A PDF of this report is available from the NORA, the NERC archive Barron, H F, Gillespie, M R and Merritt, J W 2011. Geodiversity of the Cairngorms National Park. British Geological Survey Open Report, OR/10/019

Site no.: B16

Site name: Blargie Craig

Grid reference: [NN 59683 95043]

Locality: ~2 km WNW of Laggan, the site extends from Coull Farm north-eastwards for about 3 km to Gergask Craig.

GCR Status: Confirmed

GCR No.: 2704

Type: Natural exposures

Description: Scattered exposures in SE-facing crags and small cliffs rising to 750 metres, including key sections at Blargie Craig and Coull Farm. The site contains evidence for an unconformity separating Dalradian rocks from an underlying crystalline basement (Glen Banchor Subgroup/ Badenoch Group), and excellent examples of key lithologies on either side of the unconformity. The site also contains good evidence for major stratigraphical omission (>5 km of Grampian Group strata) across an unconformity between Appin Group strata and Glen Banchor strata. The GCR volume 'Dalradian rocks of Scotland' (Stephenson et al., 2010) contains a full description of the site.

Justification: The evidence preserved at this site for a major break in Dalradian sedimentation is critical in elucidating the geometry of Dalradian sedimentary basins in the Northern Grampian Highlands, and their subsequent deformation during the Caledonian Orogeny. The site also preserves features of a major zone of high ductile strain, the Grampian Shear Zone, in the Glen Banchor strata.

References