| Computer Code: |
WS |
Preferred Map Code: |
WS |
| Status Code: |
Full |
| Age range: |
Bolsovian Substage (CC)
— Asturian Substage (CAS) |
| Lithological Description: |
A red-bed succession. The lower part, the Bransty Cliff Sandstone Member (the Whitehaven Sandstone of Akhurst et al., 1997), comprises red to deep purple or purplish brown, cross-bedded, micaceous, medium- to coarse-grained sandstone. There are interbeds of pink to red or grey mudstone and siltstone and thin palaeosols are present locally. These beds are overlain by a thick heterogenous, dominantly red succession (the Millyeat Member) of mudstone, sandstone and marl with thin coals and limestones with Spirorbis sp.
The lower part of the formation was deposited from a major braided river system that flowed from the north-east. The upper part of the formation represents deposition in interdistributary bay or lacustrine environments with minor river channels (Akhurst et al., 1997). The reddening was either primary or early diagenetic.
Late Bolsovian to early Asturian (Westphalian D). |
| Definition of Lower Boundary: |
The base of the formation is taken where the non-reddened, cyclical, mudstone-dominated succession with thin coals of the underlying Pennine Coal Measures Group are succeeded unconformably by red sandstones. The unconformity cuts down to the Aegiranum Marine Band (AGMB) or, locally older strata (Akhurst et al., 1997). |
| Definition of Upper Boundary: |
The upper boundary of the formation is the base of the sub-Permian unconformity, which is overlain by the coarse, poorly bedded, poorly to moderately sorted, generally massive, matrix or clast-supported, typically pebble-grade, breccias of the Permian Brockram (Appleby Group). |
| Thickness: |
The formation is at least 280 m thick. The Bransty Cliff Sandstone Member is at least 100 m thick. The Millyeat Member is 180 m thick. |
| Geographical Limits: |
Within the Northern England Province the formation is recognised in north and west Cumbria. |
| Parent Unit: |
Warwickshire Group (WAWK)
|
| Previous Name(s): |
Whitehaven Sandstone Series [Obsolete Name and Code: Use WS]
(-3770)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Whitehaven harbour cliff sections where the lower arenaceous part of the formation (the Bransty Cliff Sandstone Member with mainly sandstone and subsidiary mudstone and siltstone interbeds) is well exposed. |
| Partial Type Section |
Frizington Hall borehole, NY01NW/174 from 12.8 m depth to the bottom of the borehole at 174.65 m depth. |
| Reference(s): |
| Dean, M T, Browne, M A E, Waters, C N and Powell, J H. 2011. A lithostratigraphical framework for the Carboniferous successions of northern Great Britain (onshore). British Geological Survey Research Report, RR/10/007. 165pp. |
| Eastwood, T, Dixon, E E L, Hollingworth, S E, and Smith, B. 1931. The geology of the Whitehaven and Workington District. Memoir of the Geological Survey of Great Britain, Sheet 28 (England and Wales). |
| Akhurst, M C, Chadwick, R A, Holliday, D W, McCormac, M, McMillan, A A, Millward, D, Young, B, Ambrose, K, Auton, C A, Barclay, W J, Barnes, R P, Beddoe-Stephens, B, James, J C W, Johnson, H, Jones, N S, Glover, B W, Hawkins, M P, Kimbell, G S, MacPherson, K A T, Merritt, J W, Milodowski, A E, Riley, N J, Robins, N S, Stone, P, and Wingfield, R T R. 1997. The geology of the west Cumbria district. Memoir of the British Geological Survey, Sheets 28, 37 and 47 (England and Wales). 138pp. |
| Eastwood T, and others. 1968. Geology of the country around Whitehaven. Memoir of the Geological Survey of Great Britain, Sheet 28 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E028
|
