The BGS Lexicon of Named Rock Units — Result Details

Allt Nam Biorag Psammite Member

Computer Code: ABIP Preferred Map Code: notEntered
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Feldspathic and quartzose psammites with some interbanded calc-silicates and semipelite units up to 0.5m thick; some cross-bedding seen.
Definition of Lower Boundary: Top of the Creag na Sanais Semipelite Formation, where the predominant semipelite is overlain by predominantly feldspathic and quartzose psammites of the Allt nam Biorag Member
Definition of Upper Boundary: Incoming of the grey psammites of the typical Fara Psammite Formation, above the feldspathic and quartzose psammites, with or without calc-silicates, and semipelites of the Allt nam Biorag Member.
Thickness: c.400m
Geographical Limits: South of Newtonmore, between the Ericht - Laidon and Creag Liath faults
Parent Unit: Gaick Psammite Formation (GCKP)
Previous Name(s): Part of the Moine Psammites [Obsolete Name and Code: Use ABIP, CDHP] (-4416)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Outcrops on the North side of Meall Ruigh nam Biorag. Leslie, A G et al., BGS Internal Report IR/03/048. 
Reference(s):
Leslie, A G, Krabbendam, M and Smith, R A, 2003. Progress Report on the Geology of 1:50 k Sheet 64W (Newtonmore) British Geological Survey Internal Report, IR/03/048. 23pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable