The BGS Lexicon of Named Rock Units — Result Details

Pitmain Semipelite Member

Computer Code: PTMN Preferred Map Code: PT
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Gneissose semipelite with quartzose psammites and micaceous psammites, distinctive garnetiferous calc-silicate bands and pods.
Definition of Lower Boundary: Transitional contact. Quartzose psammites and semipelites at base contrast with underlying striped micaceous psammites / semipelites of the Loch Laggan Psammite Formation.
Definition of Upper Boundary: Transitional contact, marked in places by quartzose psammites and semipelite passing up into overlying micaceous and feldspathic psammites of the Loch Laggan Psammite Formation.
Thickness: 270m in type area.
Geographical Limits: Central Monadhliath Highlands: Speyside, Kingussie - Newtonmore area. Possibly extending southwest to Crubenmore area.
Parent Unit: Loch Laggan Psammite Formation (LLGN)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Raitts Burn, 1 km north of Creag Bheag, Speyside. 
Reference Section  North-eastern flanks and summit areas of Creag Mhor - Creag Dubh. 
Reference Section  Summit area of Creag Bheag 1 km NW of Kingussie. 
none recorded or not applicable
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S074 S064