The BGS Lexicon of Named Rock Units — Result Details

Mains Hill Agglomerate Formation

Computer Code: MHF Preferred Map Code: MHF
Status Code: Full
Age range: Tremadoc Series (O1) — Arenig Series (OR)
Lithological Description: Volcanic agglomerate with subordinate tuff and chert. The volcanic lava clasts are remarkable in containing large and abundant phenocrysts of clinopyroxene and plagioclase, with some olivine.
Definition of Lower Boundary: Not seen: cut out by the Stinchar Valley Fault.
Definition of Upper Boundary: Not seen: faulted against serpentinite of the Ballantrae Ophiolite Complex.
Thickness: At least 500m
Geographical Limits: Ballantrae area, Ayrshire, southwest Scotland.
Parent Unit: Balcreuchan Group (BCN)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Area  Crags and roches moutonnees on the hillside between Ballantrae Castle and the summit of Mains Hill. Stone and Smellie, 1988. 
Stone, P and Smellie, J L, 1988. Classical areas of British Geology: The Ballantrae area: a description of the solid geology of parts of 1:25 000 sheets NX 08, 18 and 19. [London: HMSO for British Geological Survey.] 
Thirlwall, M F and Bluck, B J, 1984. Sr-Nd isotope and geological evidence that the Ballantrae "ophiolite", SW Scotland, is polygenetic. 215-230 in Gass, I G, Lippard, S J and Shelton, A W (editors), Opiolites and oceanic lithosphere. Special Publication of the Geological Society of London, No.13. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: