| LILSTOCK FORMATION | |||||
| Computer Code: | LTK | Status Code: | FORMAL ENTRY | ||
| Preferred Map Code: | |||||
| Age or Age Range: | [ TR ] | RHAETIAN | to | [ ] | |
| 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: | Parent Unit Code: |
| PENARTH GROUP | PNG |
| Previous Name(s): | Previous Code(s): |
| none recorded or not applicable | 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: | |
| Map Code | Sheet Name |
| E | 342 |
| E | 264 |
| E | 127 |
| E | 141 |
| E | 142 |
| E | 341 |