The BGS Lexicon of Named Rock Units — Result Details

Budleigh Salterton Pebble Beds Formation [Obsolete Name And Code Use: CHES]

Computer Code: BSP Preferred Map Code: BSP
Status Code: Pending Upgrade
Age range: Early Triassic Epoch (TE) — Early Triassic Epoch (TE)
Lithological Description: In Exeter and Newton Abbot districts: predominantly brown horizontally-bedded gravel with subordinate lenticular beds of trough cross-bedded pebbly sand and sand. The gravel is composed of well-rounded pebbles, cobbles and boulders in a coarse to fine gravel and silty sand matrix. The clasts are mainly (84 to 90%) metaquartzite together with porphyry, vein quartz, tourmalinite, and feldspathic conglomerate. From just south of Hillhead (ST 067 136), locally derived Devonian and Carboniferous clasts begin to appear. Near Milverton, the Formation is massive calcareous conglomerate with limestone clasts.
Definition of Lower Boundary: Rests sharply with marked lithological contrast on Aylesbeare Mudstone Group. Probable disconformity at the contact.
Definition of Upper Boundary: Ventifact bed at top of the formation is present from Budleigh Salterton to Hillhead: it is overlain by sands or pebbly sands of the Otter Sandstone.
Thickness: Budleigh Salterton: 30m. Exeter district: 15-20m. Hillhead: 24m. Taunton district: 30-35m.
Geographical Limits: Extends from Budleigh Salterton on south Devon coast to near Minehead on north Somerset coast.
Parent Unit: none recorded or not applicable
Previous Name(s): PEBBLE BEDS
BUDLEIGH SALTERTON PEBBLE BED
BUDLEIGH SALTERTON CONGLOMERATE
BUDLEIGH SALTERTON PEBBLE BEDS (BSP)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Sea-cliff at Budleigh Salterton. Whole thickness visible but base may be obscured by landslip. Sharp base on Littleham Mudstone. Ventifact bed at top of formation overlain by aeolian sands at base of Otter Sandstone. 
Reference(s):
Henson, M R, 1971. The Permo-Triassic rocks of south Devon. Unpublished PhD Thesis, University of Exeter. 
Selwood, E B, Edwards, R A, Simpson, S, Chesher, J A, Hamblin, R J O, Hanson, M R, Riddolls, B W and Waters, R A. 1984. Geology of the countryside around Newton Abbot. Memoir of the British Geological Survey, Sheet 339. 
Ussher, W A E, 1902. The Geology of the country around Exeter. Memoir of the Geological Survey of Great Britain, Sheet 325. (England and Wales). 
Irving, A, 1888. The red rock series of the Devon coast section. QuarterlyJournal of the Geological Society of London, Vol.44, p.149-163. 
Hull, E, 1891. A comparison of the red rocks of the south Devon coast with those of the Midland and Western counties. Quarterly Journal of the Geological Society of London, Vol.48, p.60-67. 
Laming, D J C, 1968. New Red Sandstone stratigraphy in Devon and West Somerset. Proceedings of the Ussher Society, Vol.2, p.23-25. 
Smith, S A and Edwards, R A, 1991. Regional sedimentological variations in lower Triassic fluvial conglomerates (Budleigh Salterton Pebble Beds), southwest England: some implications for palaeogeography and basin evolution. Geological Journal, Vol.26, p.65-83 
Lithology of the Sherwood Sandstone Group of England, Wales and south west Scotland. British Geological Survey Research Report RR/14/01. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E339 E310 E311 E326 E340