The BGS Lexicon of Named Rock Units — Result Details

Pinbain Lava Formation

Computer Code: PIN Preferred Map Code: PIN
Status Code: Full
Age range: Arenig Series (OR) — Arenig Series (OR)
Lithological Description: Thick, massive and pillowed, porphyritic and aphric basalt lavas, partly brecciated. Rare beds of lithic arenite, siltstone, mudstone and polymict basalt lava breccia.
Definition of Lower Boundary: Succeeds and locally interdigitates with Kilranny Hill Formation (KRY). Distinguished by incoming lava facies.
Definition of Upper Boundary: Succeeded by Slockenray Hyaloclastite and Lava Formation (SLO). Distinguised by incoming of hyalocastite and basalt lava with large bladed plagioclase phenocrysts.
Thickness: c.475m
Geographical Limits: Area between Girvan and Ballantrae, southwest Scotland.
Parent Unit: Balcreuchan Group (BCN)
Previous Name(s): Pinbain Formation (-451)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Pinbain Hill, 2.5km northeast of Lendalfoot. 
Reference(s):
Ingham, J K. 2000. In Fortey, R A, Harper, D A T, Ingham, J K, Owen, A W, Parkes, M A, Rushton, A W A and Woodcock, N H. 2000. A revised correlation of Ordovician rocks in the British Isles. Geological Society Special Report, No.24. 
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.] 
Bluck, B J, 1982. Hyalotuff deltaic deposit in the Ballantrae Ophiolite of SW Scotland: evidence for the crustal position of the lava sequence. Transactions of the Royal Society of Edinburgh: Earth Sciences, Vol.72 (for 1981), 217-228. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S007