The BGS Lexicon of Named Rock Units — Result Details

Poltimore Mudstone Member

Computer Code: POM Preferred Map Code: PM
Status Code: Full
Age range: Permian Period (P) — Permian Period (P)
Lithological Description: Reddish brown mudstone, sandy mudstone and clayey fine-grained sandstone, weathering to clay and clayey sand.
Definition of Lower Boundary: Sharp lower boundary on fine-medium and coarse-grained, locally pebbly, sandstone.
Definition of Upper Boundary: Change from predominantly clayey Poltimore Mudstone to overlying sandstones; marked by pronounced feature.
Thickness: c.15m
Geographical Limits: Outcrop extends from around Poltimore village [SX 966 970], northeastwards to near Hay House, [SX 986 988], Broadclyst.
Parent Unit: Dawlish Sandstone Formation (DAS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Name derived from Poltimore Village (SX 966 970), near Exeter, Devon. Poor exposures around the village. Outcrop mainly determined by augering. 
Reference(s):
Bristow, C R, 1983. Geology of Sheet SX99NE (Broad Clyst, Devon). Geological Report for DOE: Land Use Planning. (Exeter: Institute of Geological Sciences). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable