The BGS Lexicon of Named Rock Units — Result Details

Weaver Valley Formation

Computer Code: WVRVA Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Holocene Epoch (QH)
Lithological Description: Probably silt, sand and clay alluvial deposits grading to gravel at base. River Terraces are composed of gravel or gravelly sand.
Definition of Lower Boundary: Probably unconformable, irregular and in places strongly incised into lithologically variable sediments of the Caledonia or Albion Glacigenic groups or into bedrock.
Definition of Upper Boundary: Ground surface or unconformable below artificial deposits.
Thickness: Highly variable depending on the relative stratigraphical positions of each of the component units. In the major river valley the thickness may vary from between 2 and 5m, but probably does not exceed 10m.
Geographical Limits: Cheshire within the river valley and tributaries of the River Weaver.
Parent Unit: Cheshire - North Wales Catchments Subgroup (CNWCA)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Alluvium and River Terrace deposits of the river valley and tributary valleys of the River Weaver. Thomas in Bowen (1999), 95. 
Reference(s):
Johnson, R H. 1969. A Reconnaissance Survey of some River Terraces in parts of the Mersey and Weaver Catchments. Manchester Literary and Philosophical Society (Memoirs and Proceedings), Vol.112, 1969-1970. 
Evans, W B, Wilson, A A, Taylor, B J and Price, D. 1968. Geology of the country around Macclesfield, Congleton, Crewe and Middlewich. Memoir of the Geological Survey of Great Britain, Sheet 110 (England and Wales). 
Thomas, G S P. 1999. Northern England. 91-98 in Bowen, D Q (Editor), A revised correlation of Quaternary and Neogene deposits in the British Isles. Geological Society Special Report No.23. 
McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable