Computer Code: |
SHSA |
Preferred Map Code: |
SHS |
Status Code: |
Full |
Age range: |
Anisian Age (TA)
— Ladinian Age (TD) |
Lithological Description: |
Red to brown, angular or subangular, fine- to medium-grained sandstone, generally parallel-bedded, with concentrations of angular Charnian clasts forming matrix-supported conglomerates. Siltstones and mudstones in upper part. |
Definition of Lower Boundary: |
Unconformable on Precambrian rocks of Charnian Supergroup, and on Carboniferous rocks north and east of Charnwood Forest. |
Definition of Upper Boundary: |
Gradational, by increase in siltstones and mudstones, into the Sneinton Formation (Mercia Mudstone Group). Probably also grades laterally into the main part of the Bromsgrove Formation. |
Thickness: |
0-30m, may be 60m locally in palaeovalley situation in Charnwood Forest. |
Geographical Limits: |
Mainly restricted to northern part of Charnwood Forest, between Newhurst Quarry and Whitwick. May also occur farther west, near Coleorton. |
Parent Unit: |
Helsby Sandstone Formation (HEY)
|
Previous Name(s): |
Lower Keuper Sandstone and Waterstones [Obsolete Name and Code: Use SHSA]
(-3674)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Section |
Southern face of Newhurst Quarry (part of Charnwood Quarry complex). |
Reference(s): |
Fox-Strangways, C, 1905. The geology of the country between Derby, Burton-on-Trent, Ashby de la Zouch and Loughborough. Memoir of the Geological Survey of Great Britain, Sheet 141 (England and Wales). |
Carney, J N. 1994. Geology of the Thringstone, Shepshed and Loughborough districts (SK41NW, SK41NE and SK51NW). British Geological Survey Technical Report WA/94/08. |
Bosworth, T O, 1912. The Keuper Marls around Charnwood Forest. Leicester Literary and Philosophical Society. (Leicester: Thomley and Son). |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E141
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