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)
Torduff Hill Volcanic Formation (TDF)
Torduff Hill Brecciated Trachyte (-564)
Bell's Hill And Howden Burn Group (-3849)
Bed C (-3303)
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):
Thirlwall, M F, 1988. Geochronology of Late Caledenian magmatism in northern Britain. Journal of the Geological Society, Vol.145, 951-967. 
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). 
Cameron, I B and Stephenson, D, 1985. British Regional Geology: The Midland Valley of Scotland (3rd Edition). (London: HMSO for British Geological Survey). 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S032