The BGS Lexicon of Named Rock Units — Result Details
Grimley Andesite
Computer Code: | GYA | Preferred Map Code: | GyA |
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Status Code: | Full | ||
Age range: | Ediacaran Period (AD) — Ediacaran Period (AD) | ||
Lithological Description: | Grey to green, massive to autobrecciated, sparsely porphyritic high-silica andesite or dacite. Locally grades to monomictic (andesite-clast) block-breccia in Bardon Quarry. | ||
Definition of Lower Boundary: | All boundaries seen are faulted, except where one small sheet is chilled against the Peldar Dacite Breccia in Whitwick Quarry. | ||
Definition of Upper Boundary: | All boundaries seen are faulted, except where one small sheet is chilled against the Peldar Dacite Breccia in Whitwick Quarry. | ||
Thickness: | 0-500m | ||
Geographical Limits: | Extends from Whitwick Quarry northwards into Whitwick and Thringstone villages, and eastwards to Hob's Hole. To the south, it is last seen in Bardon Quarry. | ||
Parent Unit: | Whitwick Volcanic Complex (WVO) | ||
Previous Name(s): | Grimley-Type Porphyroid [Obsolete Name and Code: Use GYA]
(-1580)
Bardon 'Good Rock' [Obsolete Name and Code: Use GYA] (-2225) |
||
Alternative Name(s): | none recorded or not applicable | ||
Stratotypes: | |||
Type Section | Crags to east of Cademan Street, Whitwick. | ||
Reference Section | Grimley Rock to Whitwick Quarry. | ||
Reference Section | Bardon Quarry. | ||
Reference(s): | |||
Carney, J N. 1994. Geology of the Thringstone, Shepshed and Loughborough districts (SK41NW, SK41NE and SK51NW). British Geological Survey Technical Report WA/94/08. | |||
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. | |||
Watts, W W, 1947. Geology of the ancient rocks of Charnwood Forest, Leicestershire. Leicester: Leicester Literary and Philosophical Society. | |||
1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
E141 |