The BGS Lexicon of Named Rock Units — Result Details

Shellesder Member

Computer Code: SHDER Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Triassic Period (T) — Triassic Period (T)
Lithological Description: Basal member of the Monadh Dubh Sandstone Formation, exposed as a thin alluvial fan infilling Torridonian topography. The Member commences with cornstones, overlain by extensive Torridonian-clast-rich conglomerates and laterally discontinuous interbedded sandstones. Not shown on 50K maps.
Definition of Lower Boundary: Unconformable base on Torridonian sandstone (quartzite).
Definition of Upper Boundary: Contact overlain by 'red beds' of the Sgaorishal Member.
Thickness: 16m
Geographical Limits: Sea of the Hebrides Basin/Isle of Rum.
Parent Unit: Monadh Dubh Sandstone Formation (MODS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Glen Shellesder, northwest Rum. Emeleus, 1997. 
Steel, R J. 1974. New Red Sandstone piedmont and floodplain sedimentation in the Hebridean province, Scotland. Journal of Sedimentary Petrology, Vol.44, 336-357. 
Emeleus, C H. 1997. Geology of Rum and the adjacent islands. Memoir (sheet) of the Geological Survey of Great Britain (Scotland) (60). (The Stationery Office for the British Geological Survey.) 171pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: