Eilean Chlamail - Camas nan Ceann

Also within

Ross and Cromarty County Knoydart Scenic Area

Condition (NatureScot)

Geology & landscape

Rock Type: Gneiss

Description

EILEAN CHLAMAIL – CAMAS NAN CEANN Eilean Chlamail – Camas nan Ceann Site of Special Scientific Interest (SSSI) lies on the south west shore of the Glenelg peninsula from where it overlooks the mouth of Loch Hourn. Exposures of an area of rock called the Glenelg Inlier are found here. The Glenelg Inlier is termed ‘basement’, as its gneiss rocks are the most ancient and most highly altered by heat and pressure (metamorphosed) in the area. The differing gneisses on either side of a major zone of shearing are termed the Eastern and Western Units. This SSSI contains an excellent, almost continuous section across the Western Unit. The Western Unit of the Glenelg Inlier is exceptionally important for investigating the history of the basement rocks before about 1 billion years ago. This is because it was relatively little affected by later deformation. The site provides clear evidence of the following sequence of events: the oldest parts of the inlier (formed from cooled molten rock) were intruded by granodiorite, then by basic dykes and sheets; the rocks were then highly metamorphosed, with partial melting forming pegmatite veins; a second series of basic dykes were intruded at a later stage. The timing of these events is crucial to establishing whether the Western Unit has a different tectonic history from the Lewisian basement gneisses that occur further west and north. Thus the site is nationally important for understanding how the ancient continental crust of northern Scotland evolved.