The BGS Lexicon of Named Rock Units — Result Details

Brora Shale Member

Computer Code: BROR Preferred Map Code: Bror
Status Code: Full
Age range: Callovian Age (JC) — Callovian Age (JC)
Lithological Description: Predominantly bituminous fissile mudstone with minor medium-grained sandstone and silty sand.
Definition of Lower Boundary: Overlies the Brora Coal Formation, distinguished by an erosional boundary and sharp lithological change.
Definition of Upper Boundary: Passes upwards into silty sandstones of the Glauconitic Sandstone Member.
Thickness: c. 30 m.
Geographical Limits: Brora area, Sutherland, Scotland.
Parent Unit: Strathsteven Mudstone Formation (SSTV)
Previous Name(s): Brora Coal, Shales, Shelly Clays and Sandstones, and 'Roof Bed' [Obsolete Name and Code: Use BROR] (-4500)
Brora Shale Formation (-724)
Alternative Name(s): Brora Argillaceous Series [Obsolete: use BRARG, SSTV]
Stratotypes:
Type Section  The type section of the Brora Shale Member is the foreshore [NC 904 031] south of the River Brora estuary, to the east of Inverbrora Farm [NC 893 034]. 
Reference(s):
Barron, A J M, and Riding, J B. 2014. A revision of the Jurassic (Bathonian to Oxfordian) lithostratigraphy of the onshore Moray Firth Basin, north-east Scotland. Proceedings of the Geologists' Association, Vol. 125, pp. 74-82. 
Barron, A J M, Lott, G K, and Riding, J B. 2012. Stratigraphical framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf. British Geological Survey Research Report RR/11/06. 
Hurst, A, 1993. Bathonian to Oxfordian strata of the Brora area. Fig.2 in Excursion guide to the geology of East Sutherland and Caithness. Trewin, N H and Hurst, A (editors). (Edinburgh:Scottish Academic Press). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S103 S103