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
|