The BGS Lexicon of Named Rock Units — Result Details

Keith Limestone Formation

Computer Code: KTHL Preferred Map Code: symb
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Mostly semipelite with thick beds of metalimestone and thinner impure metalimestone, calc-silicate rock and quartzite.
Definition of Lower Boundary: Bounded by lowest thrust plane in the Keith Shear-zone, normally marked by a sheet of highly sheared, gneissose metagranite.
Definition of Upper Boundary: Highest thrust plane in the Keith Shear-zone, normally marked by a sheet of highly sheared metagranite.
Thickness: Maximum seen 300 m, but this is attenuated by shearing.
Geographical Limits: Entirely within the Keith Shear-zone between Blackhill Wood (NJ 403 490) and Clochmacreich (NJ 493 582), Keith, Banffshire. Also between Rosarie (NJ 380 501) and Hillockhead (NJ 400 497)
Parent Unit: Appin Group (APP)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  River Isla at Union Bridge (NJ4288 5083); continuing along railway cutting in Old Keith between Union Bridge (NJ 4285 5074) and Cuthill Quarry (NJ 4260 5035); then along track between Cuthill Quarry (NJ 4260 5032) and Brandy Pool (NJ 4252 4963). 
Reference Section  British Geological Survey Rosarie Borehole, Rosarie Quarry, 4 km west of Keith. 0.9 m to 72.1 m (base, possibly faulted). 
Reference(s):
Sheet Explanation Scotland Sheet 85. (In preparation) 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S085 S086