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 A PDF of this report is available from the NORA, the NERC archive

Site no.: B12

Site name: Lower Glen Gairn

Grid reference: [NO 32244 99783]

Locality: Ground around West Milton Burn and Hill of Candacraig

GCR Status: N/A

GCR No.: N/A

Type: Natural exposures

Description: The ground is underlain by part of the Coilacreich Granite Pluton, scattered exposures of which contain unusual minerals and mineral associations associated with geochemically highly evolved magma and hydrothermal alteration. A ferrous lithium mica forms up to 20% of the rock locally.

Greisen (strongly hydrothermally altered rock) with associated quartz veins occurs in ground around West Milton Burn and south towards Creag na Creiche. Unusual minerals associated with the alteration include topaz, fluorite and blue beryl.

Justification: The style of granite alteration (greisenisation) and the assemblage of minerals are unique to the CNP and rare in Britain.

References