V.—The Ore-bearing Pegmatites of Carrock Fell, and the Genetic Significance of Tungsten-ores

The wolfram veins in the Grainsgill greisen, near Carrock Fell, are an example of ore-bearing pegmatites, a vein-type uncommon in the British Isles, and one, moreover, the study of which is of much interest in its relation to ore-genesis. The veins have long been known, and intermittently exploited for tungsten-ore, but their economic prospects are not bright. Of previous workers, Mr. Alfred Harker has described the greisen which carries the veins, while the various mineral occurrences have been recorded by Mr. J. G. Goodchild and others.