| Computer Code: |
DST |
Preferred Map Code: |
DST |
| Status Code: |
Full |
| Age range: |
Anisian Age (TA)
— Anisian Age (TA) |
| Lithological Description: |
[Obsolete: use TPSF]
Red-brown siltstones, thinly interlayered with very fine- to fine-grained sandstones and mudstones. Ripple marks, halite pseudomorphs, micaceous surfaces common. |
| Definition of Lower Boundary: |
Where a dominantly arenaceous sequence passes up into a dominantly argillaceous sequence (locally conformable on the Hawksmoor Formation). |
| Definition of Upper Boundary: |
Transitional, where mudstone assumes equal importance with siltstone, and sandstone becomes rare or absent. |
| Thickness: |
0 - >50m; maximum known 57m. |
| Geographical Limits: |
Needwood Basin. |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
Waterstones [Obsolete Name and Code: Use DST, SGBK, TPSF]
(-4008)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Windyharbour Borehole (between 51.57 and 103.16m) near Denstone: SK04SE/16. |
| Reference Section |
Stream and tributary in Broadgatehall, Drumble, 2km west-south-west of Hollington. |
| Reference Section |
Stream, west of Upper Tean. |
| Reference(s): |
| Howard, A S, Warrington, G, Ambrose, K, and Rees, J G. 2008. A formational framework for the Mercia Mudstone Group (Triassic) of England and Wales. British Geological Survey Research Report, RR/08/04. |
| Warrington, G, Audley-Charles, M G, Elliott, R E, Evans, W B, Ivimey-Cook, H C, Kent, P E, Robinson, P L, Shotton, F W and Taylor, F M. 1980. A correlation of the Triassic rocks in the British Isles. Special Report of the Geological Society of London, No.13. |
| 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. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E123
E124
|
