The BGS Lexicon of Named Rock Units — Result Details

Crosskirk Bay Formation

Computer Code: CKBA Preferred Map Code: notEntered
Status Code: Full
Age range: Givetian Age (DV) — Givetian Age (DV)
Lithological Description: Sandstone-dominated rhythmic cycles of interbedded sandstone, siltstone and calcareous laminite limestone.
Definition of Lower Boundary: Base of lowest medium-grained sandstone unit overlying siltstone-dominated cyclic sequence of the Dounreay Shore Formation.
Definition of Upper Boundary: Highest unit in local stratigraphy. Top not seen.
Thickness: More than 290m
Geographical Limits: Onshore and immediately offshore of the Dounreay area, Caithness, Northern Scotland.
Parent Unit: Caithness Flagstone Group (CNFL)
Previous Name(s): Achreamie Sandstone Formation (-3301)
Crosskirk Flagstone Formation (-3302)
Buldoo Flagstone Formation (-1432)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Brims Ness coastal section, c.7.5km northwest of Thurso, northeast Caithness, Highland Region. 
Partial Type Section  Coastal section from Lower Dounreay [southeast end of Dounreay Nuclear Establishment] to Crosskirk Bay, northeast Caithness. 
Reference(s):
Fletcher, T P and Key, R M. 1991. Solid geology of the Dounreay District. British Geological Survey Technical Report WA/91/35C. 
British Geological Survey. (In preparation, to be published in 2005). Bedrock geology. Scotland Special Sheet (Dounreay).1:25 000. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable