| Computer Code: |
MER |
Preferred Map Code: |
Mer |
| Status Code: |
Full |
| Age range: |
Anisian Age (TA)
— Anisian Age (TA) |
| Lithological Description: |
[Obsolete: use TPSF]
Siltstone, interbedded and interlaminated with subordinate mudstones and sandstones. Most siltstones are red-brown and most of the sandstones are grey-green. Ripple marks and pseudomorphs after halite are common. |
| Definition of Lower Boundary: |
Conformable at the base of the siltstone-dominated sequence above the Sherwood Sandstone Group in the Stafford-Eccleshall Basin. |
| Definition of Upper Boundary: |
Conformable at the base of the mudstone dominated sequence of the overlying part of the Mercia Mudstone Group. |
| Thickness: |
c.15m in the Stoke-on-Trent district, though thickens to 60m in the Coton Fields No.1 Borehole at Stafford, near the centre of the Stafford-Eccleshall Basin. |
| Geographical Limits: |
Stafford-Eccleshall Basin. |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Cutting through which track to Ashley from Maer passes, immediately outside Maer, off road to Bates' Farm. |
| Reference Section |
Coton Fields No.1 Borehole (Stafford) record of cored borehole, 769ft 10ins - 967ft 0ins. SJ92SW/27. |
| Reference Section |
Mill Meece Borehole (Swynnerton) record of cored borehole, 613ft 6ins - 662ft 6ins. SJ83SW/4A. |
| 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. |
| Rees, J G and Wilson, A A. 1998. Geology of the country around Stoke-on-Trent. Memoir of the British Geological Survey, Sheet 123 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E123
|
