The BGS Lexicon of Named Rock Units — Result Details

Torduff Hill Volcanic Member

Computer Code: TDH Preferred Map Code: TDH
Status Code: Full
Age range: Pridoli Epoch (SO) — Lochkovian Age (DO)
Lithological Description: Aphanitic, fine-grained, pale grey, rarely porphyritic trachyte. Flow- banding common.
Definition of Lower Boundary: Not exposed.
Definition of Upper Boundary: Not seen: Faulted against Warklaw Hill Volcanic Member to west, Bonaly Volcanic Member to east and Ballagan Formation to north, unconformably overlain by Kinneswood Formation to south.
Thickness: c.200m
Geographical Limits: Pentland Hills.
Parent Unit: Pentland Hills Volcanic Formation (PDH)
Previous Name(s): Volcanic Neck (-2479)
Bell's Hill And Howden Burn Group (-3849)
Torduff Hill Brecciated Trachyte (-564)
Bed C (-3303)
Torduff Hill Volcanic Formation (TDF)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Crags around summit of Torduff Hill and crags on east shore of Torduff Reservoir. 
Reference(s):
Geikie, A, 1897. The Ancient Volcanoes of Great Britain. Vol.1, 317-325. (London: Macmillan). 
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. 
Thirlwall, M F, 1988. Geochronology of Late Caledenian magmatism in northern Britain. Journal of the Geological Society, Vol.145, 951-967. 
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). 
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