| Computer Code: |
TYM |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Abereiddian Stage (O2)
— Abereiddian Stage (O2) |
| Lithological Description: |
Mudstone matrix, volcanic debris flow. Comprises dominantly basaltic, angular clasts in a mudstone matrix-matrix-to clast-supported. |
| Definition of Lower Boundary: |
Lower boundary, with mudstones of Bifidus Slate Formation, is not seen and is inferred at change in slope. |
| Definition of Upper Boundary: |
Upper boundary, with mudstones of Bifidus Slate Formation, is not seen and is inferred at change in slope. |
| Thickness: |
0 - approximately 6m. |
| Geographical Limits: |
Extends from the coast north of Tywyn, inland to Castell Mawr, (5848 0492) where it is last seen. Length of outcrop c. 2km. |
| Parent Unit: |
Bifidus Slate Formation (BFDS)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Small crag on flank of Tal-y-Gareg Hill, c.370 metres west-north-west of Fron Newydd Farm. |
| Reference(s): |
| Pratt, W T, Woodhall, D G and Howells, M F. 1995. Geology of the country around Cadair Idris. Memoir of the British Geological Survey, Sheet 149. (England and Wales). (London: HMSO), 111pp |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E149
|
