The BGS Lexicon of Named Rock Units — Result Details

Dunbarella Bed

Computer Code: DUA Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Arundian Substage (CJ) — Arundian Substage (CJ)
Lithological Description: Dark, fissile, calcareous mudstone with sporadic petroliferous, wackestone nodules - 'bullions'. Bed crowded with bivalves - 'Dunbarella' and 'Pteronites'.
Definition of Lower Boundary: Not defined.
Definition of Upper Boundary: Not defined.
Thickness: 0.2m
Geographical Limits: Craven Basin, northwest England.
Parent Unit: Chaigley Limestone Member (CHGL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Bonstone Brook, Ashnott, Newton, near Clitheroe, Lancashire, England. 
Reference Section  Leagram Brook, near Clitheroe, Lancashire, England. 
Reference Section  Stream at Paper Mill Wood, Sandal Holme Farm, Clitheroe, Lancashire, England. 
Reference(s):
Hind, W and Howe, J A. 1901. The geological succession and palaeontology of the beds between the Millstone Grit and the Limestone-Massif at Pendle Hill and their equivalents in certain other parts of Britain. Quarterly Journal of the Geological Society of London, Vol.57, 347-402. 
Riley N J. 1990. Stratigraphy of the Worston Shale Group (Dinantian) Craven Basin, north-west England. Proceedings of the Yorkshire Geological Society, Vol. 48, 163-187. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable