The BGS Lexicon of Named Rock Units — Result Details

Allargue Graphitic Schist Member

Computer Code: ALGS Preferred Map Code: SYMB
Status Code: Full
Age range: Neoproterozoic Era (AZ) — Neoproterozoic Era (AZ)
Lithological Description: Schistose graphitic pelite and subsidiary semipelite. Banded, slaty in parts.
Definition of Lower Boundary: At lower limit of graphitic pelite. Overlying calcareous semipelites and psammites of the Cock Burn Calcarous Schist Formation.
Definition of Upper Boundary: At upper limit of graphitic pelite where it passes into semipelites of the Tornahaish Dark Schist and Limestone Formation.
Thickness: 15 - 90m.
Geographical Limits: Poorly exposed on the valley sides in Upper Donside (around Corgarff and Allargue). Extends southeast approximately along A939 to Upper Fenzie.
Parent Unit: Tornahaish Dark Schist And Limestone Formation (TDSL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Partial Type Section  Quarry 250m WNW of Allargue Arms Hotel. 
Memoir of the British Geological Survey, Sheet 75, in preparation. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: