| Computer Code: |
BRORO |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Callovian Age (JC)
— Callovian Age (JC) |
| Lithological Description: |
Bioturbated, shelly medium-grained sandstone with scattered quartzite pebbles and coal fragments. Occurs at the base of the Cadh'-an-Righ Shale Member (CARSH) at Balintore, and at the base of the Brora Shale Member (BROR) in the Brora area, where it forms prominent outcrops on the foreshore. |
| Definition of Lower Boundary: |
A sharp planar lithological change where bioturbated medium-grained sandstone of the Brora Roof Bed (BRORO) rests on the Brora Coal (BRORC). The boundary appears to be erosional. |
| Definition of Upper Boundary: |
At Balintore, is overlain by the bituminous fissile mudstone of the Cadh'-an-Righ Shale Member (CARSH). At Brora, is overlain by the silty sand of the Brora Shale Bed (BROSH). |
| Thickness: |
0.5 m at Balintore. Up to 2.3 m in the Brora area. |
| Geographical Limits: |
Brora and Balintore, Moray Firth area, north-east Scotland. |
| Parent Unit: |
Brora Shale Member (BROR)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Foreshore at Cadh'-an-Righ and Port-an-Righ [NH 849 723 to 853 733] (Cox and Sumbler, 2002, pp. 376-379; Sykes, 1975; Wright and Cox, 2001, pp. 188-190). |
| Reference Section |
Shaft for coal [NC 8831 0185] at Strathsteven exposes Brora Roof Bed near the surface, overlying Brora Coal (Lee, 1925, p.79). |
| Reference(s): |
| 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. |
| Cox, B M, and Sumbler, M G. 2002. British Middle Jurassic Stratigraphy. Geological Conservation Review Series No. 26. (Peterborough: Joint Nature Conservation Committee.) |
| Lee, G.W., 1925. Mesozoic rocks of East Sutherland and Ross, In: Read, H.H., Ross, G., Phemister, J. (Eds.), The geology of the country around Golspie, Sutherlandshire. Memoir of the Geological Survey, pp. 65-114. |
| 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. |
| Wright, J K, and Cox, B M. 2001. British Upper Jurassic Stratigraphy (Oxfordian to Kimmeridgian). Geological Conservation Review Series. No. 21. (Peterborough: Joint Nature Conservation Committee/Chapman and Hall.) |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
