Computer Code: |
BLCK |
Preferred Map Code: |
BLCK |
Status Code: |
Full |
Age range: |
Pridoli Epoch (SO)
— Lochkovian Age (DO) |
Lithological Description: |
A thin local bed of tuff (3m), overlain by a thick flow of pyroxene andesite (100m), overlain by thin flows of feldspar-macro porphyritic olivine basalt (30m seen). |
Definition of Lower Boundary: |
At base of tuff (where present) overlying trachytes and biotite andesites of Brad Hills Member, otherwise at base of thick pyroxene andesite flow. |
Definition of Upper Boundary: |
Not seen - unconformably overlain by Kinnesswood Formation rocks. |
Thickness: |
At least 130m |
Geographical Limits: |
Blackford Hill, Craigmillar Park Golf Course and King's Buildings campus, Edinburgh. |
Parent Unit: |
Pentland Hills Volcanic Formation (PDH)
|
Previous Name(s): |
Fairmilehead, Braids and Blackford [Obsolete Name and Code: Use BRAI, FAI, BLCK]
(-1989)
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Alternative Name(s): |
none recorded or not applicable
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Stratotypes: |
Partial Type Section |
From 80m southwest of the southwest end of Blackford Pond to the Wireless Mast at the top of Blackford Hill. |
Reference(s): |
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). |
Cameron, I B and Stephenson, D, 1985. British Regional Geology: The Midland Valley of Scotland (3rd Edition). (London: HMSO for British Geological Survey). |
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, 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. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
S032
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