IV.—Albite-Granophyre and Quartz-Poephyby from Brandy Gill, Carrock Fell

In the course of an investigation into British resources of sands and rocks for glass-making and refractory purposes, which is being carried out by my colleague Dr. P. G. H. Boswell, it became desirable to search for an alumina-bearing siliceous rock low in iron-content. Among other rocks considered by Dr. Boswell was the granophyre of Brandy Gill, and a sample, obtained from Mr. W. Hemingway, was submitted to Dr. H. F. Harwood for analysis. So far as industry is concerned, the analysis indicates that the iron-percentage of the rock is too high for its use in glass manufacture. As such an analysis would be of interest and value to geologists—there being few first-class analyses of Lake District igneous rocks—and as it seemed undesirable that only a bare record should occur in a technological publication, Dr. Boswell handed to me the analysis and a sample of the granophyre, with the suggestion that the rock might be described in the pages of the Geological Magazine.