| Computer Code: |
CMSH |
Preferred Map Code: |
CmSh |
| Status Code: |
Index Level |
| Age range: |
Courceyan Substage (CF)
— Chadian Substage (CI) |
| Lithological Description: |
[Obsolete: use CMMU] Highly fissile bluish-black or black shales and slates, locally characterised by white, silty laminations and closely spaced vertical joints, particularly in higher horizons. |
| Definition of Lower Boundary: |
Base taken at change from grey micaceous and green shales of the Trusham Shale to the typical black shales of the Combe Shale. |
| Definition of Upper Boundary: |
Top taken at bottom of the lowest bedded chert of Teign Chert. |
| Thickness: |
90 - 150m (Middle Teign Valley); 45m (Ilsington area). |
| Geographical Limits: |
Middle Teign Valley, Devon, and Ilsington area. |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
Combe Formation [Obsolete Name and Code: Use CMMU, CMSH]
(-144)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Road cutting immediately north of Lower Ashton, Devon. |
| Reference Section |
Road cutting from Ilsington to Woodhouse shows lower boundary with Trusham Shale. |
| Reference(s): |
| Selwood, E B, Edwards, R A, Simpson, S, Chesher, J A, Hamblin, R J O, Henson, M R, Riddolls, B W and Waters, R A. 1984. Geology of the countryside around Newton Abbot. Memoir of the British Geological Survey, Sheet 339 (England and Wales). |
| Chesher, J A. 1968. The succession and structure of the Middle Teign Valley. Proceedings of the Ussher Society, Vol. 2, 15-17. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E339
|
