| Computer Code: |
DCS |
Preferred Map Code: |
DCS |
| Status Code: |
Full |
| Age range: |
Pridoli Epoch (SO)
— Pridoli Epoch (SO) |
| Lithological Description: |
Ludlow Bone Bed Member locally at base; Platyschisma Shale Member (to 2m) above; mainly yellow, fine-grained, micaceous, well-sorted cross-bedded sandstone (Sandstone Member), with siltstone and olive green mudstone. |
| Definition of Lower Boundary: |
Base of Ludlow Bone Bed Member (if present); sharp junction with underlying Upper Ludlow Shale (Upper Whitcliffe Formation). |
| Definition of Upper Boundary: |
Top of highest sandstone below red mudstones of the Ledbury (Raglan Mudstone) Formation or below the conformable base of the olive green mudstones and siltstones of the Temeside Shales Formation. |
| Thickness: |
About 15m in type area; 17m at Ludlow, 15-20m in South Staffordshire |
| Geographical Limits: |
Welsh Borderland. |
| Parent Unit: |
Milford Haven Subgroup (MIH)
|
| Previous Name(s): |
Downton Castle Sandstone Group [Obsolete Name and Code: Use DCS]
(-4596)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
[Sandstone Member]. Old quarry in Tin-Mill Wood, south bank of River Teme near Bringewood Forge Bridge, Downton, Hereford and Worcester (Elles and Slater, 1906). |
| Reference Section |
[All members]. Northwest end of old quarry near Downton Castle Bridge, Downton, Hereford and Worcester (Elles and Slater, 1906). |
| Reference Section |
[Ball, 1951]: Disused quarry, Holloway Street, Upper Gornal, NW of Dudley. |
| Reference Section |
[Ludlow Bone Bed and Platyschisma Shale Members]. Cutting in car park adjacent to the Swan Inn, Munslow Aston, Corve Dale, Shropshire (Greig and others, 1968). |
| Type Section |
[Ludlow Bone Bed and Platyschisma Shale members]. Roadside section, south side of junction of Whitcliffe Road with main Ludlow to Leominster road, near Ludlow, Shropshire (Bassett and others, 1982). |
| Reference(s): |
| Ball, H W. 1951. The Silurian and Devonian rocks of Turners Hill and Gornal, South Staffordshire. Proceedings of the Geologists' Association, 62, 225-236. |
| Bassett, M G, Lawson, J D, and White, D E. 1982. The Downton Series as the fourth series of the Silurian System. Lethaia, Vol. 15, 1-24. |
| Cocks, L R M, Holland, C H, Rickards, R B and Strachan, I, 1971. A correlation of Silurian rocks in the British Isles. Geological Society of London, Special Report No.1. |
| 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. |
| Elles, G L and Slater, I L, 1906. The highest Silurian rocks of the Ludlow district. Quarterly Journal of the Geological Society of London, 61, 195-221. |
| White, D E and Lawson, J D, 1989. The Pridoli Series in the Welsh Borderland and south central Wales. 131-141 in A global standard for the Silurian System. Holland, C H and Bassett, M G (editors) National Museum of Wales, Geological Series No. 9, Cardiff. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E198
E216
E232
E168
E249
E234
E233
E199
E181
E250
E167
|
