| Computer Code: |
MOH |
Preferred Map Code: |
MoH |
| Status Code: |
Full |
| Age range: |
Soudleyan Substage (OY)
— Longvillian Substage (OL) |
| Lithological Description: |
Well-bedded microconglomerates locally containing larger clasts of felsic tuff, coarse-grained sandstones and subordinate thinner silty sandstones. Many sedimentary structures including large-scale cross-bedding, ripple lamination, grading and channels as well as convolute lamination and slump structures. |
| Definition of Lower Boundary: |
Conformable within the Cwm Eigiau Formation. |
| Definition of Upper Boundary: |
Conformably overlain by the felsic ash-flow tuffs of the Pitts Head Tuff Formation. |
| Thickness: |
To 250m |
| Geographical Limits: |
Snowdonia, North Wales. |
| Parent Unit: |
Cwm Eigiau Formation (CEI)
|
| Previous Name(s): |
Gorllwyn Grits [Obsolete Name and Code: Use MOH]
(-3558)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Eastern flanks of Moel Hebog, Snowdonia, North Wales. Howells, M F and Smith, M. 1997. |
| Reference(s): |
| Shackleton, R M. 1959. The stratigraphy of the Moel Hebog district between Snowdon and Tremadoc. Liverpool and Manchester Geological Journal, Vol.2, 216-252. |
| Howells, M F and Smith, M. 1997. Geology of the country around Snowdon. Memoir of the British Geological Survey, Sheet 119 (England and Wales). (London: The Stationery Office). 104pp. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E119
|
