| Computer Code: |
TLL |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Lochkovian Age (DO)
— Lochkovian Age (DO) |
| Lithological Description: |
Thinly interbedded red, fine-grained, commonly bioturbated sandstones and siltstones.
Perennial flood basin lakes; reduced amounts of calcrete and an abundance of burrowing structures suggest a high water table and less prolonged periods of subaerial exposure.
Probably Lochkovian, but no diagnostic fauna has yet been found. |
| Definition of Lower Boundary: |
The lower boundary is placed 477 m (1565 feet) from the base of the section measured by Allen (1965a), where the basal sandstone of a thinly bedded sandstone/red siltstone succession of this formation overlies the thicker bedded succession of the underlying Porth-y-Mor Formation. |
| Definition of Upper Boundary: |
The upper boundary is not seen. |
| Thickness: |
25 m+. |
| Geographical Limits: |
Confined to a small area in the core of a syncline on the north side of Traeth Lligwy. |
| Parent Unit: |
Dulas Bay Subgroup (DULB)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Cliffs on the north side of Traeth Lligwy [SH 494 878-493 875]. |
| Reference(s): |
| Allen, J R L. 1965. The sedimentation and palaeogeography of the Old Red Sandstone of Anglesey, North Wales. Proceedings of the Yorkshire Geological Society, Vol. 35, 139-185. |
| 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. |
| Waters, C N, Smith, K, Hopson, P M, Wilson, D, Bridge, D M, Carney, J N, Cooper, A H, Crofts, R G, Ellison, R A, Mathers, S J, Moorlock, B S P, Scrivener, R C, McMillan, A A, Ambrose, K, Barclay, W J, and Barron, A J M. 2007. Stratigraphical Chart of the United Kingdom: Southern Britain. British Geological Survey, 1 poster. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
