The BGS Lexicon of Named Rock Units — Result Details

Benscliffe Breccia Member [Obsolete Code: Use CMBA]

Computer Code: BENS Preferred Map Code: Ben
Status Code: Index Level
Age range: Ediacaran Period (AD) — Ediacaran Period (AD)
Lithological Description: Massive to thickly bedded sequence of dacitic volcanic breccia, lapilli tuffs and tuffaceous mudstones/siltstones.
Definition of Lower Boundary: Not exposed; rests on fine-grained beds of Blackbrook Reservoir Formation, latter greenish-grey and commonly well-laminated.
Definition of Upper Boundary: Overlain by Beacon Tuff Member in east, and by Charnwood Lodge Volcanic Formation (undivided beds) in west.
Thickness: c.21m in east, possibly over 100m in west.
Geographical Limits: Discontinuously exposed from Nanpantan (Rhododendron Hill) south to Benscliffe Wood, then north to Flat Hill. Possibly merges with Kite Hill Tuff north of latter.
Parent Unit: Charnwood Lodge Volcanic Formation (CMCL)
Previous Name(s): Felsitic Agglomerate (-3204)
Benscliffe Agglomerate (-2596)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Benscliffe Wood. 
Reference Section  Hanging Stone to Flat Hill, Charnwood Lodge Nature Reserve. 
Reference(s):
Moseley, J and Ford, T D, 1985. A stratigraphic revision of the Late Precambrian rocks of Charnwood Forest, Leicestershire. Mercian Geologist, Vol.10(I), 1-18. 
Carney, J N. 1994. Geology of the Thringstone, Shepshed and Loughborough districts (SK41NW, SK41NE and SK51NW). British Geological Survey Technical Report WA/94/08. 
Watts, W W, 1947. Geology of the ancient rocks of Charnwood Forest, Leicestershire. Leicester: Leicester Literary and Philosophical Society. 
Worssam, B C and Old, R A, 1988. Geology of the country around Coalville. Memoir of the British Geological Survey, Sheet 155 (England and Wales) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E155 E141