| Computer Code: |
ALG |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Devonian Period (D)
— Devonian Period (D) |
| Lithological Description: |
[Obsolete: use ALMR, CPW] Basic andesites and olivine-basalts with intercalations of grits, basic tuffs and breccias; local rhyolite and rhyolitic tuff. |
| Definition of Lower Boundary: |
Drawn at the base of the Allermuir Group where fine-grained, red-weathered microporphyritic pyroxene-andesites and olivine-basalts rest conformably upon dacite or feldspar-phyric rhyolite of the Capelaw Acid Group. |
| Definition of Upper Boundary: |
Drawn at the conformable upward passage of the Allermuir Group where fine- grained, relatively unweathered microporphyritic, augite and hypersthene-andesites are overlain by acid tuff of the Caerketton Group. |
| Thickness: |
Approx. 400 metres. |
| Geographical Limits: |
From Allermuir Hill in the vicinity of Swanston to Monk's Burn in the Pentland Hills on the southern outskirts of Edinburgh. |
| 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 from Swanston to Monk's Burn. |
| 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. |
| Peach, B N, Horne, J, Gibson, W, Anderson, E M, Grabham, G W and Flett, J S, 1910. The geology of the neighbourhood of Edinburgh. (Sheet 32, with part of Sheet 31). Memoir of the Geological Survey of Great Britain (Scotland), p.20 and 25. |
| Cockburn, A M, 1956. Notes on the geology of the eastern slopes of Blackford Hill, Edinburgh. Transactions of the Edinburgh Geological Society, Vol.16, 307-312. |
| 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). |
| Cockburn, A M, 1952. Minor Intrusions of the Pentland Hills. Transactions of Edinburgh Geological Society, Vol.15, 84-99. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
