The BGS Lexicon of Named Rock Units — Result Details

Arnbath Psammite Formation

Computer Code: ARPS Preferred Map Code: ArPs
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Medium- to thickly-bedded psammite and semipelite; coastal section contains a basal quartzite member; elsewhere locally contains units of 'boulder bed', a metadiamicton with sparse cobble clasts of granitic and metasedimentary rocks.
Definition of Lower Boundary: Base faulted out in coast section; elsewhere rapid transition is inferred from graphitic semipelites and limestones of Fordyce Limestone Formation.
Definition of Upper Boundary: Change from interbedded psammite and semipelite to thick-bedded quartzite.
Thickness: Increases from c.75m at Newton [542 619] to c.200m at coast, where it is partly repeated by a ductile thrust of the Keith Shear Zone.
Geographical Limits: Coast section from Red Haven to 150m southeast of Foul Hole [NJ 563 663-579 666]; extends southwards as far as Newpark [NJ 530 606].
Parent Unit: Islay Subgroup (DBIS)
Alternative Name(s): none recorded or not applicable
Type Section  Coastal section from to Red Haven to 150m south-east of Foul Hole. 
Harris, A L, Haselock, P J, Kennedy, M J and Mendum, J R, 1994. The Dalradian Supergroup in Scotland, Shetland and Ireland. 33-53 in Gibbons, W E and Harris, A L (editors). A revised correlation of Precambrian rocks in the British Isles. Special Report of the Geological Society, London, No.22. 
Spencer, A M and Pitcher, W S, 1968. Occurrence of the Portaskaig Tillite in north-east Scotland. Proceedings of the Geological Society of London, No.1650, 195-198. 
Read, H H, 1923. Geology of the country around Banff, Huntly and Turriff, Lower Banffshire and north-west Aberdeenshire. Memoir of the Geological Survey, Scotland Sheets 86 and 96 (Scotland). 
Stephenson, D, et al, 1993. Stratigraphy and correlation of the Dalradian rocks of the East Grampian Project area. British Geological Survey Technical Report WA/93/91. 
Stephenson, D and Gould, D , 1995. British Regional Geology: the Grampian Highlands (4th edition). (London: HMSO for the British Geological Survey), 67-68. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: