The BGS Lexicon of Named Rock Units — Result Details

Marl Slate Formation

Computer Code: MLSL Preferred Map Code: MSF
Status Code: Full
Age range: Guadalupian Epoch (PUG) — Lopingian Epoch (PUL)
Lithological Description: Laminated, bituminous, silty, argillaceous dolostone with an unusually high concentration of metallic minerals and a distinctive fish fauna.
Definition of Lower Boundary: Sharp, unconformable contact on either the aeolian Yellow Sands Formation or on Carboniferous, usually Coal Measures, strata: represents a rapid marine transgression with the incoming of marine, bituminous, silty, argillaceous dolostone.
Definition of Upper Boundary: Taken at the base of the overlying dolostones and limestones of the Raisby Formation in the Durham Province or the equivalent Cadeby Formation in the Yorkshire Province.
Thickness: To 5.48m. (18 ft.) in the Durham Province.
Geographical Limits: Durham and Yorkshire provinces of the English Zechstein. Equivalent to the Kupferschiefer Formation in the North Sea, Dutch and German provinces.
Parent Unit: Zechstein Group (ZG)
Previous Name(s): Marl Slate [Obsolete Name and Code: Use MLSL] (-1067)
Alternative Name(s): Kupferschiefer Formation
Lower Permian Marl
Stratotypes:
Reference Section  Quarrington Hill (Hepplewhites) Quarry, near Durham; exposed in quarry workings that were still active in 1999 (Smith and Francis, 1967). 
Reference Section  Crime Rigg Quarry, Sherburn Hill, near Durham. Exposed in quarry workings that were still active in 1999 (Smith and Francis, 1967). 
Type Section  Thickley Quarry, East Thickley, near Shildon, Co. Durham. "Yellow coloured calcareous shale and marl slate, in thickness about nine feet" (Sedgwick, 1829, p.76; Mills and Hull, 1976, p.137). 
Reference Section  Railway cutting at Ferryhill (Smith and Francis, 1967). 
Reference(s):
Smith, D B, 1995. Marine Permian of England. Geological Conservation Review Series No. 8. [London: Chapman and Hall.] 
Smith, D B, Brunstrom, R G W, Manning, D I, Simpson, S and Shotton, F W. 1974. A correlation of Permian rocks in the British Isles. Geological Society of London Special Report No. 5. 
Smith, D B and Francis, E A. 1967. Geology of the country between Durham and West Hartlepool. Memoir of the Geological Survey of Great Britain, Sheet 27 (England and Wales). 
Eden, R A, Stevenson, I P and Edwards, M A. 1957. Geology of the area around Sheffield, BGS Memoir (England and Wales). 
Sedgwick, A. 1829. On the geological relations and internal structure of the Magnesian Limestone and the lower portions of the New Red Sandstone Series in their range through Nottinghamshire, Derbyshire, Yorkshire and Durham to the southern extremity of Northumberland. Transactions of the Geological Society of London, Second Series, Vol. 3, p. 37 - 124. 
Deegan, C E and Scull, B J. 1977. A standard lithostratigraphic nomenclature for the Central and Northern North Sea. Report of the Institute of Geological Sciences, 77/25; NPD Bulletin No.1. 
Mills, D A C. and Hull, J H. 1976. Geology of the country around Barnard Castle. Memoir of the Geological Survey of Great Britain. HMSO. 385pp. 
Smith, D B, 1994. Geology of the country around Sunderland. Memoir of the British Geological Survey, Sheet 21, (England and Wales). 
Hirst, D M and Dunham, K C. 1963. Chemistry and Petrology of the Marl Slate of SE Durham, England. Economic Geology Vol. 58, p. 912 - 940. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E043 E015 E021 E026 E027 E032 E033 E042 E052 E061 E062 E070 E078 E055 E065 E080 E081 E090 E091