The BGS Lexicon of Named Rock Units — Result Details

Fairmilehead Volcanic Member

Computer Code: FAI Preferred Map Code: FAI
Status Code: Full
Age range: Pridoli Epoch (SO) — Lochkovian Age (DO)
Lithological Description: A varied succession of pryroxene and hornblende andesites and biotite trachytes, with olivine basalt flows at the top, and beds of andesitic and rhyolitic tuff.
Definition of Lower Boundary: Not seen: faulted against andesite lavas of the Carnethy Volcanic Member.
Definition of Upper Boundary: At the possibly unconformable base of the Braid Hills Member, which is marked by an inpersistent bed of basaltic tuff between olivine basalt of the Fairmilehead Member and trachyte of the Braid Hills Member.
Thickness: At least 430m: succession disrupted by faulting.
Geographical Limits: Bounded on the south by the fault running parallel to the Edinburgh City bypass (NT 242 676-260 671); on the north a fault and by the overlying Braid Hills Member (NT 250 692-264 690) and on the east and west by unconformably overlying Kinneswood Formation rocks (NT 242 676-242 694 and NT 260 671-264 690).
Parent Unit: Pentland Hills Volcanic Formation (PDH)
Previous Name(s): Fairmilehead, Braids And Blackford (-1989)
Alternative Name(s): none recorded or not applicable
Partial Type Section  Mortonhall Quarry. 
Type Area  Between junction of Braid Road and Buckstone Gardens and Morton Hall House. 
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). 
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. 
Cameron, I B and Stephenson, D, 1985. British Regional Geology: The Midland Valley of Scotland (3rd Edition). (London: HMSO for British Geological Survey). 
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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used: