| Computer Code: |
ALBS |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Ludlow Epoch (SU)
— Pridoli Epoch (SO) |
| Lithological Description: |
Westerly derived pale yellow to buff, quartz-rich sandstones and pebbly sandstones with subordinate red mudstones and conglomerates, and thin air-fall dust and crystal-lithic tuffs. Hillier and Williams (2004) provided a recent description. |
| Definition of Lower Boundary: |
The lower boundary of the formation is placed at the base of the pale quartz-rich sandstones, where they overlie red mudstones of the Red Cliff Formation. |
| Definition of Upper Boundary: |
The upper boundary is placed at the top of metre-thick, massive coarse-grained mud-matrix quartz-rich sandstones of the Albion Sands Formation, where they are succeeded conformably by red mudstones of the overlying Moor Cliffs (formerly Sandy Haven) Formation exposed at the base of Gateholm Stack [SM 773 075]. |
| Thickness: |
Up to 95 m. |
| Geographical Limits: |
Confined to the area between the Ritec Fault in the south and the Musselwick Fault to the north. |
| Parent Unit: |
Milford Haven Subgroup (MIH)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Cliffs at Albion Sands [SM 771 077], north of Gateholm Island, west-south-west of Marloes (Barclay et al., 2015). |
| Reference(s): |
| Barclay, W J, Davies, J R, Hillier, R D, and Waters, R A. 2015. Lithostratigraphy of the Old Red Sandstone successions of the Anglo-Welsh Basin. British Geological Survey Research Report, RR/14/02. 96pp. |
| Allen, J R L, and Williams, B P J. 1978. The sequence of the earlier Lower Old Red Sandstone (Siluro - Devonian) north of Milford Haven, southwest Dyfed (Wales). Geological Journal, Vol. 13, 113-136. |
| Hillier, R D, and Williams, B J P. 2004. Sedimentation and tectonics: the marine Silurian-basal Old Red Sandstone transition in southern Pembrokeshire, UK. Geological Journal, Vol. 39, 237-256. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
