| Computer Code: |
TGR |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Eifelian Age (DI)
— Eifelian Age (DI) |
| Lithological Description: |
Thick sequence mainly of grey, purple and green quartzitic fine- to medium-grained sandstone, commonly parallel laminated and convolute-bedded, with shale and silty shale interbeds. Abundant scoured surfaces and silty drapes. Scattered scarce remains of Psilophyton sp. and a calamitid-like stem. Local distictive facies of deformed laminae of red siltstones and very fine-grained sandstones in which desiccation cracks alternate with convolute laminae. |
| Definition of Lower Boundary: |
?Conformable on rocks of the Hollowbrook Member (q.v.). |
| Definition of Upper Boundary: |
Overlain ?conformably by rocks of the Rawns Member (q.v.) |
| Thickness: |
c. 1250 m (Tunbridge, 1978). |
| Geographical Limits: |
North Devon - west Somerset. |
| Parent Unit: |
Hangman Sandstone Formation (HASA)
|
| Previous Name(s): |
Trentishoe Grits
(-960)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Cliff sections between Combe Martin Bay and Woody Bay, and between Lynmouth Bay and Minehead. |
| Reference(s): |
| Edmonds, E A, Whittaker, A, and Williams, B J. 1985. Geology of the country around Ilfracombe and Barnstaple. Memoir of the British Geological Survey, Sheets 277 and 293 (England and Wales). |
| Evans, J W. 1922. The geological structure of the country round Combe Martin. Proceedings of the Geologists' Association, Vol. 33, 201-228. |
| Tunbridge, I P. 1978. North Devon - Lower and Middle Devonian: Hangman Sandstone Group. 9-13 in Scrutton, C T (Editor), A field guide to selected areas of the Devonian of south-west England. International Symposium on the Devonian System. (PADS 78). (Palaeontological Association). |
| Lane, R. 1965. The Hangman Grits - an introduction and stratigraphy. Proceedings of the Ussher Society, Vol.1, 166-167. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
