III.—Chromite in Beer Stone

Extract

The Beer Stone is a gritty limestone, made up largely of shell fragments with some foraminifera, quartz grains, and 6oft chalky material, occurring in the Rhynchonella Cuvieri zone of the Middle Chalk near Beer Head in the south-east of Devon. It has long been worked for building purposes in underground galleries about one mile west of the village of Beer, and has been described by W. Hill and W. F. Hume in the Geological Survey memoir on the Lower and Middle Chalk. Dr. Hume records the following minerals as present in the insoluble residue of the stone: quartz, muscovite, glauconite, chalcedony, pyrites, tourmaline, rutile, andalusite, and possibly anatase. A. J. Jukes-Browne says the residue “contains a variety of minerals which have clearly been derived from land consisting of granite and Palaeozoic rocks such as occur in South Devon and Cornwall”.