The BGS Lexicon of Named Rock Units — Result Details

Dorset Stour Formation

Computer Code: DOST 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 overbank deposits of mottled dark grey and orange organic silt, silty clay and clayey sand, and peat, overlying sand and gravel. Thirteen river terraces are preserved. The river terrace deposits comprise very sandy gravels. The clasts are sub-angular to sub-rounded, poorly sorted, up to 10cm in diameter, dominantly flint, with a little Upper Greensand chert, "sarsen" stone, vein quartz, Jurassic limestone, Chalk, and well-rounded flints from the Palaeogene, in a matrix of clayey sand. Deposits of the higher terraces are cryturbated.
Definition of Lower Boundary: The fluvial deposits rest unconformably on Jurassic, Cretaceous and Palaeogene strata.
Definition of Upper Boundary: Surface.
Thickness: Up to 11m, including up to 4m of alluvial overbank deposits.
Geographical Limits: The catchment of the Dorset Stour and its tributaries.
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 the River Stour, River Allen, Moors River, Uddens Water and their tributaries, from Christchurch to Wincanton. Bristow et al., 1991. 
Reference(s):
Bristow, C R, Freshney, E C and Penn, I E. 1991. Geology of the country around Bournemouth. Memoir for 1:50 000 geological sheet 329 (England and Wales). HMSO, London. 
Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M, Ivimey-Cook, H C, and Taylor, R T. 1995. Geology of the country around Shaftesbury. Memoir of the British Geological Survey, Sheet 313 (England and Wales). 
White, H J O. 1923. The geology of the country south and west of Shaftesbury. Memoir of the Geological Survey of Great Britain, Sheet 313 (England and Wales). 
White, H J O. 1917. Geology of the country around Bournemouth (2nd edition). Memoir of the Geological Survey of Great Britain, Sheet 329 (England and Wales). 
Clarke, M R. 1981. The sand and gravel resources of the country north of Bournemouth, Dorset. Description of parts of 1:25000 Sheets SU00, 10, 20, SZ09, 19 and 29. Mineral Assessment Report of the Institute of Geological Sciences, 51. 
Reid, C. 1902. The geology of the country around Ringwood. Memoir of the Geological Survey of Great Britain, Sheet 314 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E297 E312 E313 E314 E328 E329