Rocks and Their Origins

The Cambridge Manuals of Science and Literature
ROCKS AND THEIR ORIGINS
CAMBRIDGE UNIVERSITY PRESS London: FETTER LANE, E.C. C. F. CLAY, Manager
Edinburgh: 100, PRINCES STREET London: WILLIAM WESLEY & SON, 28, ESSEX STREET, STRAND Berlin: A. ASHER AND CO. Leipzig: F. A. BROCKHAUS New York: G. P. PUTNAM'S SONS Bombay and Calcutta: MACMILLAN AND CO., Ltd.
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ROCKS AND THEIR ORIGINS BY GRENVILLE A. J. COLE Professor of Geology in the Royal College of Science for Ireland Cambridge: at the University Press 1912
Cambridge: PRINTED BY JOHN CLAY, M.A. AT THE UNIVERSITY PRESS
With the exception of the coat of arms at the foot, the design on the title page is a reproduction of one used by the earliest known Cambridge printer, John Siberch, 1521
This little book is intended for those who are not specialists in geology, and it may perhaps be accepted as a contribution for the general reader. To all who are interested in the earth, the study of rocks is an important branch of natural history. If detailed works on petrology are to be consulted later, F. W. Clarke's Data of Geochemistry (Bulletin, U.S. Geological Survey, ed. 2, 1911) must on no account be overlooked. Its numerous references to published papers, and the attention given to rock-origins, make it a worthy companion to C. Doelter's Petrogenesis . Many things have perforce been omitted from the present essay. It seemed unnecessary to review the Carbonaceous rocks, since the most important of these have been admirably dealt with in E. A. N. Arber's Natural History of Coal , published as a volume in this series. I should like to have described occurrences of rock-salt, of massive gypsum, and other products of arid lands, where black alkali poisons the surface, and the casual pools are fringed with white and crumbling crusts. Rock-taluses, and all the varied alluvium carried seaward as the outwash of continental land, well deserve a chapter to themselves. But there is really no end to the subject, which embraces all the accumulative processes of the earth. A few vacation-journeys, judiciously planned out, teach us that text-books are merely signposts to set us on what is believed to be the way. When the path enters the great forest, or rises above green lakelets to the crags, we find there those who went before us, pointing to unconquered lands.