The BGS Lexicon of Named Rock Units — Result Details

Ross Sand Member

Computer Code: RSSA Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: The lithological association consists of flat and ripple-laminated medium- to fine-grained sand with laminae and thin bands of silt. It is moderately dense. Sedimentary structures were formerly visible at Ferniegair Gravel Pit [NS 734 543] and at Bothwell [NS 708 589]. At Ferniegair the dominant structures were large-scale trough cross-bedding in sands and gravelly sands and horizontal bedding in finer sands. At Bothwell, the sedimentary structures were largely horizontal lamination and ripple lamination. The climbing ripples preserved rose southwards (sediment transport up the Clyde valley). Thin beds of reddish brown silty clay were also present. The sedimentological features of the Member are consistent with deposition by glaciodeltaic processes. At Ferniegair, the Avon was probably building a lateral delta into the ice-dammed "Lake Clydesdale". It also seems likely that the Bothwell deposit was deltaic, with the interfingering bands of laminated clay passing laterally southwards into the Bellshill Clay Member.
Definition of Lower Boundary: Uncomformity on bedrock or more commonly on older Quaternary strata, particularly the Wilderness Till Formation of the Midland Valley Glacigenic Subgroup. Conformably with the Bellshill Clay Member.
Definition of Upper Boundary: Unconformity below younger Quaternary strata such as the Clyde Clay Formation but also exposed at the surface. Locally passes conformably laterally and upwards with the Bellshill Clay Member.
Thickness: Veneer to about 20m.
Geographical Limits: Central Scotland; Glasgow area in the lower Clyde valley below Lanark and in tributary valleys.
Parent Unit: Broomhouse Sand And Gravel Formation (BHSE)
Previous Name(s): Ross Sand Formation (-1149)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Lower Clyde valley between Baillieston and Crossford. 
Reference(s):
Hall, I H S, Browne, M A E and Forsyth, I H. 1998. Geology of the Glasgow district. Memoir of the British Geological Survey, Sheet 30E (Scotland). 
Paterson, I B, McAdam, A D and MacPherson, K A T. 1998. Geology of the Hamilton district. Memoir of the British Geological Survey, Sheet 23W (Scotland). 
Forsyth, I H, Hall, I H S and McMillan, A A. 1996. Geology of the Aidrie district. Memoir of the British Geological Survey, Sheet 31W (Scotland). 
Browne, M A E and McMillan, A A. 1989b. Geology for land use planning: drift deposits of the Clyde valley Volume 1: Planning Report. British Geological Survey Technical Report, WA/89/78. 
Browne, M A E and McMillan, A A. 1989a. Quaternary geology of the Clyde valley. British Geological Survey Research Report, SA/89/1. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S023 S030 S031