| Computer Code: |
MCV |
Preferred Map Code: |
MCV |
| Status Code: |
Full |
| Age range: |
Woolstonian Substage (OS)
— Woolstonian Substage (OS) |
| Lithological Description: |
Tuffs, tuffites and sedimentary rocks. |
| Definition of Lower Boundary: |
On Lower Crafnant Volcanic Formation, dominated by ash-flow tuffs. |
| Definition of Upper Boundary: |
Under Upper Crafnant Volcanic Formation. |
| Thickness: |
30-120m |
| Geographical Limits: |
Eastern Snowdonia, around Betws-y-Coed. Farther north is not readily separated from the Upper Crafnant Volcanic Formation. |
| Parent Unit: |
Snowdon Volcanic Group (SV)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Between Llyn Bodgynydd and Coed Mawr. |
| Reference(s): |
| Howells, M F, Francis, E H, Leveridge, B E and Evans, C D R, 1978. Classical areas of British Geology. Capel Curig and Betws-y-Coed. Description of 1:25 000 Sheet SH75. London: HMSO for Institute of Geological Sciences. |
| Howells, M F, Leveridge, B E, Evans, C D R and Nutt, M J C, 1981. Classical areas of British Geology. Dolgarrog. Description of 1:25 000 Sheet SH76. London: HMSO for Institute of Geological Sciences. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E106
|
