The BGS Lexicon of Named Rock Units — Result Details

Holly Bush Member

Computer Code: HYBH Preferred Map Code: HyB
Status Code: Full
Age range: Chadian Substage (CI) — Chadian Substage (CI)
Lithological Description: Fine to coarsely crystalline sandy dolostone, dolomitic sandstones and dolomites with thin stylolitic shaly mudstone and clay partings.
Definition of Lower Boundary: The incoming of common beds of sandy dolostone/dolomitic sandstone in the Milldale Limestone.
Definition of Upper Boundary: In the type section the top is taken at the top of the highest sandy dolomite, here additionally containing derived pebbles. The member is suceeded by grey, medium to thickly-bedded dolostones of the undivided Milldale Limestone Formation.
Thickness: 0-61m
Geographical Limits: Only known in Cloud Hill Quarry.
Parent Unit: Milldale Limestone Formation (MI)
Previous Name(s): Cloud Hill Dolomite Formation (-133)
Carboniferous Limestone [Obsolete entry, see Supplementary Information] (-4550)
Alternative Name(s): none recorded or not applicable
Type Section  Cloud Hill Quarry, southern face of 4m quarry level. 
Ambrose, K and Carney, J N, 1997. Geology of the Breedon on the Hill area. British Geological Survey Technical Report WA/97/42. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: