| Computer Code: |
LTK |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Rhaetian Age (TR)
— Rhaetian Age (TR) |
| Lithological Description: |
Includes Cotham Member (grey and grey-green shales and siltstones) and Langport Member (porcellanous limestone below, calcareous mudstone above). |
| Definition of Lower Boundary: |
Placed at base of Cotham Member, sharp, commonly channeled on the Westbury Formation. |
| Definition of Upper Boundary: |
Placed at top of Langport Member, where there is a sharp but conformable junction with the overlying 'paper shale' of the "Blue Lias". |
| Thickness: |
1-10m |
| Geographical Limits: |
Present throughout the United Kingdom. |
| Parent Unit: |
Penarth Group (PNG)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Lilstock, west Somerset. |
| Reference Section |
Immediately north of Lavernock Point, south Glamorgan. |
| Reference Section |
Lilstock, west Somerset. |
| Reference(s): |
| Waters, R A and Lawrence, D J D. 1987. Geology of the South Wales Coalfield - Part III: the country around Cardiff. Memoir of the British Geological Survey, Sheet 263. (England and Wales). |
| 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. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E127
E142
E141
E341
E342
E264
|
