The Deposits of the Useful Minerals Rocks, Vol. 2

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Excerpt from The Deposits of the Useful Minerals Rocks, Vol. 2: Their Origin, Form, and Content I have gratefully to acknowledge the several helpful reviews upon Vol. I. Of this translation. It has been suggested 1 that it would have been better not to have used eruptive as synonymous with igneous, but rather with volcanic. That is a suggestion which many would urge. The authors, however, whose views I am representing, actually use eruptive. Moreover, this term, in association with sedimentary as counterpart, is common among both British and American authorities. Geikie, for instance, in his text-book of Geology' gives eruptive undoubted preference over igneous, and, accord ing to him, 2 the eruptive rocks include both the plutonic and the volcanic. It appeared to me also that in, discussing ore-deposits the term eruptive assisted in conveying the idea of the part played by material coming upwards through the crust. The term sedimentary, its counter part, similarly conveyed the idea of settlement upon the crust. In these two words we therefore have the magmatic and meteoric sources of ore deposits suggested. The term igneous, properly speaking, should have aqueous for counterpart, these two terms suggesting the elements fire and water respectively, a suggestion less pertinent than the one above. F. L. Ransome regrets the confusion in the English and American terms for the principal oxidized zinc ores. To avoid this confusion I have adopted a suggestion by Prof. Cullis, and described these ores as zinc carbonate and zinc hydrosilicate respectively, and the mixture of the two as zinc oxidized ore. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.