The BGS Lexicon of Named Rock Units — Result Details
Bruce Sandstone Member
| Computer Code: | BUSA | Preferred Map Code: | notEntered |
|---|---|---|---|
| Status Code: | Full | ||
| Age range: | Callovian Age (JC) — Oxfordian Age (JO) | ||
| Lithological Description: | White to brown, generally very fine- to very fine-grained (occasionally medium- to coarse-grained) sandstones, which are poorly to well sorted, locally calcite cemented, and sometimes micaceous. The sandstones may be massive, several tens of metres thick, or thinly bedded with thin interbedded mudstones. The member interdigitates with the mudstones of the Heather Formation. | ||
| Definition of Lower Boundary: | The base is defined by a sharp down-section change from sandstones to mudstones (Heather Formation) and a down-section increase in gamma-ray values. | ||
| Definition of Upper Boundary: | The top is characterised by a down-section change from mudstones (Heather Formation) to sandstones. It is accompanied by a down-section decrease in gamma-ray values, and in many wells, an increase in velocity. | ||
| Thickness: | Up to 95 m. | ||
| Geographical Limits: | Along the faulted western margin of the Beryl Embayment and on the eastern side of some intrabasinal faults. | ||
| Parent Unit: | Heather Formation (HTHE) | ||
| Previous Name(s): | Katrine Member
(-5140)
Nevis Member (-5141) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | North Sea well 9/12a- 5 between the depths 9202 and 9562 m below KB (Richards et al., 1993). | ||
| Reference Section | North Sea well 9/13a- 34 between the depths 3322.5 and 3392.5 m (Richards et al., 1993). | ||
| Reference(s): | |||
| Richards, P C, Lott, G K, Johnson, H, Knox, R W O'B. and Riding, J B. 1993. 3. Jurassic of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G (eds.). Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| none recorded or not applicable | |||