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). This area also covered by several boreholes from the Keith Bypass investigation (SE 12866) 
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