The BGS Lexicon of Named Rock Units — Result Details

Barras Conglomerate Member

Computer Code: BACO Preferred Map Code: BACO
Status Code: Full
Age range: Lochkovian Age (DO) — Pragian Age (DP)
Lithological Description: A bimodal, clast-supported conglomerate with clasts mainly of lava, with psammite, quartzite, vein-quartz and feldspar porphyry in a coarse-grained lithic sandstone matrix.
Definition of Lower Boundary: A conformable and diachronous passage down and laterally south into the St. John's Knap Sandstone Member, delineated at the point where conglomerate becomes predominant upwards from the underlying formation.
Definition of Upper Boundary: Apparently conformable, probably diachronous, at the base of the lavas of the Montrose Volcanic Formation.
Thickness: From 100 m to 255 m thick.
Geographical Limits: Between Law of Lumgair (NO 8525 8180) and Chapel of Barras (NO 8355 7812).
Parent Unit: Catterline Conglomerate Formation (CATC)
Previous Name(s): JOHNSHAVEN FORMATION
BARRAS CONGLOMERATE FORMATION (BACO)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Catterline Burn, between Brakes of Barras [NO 783 839] and Chapel of Barras [NO 8355 7812]. 
Reference(s):
Carroll, S, 1995a. Geology of the Stonehaven district. British Geological Survey Technical Report No.WA/94/19. 
Carroll, S, 1995b. Geology of the Inverbervie and Catterline district. British Geological Survey Technical Report No.WA/94/20. 
Armstrong, M and Paterson, I B, 1970. The Lower Old Red Sandstone of the Strathmore region. Report of the Institute of Geological Sciences. No.70/12, 23.pp. 
Browne, M A E, Smith, R A and Aitken, A M. 2001. A lithostratigraphical framework for the Devonian (Old Red Sandstone) rocks of Scotland south of a line from Fort William to Aberdeen. Version 3. British Geological Survey Research Report RR/01/04. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S067