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
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