The BGS Lexicon of Named Rock Units — Result Details

Dolphinholme Mudstone

Computer Code: DLP Preferred Map Code: Dlp
Status Code: Full
Age range: Chokierian Substage (CH) — Alportian Substage (CO)
Lithological Description: Mudstone, dark grey, with poor bivalve fauna.
Definition of Lower Boundary: Top of Accerhill Sandstone; medium- to coarse-grained sandstones with abundant plant debris, overlain sharply by the mudstone-dominated Dolphinholme Mudstone.
Definition of Upper Boundary: Abrupt change to medium-grained, thinly bedded sandstone of the succeeding Ellel Crag Sandstone, with abundant plant debris, allochtonous coal lenses and thin siltstone interbeds.
Thickness: c 60m
Geographical Limits: Ellel, Forton, Lancashire.
Parent Unit: Samlesbury Formation (SAML)
Previous Name(s): Dolphinholme Mudstone Formation (-2757)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  100m to east of Dolphinholme Church in Wyre Valley, Lancashire. 
Reference(s):
Aitkenhead, N, Bridge, D M, Riley, N J and Kimbell, S F. 1992. Geology of the country around Garstang. Memoir of the British Geological Survey, Sheet 67 (England and Wales) 
Waters, C N, Waters, R A, Barclay, W J, and Davies, J R. 2009. Lithostratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/09/01. 184pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E067 E059