The BGS Lexicon of Named Rock Units — Result Details
Fresgoe Sandstone Member
Computer Code: | FGSA | Preferred Map Code: | notEntered |
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Status Code: | Full | ||
Age range: | Eifelian Age (DI) — Eifelian Age (DI) | ||
Lithological Description: | A thickly bedded, cross-stratified, pale grey to pale yellow, medium-grained sandstone. The unit represents the first thick sandstone in a generally more thinly-bedded sequence. It is consequently a mappable unit. It is a notable reflector in seismic sections and a marker horizon in borehole cores, marking the top of the Bighouse Formation in the Dounreay area. | ||
Definition of Lower Boundary: | Overlies a thinly interbedded, sandstone-dominated rhythmic sequence of sandstones, siltstones and laminated carbonate mudstones (fish beds) of the Bighouse Formation. | ||
Definition of Upper Boundary: | The base of the overlying Sandside Bay Formation, which displays a cyclic depositional sequence dominated by sandstones, with thicker well-developed carbonate laminated mudstones (fish beds). | ||
Thickness: | 32m | ||
Geographical Limits: | Onshore and immediate offshore of the Dounreay area, Caithness, northern Scotland. | ||
Parent Unit: | Bighouse Formation (BIGH) | ||
Previous Name(s): | Fresgoe Sandstone
(-907)
Fresgeo Sandstone [Unit Name And Code Obsolete: Use FGSA] (FRSB) Fresgoe Sandstone Bed [Obsolete Name and Code: Use FGSA] (-246) |
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Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Section | Sea cliff beneath carpark, 70 m southsouthwest of Fresgoe Harbour, on the western side of Sandside Bay, 1.3 km northwest of Reay village, Caithness (Mendum, 1991). | ||
Reference Section | Sea cliff, 550m west of Isauld House, on the eastern side of Sandside Bay, about 900 m north of Reay village, Caithness (Mendum, 1991). | ||
Reference(s): | |||
Auton, C A. 2003. The Quaternary and Devonian geology of Scotland Sheet 115E (Reay). British Geological Survey Commissioned Report CR/03/030 for UKAEA. 78pp. | |||
Mendum, J R. 1991. Geology of NC 96SW. BGS Report. HI/JRM/91/1 | |||
British Geological Survey. 2003. Bedrock and superficial deposits. Scotland Sheet 115E (Reay).1:50 000. | |||
Fletcher, T P and Key, R M. 1991. Solid geology of the Dounreay District. British Geological Survey Technical Report WA/91/35C. | |||
British Geological Survey. (In preparation, to be published in 2005). Bedrock geology. Scotland Special Sheet (Dounreay).1:25 000. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
S115 |