RR/99/06, section 5.1. Pyroxene-olivine-melilitolite - A type of ultramafic-melilitic-rock. Melilitolite is the general name for coarse-grained melilitic rocks, and they are classified according to their melilite - olivine - clinopyroxene content. British Geological Survey Research Report RR/99/06, section 6.2 and fig. 28a. Pyroxene-olivine-micromelilitolite Pyroxene-peridotite - A type of peridotite. In the Rock Classification Scheme, it is a peridotite with olivine 40 - 90%, pyroxene 5 - 60% and hornblende <5% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Pyroxene-rock - A type of meta-ultramafic-rock in which the dominant mineral is pyroxene. British Geological Survey Research Report RR/99/02, section 5.2. Pyroxene-rock, appinitic-biotite Pyroxenite (s.s.) - A type of pyroxene-rich (>90%) pyroxenite. In the Rock Classification Scheme, it is a pyroxenite with pyroxene >90%, olivine <10% and hornblende <10% of olivine + pyroxene + hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Pyroxenite - A type of ultramafic-rock. In the Rock Classification Scheme, it is a coarse-grained ultramafic rock with less than 40% olivine, and pyroxene dominant over hornblende. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 15, 16. Pyroxenite, biotite Pyroxenite, kalsilite-bearing-biotite Pépérite - A lithified, fluidised mixture of hyaloclastite and sediment formed by the disruption and rapid chilling of magma when it is intruded into, or flows over, wet sediment. British Geological Survey Research Report RR/99/06, section 8.2. Quarry waste - A type of artifical deposit. It is a general term for waste materials consisting mostly of rock with overburden drift deposits, derived from quarrying. British Geological Survey Research Report RR/99/04, appendix 1. See also: rock waste, slate waste, shale waste. Quartz (vein) - A type of vein rock. Quartz breccia (vein) - A type of vein rock. Quartz-alkali-feldspar-microsyenite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-alkali-feldspar-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-alkali-feldspar-syenite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 6* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-alkali-feldspar-trachyte - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 6* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Quartz-anorthosite - A type of anorthositic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Quartz-diorite, quartz-gabbro and quartz-anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is less than 10% the rock is quartz-anorthosite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-arenite - A type of arenite. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Quartz-biotite-rock Quartz-diorite - A type of dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Quartz-diorite, quartz-gabbro and quartz-anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is greater than 10% and An (the anorthite content of plagioclase) is less than 50% the rock is quartz-diorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-diorite, foliated Quartz-dolerite. Synonym: quartz-microgabbro Quartz-feldspar-porphyry Quartz-gabbro - A type of gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 10* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Quartz-diorite, quartz-gabbro and quartz-anorthosite are separated according to the average composition of their plagioclase and the proportion of mafic minerals (M): if M is greater than 10% and An (the anorthite content of plagioclase) is greater than 50% the rock is quartz-gabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-gabbro, biotite Quartz-garnet-magnetite-rock Quartz-latite - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 8* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Quartz-leucomicrodiorite Quartz-leucomicromonzodiorite Quartz-melamicrodiorite Quartz-melamicromonzodiorite Quartz-micro-anorthosite - A type of micro-anorthositic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-anorthosite. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-microdiorite - A type of microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-diorite. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-microdiorite, foliated Quartz-microgabbro - A type of microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-gabbro. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-micromonzodiorite - A type of microdioritic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-micromonzogabbro - A type of microgabbroic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-micromonzonite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-monzonite. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-micronorite Quartz-microsyenite - A type of microsyenitic-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-syenite. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-monzodiorite - A type of dioritic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 9* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Quartz-monzodiorite and quartz-monzogabbro are separated according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is less than 50% the rock is quartz-monzodiorite. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-monzogabbro - A type of gabbroic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 9* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Quartz-monzodiorite and quartz-monzogabbro are separated according to the average composition of their plagioclase: if An (the anorthite content of plagioclase) is greater than 50% the rock is quartz-monzogabbro. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-monzonite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 8* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-porphyry Quartz-rich-coarse-grained-crystalline-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes quartzolite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Quartz-rich-granitic-rock - A type of quartz-rich-coarse-grained-crystalline-rock. In the Rock Classification Scheme, it is a collective term for granitic rocks in which quartz comprises more than 60% of the felsic minerals. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-rich-medium-grained-crystalline-rock - A type of medium-grained normal crystalline rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-rich-coarse-grained-crystalline-rock. The class includes microquartzolite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-rich-microgranitic-rock - A type of quartz-rich-medium-grained-crystalline-rock. In the Rock Classification Scheme, it is the medium-grained equivalent of quartz-rich-granitic-rock. British Geological Survey Research Report RR/99/06, section 5.1. Quartz-syenite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 7* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartz-trachyte - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 7* of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Quartz-wacke - A type of wacke. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Quartzite - A type of metasedimentary rock composed largely of quartz, feldspar and mica. In the Rock Classification Scheme, quartzite is a psammite containing more than 80% quartz. British Geological Survey Research Report RR/99/02, section 3.2 and fig. 5. Quartzite, brecciated Quartzite, dolomitic Quartzite, feldspathic Quartzite, feldspathic-gneissose Quartzite, flaggy Quartzite, gneissose Quartzite, hornfelsed Quartzite, hornfelsed gneissose Quartzite, mylonitic Quartzite, pebbly Quartzite, pyritic Quartzite, sheared Quartzolite - A type of quartz-rich-coarse-grained-crystalline-rock. In the Rock Classification Scheme, it is a collective term for coarse-grained crystalline rocks in which quartz comprises more than 90% of the felsic minerals. These extremely rare rocks are unlikely to be wholly of primary igneous origin. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Quartzose-chert - A type of chert in which the silica consists predominantly of quartz. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Quartzose-metachert Quartzose-porcellanite - A type of porcellanite in which the silica consists predominantly of quartz. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Radioactive waste - A type of artifical deposit. It is a general term for waste materials derived from nuclear processes that are contaminated with radionuclides. It may be classified as low-level, intermediate or high-level waste. British Geological Survey Research Report RR/99/04, appendix 1. Radiolarian-ooze - A type of siliceous-ooze which is predominantly composed of radiolaria. It is the unlithified equivalent of radiolarite. British Geological Survey Research Report RR/99/03, section 8.1 and fig. 12. Radiolarite - A type of siliceous rock which is predominantly composed of radiolaria. It is the lithified equivalent of radiolarian-ooze. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Regolith - A type of residual deposit. It is a general term used to describe the in situ or nearly in situ weathered products (including disintegrated rock, rock fragments and mineral grains) overlying fresh or relatively fresh rock (the weathered mantle). It can be subdivided into weathered rock and saprolite, and classified according to engineering geological weathered rock grades. British Geological Survey Research Report RR/99/04, appendix 2. Synonym: blanket head. Residual deposit - A type of natural superficial deposit. In the Rock Classification Scheme, this class includes duricrust and regolith. British Geological Survey Research Report RR/99/04, section 4.8. Rhyolite (TAS) - A type of rhyolitic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of rhyolite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Rhyolite - A type of rhyolitic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 3 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. It is the fine-grained equivalent of granite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Rhyolite, columnar Rhyolite, comenditic - A type of rhyolite (TAS). In the Rock Classification Scheme, rhyolite (TAS) may be separated into comenditic and pantelleritic types as shown in British Geological Survey Research Report RR/99/06, section 5.2 and fig. 24. Rhyolite, flow-laminated Rhyolite, glassy Rhyolite, pantelleritic - A type of rhyolite (TAS). In the Rock Classification Scheme, rhyolite (TAS) may be separated into comenditic and pantelleritic types as shown in British Geological Survey Research Report RR/99/06, section 5.2 and fig. 24. Rhyolite, peralkaline - A type of rhyolite (TAS). In the Rock Classification Scheme, rhyolite (TAS) may be classified as peralkaline if the peralkaline index is greater than 1. British Geological Survey Research Report RR/99/06, section 5.2. Rhyolite, porphyritic Rhyolitic-rock (TAS) Rhyolitic-rock - A type of felsite. In the Rock Classification Scheme, this class includes rhyolite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Rhyolitic-rock, biotite-phyric Rock - This term is used for any unidentified rock. Rock and sediment Rock of restricted mineralogy - A type of coarse-grained normal crystalline rock. Igneous rocks of unusual composition can be formed by extreme versions of magma differentiation and fractionation. British Geological Survey Research Report RR/99/06, section 8.2. Rock or diamicton (Sea bed sediment, based on Folk) Rock, charnockitic - A type of coarse-grained normal crystalline rock. The charnockitic suite of rocks is usually characterised by the presence of orthopyroxene (or fayalite plus quartz, though in such assemblages fayalite is invariably altered) and, in many such rocks, perthite, mesoperthite or antiperthite. Primary hydrous minerals are generally absent. They are commonly associated with norites and anorthosites and are linked closely with high-grade metamorphic terrains. Despite being composed largely of feldspar and quartz, charnockitic rocks are generally melanocratic due to very dark feldspar crystals, which also have a characteristically greasy appearance. British Geological Survey Research Report RR/99/06, section 5.1. Examples (root name and qualifier): charnockitic granite, charnockitic monzonite, charnockitic tonalite. Rock, mineralized - This term is used for any rock showing a significant degree of mineralization. Rock, quartz-albite Rodingites - A type of metasomatic-rock. They are rocks associated with serpentinites comprising Ca-rich minerals, for example Ca-pyroxene, grossular, hydrogrossular. They represent the Ca-rich fraction expelled during serpentinisation. British Geological Survey Research Report RR/99/02, section 8. Sand Sand (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: S Sand (unknown/industrial) Sand [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). Sand, bouldery [Unlithified Deposits Coding Scheme] Sand, bouldery, cobbly [Unlithified Deposits Coding Scheme] Sand, bouldery, peaty [Unlithified Deposits Coding Scheme] Sand, clayey Sand, clayey [Unlithified Deposits Coding Scheme] Sand, clayey, bouldery [Unlithified Deposits Coding Scheme] Sand, clayey, cobbly [Unlithified Deposits Coding Scheme] Sand, clayey, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, clayey, cobbly, gravelly [Unlithified Deposits Coding Scheme] Sand, clayey, gravelly [Unlithified Deposits Coding Scheme] Sand, clayey, gravelly, bouldery [Unlithified Deposits Coding Scheme] Sand, clayey, gravelly, bouldery, silty [Unlithified Deposits Coding Scheme] Sand, clayey, gravelly, cobbly [Unlithified Deposits Coding Scheme] Sand, clayey, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, clayey, gravelly, shelly [Unlithified Deposits Coding Scheme - Extended] Sand, clayey, gravelly, silty [Unlithified Deposits Coding Scheme] Sand, clayey, peaty [Unlithified Deposits Coding Scheme] Sand, clayey, peaty, gravelly [Unlithified Deposits Coding Scheme] Sand, clayey, peaty, silty [Unlithified Deposits Coding Scheme] Sand, clayey, silty [Unlithified Deposits Coding Scheme] Sand, clayey, silty, gravelly [Unlithified Deposits Coding Scheme] Sand, clayey, silty, gravelly, cobbly [Unlithified Deposits Coding Scheme] Sand, clayey, silty, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, clayey, silty, gravelly, peaty [Unlithified Deposits Coding Scheme] Sand, clayey, silty, peaty [Unlithified Deposits Coding Scheme] Sand, cobbly [Unlithified Deposits Coding Scheme] Sand, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, cobbly, clayey [Unlithified Deposits Coding Scheme] Sand, cobbly, gravelly [Unlithified Deposits Coding Scheme] Sand, cobbly, peaty [Unlithified Deposits Coding Scheme] Sand, glauconitic Sand, gravelly Sand, gravelly (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: gS Sand, gravelly [Unlithified Deposits Coding Scheme] Sand, gravelly muddy Sand, gravelly muddy (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: gmS Sand, gravelly, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, clayey [Unlithified Deposits Coding Scheme] Sand, gravelly, clayey, cobbly [Unlithified Deposits Coding Scheme] Sand, gravelly, clayey, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, clayey, peaty [Unlithified Deposits Coding Scheme] Sand, gravelly, clayey, silty [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, bouldery, silty [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, clayey [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, clayey, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, peaty [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, silty [Unlithified Deposits Coding Scheme] Sand, gravelly, cobbly, silty, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, peaty [Unlithified Deposits Coding Scheme] Sand, gravelly, peaty, clayey [Unlithified Deposits Coding Scheme] Sand, gravelly, peaty, silty [Unlithified Deposits Coding Scheme] Sand, gravelly, shelly [Unlithified Deposits Coding Scheme - Extended] Sand, gravelly, shelly, clayey [Unlithified Deposits Coding Scheme - Extended] Sand, gravelly, silty [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, clayey [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, cobbly [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, peaty [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, peaty, clayey [Unlithified Deposits Coding Scheme] Sand, gravelly, silty, shelly [Unlithified Deposits Coding Scheme - Extended] Sand, micaceous Sand, muddy (Sea bed sediment, based on Folk) - A type of marine sediment. British Geological Survey Research Report RR/99/04, table 8c. Symbol: mS Sand, organic Sand, peaty [Unlithified Deposits Coding Scheme] Sand, peaty, clayey, silty [Unlithified Deposits Coding Scheme] Sand, peaty, gravelly [Unlithified Deposits Coding Scheme] Sand, peaty, silty [Unlithified Deposits Coding Scheme] Sand, peaty, silty, clayey [Unlithified Deposits Coding Scheme] Sand, pebbly (gravelly) Sand, shell Sand, shelly [Unlithified Deposits Coding Scheme - Extended] Sand, shelly, clayey [Unlithified Deposits Coding Scheme - Extended] Sand, shelly, silty [Unlithified Deposits Coding Scheme - Extended] Sand, silty Sand, silty [Unlithified Deposits Coding Scheme] Sand, silty, bouldery [Unlithified Deposits Coding Scheme] Sand, silty, bouldery, cobbly [Unlithified Deposits Coding Scheme] Sand, silty, calcareous [Unlithified Deposits Coding Scheme - Extended] Sand, silty, clayey [Unlithified Deposits Coding Scheme] Sand, silty, clayey, gravelly [Unlithified Deposits Coding Scheme] Sand, silty, cobbly [Unlithified Deposits Coding Scheme] Sand, silty, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, silty, gravelly [Unlithified Deposits Coding Scheme] Sand, silty, gravelly, bouldery [Unlithified Deposits Coding Scheme] Sand, silty, gravelly, clayey [Unlithified Deposits Coding Scheme] Sand, silty, gravelly, cobbly [Unlithified Deposits Coding Scheme] Sand, silty, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Sand, silty, gravelly, peaty [Unlithified Deposits Coding Scheme] Sand, silty, gravelly, shelly [Unlithified Deposits Coding Scheme - Extended] Sand, silty, peaty [Unlithified Deposits Coding Scheme] Sand, silty, peaty, gravelly [Unlithified Deposits Coding Scheme] Sand, silty, shelly [Unlithified Deposits Coding Scheme - Extended] Sand, slightly gravelly (Sea bed sediment, based on Folk) - A type of marine sediment. Symbol: (g)S Sand, slightly gravelly muddy (Sea bed sediment, based on Folk) - A type of marine sediment. Symbol: (g)mS Sand, slightly muddy (Sea bed sediment, based on Folk) - A type of marine sediment. Symbol: (m)S Sandstone - An arenaceous sedimentary rock based on grain size or crystal size. British Geological Survey Research Report RR/99/03, fig. 13. See: silicate-sandstone. Sandstone, bleached Sandstone, calcareous Sandstone, carbonaceous Sandstone, carbonaceous, argillaceous Sandstone, clayey Sandstone, dolomitic Sandstone, ferruginous Sandstone, glauconitic Sandstone, gritty Sandstone, hornfelsed Sandstone, micaceous Sandstone, muddy Sandstone, pebbly (gravelly) Sandstone, phosphate-nodular Sandstone, pisoidal Sandstone, seat-earth Sandstone, shelly Sandstone, silica-cemented Sandstone, silty Sandstone, slumped Sandy-peat - A type of peat. It is an unlithified end-member of the impure humic coal series. The impure humic coal series can be subdivided into muddy-peat / sandy-peat (the unlithified form) and impure-coal (the lithified form). Muddy-peat and sandy-peat are distinguished on the basis of their mineral content. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Sannaite - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which orthoclase is the dominant feldspar, feldspar dominates over feldspathoids, and the predominant mafic minerals are amphibole, Ti-rich augite, olivine, and biotite. British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Saprolite - A type of regolith. It consists of highly to completely weathered materials derived from the in situ alteration and decomposition of parent rock mainly by chemical weathering processes, but which retain evidence of the original rock texture, fabric and structure. It may be classified as engineering soils falling into rock weathering grades IV (highly weathered) and V (completely weathered); that is, those weathering grades where more than 50% of the parent rock material is decomposed or disintegrated to soil. British Geological Survey Research Report RR/99/04, appendix 2. Sapropelic-coal - A type of coal. It is a member of the sapropelic coal series. The members of the sapropelic coal series can be ranked in order as sapropel (the unlithified form), sapropelic-lignite, and sapropelic-coal (the lithified forms) based on increasing carbon content and decreasing volatile content. It is characteristically fine-grained, faintly bedded to homogeneous and massive. It is generally dark in colour with dull to greasy lustre and typically displays conchoidal fracture. Sapropelic coals are subdivided into cannel-coal and boghead-coal based on type of organic matter and other physical properties. British Geological Survey Research Report RR/99/03, section 6.2, table 17 and fig. 10. Sapropelic-lignite - A type of coal. It is a member of the sapropelic coal series. The members of the sapropelic coal series can be ranked in order as sapropel (the unlithified form), sapropelic-lignite, and sapropelic-coal (the lithified forms) based on increasing carbon content and decreasing volatile content. Sapropelic-lignite is macroscopically similar to humic lignite. It may be possible to distinguish sapropelic lignites by their homogeneous, non-stratified appearance. If differentiation is difficult, sapropelic lignites can be accurately differentiated by chemical analysis. British Geological Survey Research Report RR/99/03, section 6.2, table 17 and fig. 10. Sapropelite - A type of sedimentary-rock rich in organic matter. Sapropelite and cannel-mudstone are both derived from the unlithified fine organic mud termed sapropel. These sapropels contain more inorganic matter and plant matter than the sapropels that form sapropelic coals. Inorganic sedimentary rocks rich in sapropel are classified according to their type of organic matter. Sapropelite is rich in alginite, whereas cannel-mudstone is rich in miospores. The total organic carbon content (TOC) can vary from less than 1% to as much as 81% in a sapropelite from Tasmania, although most sapropelites fall in the range of 8 to 55% TOC. In the Rock Classification Scheme, it is recommended that the lower limit for sapropelite should be 8% TOC and the upper limit 50% TOC. A sapropelite can be recognised in hand specimen by its bituminous smell and by the curled sliver of rock produced when it is scraped with a pen knife. Sapropelites can be subdivided into lamalginite and telaginite by reference to the properties of the organic matter. British Geological Survey Research Report RR/99/03, section 6.3, table 18 and fig. 10. Synonym: oil shale. Schist - A type of metamorphic rock with unknown protolith based on textural attributes. In the Rock Classification Scheme, it is defined as a medium-grained strongly foliated rock that can be readily split into flakes or slabs due to the well-developed preferred orientation of the majority of the minerals present, particularly those of platy or prismatic habit. Schists occur characteristically in areas of medium-grade metamorphism and can encompass a wide range of lithologies. Note that orthoschist indicates a rock that is thought to have an igneous protolith, and paraschist indicates a rock that is thought to have a sedimentary protolith. British Geological Survey Research Report RR/99/02, sections 3.3, 6.1 and fig. 1. Schist, calcareous Schist, chlorite-epidote Schist, clinopyroxene-garnet-hornblende Schist, garnet-hornblende Schist, glaucophane Schist, graphitic Schist, hornblende Schist, mica Schist, phyllitic Schist, quartz Schist, tremolite Schist, tremolite-microcline Seat-earth - A term for a bed of rock underlying a coal seam. It represents the soil that supported the vegetation from which the coal was formed. A highly siliceous seat earth is known as a ganister. British Geological Survey Research Report RR/99/03, section 13.6. Sediment Sediment and sedimentary rock - In the Rock Classification Scheme, this high level class includes siliciclastic sediment and sedimentary rock, carbonate sediment and sedimentary rock, phosphate-sediment and phosphorite, iron-sediment and ironstone, organic-rich sediment and sedimentary rock, sedimentary rock and sediment composed of non-carbonate salts, non-clastic siliceous sediment and sedimentary rock, miscellaneous hydroxide, oxide and silicate sediment and sedimentary rock, sedimentary rock based on grain size or crystal size, and hybrid sediment and sedimentary rock. British Geological Survey Research Report RR/99/03. Sediment rich in organic matter - British Geological Survey Research Report RR/99/03, section 6. Sediment rich in sapropel (coorongite) - A type of sediment rich in organic matter. Sapropel is the unlithified end-member of the sapropelic coal series. The members of the sapropelic coal series can be ranked in order as sapropel (the unlithified form), sapropelic-lignite, and sapropelic-coal (the lithified forms) based on increasing carbon content and decreasing volatile content. Sapropel is an unlithified dark, pulpy, fine organic mud containing concentrations of algae and miospores that are more or less identifiable. It is recommended that the term sapropel is used in preference to terms such as gyttja, dy, afja, forna etc. which have been used inconsistently and haphazardly in the past. Coorongite is a rubber-like, highly resilient structureless algal deposit. British Geological Survey Research Report RR/99/03, section 6.2, tables 17, 18, and fig. 10. Sediment, sandy, clayey Sediment, shell (shells) Sedimentary rock and sediment composed of non-carbonate salts - In the Rock Classification Scheme, this is a non-genetic term for what are commonly called evaporite minerals. Non-carbonate salts are commonly present in a host rock. The host rock may consist of other non-carbonate salts or other types of sediment. British Geological Survey Research Report RR/99/03, section 7 and fig. 11. Sedimentary rock based on grain size or crystal size - In the Rock Classification Scheme, if the composition of a sedimentary rock is unknown it may be simply classified by reference to its clast or crystal size. For clastic rocks, the classes are defined in the same way as the siliciclastic sedimentary rocks. British Geological Survey Research Report RR/99/03, section 10 and fig. 13. Sedimentary rock rich in sapropel Sedimentary rock, dolomitic Sedimentary rocks, gneissose Sedimentary rocks, gneissose-feldspar-porphyroblastic Sedimentary-rock rich in organic matter - British Geological Survey Research Report RR/99/03, section 6. Semipelite - A type of metasedimentary rock composed largely of quartz, feldspar and mica. In the Rock Classification Scheme, it is one with mica component 20 - 40%, and quartz + feldspar 60 - 80% of quartz + feldspar + mica. The mica component includes all minerals other than quartz and feldspar, with the exception of calcsilicate and carbonate minerals. British Geological Survey Research Report RR/99/02, section 3.2, table 1 and fig. 5. Semipelite, amphibole Semipelite, banded Semipelite, calcareous Semipelite, calcareous, garnet-bearing Semipelite, flaggy Semipelite, garnet Semipelite, gneissose Semipelite, gneissose migmatitic Semipelite, gneissose schistose Semipelite, granofelsic Semipelite, graphitic Semipelite, hornfelsed Semipelite, hornfelsed mylonitic Semipelite, laminated Semipelite, migmatitic Semipelite, mylonitic Semipelite, phyllitic Semipelite, phyllitic graphitic Semipelite, pyritic Semipelite, quartz-muscovite Semipelite, quartzose Semipelite, schistose Serpentinite - A type of meta-ultramafic-rock in which the dominant mineral is serpentine. British Geological Survey Research Report RR/99/02, section 5.2. Sewage - A type of artifical deposit. It consists of waste material from sewage treatment work. British Geological Survey Research Report RR/99/04, appendix 1. Shale waste - A type of artifical deposit. It consists of waste material derived from quarrying or mining of fissile mudstone (for example alum shale, bituminous shale). British Geological Survey Research Report RR/99/04, appendix 1. Shell-lime-sediment - A type of lime-sediment that is composed almost entirely of shells. British Geological Survey Research Report RR/99/03, section 3.1 and fig. 6. Shell-limestone - A type of limestone composed dominantly of shells. British Geological Survey Research Report RR/99/03, section 3.1, table 4 and fig. 6. Shells [Unlithified Deposits Coding Scheme - Extended] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme - Extended is an extension to the Unlithified Deposits Coding Scheme, for deposit types not defined in the original scheme. Shells, clayey [Unlithified Deposits Coding Scheme - Extended] Shells, sandy, clayey [Unlithified Deposits Coding Scheme - Extended] Shells, sandy, silty [Unlithified Deposits Coding Scheme - Extended] Shells, silty [Unlithified Deposits Coding Scheme - Extended] Shoshonite - A potassic basaltic-trachyandesite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Siderite-mudstone - An iron-mudstone in which the iron mineral is siderite. Silcrete - A type of silicate-conglomerate, consisting of surficial sand and gravel cemented into a hard mass by silica. British Geological Survey Research Report RR/99/03, section 8.5. Silcrete, concretionary Silcrete, nodular Silicate-clay - A type of silicate-mud. In the Rock Classification Scheme, it is a silicate-mud consisting of greater than 50% clay-grade particles. Typically, the sediment displays plastic properties. British Geological Survey Research Report RR/99/03, section 2.3 and table 1. Silicate-claystone - A type of silicate-mudstone. In the Rock Classification Scheme, it is a silicate-mudstone consisting of greater than 50% clay-grade particles. The rock is extremely fine-grained with a homogeneous appearance. British Geological Survey Research Report RR/99/03, section 2.3 and table 1. Silicate-conglomerate - A type of siliciclastic rudaceous rock. In the Rock Classification Scheme, all siliciclastic rudaceous rocks are given this group name. British Geological Survey Research Report RR/99/03, section 2.1 and fig. 2. Silicate-gravel - A type of siliciclastic rudaceous sediment. In the Rock Classification Scheme, all siliciclastic rudaceous sediments are given this root name. British Geological Survey Research Report RR/99/03, section 2.1 and fig. 2. See also: lime-gravel. Silicate-mud - A type of siliciclastic argillaceous sediment. In the Rock Classification Scheme, all siliciclastic argillaceous sediments are given this group name. They may be further classified as silicate-silt or silicate-clay based on the proportion of silt to clay. British Geological Survey Research Report RR/99/03, section 2.3 and fig. 5. See also: lime-mud. Silicate-mud, calcareous Silicate-mudstone - A type of siliciclastic argillaceous rock. In the Rock Classification Scheme, all siliciclastic argillaceous rocks are given this group name. They may be further classified as silicate-siltstone or silicate-claystone based on the proportion of silt to clay. British Geological Survey Research Report RR/99/03, section 2.3 and fig. 5. Silicate-mudstone, dolomitic Silicate-mudstone, ferruginous Silicate-mudstone, fissile Silicate-sand - A type of siliciclastic arenaceous sediment. In the Rock Classification Scheme, all siliciclastic arenaceous sediments are given this root name. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. See also: lime-sand. Silicate-sandstone - A type of siliciclastic arenaceous rock. In the Rock Classification Scheme, all siliciclastic arenaceous rocks are given this group name. Silicate-sandstones are divided into arenite and wacke on the proportion of matrix. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. Silicate-sandstone, coarse Silicate-sandstone, dolomitic Silicate-silt - A type of silicate-mud. In the Rock Classification Scheme, it is a silicate-mud consisting of less than 50% clay-grade particles. Typically, abundant silt is visible with a hand lens and the sediment has a gritty texture. British Geological Survey Research Report RR/99/03, section 2.3 and table 1. Silicate-siltstone - A type of silicate-mudstone. In the Rock Classification Scheme, it is a silicate-mudstone consisting of less than 50% clay-grade particles. Typically, abundant silt is visible with a hand lens. British Geological Survey Research Report RR/99/03, section 2.3 and table 1. Silicate-siltstone, dolomitic Siliceous rock - In the Rock Classification Scheme, these are rocks which are composed of more than 50% silica of biogenic or chemical origin. This is the lithified equivalent of non-clastic siliceous sediment. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Siliceous-ooze - A type of non-clastic siliceous sediment. All non-clastic siliceous sediments are given the group name siliceous-ooze. Oozes have little strength and are readily deformed under the finger or broad blade of a spatula. Detailed analysis by X-ray powder diffractogram would show the silica to be composed of amorphous opal, frequently referred to as opal-A. They may be given a more detailed root name on the basis of their biogenic fossil type. British Geological Survey Research Report RR/99/03, section 8.1 and fig. 12. Siliciclastic arenaceous metarock Siliciclastic arenaceous metasedimentary rock Siliciclastic arenaceous rock - In the Rock Classification Scheme, these are siliciclastic rocks that are predominantly in size range 32 µm - 2 mm, with less than 75% of clasts smaller than 32 µm and less than 25% larger than 2 mm. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. Siliciclastic arenaceous sediment - In the Rock Classification Scheme, these are siliciclastic sediments that are predominantly in size range 32 µm - 2 mm, with less than 75% of clasts smaller than 32 µm and less than 25% larger than 2 mm. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. Siliciclastic arenaceous sediment and rock - In the Rock Classification Scheme, this class includes siliciclastic arenaceous sediment and siliciclastic arenaceous rock. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. Siliciclastic argillaceous metarock Siliciclastic argillaceous metasedimentary rock Siliciclastic argillaceous rock - In the Rock Classification Scheme, these are siliciclastic rocks with over 75% of the clasts smaller than 32 µm. British Geological Survey Research Report RR/99/03, section 2.3 and fig. 5. Siliciclastic argillaceous sediment - In the Rock Classification Scheme, these are siliciclastic sediments with over 75% of the clasts smaller than 32 µm. British Geological Survey Research Report RR/99/03, section 2.3 and fig. 5. Siliciclastic argillaceous sediment and rock - In the Rock Classification Scheme, this class includes siliciclastic argillaceous sediment and siliciclastic argillaceous rock. British Geological Survey Research Report RR/99/03, section 2.3 and fig. 5. Siliciclastic metasedimentary rock Siliciclastic rudaceous metarock Siliciclastic rudaceous metasedimentary rock Siliciclastic rudaceous rock - In the Rock Classification Scheme, these are siliciclastic rocks with more than 25% of clasts larger than 2 mm. British Geological Survey Research Report RR/99/03, section 2.1 and fig. 2. Siliciclastic rudaceous sediment - In the Rock Classification Scheme, these are siliciclastic sediments with more than 25% of clasts larger than 2 mm. British Geological Survey Research Report RR/99/03, section 2.1 and fig. 2. Siliciclastic rudaceous sediment and rock - In the Rock Classification Scheme, this class includes siliciclastic rudaceous sediment and siliciclastic rudaceous rock. British Geological Survey Research Report RR/99/03, section 2.1 and fig. 2. Siliciclastic sediment and sedimentary rock - In the Rock Classification Scheme, siliciclastic sediments and rocks are defined as rocks in which clastic fragments derived from preexisting siliceous rocks form more than 50% of the sediment or rock. The class includes siliciclastic rudaceous sediment and rock, siliciclastic arenaceous sediment and rock, and siliciclastic argillaceous sediment and rock. British Geological Survey Research Report RR/99/03, section 2. Silt Silt [Unlithified Deposits Coding Scheme] - A type of natural superficial deposit. The Unlithified Deposits Coding Scheme was developed as a way of coding unlithified deposits (also commonly referred to as superficial deposits, unconsolidated deposits, or engineering soils) that is consistent with civil engineering industry usage (BS5930). Silt, bouldery [Unlithified Deposits Coding Scheme] Silt, bouldery, peaty [Unlithified Deposits Coding Scheme] Silt, calcareous, sandy [Unlithified Deposits Coding Scheme - Extended] Silt, clayey Silt, clayey [Unlithified Deposits Coding Scheme] Silt, clayey, bouldery [Unlithified Deposits Coding Scheme] Silt, clayey, cobbly [Unlithified Deposits Coding Scheme] Silt, clayey, gravelly [Unlithified Deposits Coding Scheme] Silt, clayey, gravelly, bouldery [Unlithified Deposits Coding Scheme] Silt, clayey, gravelly, cobbly [Unlithified Deposits Coding Scheme] Silt, clayey, gravelly, peaty [Unlithified Deposits Coding Scheme] Silt, clayey, gravelly, sandy [Unlithified Deposits Coding Scheme] Silt, clayey, peaty [Unlithified Deposits Coding Scheme] Silt, clayey, peaty, sandy [Unlithified Deposits Coding Scheme] Silt, clayey, sandy [Unlithified Deposits Coding Scheme] Silt, clayey, sandy, gravelly [Unlithified Deposits Coding Scheme] Silt, clayey, sandy, gravelly, cobbly [Unlithified Deposits Coding Scheme] Silt, clayey, sandy, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Silt, clayey, sandy, gravelly, peaty [Unlithified Deposits Coding Scheme] Silt, clayey, sandy, gravelly, peaty, cobbly [Unlithified Deposits Coding Scheme] Silt, clayey, sandy, peaty [Unlithified Deposits Coding Scheme] Silt, clayey, shelly [Unlithified Deposits Coding Scheme - Extended] Silt, cobbly [Unlithified Deposits Coding Scheme] Silt, cobbly, bouldery [Unlithified Deposits Coding Scheme] Silt, cobbly, gravelly [Unlithified Deposits Coding Scheme] Silt, cobbly, peaty [Unlithified Deposits Coding Scheme] Silt, gravelly Silt, gravelly [Unlithified Deposits Coding Scheme] Silt, gravelly, bouldery [Unlithified Deposits Coding Scheme] Silt, gravelly, clayey [Unlithified Deposits Coding Scheme] Silt, gravelly, clayey, sandy [Unlithified Deposits Coding Scheme] Silt, gravelly, cobbly [Unlithified Deposits Coding Scheme] Silt, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Silt, gravelly, cobbly, bouldery, sandy [Unlithified Deposits Coding Scheme] Silt, gravelly, cobbly, sandy [Unlithified Deposits Coding Scheme] Silt, gravelly, peaty [Unlithified Deposits Coding Scheme] Silt, gravelly, peaty, cobbly [Unlithified Deposits Coding Scheme] Silt, gravelly, peaty, sandy, clayey [Unlithified Deposits Coding Scheme] Silt, gravelly, sandy [Unlithified Deposits Coding Scheme] Silt, gravelly, sandy, clayey [Unlithified Deposits Coding Scheme] Silt, gravelly, sandy, cobbly [Unlithified Deposits Coding Scheme] Silt, gravelly, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Silt, organic Silt, peaty [Unlithified Deposits Coding Scheme] Silt, peaty, clayey [Unlithified Deposits Coding Scheme] Silt, peaty, clayey, sandy [Unlithified Deposits Coding Scheme] Silt, peaty, cobbly [Unlithified Deposits Coding Scheme] Silt, peaty, gravelly [Unlithified Deposits Coding Scheme] Silt, peaty, gravelly, cobbly [Unlithified Deposits Coding Scheme] Silt, peaty, sandy [Unlithified Deposits Coding Scheme] Silt, peaty, sandy, clayey [Unlithified Deposits Coding Scheme] Silt, peaty, sandy, gravelly [Unlithified Deposits Coding Scheme] Silt, sandy Silt, sandy [Unlithified Deposits Coding Scheme] Silt, sandy, bouldery [Unlithified Deposits Coding Scheme] Silt, sandy, bouldery, gravelly [Unlithified Deposits Coding Scheme] Silt, sandy, calcareous [Unlithified Deposits Coding Scheme - Extended] Silt, sandy, clayey [Unlithified Deposits Coding Scheme] Silt, sandy, clayey, gravelly [Unlithified Deposits Coding Scheme] Silt, sandy, clayey, gravelly, bouldery [Unlithified Deposits Coding Scheme] Silt, sandy, clayey, peaty [Unlithified Deposits Coding Scheme] Silt, sandy, cobbly [Unlithified Deposits Coding Scheme] Silt, sandy, cobbly, bouldery [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly, bouldery [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly, clayey [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly, cobbly [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly, cobbly, bouldery [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly, peaty [Unlithified Deposits Coding Scheme] Silt, sandy, gravelly, peaty, cobbly [Unlithified Deposits Coding Scheme] Silt, sandy, peaty [Unlithified Deposits Coding Scheme] Silt, sandy, peaty, clayey [Unlithified Deposits Coding Scheme] Silt, sandy, peaty, gravelly [Unlithified Deposits Coding Scheme] Silt, sandy, shelly [Unlithified Deposits Coding Scheme - Extended] Silt, shell Silt, shelly [Unlithified Deposits Coding Scheme - Extended] Silt, shelly, gravelly [Unlithified Deposits Coding Scheme - Extended] Silt, shelly, sandy [Unlithified Deposits Coding Scheme - Extended] Siltstone - A type of mudstone. British Geological Survey Research Report RR/99/03, fig. 13. See: silicate-siltstone. Siltstone, calcareous Siltstone, carbonaceous Siltstone, dolomitic Siltstone, ferruginous Siltstone, hornfelsed Siltstone, micaceous Siltstone, muddy Siltstone, pebbly Siltstone, phosphate-nodular Siltstone, sandy Siltstone, seat-earth Siltstone, shelly Siltstone, slumped Sinter - A type of siliceous rock which is predominantly composed of a lightweight, porous, white, opaline variety of silica. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Skarn - A type of metasomatic-rock. In many cases they result from metasomatism of calcareous rocks in thermal aureoles. British Geological Survey Research Report RR/99/02, section 8. Slate - A type of metamorphic rock with unknown protolith based on textural attributes. In the Rock Classification Scheme, it is defined as a compact fine-grained rock with a strong fissility along planes in which the rock can be parted into thin plates indistinguishable from each other in terms of lithological characteristics. Slates are typically low-grade metamorphosed mudstones. However, some may be derived from volcaniclastic rocks. British Geological Survey Research Report RR/99/02, section 6.1 and fig. 1. Slate waste - A type of artifical deposit. It consists of waste material derived from quarrying or mining of slate (cleaved, fissile, low-grade metamorphosed mudstone). British Geological Survey Research Report RR/99/04, appendix 1. Slate, hornfelsed Smectite-clay - A type of monomineralic aluminium-silicate sediment in which the aluminium-silicate mineral is smectite. It is the unlithified equivalent of smectite-claystone. British Geological Survey Research Report RR/99/03, section 9.1 and table 19. Smectite-claystone - A type of monomineralic aluminium-silicate sedimentary rock in which the aluminium-silicate mineral is smectite. It is the lithified equivalent of smectite-clay. Bentonite and fullers earth may be considered synonyms for smectite-claystone. Bentonite is a soft, plastic, porous, light-coloured rock composed essentially of clay minerals from the smectite group plus colloidal silica, and produced by chemical alteration of volcanic ash. Fullers earth is a clay consisting largely of hydrated aluminium silicates (e.g. smectite), with a high proportion of water and little plasticity. It is formed by in-situ decomposition of igneous rocks containing a high proportion of glass. British Geological Survey Research Report RR/99/03, sections 9.1 and 13.6, and table 19. Sodalite-monzosyenite - A foid-monzosyenite in which the dominant feldspathoid mineral is sodalite. British Geological Survey Research Report RR/99/06, section 5.1 and fig. 9. Soil Spessartite - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which plagioclase is the dominant feldspar, and the predominant mafic minerals are hornblende and diopsidic augite (with/without olivine). British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Spiculite - A type of siliceous rock which is predominantly composed of sponge spicules. It is the lithified equivalent of sponge-spicular-ooze. British Geological Survey Research Report RR/99/03, section 8.2 and fig. 12. Sponge-spicular-ooze - A type of siliceous-ooze which is predominantly composed of sponge spicules. It is the unlithified equivalent of spiculite. British Geological Survey Research Report RR/99/03, section 8.1 and fig. 12. Subfeldspathic-arenite - A type of arenite. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Sublithic-arenite - A type of arenite. In the Rock Classification Scheme, it is defined as shown in British Geological Survey Research Report RR/99/03, section 2.2 and figs. 3, 4. Superficial deposit (natural and/or artificial) - In the Rock Classification Scheme, this high level class includes artificially modified ground, and natural superficial deposits. British Geological Survey Research Report RR/99/04. Syenite - A type of syenitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 7 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Syenite, kalsilite-bearing Syenite, mafic Syenitic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, this class includes syenite, monzonite, and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 10. Syenogranite - A type of granite. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 3a of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Sylvite-stone - A type of non-carbonate salt that is composed of particles of the chloride mineral sylvite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Talc-rock - A type of meta-ultramafic-rock in which the dominant mineral is talc. British Geological Survey Research Report RR/99/02, section 5.2. Telaginite - A type of sapropelite. It is one in which organic matter is present in large discretely occurring algal bodies. British Geological Survey Research Report RR/99/03, section 6.3 and fig. 10. Tephra. Synonym: pyroclastic-sediment Tephri-phonolite - A type of phonolitic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of tephri-phonolite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Tephrite (TAS) - A type of tephritic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of Tephrite (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Tephrite - A type of tephritic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 14 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Basanite and tephrite are distinguished by the amount of olivine in the CIPW norm: if normative olivine is less than 10% the rock is tephrite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Tephritic-foidite - A type of foiditic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 15b of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. Basanitic-foidite and tephritic-foidite are distinguished by the amount of olivine in the CIPW norm: if normative olivine is less than 10% the rock is tephritic-foidite. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Tephritic-leucitite - A type of leucitite. In the Rock Classification Scheme, this rock plots in field 15b on the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram; foids constitute 60 to 90% of light-coloured constituents; plagioclase is dominant over alkali feldspar. British Geological Survey Research Report RR/99/06, sections 5.2, 6.6. Tephritic-phonolite - A type of phonolitic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 12 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Tephritic-rock - A type of mafite. In the Rock Classification Scheme, this class includes tephrite, basanite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Thermonatrite - A type of Na carbonate sedimentary rock. Thermonatrite (Na2CO3.H2O) forms orthorhombic crystals and efflorescent crusts. British Geological Survey Research Report RR/99/03, section 3.3. Tonalite - A type of granitic-rock. In the Rock Classification Scheme, it is a coarse-grained crystalline igneous rock whose mineral mode plots in field 5 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 11, 12. Tonalite, charnockitic Tonalite, foliated Tonalite, pegmatitic Tonalite, porphyritic Tonstein - A type of monomineralic aluminium-silicate sedimentary rock. It is a band of mudstone composed dominantly of kaolinite and associated with coal seams. British Geological Survey Research Report RR/99/03, section 13.6. Trachyandesite - A type of trachytic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of trachyandesite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Trachyandesite, feldspar-macroporphyritic Trachybasalt - A type of trachytic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of trachybasalt is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Trachybasalt to trachyandesite Trachydacite - A type of trachytic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of trachydacite is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Trachyte (TAS) - A type of trachytic-rock, classified using the total alkali silica (TAS) classification. The TAS classification may be used if the mineral mode of a normal fine-grained crystalline rock cannot be determined due either to the presence of glass or to the fine-grained nature of the rock. The definition of trachyte (TAS) is as shown in British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17b, 20. Trachyte - A type of trachytic-rock. In the Rock Classification Scheme, this name is used for a fine-grained crystalline igneous rock when the modal mineralogy is available, and the mineral mode plots in field 7 of the quartz - alkali feldspar - plagioclase - feldspathoid (QAPF) diagram. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17a, 19. Trachyte, biotite Trachyte, biotite, phonolitic Trachyte, comenditic - A type of trachyte (TAS). In the Rock Classification Scheme, trachyte (TAS) may be separated into comenditic and pantelleritic types as shown in British Geological Survey Research Report RR/99/06, section 5.2 and fig. 24. Trachyte, pantelleritic - A type of trachyte (TAS). In the Rock Classification Scheme, trachyte (TAS) may be separated into comenditic and pantelleritic types as shown in British Geological Survey Research Report RR/99/06, section 5.2 and fig. 24. Trachytic-rock - A type of felsite. In the Rock Classification Scheme, this class includes trachyte, latite and similar rocks. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and figs. 17, 18. Troctolite - A type of gabbro. In the Rock Classification Scheme, it is a gabbro with plagioclase 10 - 90%, pyroxene >5% and olivine 5 - 85% of plagioclase + pyroxene + olivine. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 13, 14. Troctolite, bytownite Trona - A type of Na carbonate sedimentary rock. Trona (Na2CO3.NaHCO3.2H2O) is characterised by monoclinic crystals that form in fibrous or columnar layers and masses. British Geological Survey Research Report RR/99/03, section 3.3. Tufa - A type of chemical deposit (natural superficial). It is a sedimentary rock composed of calcium carbonate or silica, formed by evaporation as a thin, surficial, soft, spongy, semifriable encrustation around the mouth of springs, seeps or along streams carrying calcium carbonate in solution, and exceptionally as a thick deposit along lake shores. Travertine is a hard, dense variety of tufa; it also occurs in caves as stalactites and stalagmites. British Geological Survey Research Report RR/99/03; RR/99/04, appendix 2 and tables 5, 17. Synonyms: sinter, travertine. Tufa, calcareous - A type of tufa. British Geological Survey Research Report RR/99/04, section 4 and tables 5, 17. Tufa, siliceous - A type of tufa. British Geological Survey Research Report RR/99/04, section 4 and tables 5, 17. Tuff - A type of pyroclastic-rock. In the Rock Classification Scheme, it is a pyroclastic-rock in which the average size of more than 75% of the pyroclastic fragments is less than 64 mm. Lapillistone, lapilli-tuff, and tuff are separated according to the relative proportion of lapilli-grade (2 - 64 mm) and ash-grade (<2 mm) fragments: if less than 25% of the fragments are lapilli the rock is tuff. It is the consolidated equivalent of ash. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuff, andesitic Tuff, basalt Tuff, basaltic Tuff, basaltic-trachyandesitic Tuff, calcareous Tuff, calcareous-basaltic Tuff, crystal Tuff, dacitic Tuff, eutaxitic-crystal Tuff, felsic Tuff, lithic Tuff, mafic Tuff, rhyolitic Tuff, trachyandesite Tuff, trachyandesitic Tuff, trachydacitic Tuff, trachytic Tuff, vitric Tuff, welded-crystal Tuff, welded-eutaxitic Tuff-breccia - A type of pyroclastic-rock. In the Rock Classification Scheme, it is a pyroclastic-rock which contains more than 25% of each of the main pyroclastic fragment size divisions: blocks and bombs (>64 mm), lapilli (2 - 64 mm), and ash (<2 mm). It is the consolidated equivalent of ash-breccia. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuff-breccia, trachydacitic Tuffaceous-breccia - A type of tuffaceous-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: breccia. Tuffaceous-conglomerate - A type of tuffaceous-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: conglomerate. Tuffaceous-gravel - A type of tuffaceous-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuffaceous-mud - A type of tuffaceous-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuffaceous-mudstone - A type of tuffaceous-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: mudstone. Tuffaceous-sand - A type of tuffaceous-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuffaceous-sandstone - A type of tuffaceous-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: sandstone. Tuffaceous-sediment - In the Rock Classification Scheme, a tuffaceous-sediment consists of 25 - 75% by volume pyroclastic fragments. It is the unconsolidated equivalent of tuffaceous-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuffaceous-sedimentary-rock - In the Rock Classification Scheme, a tuffaceous-sedimentary-rock consists of 25 - 75% by volume pyroclastic fragments. It is the consolidated equivalent of tuffaceous-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Tuffaceous-siltstone - A type of tuffaceous-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: siltstone. Tuffisite - A type of intrusion-breccia. It comprises brecciated and lithified country-rock fragments found in intrusive pipes which are formed by the explosive release of gas. British Geological Survey Research Report RR/99/06, section 8.2. Tuffite - A type of volcaniclastic igneous rock and sediment. In the Rock Classification Scheme, tuffite is a general term for volcaniclastic rocks and sediments which consist of 25 - 75% by volume pyroclastic fragments. The class includes tuffaceous-sedimentary-rock, and tuffaceous-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and figs. 1, 4. Tuffite, felsic Tuffite, mafic Ulexite-stone - A type of non-carbonate salt that is composed of particles of the borate mineral ulexite. British Geological Survey Research Report RR/99/03, section 7.1 and fig. 11. Ultracataclasite - A type of cataclastic-rock. In the Rock Classification Scheme, it is one in which fragments significantly coarser than the matrix comprise less than 10% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.2 and table 4. Ultramafic rock, appinitic Ultramafic rock, appinitic-foliated Ultramafic-melilitic-rock - A type of melilitic rock. In the Rock Classification Scheme, ultramafic-melilitic-rock and non-ultramafic-melilitic-rock are distinguished using colour index M: ultramafic-melilitic-rock has M greater than 90%. British Geological Survey Research Report RR/99/06, section 6.2 and figs. 27, 28. Ultramafic-micromelilitic-rocks Ultramafic-rock - A type of coarse-grained normal crystalline rock. In the Rock Classification Scheme, a rock is ultramafic if the proportion of mafic minerals (M) is greater than 90%. They are classified according to their mafic mineral content, namely olivine, orthopyroxene, clinopyroxene and hornblende. The class includes peridotite, pyroxenite, and hornblendite. The term may be used as a field classification when an accurate mineral mode from thin section examination is not available. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 9, 12. Ultramafic-rock, foliated Ultramafitite - A type of mafite. In the Rock Classification Scheme, it is the fine-grained equivalent of ultramafic-rock. The term may be used as a field classification when an accurate mineral mode from thin section examination, or a chemical analysis, is not available. British Geological Survey Research Report RR/99/06, section 5.2 and fig. 17. Ultramylonite - A type of mylonitic-rock. In the Rock Classification Scheme, it is one in which porphyroclasts comprise less than 10% by volume of the rock. British Geological Survey Research Report RR/99/02, section 7.3 and table 5. Unfoliated mechanically broken rock with primary cohesion - British Geological Survey Research Report RR/99/02, section 7.2. Uranium (vein) - A type of vein rock. Vein rock. Vitrain - A type of bituminous-coal, classified according to lithotype. It is a black, glassy, vitreous coal. It occurs as thin bands, commonly less than 6 or 8 mm in thickness. It is usually very closely jointed and breaks into cubic pieces generally with a conchoidal fracture. British Geological Survey Research Report RR/99/03, section 6.1 and fig. 10. Vogesite - A type of lamprophyre. In the Rock Classification Scheme, it is a lamprophyre in which orthoclase is the dominant feldspar, and the predominant mafic minerals are hornblende and diopsidic augite (with/without olivine). British Geological Survey Research Report RR/99/06, section 6.7 and figs. 31, 32. Volcaniclastic igneous rock and sediment - In the Rock Classification Scheme, this class includes volcaniclastic sedimentary rock and sediment, tuffite, and pyroclastic rock and sediment. British Geological Survey Research Report RR/99/06, section 4 and figs. 1, 4. Volcaniclastic sedimentary rock and sediment - British Geological Survey Research Report RR/99/06, section 4 and figs. 1, 4. Volcaniclastic-breccia - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: breccia. Volcaniclastic-breccia, basaltic Volcaniclastic-breccia, pillowed Volcaniclastic-conglomerate - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: conglomerate. Volcaniclastic-gravel - A type of volcaniclastic-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Volcaniclastic-megabreccia - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: breccia. Volcaniclastic-mesobreccia - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: breccia. Volcaniclastic-mud - A type of volcaniclastic-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Volcaniclastic-mudstone - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: mudstone. Volcaniclastic-rock, hydrothermally-altered Volcaniclastic-sand - A type of volcaniclastic-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Volcaniclastic-sandstone - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: sandstone. Volcaniclastic-sandstone, andesitic Volcaniclastic-sandstone, basaltic Volcaniclastic-sandstone, dacitic Volcaniclastic-sandstone, pebbly Volcaniclastic-sandstone, rhyolitic Volcaniclastic-sediment - In the Rock Classification Scheme, a volcaniclastic-sediment has more than 10% volcanic debris but less than 25% pyroclastic fragments. It is the unconsolidated equivalent of a volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Volcaniclastic-sedimentary-rock - In the Rock Classification Scheme, a volcaniclastic-sedimentary-rock has more than 10% volcanic debris but less than 25% pyroclastic fragments. It is the consolidated equivalent of a volcaniclastic-sediment. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. Volcaniclastic-siltstone - A type of volcaniclastic-sedimentary-rock. British Geological Survey Research Report RR/99/06, section 4.2 and fig. 4. See also: siltstone. Wacke - A type of silicate-sandstone. In the Rock Classification Scheme, wackes have 15 - 75% matrix. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3. Waste, rock Weathered rock - A type of regolith. It consists of weathered material which, depending on degree of disintegration, may be described in terms of rock material weathering grades II (slightly weathered), III (moderately weathered), IV (highly weathered), V (completely weathered), or VI (residual soil). In engineering geology terms, slightly to moderately weathered material falling into weathering grades II and III are considered as weathered rock for engineering purposes, and grades IV to VI as soil. Saprolite refers to soil-like grade IV and V material which has been altered and decomposed by chemical weathering processes. British Geological Survey Research Report RR/99/04, appendix 2. Weathered-grade I rock - A type of weathered rock. Fresh, no visible sign of rock material weathering. Perhaps slight discolouration on major discontinuity surfaces. British Geological Survey Research Report RR/99/04, table 12. Weathered-grade II rock - A type of weathered rock. Slightly weathered. Discolouration indicates weathering of rock material and discontinuity surfaces. All the rock material may be discoloured by weathering. British Geological Survey Research Report RR/99/04, table 12. Weathered-grade III rock - A type of weathered rock. Moderately weathered. Less than half of the rock material is decomposed or disintegrated to a soil. Fresh or discoloured rock is present either as a continuous framework or as corestones. British Geological Survey Research Report RR/99/04, table 12. Weathered-grade IV rock - A type of weathered rock. Highly weathered. More than half of the rock material is decomposed or disintegrated to a soil. Fresh or discoloured rock is present either as a continuous framework or as corestones. British Geological Survey Research Report RR/99/04, table 12. Weathered-grade V rock - A type of weathered rock. Completely weathered. All rock material is decomposed and/or disintegrated to soil. The original mass structure is still largely intact. British Geological Survey Research Report RR/99/04, table 12. Weathered-grade VI rock - A type of weathered rock. Residual soil. All rock material is converted to soil. The mass structure and material fabric are destroyed. There is a large change in volume, but the soil has not been significantly transported. British Geological Survey Research Report RR/99/04, table 12. Websterite - A type of pyroxenite (s.s.) in which orthopyroxene and clinopyroxene are both present in significant proportion. In the Rock Classification Scheme, it is a pyroxenite with olivine <5%, clinopyroxene 5 - 90% and orthopyroxene 5 - 90% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Wehrlite - A type of pyroxene-peridotite. In the Rock Classification Scheme, it is a pyroxene-peridotite with olivine 40 - 90%, clinopyroxene 5 - 60% and orthopyroxene <5% of olivine + orthopyroxene + clinopyroxene. British Geological Survey Research Report RR/99/06, section 5.1 and figs. 15, 16. Wood - A type of artificial deposit (when used in the context of artificially modified ground). Zinc (vein) - A type of vein rock.