| Computer Code: |
NODV |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Arundian Substage (CJ)
— Asbian Substage (CR) |
| Lithological Description: |
Purple basaltic tuffs, agglomerates and pyroclastic breccias with some bedded volcaniclastic sandstones. A complete section through the unit is recorded in the Largs Borehole [NS 2158 5936] with 44 m of volcanic detritus, fine to coarse grained with basaltic lava blocks up to 0.2 m long, bedded in places. Fine grained with accretionary lapilli in basal 3 m. The volcanic detritus is underlain by 11 m of silty mudstone and then 7 m of tuffaceous sandstone containing lava clasts and quartz. Clasts of lava in sandstones and agglomerates are locally derived. Fine-grained tuffs are commonly well bedded and grade into water-laid volcaniclastic and quartzose sandstones containing some carbonised plant debris. |
| Definition of Lower Boundary: |
In the area between Loch Thom [NS 26 72] and Largs [NS 20 59], east of the Largs Fault-zone, the basal tuffs, agglomerates and breccias of the Noddsdale Volcaniclastic Member rest upon cornstone-bearing sandstone of the Kinnesswood Formation. Farther north and to the west of the Largs Fault-zone between Outerwards Reservoir [NS 232 654] and Rottenburn Bridge [NS 25 69], the Noddsdale Volcaniclastic Member overlies strata from the Clyde Sandstone Formation. |
| Definition of Upper Boundary: |
The tuffs, agglomerates and pyroclastic breccias of the Noddsdale Volcaniclastic Member are overlain by the olivine-microphyric basalt (Dalmeny) lavas of the Largs Lava Member. In the Largs Borehole 107 m of grey feldspar-phyric lava overlie the volcaniclastic sedimentary rocks. |
| Thickness: |
0-200 m |
| Geographical Limits: |
Restricted to the western margin of the Renfrewshire Hills, the unit forms the base of the volcanic formation in the area between Loch Thom [NS 26 72] and Largs [NS 20 59]. Does not crop out south of Largs but is inferred beneath Largs Lava Member to the A760 [NS 21 57]. |
| Parent Unit: |
Clyde Plateau Volcanic Formation (CPV)
|
| Previous Name(s): |
Noddsdale Volcaniclastic Beds [Obsolete Name and Code: Use NODV]
(-3586)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
A complete sequence through the Noddsdale Volcaniclastic Member is seen in the Largs Borehole [NS 2158 5936]. Paterson et al., 1990. A full description of the borehole is available in BGS borehole records. |
| Reference(s): |
| Dean, M T, Browne, M A E, Waters, C N and Powell, J H. 2011. A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore). British Geological Survey Research Report, RR/10/007. 165pp. |
| Monro, S K. 1999. Geology of the Irvine District. Memoir of the British Geological Survey, Sheet 22W and part of 21E (Scotland). |
| Paterson, I B, Hall, I H S and Stephenson, D. 1990. Geology of the Greenock district: Memoir for 1:50000 geological sheet 30W and part of sheet 29E (Scotland). |
| Johnstone, G S. 1965. The volcanic rocks of the Misty Law-Knockside Hills district, Renfrewshire. Bulletin of the Geological Survey of Great Britain. No. 22. pp 53-64. |
| Richey, J E. 1928. The north Ayrshire sequence of Calciferous Sandstone volcanic rocks. Transactions of the Geological Society of Glasgow. 18. pp 247-255. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S030
|
