Author: Samuel Franklin Emmons

Publisher: Forgotten Books

Published: 2018-02-10

Total Pages: 122

ISBN-13: 9780656232437

Excerpt from Geological Sketches of the Precious Metal Deposits of the Western United States Cinnabar does not occur in well-marked veins, but generally in irregular bodies distributed through the rock. In the New Almaden mine, which has been much more extensively worked than any other in the state, these bodies appear, from a model constructed by the owners, to lie on a curved surface, indicating a geometrical relation between the positions of the several ore-bodies, though an obscure one. At this mine the masses of ore are usually connected by tiny seams of the same material. There is a strong similarity between this mode of occurrence and that of many lead-ore deposits in limestone, and it may be that the problem of their true character is the same. The quicksilver country north of San Francisco is a volcanic region, while to the south volcanic rocks are subordinate in some localities and wanting in, others. To the south, too, there is no indication of any recent deposition of the ore, while to the north deposition is still actually in progress. No general inference as to the genesis or the age of the deposits can therefore be drawn without further investigation, while the great similarity in the association of minerals suggests a similar origin for most of them. 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.