| Computer Code: |
TYF |
Preferred Map Code: |
TyF |
| Status Code: |
Full |
| Age range: |
Comley Series (EC)
— St David's Series (ED) |
| Lithological Description: |
Manganiferous siltstones with fine- to medium-grained sandstones in thin to medium beds. |
| Definition of Lower Boundary: |
Underlain by coarse- to medium-grained green sandstones and interbedded siltstones of the Hell's Mouth Formation. |
| Definition of Upper Boundary: |
Overlain by coarse-grained, thickly bedded turbidites of the Cilan Formation. |
| Thickness: |
37m |
| Geographical Limits: |
Pwllheli area, northwest Wales. |
| Parent Unit: |
Harlech Grits Group (HGG)
|
| Previous Name(s): |
Mulfran Beds
(-582)
|
| Alternative Name(s): |
Hafotty Formation
|
| Stratotypes: |
| Type Section |
Trwyn y Careg-y-tir from the old manganese trials. [SH 2877 2402], eastwards onto the hillside above [SH 2885 2394]. |
| Reference(s): |
| Young, T P, Martin, F, Dean, W T and Rushton, A W A. 1994. Cambrian stratigraphy of St Tudwal's Peninsula, Gwynedd, northwest Wales. Geological Magazine, Vol.131, 335-360. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E134
|
