| Computer Code: |
BODA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Silurian Period (S)
— Early Devonian Epoch (DL) |
| Lithological Description: |
Conglomerates and pebbly sandstones with abundant clasts of the adjacent Precambrian and Ordovician rocks.
Basin-margin alluvial fan deposition of gravels sourced from Precambrian and older lower Palaeozoic rocks to the south-west.
Age not known, but probably late Silurian to Early Devonian. |
| Definition of Lower Boundary: |
The lower boundary of the formation is an unconformity, where the lowest conglomerate of the Bodafon Formation rests on the underlying lower Palaeozoic or Precambrian rocks. |
| Definition of Upper Boundary: |
The upper boundary is placed at the top of the main conglomerate development, where fine-grained calcareous strata of the Traeth Bach Formation overlie the conglomerates. The boundary is gradational, the conglomerates interfingering with both the Traeth Bach and Porth-y-Mor formations. |
| Thickness: |
3 to 45 m. |
| Geographical Limits: |
Confined to a narrow outcrop extending north-south on the east coast of Anglesey from Traeth Dulas southwards to the flanks of Mynydd Bodafon and from there south to 0.8 km north of Llangefni. |
| Parent Unit: |
Dulas Bay Subgroup (DULB)
|
| Previous Name(s): |
Bodafon Beds
(-5245)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Crags on the north-east slopes of Mynydd Bodafon [SH 474 866-477 863]. |
| Reference Section |
Coast exposures at Trwyn Cwmrwd [SH 492 902]. |
| 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. 1965. The sedimentation and palaeogeography of the Old Red Sandstone of Anglesey, North Wales. Proceedings of the Yorkshire Geological Society, Vol. 35, 139-185. |
| 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 |
