| Computer Code: |
EI |
Preferred Map Code: |
EI |
| Status Code: |
Index Level |
| Age range: |
Longvillian Substage (OL)
— Longvillian Substage (OL) |
| Lithological Description: |
[Obsolete: use CEI] Yellow-grey to grey and greenish-grey sandy-siltstones, fine-grained sandstones and subordinate siltstones. Includes Blaen Eidda Member at its base and a laharic debris flow towards its top. It is highly fossiliferous. |
| Definition of Lower Boundary: |
Volcaniclastic green fossiliferous sandstone (Blaen Eidda Member) overlies grey siltstones and fine-grained sandstones of the Carn-y-Parc Formation. |
| Definition of Upper Boundary: |
Overlain by ash-flow tuff of the Lower Crafnant Volcanic Formation. |
| Thickness: |
50 metres. Lateral variations 0-50 metres. |
| Geographical Limits: |
Not defined. |
| Parent Unit: |
none recorded or not applicable
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Corwen, Sheet 120. |
| Reference(s): |
| Campbell, S D G. 1983. The geology of an area between Bala and Betws-y-Coed, North Wales. Unpublished PhD Thesis, University of Cambridge. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E120
|
