| Computer Code: |
BROBC |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Callovian Age (JC)
— Callovian Age (JC) |
| Lithological Description: |
Bituminous sandy siltstone with mudstone intercalations; five fining-upwards cycles have been recognised (Arkell, 1933; Sykes, 1975). |
| Definition of Lower Boundary: |
Overlies the Glauconitic Sandstone Member (GLCSA). |
| Definition of Upper Boundary: |
Defined by a change up from the bituminous sandy siltstone with mudstone intercalations of the Brora Brick Clay Member (BROBC) to the coarse siltstone to silty fine-grained sandstone of the Fascally Siltstone Member (FCYSI) of the Clynekirkton Sandstone Formation (CYK). The boundary is conformable. |
| Thickness: |
15 m. |
| Geographical Limits: |
Brora area, Sutherland, Scotland. |
| Parent Unit: |
Strathsteven Mudstone Formation (SSTV)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Brick pit section [NC 897 040] near the village of Brora, exposes middle to upper part of the Brora Brick Clay Member (Sykes, 1975). |
| Type Section |
West end of cliffs of the River Brora [NC 887 038] (Sykes, 1975; British Geological Survey, 1998b; Trewin and Hurst, 1993). |
| Type Section |
Foreshore [NC 907 032] south of the mouth of the River Brora (Sykes, 1975; British Geological Survey, 1998b; Trewin and Hurst, 1993). |
| Reference(s): |
| Arkell, W J. 1933. The Jurassic System in Great Britain (Oxford: Clarendon Press.) |
| British Geological Survey. 1998. Helmsdale. Scotland Sheet 103E. Solid and Drift. 1:50 000 Geology Series. (Keyworth, Nottingham: British Geological Survey.) |
| Sykes, R M. 1975. The stratigraphy of the Callovian and Oxfordian stages (Middle-Upper Jurassic) in northern Scotland. Scottish Journal of Geology, Vol.11, 51-78. |
| Trewin, N H, and Hurst, A R (editors). 1993. Excursion guide to the geology of east Sutherland and Caithness. (Edinburgh: Scottish Academic Press.) |
| 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. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
