The BGS Lexicon of Named Rock Units — Result Details

Littleham Mudstone Formation

Computer Code: LMU Preferred Map Code: LMu
Status Code: Full
Age range: Early Triassic Epoch (TE) — Early Triassic Epoch (TE)
Lithological Description: Reddish brown silty mudstone with sporadic thin (< 0.6m) beds of silt and silty sand. Sporadic gypsum present in Venn Ottery Borehole (SY 0659 9111) - not seen at outcrop.
Definition of Lower Boundary: Rests on lenticular sandstone developed at the top of the underlying Exmouth Mudstone and Sandstone Formation.
Definition of Upper Boundary: Sharply overlain by the Budleigh Salterton Pebble Beds.
Thickness: c.200m in Exeter district. 275m on coast (Selwood and others, 1984).
Geographical Limits: Extends from south Devon coast between Littleham Cove (SY 040 802) and Budleigh Salterton, northwards through Exeter district to near Aylesbeare. Not recognised as separate formation north of Aylesbeare (SY 030 923). But Littleham Mudstone named from Taunton district by Edmonds and Williams (1985); correlation with the south Devon succession uncertain.
Parent Unit: Aylesbeare Mudstone Group (AYB)
Previous Name(s): Littleham Beds (-2295)
Littleham Mudstones (-2296)
Littleham Formation (-3534)
Alternative Name(s): none recorded or not applicable
Type Section  Sea cliffs between Littleham Cove and Budleigh Salterton. Whole Formation (c. 275m) exposed. 
Selwood, E B, Edwards, R A, Simpson, S, Chesher, J A, Hamblin, R J O, Henson, M R, Riddolls, B W and Waters, R A. 1984. Geology of the countryside around Newton Abbot. Memoir of the British Geological Survey, Sheet 339 (England and Wales). 
Edmonds, E A and Williams, B J, 1985. Geology of the country around Taunton and the Quantock Hills. Memoir of the British Geological Survey, Sheet 295. (England and Wales). 
Laming, D J C, 1968. New Red Sandstone stratigraphy in Devon and West Somerset. Proceedings of the Ussher Society, Vol.2, p.23-25. 
Henson, M R, 1971. The Permo-Triassic rocks of south Devon. Unpublished PhD Thesis, University of Exeter. 
Henson, M R, 1970. The Triassic rocks of south Devon. Proceedings of the Ussher Society, Vol.2, p.172-177. 
Henson, M R, 1972. The form of the Permo-Triassic Basin in south-east Devon. Proceedings of the Ussher Society, Vol.3, p.447-457. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: