The BGS Lexicon of Named Rock Units — Result Details

Lower Coldwell Beds [Obsolete Name And Code: See BKR]

Computer Code: LCW Preferred Map Code: LCw
Status Code: Pending Upgrade
Age range: Homerian Age (SH) — Homerian Age (SH)
Lithological Description: The type area west of Windermere consists of a sequence of thickly bedded, fine-grained sandstones with subordinate, muddy siltstones; the thick sandstones wedge out east of Windermere and show a lateral transition into a facies with a characteristic "striped" appearance consisting of laminae (0.5 mm to 15 mm) and beds of coarse-grained silt in blue-grey silty mudstone of the Brathay Flags type lithology.
Definition of Lower Boundary: Taken at base of lowest sandstone bed or of "striped facies" above the Brathay Flag Formation.
Definition of Upper Boundary: Taken at the incoming of calcareous siltstones of the Middle Coldwell Beds.
Thickness: c.200m at the type section, thins eastwards to less than 10m.
Geographical Limits: Not defined.
Parent Unit: Windermere Supergroup (WIN)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  North-west of Coldwell Quarry, Hawkshead, Cumbria, lower boundary well seen at High Cross Plantation, Sheet 38 (Ambleside). 
Reference(s):
Marr, J E. 1878. On some well defined Life Zones in the lower part of the Silurian (Sedgwick) of the Lake District. Quarterly Journal of the Geological Society, Vol.34, p.871-885. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E039