Computer Code: |
MBO |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Chadian Substage (CI)
— Holkerian Substage (CQ) |
Lithological Description: |
[Obsolete: use FELL] Interbedded sandstone, siltstone and mudstone with thin limestones (cementstones) below; mainly sandstone above. Marine faunal bands in places; local volcanic beds.
Obsolete term Middle Border Group is replaced by Fell Sandstone Formation, Lumsden et al, 1968; Day, 1970. |
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: |
550 m. |
Geographical Limits: |
Langholm and Bewcastle areas of Northumberland Trough. |
Parent Unit: |
none recorded or not applicable
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
none recorded or not applicable
|
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 |