The BGS Lexicon of Named Rock Units — Result Details

Middle Limestone Formation

Computer Code: MLG Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Brigantian Substage (CX) — Brigantian Substage (CX)
Lithological Description: Limestones, sandstones, shales and coals. Fossiliferous.
Definition of Lower Boundary: Drawn at the base of the Oxford Limestone Member where it rests conformably upon the Crosshill Limestones Member. Boundary defined on palaeontological grounds only.
Definition of Upper Boundary: Drawn at the conformable upward passage of the Middle Limestone Group with the base of the Great Limestone.
Thickness: Not known.
Geographical Limits: Northumberland.
Parent Unit: Not Entered (?)
Previous Name(s): Middle Limestone Group (*600)
Upper Bernician (-397)
Alternative Name(s): Upper Liddesdale Group
Stratotypes:
Type Area  Berwick-On-Tweed. 
Reference(s):
Smith, S, 1910. The Faunal Succession of the Upper Bernician. Transactions of the Natural History Society, Northumberland, Durham and Newcastle, Vol.3, p.595. 
Fowler, A. 1926. The geology of Berwick-upon-Tweed. Norham and Scremerston. Memoir of the Geological Survey of Great Britain. (London: HMSO.) 
Westoll, T S and others, 1955. A Guide to the geology of the district around Alnwick, Northumberland. Proceedings of the Yorkshire Geological Society, Vol.30, p.77. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E004 E006 E008 E019 E025 E001 E002 E018