| Computer Code: |
HGSA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Pridoli Epoch (SO)
— Pridoli Epoch (SO) |
| Lithological Description: |
The unit is a subgreywacke in the type area of Holdgate, typically medium grained, limonite and iron stained, relatively well sorted and consisting of subangular grains of quartz, feldspar, lithic fragments and detrital heavy minerals (Greig et al., 1968). In the Neen Solars and Abberley areas, it is a coarse-grained, gritty, commonly pebbly, ridge-forming, red-brown sandstone, locally containing fish fragments (Mitchell et al., 1962). |
| Definition of Lower Boundary: |
none recorded or not applicable
|
| Definition of Upper Boundary: |
none recorded or not applicable
|
| Thickness: |
As envisaged by King, the unit is 5 to 10 m thick at Holdgate, but the Holdgate Sandstones Group/Formation of Allen and Tarlo (1963) extends to about 120 m. |
| Geographical Limits: |
Clee Hills and West Midlands. The unit occurs in the area west of the Clee Hills around Broncroft and in the Neen Sollars to Abberley area of Shropshire. The north-east-trending Broncroft outcrops include the type area of Holdgate. The Neen Sollars outcrops lie on both sides of the Neen Sollars Thrust. |
| Parent Unit: |
Moor Cliffs Formation (MOCL)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Near Abberley, it crops out from 400 m east of Newhouse Farm [SO 7730 6925] south-westwards to 0.5 km south of Abberley church [SO 7555 6730], the outcrop displaced by several NNW-trending faults (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. |
| Dineley, D L and Gossage, D W, 1959. The Old Red Sandstone of the Cleobury Mortimer area, Shropshire, Proceedings of the Geologists' Association, Vol. 70, 221-238. |
| Greig D C, Wright, J E, Hains, B A and Mitchell, G H. 1968. Geology of the country around Church Stretton, Craven Arms, Wenlock Edge and Brown Clee. Memoir of the Geological Survey, Sheet 166 (England and Wales). (London: H.M.S.O.). 379pp. |
| King, W W, 1925. Notes on the 'Old Red Sandstone' of Shropshire. Proceedings of the Geologists' Association, Vol.36, 383-389. |
| King, W W. 1934. The Downtonian and Dittonian strata of Great Britain and north-western Europe. Quarterly Journal of the Geological Society of London, Vol. 90, 526-570. |
| Mitchell, G H, Pocock, R W, and Taylor, J H. 1962. Geology of the country around Droitwich, Abberley and Kidderminster. Memoir of the Geological Survey of Great Britain, Sheet 182 (England and Wales). |
| Allen, J R L, and Tarlo, L B. 1963. The Downtonian and Dittonian facies of the Welsh Borderland. Geological Magazine, Vol. 100, 129-155. |
| Dineley, D L. 1999a. Early Devonian fossil fishes sites of the Welsh Borders. 107–144 in Fossil Fishes of Great Britain. Dineley, D L, and Metcalf, S J (editors). Geological Conservation Review Series, No. 16. (Peterborough: Joint Nature Conservation Committee.) |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
