The BGS Lexicon of Named Rock Units — Result Details

Loch Broom Shell Bed

Computer Code: LBSH Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Very poorly sorted accumulations of shells and shell fragments, with sporadic pebbles, set in a very soft, dark greyish brown (2.5Y 4/2), muddy sandy matrix. Shell concentrations dominated by Chlamys islandica and Arctica islandica, with subordinate Tridonta elliptica.
Definition of Lower Boundary: Unconformable on the Assynt Glacigenic Formation.
Definition of Upper Boundary: In outer Loch Broom, it is unconformably overlain by the Summer Isles Formation; in the inner loch, it is overlain by the Rhiroy Member of the Assynt Glacigenic Formation.
Thickness: 0.64-0.68 m thick.
Geographical Limits: Loch Broom (as presently known)
Parent Unit: Not Entered (?)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  57.9144 deg N, 05.2213 deg W. BGS vibrocore 57-06/269, a 0.68 m-thick bed between 1.0 and 1.68 m below sea bed, outer Loch Broom. Stoker, M S and Bradwell, T. In press. Quaternary geology of the Summer Isles region - a brief explanation of the marine environment map. Sheet Explanation of the British Geological Survey. 1:50 000 Special Sheet Summer Isles (Scotland). 
Reference Section  57.8655 deg N, 05.1063 deg W. BGS vibrocore 57-06/267, between 3.4 and 4.04 m below sea bed, inner Loch Broom. Stoker, M S and Bradwell, T. In press. Quaternary geology of the Summer Isles region - a brief explanation of the marine environment map. Sheet Explanation of the British Geological Survey. 1:50 000 Special Sheet Summer Isles (Scotland). 
Reference(s):
Stoker, M S, Bradwell, T, Howe, J A, Wilkinson, I P & McIntyre, K. 2009. Lateglacial ice-cap dynamics in NW Scotland: evidence from the fjords of the Summer Isles region. Quaternary Science Reviews, 28, 3161-3184. 
Stoker, M S and Bradwell, T. In press. Quaternary geology of the Summer Isles region - a brief explanation of the marine environment map. Sheet Explanation of the British Geological Survey. 1:50 000 Special Sheet Summer Isles (Scotland). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable