The BGS Lexicon of Named Rock Units — Result Details

Warklaw Hill Volcanic Member

Computer Code: WKH Preferred Map Code: WKH
Status Code: Full
Age range: Pridoli Epoch (SO) — Lochkovian Age (DO)
Lithological Description: This formation is composed of four well-defined subdivision as follows in downward sequence: d) Several thin flows of macroporphyritic olivine-basalts with large feldspar phenocrysts up to 5mm long; c) Several flows of macroporphyritic olivine-basalt with large phenocrysts of olivine and feldspar; b) Several thick flows (to 27m) of microporphyritic olivine-basalt with fluxion texture. a) Thin flows of porphyritic olivine-basalt.
Definition of Lower Boundary: Not exposed: lowest flows faulted against Inverclyde Group sediments.
Definition of Upper Boundary: Not seen: highest flows seen are highly vesicular purplish-grey feldspar-phyric basalts, 3.0-3-7m thick.
Thickness: At least 175m
Geographical Limits: Pentland Hills.
Parent Unit: Pentland Hills Volcanic Formation (PDH)
Previous Name(s): Bed B (-3935)
Warklaw Hill Group (-4978)
Warklaw Hill Volcanic Formation (-3129)
Bonaly Group [Obsolete Name And Code: Use BNY] (BOG)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Torphin Quarry, quarry face, flows of sub-division b) and c). 
Partial Type Section  Kinleith Burn, 40m upstream from hotel to 180m upstream from bridge at Easter Kinleath. Flows of subdivision a) and b) 
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. 
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). 
Geikie, A, 1897. The Ancient Volcanoes of Great Britain. Vol.1, 317-325. (London: Macmillan). 
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). 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S032 S032