The BGS Lexicon of Named Rock Units — Result Details

Ardwell Subgroup

Computer Code: AWL Preferred Map Code: AWL
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Sandstone, siltstone, mudstone, limestone and conglomerate; highly fossiliferous in places (shelly faunas).
Definition of Lower Boundary: Coincides with lower boundary of the Balclatchie Formation (on coastal outcrops) and lower boundary of the Craighead Limestone Formation (in the Craighead Inlier).
Definition of Upper Boundary: Coincides with upper boundary of the Ardwell Farm Formation.
Thickness: To c.1600m
Geographical Limits: Girvan area, southwest Scotland.
Parent Unit: Ardmillan Group (AMN)
Previous Name(s): Ardmillan Group (AMN)
Ardmillan Group (AMN)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Coast south of Girvan, southwest Scotland. Williams, 1962. See also consituent Ardwell Farm, Balclatchie and Craighead Limestone formations. 
Reference(s):
Williams, A, 1962. The Barr and Lower Ardmillan Series (Caradoc) of the Girvan district, southwest Ayrshire, with descriptions of the Brachiopoda. Memoir of the Geological Society of London, No.3. 
Fortey, R A, Harper, D A T, Ingham, J K, Owen, A W, Parkes, M A, Rushton, A W A and Woodcock, N H. 2000. A revised correlation of Ordovician rocks in the British Isles. Geological Society Special Report, No.24. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable