| Computer Code: |
ALMR |
Preferred Map Code: |
ALMR |
| Status Code: |
Full |
| Age range: |
Pridoli Epoch (SO)
— Lochkovian Age (DO) |
| Lithological Description: |
Lowest flows are fine-grained microporphyritic pyroxene-andesites and olivine basalts, followed by feldspar phyric basalt and pyroxene andesites. Intercalations between flows include rhyolite and basic tuff, agglomerate and pebbly volcanic grit and tuff. |
| Definition of Lower Boundary: |
Conformable: in north east, where pyroxene andesites and olivine basalts overlie biotite rhyolite/dacite of Capelaw Volcanic Member. In south west where, olivine basalts and pyroxene andesites overlie rhyolites and thin lenses of conglomerate of the Bell's Hill Volcanic Member. |
| Definition of Upper Boundary: |
Conformable: where pyroxene andesites, olivine basalts and locally basic tuff and breccia are overlain by rhyolitic tuff and flow-banded rhyolite of the Caerketton Volcanic Member. |
| Thickness: |
At least 366m on Allermuir Hill. |
| Geographical Limits: |
Pentland Hills. |
| Parent Unit: |
Pentland Hills Volcanic Formation (PDH)
|
| Previous Name(s): |
Allermuir Group [Obsolete Name And Code: Use ALMR]
(ALG)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Intercalation of pebbly volcanic grit and tuff, 100m east of Loganlee Dam. |
| Partial Type Section |
Lava flows forming trap features on north slope of Allermuir Hill between Todhole Knowe and summit |
| Partial Type Section |
At least seven distinct flows in craggy exposures on south ridge of East Kip. |
| Reference(s): |
| 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). |
| 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. |
| Geikie, A. 1897. The Ancient Volcanoes of Great Britain. Vol. 1, 317-325. (London: Macmillan.) |
| Howell, H H and Geikie, A, 1861. The Geology of the neighbourhood of Edinburgh (1st edition). Memoir of the Geological Survey, Scotland. |
| Mykura, W, 1986. Pentland Hills. 161-173 in Lothian Geology. An Excursion Guide. McAdam, A D and Clarkson, E N K (editors). (Edinburgh: Scottish Academic Press.) |
| Peach, B N, Clough, C T, Hinxman, L W, Grant Wilson, J S, Crampton, C B, Maufe, H B and Bailey, E B, 1910. The geology of the Neighbourhood of Edinburgh (2nd edition). Memoir of the Geological Survey of Scotland, Sheet 32 (Scotland). |
| Thirlwall, M F, 1988. Geochronology of Late Caledenian magmatism in northern Britain. Journal of the Geological Society, Vol.145, 951-967. |
| Cameron, I B, and Stephenson, D. 1985. British Regional Geology: The Midland Valley of Scotland (3rd Edition). (London: HMSO for British Geological Survey.) |
| Browne, M A E, Smith, R A, and Aitken, A M. 2002. Stratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. British Geological Survey Research Report RR/01/04. 67 pp. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
S032
S032
|
