The BGS Lexicon of Named Rock Units — Result Details

Greenan Castle Pyroclastic Member

Computer Code: GCP Preferred Map Code: GCP
Status Code: Full
Age range: Chadian Substage (CI) — Asbian Substage (CR)
Lithological Description: Bedded pyroclastic rocks and volcaniclastic sedimentary rocks comprising lithic lapilli tuffs and tuffs.
Definition of Lower Boundary: Where seen overlying sandstones, mudstones and cementstones of the underlying Ballagan Formation on the shore at Greenan Castle, possibly disconformable on (lithified) Ballagan Formation.
Definition of Upper Boundary: Unconformably overlain by mudstones and sandstones of the Lawmuir Formation on the shore at Greenan Castle.
Thickness: Thickness of 23 m at Greenan Castle in the Ayr district, yet dies out laterally.
Geographical Limits: A local unit on the shore and around Greenan Castle (south of Ayr, Scotland), which dies out approximately 1km inland.
Parent Unit: Clyde Plateau Volcanic Formation (CPV)
Previous Name(s): Bedded agglomerate of Greenan Castle [Obsolete Name and Code: Use GCP] (-2199)
Greenan Castle Ash [Obsolete Name and Code: Use GCP] (-2200)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  On the shore and in the cliff at Greenan Castle, south of Ayr, Scotland. Eyles, et al., 1949; Whyte, 1964, 1992. 
Reference(s):
Eyles, V A, Simpson, J B and Macgregor, M C. 1949. Geology of Central Ayrshire. Memoir of the Geological Survey of Scotland, British Geological Survey, Sheet 14 (Scotland). 
Sowerbutts, A A. 1999. Geology of the Dunure, Carrick Hills and Heads of Ayr area. BGS Technical Report, WA/99/102. 
Whyte, F. 1992. Heads of Ayr. In: Lawson, J D and Weedon, W S (Eds), Geological excursions around Glasgow and Girvan. 
Whyte, F. 1964. The Heads of Ayr Vent. Transactions of the Geological Society of Glasgow, Vol.25, 72-97. 
Stephenson, M H, Williams, M, Monaghan, A, Arkley, S, and Smith, R A. 2002. Biostratigraphy and palaeoenvironments of the Ballagan Formation (lower Carboniferous) in Ayrshire, SW Scotland. Scottish Journal of Geology, Vol.38, 93-111. 
Dean, M T, Browne, M A E, Waters, C N and Powell, J H. 2011. A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore). British Geological Survey Research Report, RR/10/007. 165pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S014