| Computer Code: |
PD |
Preferred Map Code: |
PD |
| Status Code: |
Full |
| Age range: |
Arenig Series (OR)
— Arenig Series (OR) |
| Lithological Description: |
Fine-grained bioturbated muddy sandstones. |
| Definition of Lower Boundary: |
Conformably overlies thickly bedded pale weathering sandstones of the Trwyn yr Wylfa Member. |
| Definition of Upper Boundary: |
Conformable and gradationally overlain by well-bedded sandstones of the Machroes Member. |
| Thickness: |
35-40m |
| Geographical Limits: |
Pwllheli area, northwest Wales. |
| Parent Unit: |
St Tudwal's Formation (STUD)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
St Tudwals Island West. Young, T P, Gibbons, W and McCarroll, D. 2002. |
| Type Section |
Penrhyn Du, between Porth Bach and the old lifeboat station. Young, T P, Gibbons, W and McCarroll, D. 2002. |
| Partial Type Section |
Machroes (top of formation). Young, T P, Gibbons, W and McCarroll, D. 2002. |
| Reference(s): |
| Young, T P, Gibbons, W and McCarroll, D. 2002. Geology of the country around Pwllheli. Memoir of the British Geological Survey, Sheet 134 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E134
|
