The BGS Lexicon of Named Rock Units — Result Details

Farlow Sandstone Formation

Computer Code: FRL Preferred Map Code: Frl
Status Code: Full
Age range: Famennian Age (DA) — Famennian Age (DA)
Lithological Description: Large-scale, planar cross-bedded, yellow sandstone and pebbly sandstone overlain by grey pebbly calcareous sandstone.
Definition of Lower Boundary: The lower boundary of the formation is placed at an unconformity where the basal conglomerate sharply overlies red-brown mudstones of the St Maughans Formation (at the type section) or red sandstones of the Brownstones Formation.
Definition of Upper Boundary: The upper boundary is placed at an unconformity where the topmost grey sandstones of the formation are sharply overlain by the basal conglomerate of the Carboniferous-age Oreton Limestone Formation (Avon Group).
Thickness: The formation is 70 to 154m thick.
Geographical Limits: West of Farlow [SO 63 80] extending eastward to east of Prescott [SO 67 81], Shropshire.
Parent Unit: Upper Old Red Sandstone Group (ORSU)
Previous Name(s): Farlow Sandstone Group (-5075)
Farlow Group (-4050)
Farlow Series (-5076)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Farlow Bank where a 1.2m-thick basal quartz conglomerate is overlain by 4.9m of yellow pebbly sandstone [SO 639 807]. 
Reference Section  Roadside exposures at Prescott, Shropshire [SO 663 812]. Dineley (1999) 
Reference(s):
King, W W, 1925. Notes on the 'Old Red Sandstone' of Shropshire. Proceedings of the Geologists' Association, Vol.36, 383-389. 
Allen, J R L. 1974. Sedimentology of the Old Red Sandstone (Siluro-Devonian) in the Clee Hills area, Shropshire, England. Sedimentary Geology, Vol. 12, 73-167. 
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. 
House, M R, Richardson, J B, Chaloner, W G, Allen, J R L, Holland, C H and Westoll, T S. 1977. A Correlation of Devonian rocks of the British Isles. Geological Society of London, Special Report No.8, Scottish Academic Press, Edinburgh. 
Allen, J R L. 1977. Wales and the Welsh Borders. 40-54 in M R. House et al. A correlation of Devonian rocks in the British Isles. Geological Society, London, Special Report No. 7. 
Allen, J R L. 1965. Upper Old Red Sandstone (Farlovian) palaeogeography in South Wales and the Welsh Borderland. Journal of Sedimentary Petrology, Vol. 35, 167-195. 
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. 
Dineley, D L. 1999. Prescott Corner. 236-238 in Dineley, D L. and Metcalf, S J. (editors). Fossil Fishes of Great Britain. Geological Conservation Review Series No.16. Joint Nature Conservation Committee, Peterborough. 
Ball, H W and Dineley, D L, 1961. The Old Red Sandstone of Brown Clee Hill and the adjacent area. Part 1. Stratigraphy. Bulletin of the British Museum (Natural History), Geology Series. [London: British Museum (Natural History).] 177-242. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E166 E167 E181