The BGS Lexicon of Named Rock Units — Result Details

Stockport Glacigenic Formation

Computer Code: STPTG Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: A mixed glacigenic sequence of till (sandy, gravelly clay with cobbles and boulders), sand, gravel and laminated clay and silt. Erratics are dominated by Lake District (Borrowdale Volcanic rocks and Eskdale Granite), and Carboniferous derived rock fragments but include Irish Sea derived material in places.
Definition of Lower Boundary: Unconformable and in places heavily incised contact with bedrock.
Definition of Upper Boundary: Either the ground surface or various units of the Britannia Catchments Group or other formations or subgroups of the Caledonia Glacigenic Group.
Thickness: Highly variable from 3m to locally in excess of 100m.
Geographical Limits: Cheshire, Staffordshire and south Lancashire approximately corresponding to the area between the Kirkham Moraine (near Kirkham [SD420 300] ) in the north and the Ellesmere Moraine (Wood Lane Quarry, Ellesmere [SJ 4220 3280] ) in the south.
Parent Unit: Irish Sea Coast Glacigenic Subgroup (ISCG)
Previous Name(s): Upper Boulder Clay (-4662)
Lower Boulder Clay (-2079)
Middle Sands (-4253)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  On the northern bank of the River Mersey. Worsley (1967) and Maddy in Bowen, 1999, p.34. 
Reference(s):
Maddy, D. 1999. English Midlands Chapter 3 in Bowen, D Q (Editor), A revised correlation of the Quaternary deposits in the British Isles. Geological Society Special Report, No.23. 
Worsley, P. 1991. Glacial deposits of the lowlands between the Mersey and Severn rivers. 203-211 in Ehlers, J, Gibbard, P L and Rose, J (editors), Glacial deposits in Great Britain and Ireland. 
Worsley, P. 1967. Problems in naming the Pleistocene deposits of the northeast Cheshire Basin. The Mercian Geologist, Vol.2, 51-54. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable