The BGS Lexicon of Named Rock Units — Result Details

Bark Butts Silts Member

Computer Code: BBSI Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Interbedded clayey silt, sandy silt and silty sand with thin horizontal lamination and upward-fining varved interlamination towards its base.
Definition of Lower Boundary: At its type site, the Bark Butts Silts Member rests with an erosional contact on matrix-rich poorly sorted gravel of Lake District provenance (probably a cobbly upper facies of the Scale Beck Till Member).
Definition of Upper Boundary: At its type site the Bark Butts Silts Member is overlain by the erosional base of the Whin Grit Gravel Member.
Thickness: 1.9m
Geographical Limits: West Cumbria, typically within Blengdale.
Parent Unit: Blengdale Glacigenic Formation (BLGL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Face and BGS trial pit NY00NE CA705 in the lower part of small gravel pit at Bark Butts in the valley of the River Bleng, c.3km upstream (northnortheast) of Gosforth, Cumbria. Nirex Science Report SA/97/045 (Issue 2.0). 1997. 
Reference(s):
Merritt, J W and Auton, C A. 1997. Quaternary lithostratigraphy of the Sellafield district. Nirex Science Report SA/97/045 (Issue 2.0). [Report prepared for UK Nirex Ltd. 69pp, 5 tables, 20 figures, 14 enclosures and one appendix.] 
Merrit, J W and Auton, C A. 2000. An outline of the lithostratigraphy and depositional history of Quaternary deposits in the Sellafield district, west Cumbria. Proceedings of the Yorkshire Geological Society, Vol.53, 129-154 
Merritt, J W, Auton, C A, Browne, M A E, Neilson, G and McMillan, A A. 1995. Characterisation of the onshore Quaternary deposits around Sellafield, Cumbria, Phase II. Nirex Science Report 768. 
Trotter, F M, Hollingworth, S E, Eastwood T and Rose, W C C. 1937. Gosforth District. Geological Survey Memoir, England and Wales, Sheet 37. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable