The BGS Lexicon of Named Rock Units — Result Details

Murton Formation

Computer Code: MUTN Preferred Map Code: MuF
Status Code: Full
Age range: Arenig Series (OR) — Arenig Series (OR)
Lithological Description: Pale to dark grey siltstones with subordinate, interbedded, pale grey sandstone. Many exposures show complex polyphase folding with abundant sheared folds and shear planes suggestive of slumping. The sequence is also folded tectonically.
Definition of Lower Boundary: Not exposed.
Definition of Upper Boundary: The upper contact with the Kirkland Formation is faulted.
Thickness: Not known because neither base nor top of the Formation is exposed.
Geographical Limits: Occurs within the Cross Fell inlier as a narrow strip almost 11km long between Hilton Beck and Knock Ore Gill, bounded to the east by the sub-Carboniferous unconformity and to the west by the Dufton Pike and Swindale Beck faults.
Parent Unit: Skiddaw Group (SKG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  In Murton Beck. Burgess and Holliday (1979). 
Type Area  Glaciated ridge at the foot of High Cup Gill. Burgess and Holliday (1979). 
Reference(s):
Burgess, I C and Wadge, A J. 1974. The geology of the Cross Fell area. Explanation of 1:25 000 Geological Special Sheet comprising parts of sheets NY 53, 62, 63, 64, 71, 72, 73. (London HMSO). 91pp. 
Burgess, I C and Holliday, D W. 1979. Geology of the country around Brough-under-Stainmore. Memoir for 1:50 000 geological sheet 31 and parts of sheets 25 and 30. Geological Survey of Great Britain (England and Wales). [London: HMSO.] 131pp. 
Cooper, A H and Molyneux, S G, 1990. The age and correlation of Skiddaw Group [early Ordovician] sediments in the Cross Fell Inlier [northern England]. Geological Magazine, Vol.127, 147-157. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E026 E031