Mineral Analyses of Some Ordovician Rocks from Carnarvonshire

Abstract

Very little work seems to have been done on the petrology of the rarer constituents of the older Palaeozoic sediments and their associated igneous rocks, partly no doubt on account of the extra amount of work entailed in crushing these extremely hard compact rocks, and partly owing to the comparative paucity of the “heavy” residues obtained, which give small reward for the energy expended. Such work, however, is highly important as indicating further sources of supply, to which workers on the petrology of the newer rocks may look, and it may be here emphasized that Wales has unfortunately suffered neglect in this respect. It is to help remedy this defect that the present paper is put forward.