Dolomite Contact Skarns of the Broadford Area, Skye: A Preliminary Note

Extract

The metamorphism of the Durness dolomite horizons in the aureole of the Beinn an Dubhaich granite of Skye has long provided one of the best known examples of dedolomitization and progressive thermal metamorphism of siliceous dolomites recorded in the literature. Harker's study (1904) concerned itself primarily with assemblages regarded as derived without notable accession of material during metamorphism and the occurrence of products of metasomatic origin at the contact of the granite has hitherto received but little notice in print. Yet as long ago as 1897, Geikie had written of this contact: “… the most abundant and interesting deposits are metalliferous. Fragments of a kind of ‘gossan’ may be noticed all along the boundary line of the boss, and among these are pieces of magnetic iron ore and sulphides of iron and copper. The magnetite may be seen in place immediately to the south of Kilbride. A mass of this ore several feet in diameter sends strings and disseminated particles through the surrounding granophyre and is partially coated along its joints with green carbonate of copper” (Geikie, 1897, p. 384). It is of interest to note further that a record of “a mineral resembling humite” from this same contact is made in the Annual Report of the Geological Survey for 1896 (1897).