The BGS Lexicon of Named Rock Units — Result Details


Computer Code: ALV Preferred Map Code: notEntered
Status Code: Full
Age range: Quaternary Period (Q) — Quaternary Period (Q)
Lithological Description: Alluvium is a general term for clay, silt, sand and gravel. It is the unconsolidated detrital material deposited by a river, stream or other body of running water as a sorted or semi-sorted sediment in the bed of the stream or on its floodplain or delta, or as a cone or fan at the base of a mountain slope. Synonym: alluvial deposits. Normally soft to firm consolidated, compressible silty clay, but can contain layers of silt, sand, peat and basal gravel. A stronger, desiccated surface zone may be present.
Definition of Lower Boundary: none recorded or not applicable
Definition of Upper Boundary: none recorded or not applicable
Thickness: none recorded or not applicable
Geographical Limits: none recorded or not applicable
Parent Unit: Fluvial deposits (FLUV)
Previous Name(s): Freshwater alluvium [Obsolete Name and Code: Use ALV] (-4655)
Alternative Name(s): none recorded or not applicable
none recorded or not applicable
McMillan, A A, and Powell, J H. 1999. The classification of artificial (man made) ground and natural superficial deposits. British Geological Survey Research Report, RR/99/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E221 S015 S023 E237 E021 S095 S094 S094 E010 E014 E015 S031 E300 E130 E208 E225 E203 E078 E070 E077 E181 E355 E356 E142 E323 E022 E024 E028 E048 E007 S017 S018 S023 S024 S024 S025 S026 E219 E268 E003 S031 S032 S032 S036 S040 S033 S034 E059 S021 E141 S028 S049 S055 S055 S056 S056 S066 S084 S065 S030 S030 S038 S039 S039 S096 S041 S064 S064 S074 S074 S071 S072 S076 S080 S080 S081 S081 S082 S043 S044 S044 S043 S082 S083 S083 S084 S101 S093 S093 S097 S101 S053 S096 S054 S054 S102 S102 S103 S108 S109 S061 S109 S051 S110 S113 S115 S115 S116 S116 S117 S117 S119 S119 S120 S052 S065 S052 S121 S122 S126 S061 S062 S127 S128 E350 E326 E340 E281 E246 E341 E342 E343 E217 E264 E353 E354 E096 E039 E314 E171 N28 E214 E327