| Computer Code: |
SOBA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Guadalupian Epoch (PUG)
— Lopingian Epoch (PUL) |
| Lithological Description: |
The Solan Bank Formation is made up of fine- to coarse-grained sandstones, conglomeratic sandstones, pebbly sandstones and mudstones. The sandstones are dark red and purple to red, fine to coarse, moderately well sorted, angular to subrounded, hard, calcite or silica cemented, containing abundant authigenic kaolinite and are occasionally pebbly and conglomeratic with evidence of large-scale cross-bedding. The conglomeratic horizons contain up to boulder sized clasts in a red, medium- to coarse-grained sandstone matrix. The clasts are greenish or pinkish grey or white, poorly sorted, moderate to well rounded metamorphic and weathered volcanic rocks. They also show evidence of imbrication, cross-bedding and fining-upward graded intervals. |
| Definition of Lower Boundary: |
The base of the Solan Bank Formation is marked by a change from pebbly and conglomeratic sandstones, to vesicular basalt of the Nun Volcanics Formation. No wireline logs have been recorded across the transition zone between the Solan Bank and Nun Volcanics formations. |
| Definition of Upper Boundary: |
On the Solan Bank High, the top of the Solan Bank Formation is represented by a downward change from anhydride mudstones and sandstones of the West Orkney Evaporite Formation to sandstones and mudstones. On wireline logs, this transition is marked by a notable downward decrease in gamma-ray log values and a slight increase in velocity. |
| Thickness: |
In the one well where it is known it attains a thickness of 497.2 m. |
| Geographical Limits: |
The Solan Bank Formation has only been encountered in well 205/27a-l on the Solan Bank High. The formation may be present at depth to the southwest, in the North Rona Basin. |
| Parent Unit: |
Zechstein Group (ZG)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
North Sea well 205/27a- 1: 2203-2700.2 m (7228-8859 ft) (Ritchie et al., 1996). |
| Reference(s): |
| Waters, C N, Gillespie, M R, Smith, K, Auton, C A, Floyd, J D, Leslie, A G, Millward, D, Mitchell, W I, McMillan, A A, Stone, P, Barron, A J M, Dean, M T, Hopson, P M, Krabbendam, M, Browne, M A E, Stephenson, D, Akhurst, M C, and Barnes, R P. 2007. Stratigraphical Chart of the United Kingdom: Northern Britain. (British Geological Survey.) |
| Ritchie, J D, Gatliff, R W and Riding, J, 1996. 1. Pre - Tertiary lithostratigraphy. In: Stratigraphic Nomenclature of the UK North West Margin. British Geological Survey, Nottingham. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
