The BGS Lexicon of Named Rock Units — Result Details

Blackford Hill Member

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)
Alternative Name(s): none recorded or not applicable
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