The BGS Lexicon of Named Rock Units — Result Details

Main Terrace Deposits (River Severn) [Obsolete Name And Code: See HOHE]

Computer Code: MNT Preferred Map Code: symb
Status Code: Index Level
Age range: Ipswichian Stage (QI) — Devensian Stage (QD)
Lithological Description: Gravel, composed of Triassic derived quartzites, flints, Scottish Lake district erratics; local material including Malvernian Jurassic rocks. It includes a local basal fossil bed of silts and sands.Sand and gravel, locally with lenses of silt, clay or peat. [Generic description].
Definition of Lower Boundary: Where river deposits rest on bedrock, glacial or older terrace deposits.
Definition of Upper Boundary: The present day terrace surface.
Thickness: Up to 10m
Geographical Limits: River Severn Basin from ???? Chepstow to Bridgnorth.
Parent Unit: Not Entered (?)
Previous Name(s): Third Terrace (River Severn) (-1704)
Main Terrace (-1599)
Alternative Name(s): Holt Heat Member
Stratotypes:
Type Section  Gravel Pit, Holt Heath. 
Reference(s):
Wills, L J, 1938. The Pleistocene development of the Severn from Bridgnorth to the Sea. Quarterly Journal of the Geological Society, 94, 161-242. 
Barclay, W J, Ambrose K, Chadwick, R A and Pharaoh, T C. 1997. Geology of the country around Worcester. Memoir of the British Geological Survey, Sheet 199 (England and Wales). 
Dawson, M R. 1989. The Severn valley south of Bridgnorth. 78-100 in Keen, D H (Editor), The Pleistocene of the West Midlands. Field Guide. [Cambridge: Quaternary Research Association.] 
Dawson, M, Bryant, I D, 1987. Three-dimensional facies geometry in Pleistocene outwash sediments, Worcestershire, United Kingdom. International Fluvial Sedimentology Conference, 3rd, 1985,Colorado Recent developments in fluvial sedimentology Tulsa, Society of Economic Palaeontologists and Mineralogists, Special Publication 39, p191-196. 
Maddy, D, Green, C P, Lewis, S G and Bowen, D Q. 1995. Pleistocene Geology of the lower Severn Valley, UK. Quaternary Science Reviews, Vol 14, 209 - 222. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E167 E182 E199 E216 E234 E250