| Computer Code: |
DAR |
Preferred Map Code: |
Dar |
| Status Code: |
Full |
| Age range: |
Asturian Substage (CAS)
— Asturian Substage (CAS) |
| Lithological Description: |
Mudstone with subordinate sublitharenite sandstones and thin beds of Spirorbis limestone. Colour grey with mottled grey/brown palaeosols (but may be reddened). Distinctive geophysical log character, with gamma peaks. |
| Definition of Lower Boundary: |
At base of mudstone-dominated succession resting on litharenites of lower Halesowen Formation; or at change of gamma log character. |
| Definition of Upper Boundary: |
At base of overlying Salop Formation. In places where Member is grey there is a change to orange-red colours. Boundary also marked by a change of gamma log character. |
| Thickness: |
40 to 90m; 60.5m in type section. |
| Geographical Limits: |
Staffordshire, Shropshire, Warwickshire. |
| Parent Unit: |
Halesowen Formation (HA)
|
| Previous Name(s): |
Palustrine Unit [Obsolete Name and Code: Use DAR]
(-2136)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Radwood Borehole, base at 284.9 m., top at 204.3 m. (Besly & Cleal, 1997, fig. 6) (SJ 74 SE/28). |
| Type Section |
Dark Slade Borehole; base at 241.8 m., top at 181.3 m. (Besly & Cleal, 1997, fig. 10) (SJ 91 NE/16). |
| Reference(s): |
| Besly, B M, and Cleal, C J. 1997. Upper Carboniferous stratigraphy of the West Midlands (UK) revised in the light of borehole geophysical logs and detrital compositional suites. Geological Journal 32, 85-118. |
| Powell, J H, Chisholm, JI, Bridge, D M, Rees, J G, Glover, B W and Besly, B M. 2000. Stratigraphical framework for Westphalian to Early Permian red-bed successions of the Pennine Basin. British Geological Survey Technical Report WA/99/10. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
