Computer Code: |
HOL |
Preferred Map Code: |
HOL |
Status Code: |
Pending Upgrade |
Age range: |
Early Triassic Epoch (TE)
— Anisian Age (TA) |
Lithological Description: |
[Obsolete: use HEY] Sandstone, fine- to coarse-grained, part pebbly, with subordinate siltstone/mudstone; commonly in upward-fining units. |
Definition of Lower Boundary: |
Drawn where well-cemented pale coloured sandstones overlie red, softer, finer grained sandstones of the Hawksmoor Formation; erosion surface commonly present. |
Definition of Upper Boundary: |
Transitional to Denstone Formation, where sandstone-dominated sequence gives way to finer-grained lithologies. |
Thickness: |
35-50m |
Geographical Limits: |
Needwood Basin; Staffs/Leics/Derbys. |
Parent Unit: |
none recorded or not applicable
|
Previous Name(s): |
Keuper Sandstone, Lower [Obsolete name and code, use HEY]
(-709)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Reference Section |
For top of formation. Windyharbour Borehole, 103.16m to bottom at 123.50m (SK04SE/16). |
Reference Section |
For base: Mickleton Rock. 9.6m Hollington Formation on 2.6m Hawksmoor Formation; erosive contact. |
Type Area |
Between Hollington and Alton, Staffordshire. |
Reference Section |
Oldham's Quarry, Hollington (Charsley, 1982, fig.3). |
Reference Section |
Fielding's Quarry, Greatgate (Charsley, 1982, fig.3). |
Reference(s): |
Charsley, T J, 1982. A standard nomenclature for the Trassic formations of the Ashbourne district. Report of the Institute of Geological Sciences, No. 81/14. |
Hull, E, 1869. The Triassic and Permian rocks of the Midland Counties of England. Memoir of the Geological Survey of Great Britain. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E124
|