Computer Code: |
BOG |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Devonian Period (D)
— Devonian Period (D) |
Lithological Description: |
[Obsolete: use BNY, WKH] Feldspar-phyric andesites and olivine-basalts; local rhyolites. |
Definition of Lower Boundary: |
Drawn at the base of the Bonally Group where feldspar-phyric andesites rest upon purplish-grey feldspar-phyric basalts of the Warklaw Group. |
Definition of Upper Boundary: |
Drawn at the conformable upward passage of the Bonally Group where fine- grained andesites are overlain by pink aphanitic rhyolite with flow banded platy weathering of the Bell's Hill and Howden Burn Group. |
Thickness: |
Approx. 600 metres. |
Geographical Limits: |
Midland Valley of Scotland. |
Parent Unit: |
none recorded or not applicable
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Area |
The Pentland Hills, 2 kms south of Swanston, Edinburgh. |
Reference(s): |
Mykura, W, 1960. The Lower Old Red Sandstone igneous rocks of the Pentland Hills. Bulletin of the Geological Survey of Great Britain, No.16, 131-155. |
Browne, M A E, Smith, R A and Aitken, A M. 2001. A lithostratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. Version 3. British Geological Survey Research Report RR/01/04. |
Mitchell, G H. 1962. The geology of the neighbourhood of Edinburgh. (Explanation of Sheet 32) Third Edition. (Reprinted 1980). Memoir of the Geological Survey of Great Britain (Scotland). |
Cameron, I B and Stephenson, D, 1985. British Regional Geology: The Midland Valley of Scotland (3rd Edition). (London: HMSO for British Geological Survey). |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |