The BGS Lexicon of Named Rock Units — Result Details

Charles Hill Volcanic Member

Computer Code: CHVO Preferred Map Code: notEntered
Status Code: Full
Age range: Asbian Substage (CR) — Asbian Substage (CR)
Lithological Description: Consists of pale greenish-grey to grey, amygdaloidal, earthy weathered to hard microporhyritic olivine basalt (Dalmeny type) lava flows and beds of grey and "pink" volcaniclastic airfall and/or waterlain lapilli tuff. Beds of limestone and mudstone are known very locally (as on Meadulse).
Definition of Lower Boundary: Defined at the base of the lowest lava flow or bed of volcaniclastic rock resting on non-cyclic fluvial and lacustrine sedimentary rocks of the underlying Fife Ness Formation, which consists of sandstones and mudstones with beds of carbonate (limestone and dolostone). The contact is nowhere seen and therefore might be tranistional, sharp or unconformable.
Definition of Upper Boundary: Defined by the highest tuff bed that is overlain by the non-cyclic sedimentary rocks of the overlying Anstruther Formation, consisting of dark grey to black lacustrine mudstones with thin beds of argillaceous ostracod-bearing limestone and dolostone and pale grey sandstone.
Thickness: Tens of metres, but very uncertain, assessed as more than 30m thick at Charles Hill.
Geographical Limits: Known at Aberdour, Fife Coast and possibly in South Fod Borehole near Dunfermline. Volcanic rocks, now no longer exposed at Silverknowes [NT 205 776] on the shore of the Firth of Forth at Granton-Carmond, Edinburgh, have also been assigned to this member here interbedded into the Gullane Formation. This outcrop of basaltic lavas and tuffs, once quarried on the coastline, extends the supposed occurrence of the volcanic member across the Inchkeith Fault and intercalates it with the Abbeyhill Shales.
Parent Unit: Anstruther Formation (ARBS)
Previous Name(s): Charles Hill Volcanic Beds [Obsolete Name and Code: Use CHVO] (-129)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Charles Hill, Barnhill Bay, near Aberdour, Fife. 
Type Area  Craigdimas, Firth of Forth. Supplementary type area. 
Type Area  Car Craig, Firth of Forth. Supplementary type area. 
Type Area  Meadulse, Firth of Forth. Supplementary type area. 
Reference(s):
Browne, M A E, Dean, M T, Hall, I H S, McAdam, A D, Monro, S K and Chisholm, J I. 1996. A lithostratigraphical framework for the Carboniferous rocks of the Midland Valley of Scotland. British Geological Survey Technical Report, WA/96/29. 
Browne, M A E, Robins, N S, Evans, R B, Monro, S K and Robson, P G. 1987. The Upper Devonian and Carboniferous sandstones of the Midland Valley of Scotland. Investigation of the Geothermal Potential United Kingdom, British Geological Survey. 
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:
S032 S032