The BGS Lexicon of Named Rock Units — Result Details

Frome-Piddle Formation

Computer Code: FRPI Preferred Map Code: notEntered
Status Code: Full
Age range: Early Pleistocene Epoch (QPE) — Holocene Epoch (QH)
Lithological Description: Floodplain alluvium and river terrace deposits. The floodplain alluvium comprises clay and silt overbank deposits, with local peat, overlying sand and gravel. The surviving river terrace deposits are largely gravel with interstitial sand. The major pebble lithologies are flint, quartz and Mesozoic chert. The gravel units were deposited by braided rivers under periglacial conditions.
Definition of Lower Boundary: The fluvial deposits rest unconformably on Chalk Group and Palaeogene strata.
Definition of Upper Boundary: Surface.
Thickness: To 20m
Geographical Limits: The catchment of the rivers Frome and Piddle and their tributaries, Dorset, up to OD +125m.
Parent Unit: Solent Catchments Subgroup (SNTCA)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The valleys of rivers Frome and Piddle and their tributaries, in the Wareham-Dorchester area, Dorset. Allen and Gibbard, 1994. 
Reference(s):
Allen, L G and Gibbard, P L. 1994. Pleistocene evolution of the Solent River of Southern England. Quaternary Science Reviews, Vol.12, 503-528. 
Reid, C. 1899. The geology of the country around Dorchester. Memoir of the Geological Survey of Great Britain, Sheet 328 (England and Wales). 
Gibbard, P L and Preece, R C. 1999. South and southeast England. 59-65 in Bowen, D Q (Editor), A revised correlation of Quaternary deposits in the British Isles. [London: The Geological Society.] 
Mathers, S J. 1982. The sand and gravel resources of the country between Dorchester and Wareham, Dorset. Description of parts of 1:25000 Sheets SY68, 69, 78, 79, 88, 89, 98, and 99. Mineral Assessment Report of the Institute of Geological Sciences, 103. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E327 E328 E329