The BGS Lexicon of Named Rock Units — Result Details

Middle Border Group [Obsolete Name And Code: Use FELL]

Computer Code: MBO Preferred Map Code: notEntered
Status Code: Index Level
Age range: Chadian Substage (CI) — Holkerian Substage (CQ)
Lithological Description: Interbedded sandstone, siltstone and mudstone with thin limestones (cementstones) below; mainly sandstone above. Marine faunal bands in places; local volcanic beds.
Definition of Lower Boundary: At base of Harden Beds (Langholm) or the Whitberry Band (Bewcastle).
Definition of Upper Boundary: Conformable upward passage to Upper Border Group; at base of Glencartholm Volcanic Beds (Langholm) or at base of Clattering Band (Bewcastle).
Thickness: 550m
Geographical Limits: Langholm and Bewcastle areas of Northumberland Trough.
Parent Unit: Not Entered (?)
Previous Name(s): Border Group, Middle [Obsolete Code: Use MBO] (-4783)
Alternative Name(s): Border Group
Fell Sandstone Group
Stratotypes:
Type Area  Langholm district (Lumsden and others, 1967). 
Reference(s):
Day, J B W and others, 1970. Geology of the neighbourhood around Bewcastle. Memoir of the British Geological Survey, Sheet 12. (England and Wales). 
Lumsden G I, Tulloch W, Howells M F and Davies A. 1967. The geology of the neighbourhood of Langholm. Memoir of the Geological Survey, Sheet 11 (Scotland). 
George, T N, Johnson, G A L, Mitchell, M, Prentice, J E, Ramsbottam, W H C, Sevastopulo, G D and Wilson, R B. 1976. A correlation of the Dinantian rocks of the British Isles. Special Report of the Geological Society of London, No 7. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable