| Computer Code: |
HUNT |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Famennian Age (DA)
— Famennian Age (DA) |
| Lithological Description: |
Well sorted, red-brown, medium- to coarse-grained pebbly sandstones and quartz pebble conglomerates with some mudstone interbeds. The pebbles are predominantly of vein quartz, with rare quartzite, jasper and silicified igneous rocks. Bedding traces are rare, but conglomerate units can be locally seen to be cross-bedded and to fill shallow channels (Allen, 1971). |
| Definition of Lower Boundary: |
The lower boundary is placed at the base of lowest quartz pebble conglomerate, at the sharp, disconformable (or unconformable) junction with underlying red-brown sandstones of the Brownstones Formation. |
| Definition of Upper Boundary: |
The upper boundary is placed at the top of the highest quartz pebble conglomerate bed, where it is overlain by pale yellow and green sandstones of the Tintern Sandstone Formation. |
| Thickness: |
Up to 30 m. |
| Geographical Limits: |
The Forest of Dean and north of Bristol east of the Severn Estuary. |
| Parent Unit: |
Portishead Subgroup (POB)
|
| Previous Name(s): |
Quartz Conglomerate Formation (Forest Of Dean)
(QC)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Partial Type Section |
Road cutting [SO 562 167] on Huntsham Hill (Welch and Trotter, 1961). |
| Reference Section |
Road cutting at Euroclydon [SO 644 187] (Allen, 1971). The section in this cutting is now obscured by gabions. |
| Reference Section |
Crag exposures at the north end of the north-north-west-trending ridge between Huntsham Hill and Symonds Yat East provide an exposed reference section [SO 5620 1652] (T. Richards, personal communication, 2013). |
| Reference(s): |
| 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. |
| 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. 1971. The sedimentation of the Old Red Sandstone in the Forest of Dean. 9-19 in Geological excursions in South Wales and the Forest of Dean. Bassett, D A, and Bassett, M G (editors). Geologists' Association South Wales Group. Cardiff. |
| Eatwood, T. 1935. Cumbrian District and Forest of Dean. P. 59 in Summary of Progress for 1934. Geological Survey of Great Britain (England and Wales). |
| Trotter, F M, 1942. Geology of the Forest of Dean and Iron-ore Field. Memoir of the Geological Survey of Great Britain. |
| Welch, F B A and Trotter, F M. 1961. Geology of the country around Monmouth and Chepstow. Explanation of one-inch geological sheets 233 and 250. Memoir of the Geological Survey of Great Britain. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
