PREFACE 



This book is written for the student and for the professional 

 geologist. It aims to bring together those facts and principles 

 which lie at the foundation of all our attempts to interpret the his- 

 tory of the earth from the records left in the rocks. Many of 

 these facts have been the common heritage of the rising genera- 

 tion of geologists, but many more have been buried in the litera- 

 ture of the science, especially the works of foreign investigators, 

 and so have generally escaped the attention of the student, though 

 familiar to the specialist. Heretofore there has been no satisfac- 

 tory comprehensive treatise on lithogenesis in the English language, 

 and we have had to rely upon books in the foreign tongue for such 

 summaries. It is the hope of the author that the present work 

 may, in a measure, supply this need. 



The book was begun more than fifteen years ago, and the ma- 

 terial here incorporated has been collected and sifted during this 

 interval. From time to time certain phases of the work have been 

 published, and these in a revised form have been included in the 

 book. The first of these, on Marine Bionomy, appeared in 1899, 

 the latest, on Ancient Deltas, in 1913. Much of the material has, 

 however, not appeared in print before. The principles and data 

 herein treated have for years been considered and discussed in a 

 course of lectures on the "Principles of Geology," given jointly 

 by Professor Berkey and myself at Columbia University. Some 

 of the problems which have taken form during these discussions 

 have been chosen as subjects for more extensive investigations by 

 members of the classes, and the results of a number of these have 

 already appeared in print. 



My own interest in the problems, and especially the principles 

 of Orogenesis and Geodynamics, goes back to the days when, as a 

 student, I listened to the illuminating expositions of that versatile 

 and accomplished exponent of rational geology, Professor William 

 Otis Crosby, at the Massachusetts Institute of Technology. It was 

 at this time also that Alpheus Hyatt and the other eminent natural- 

 ists who foregathered at the fortnightly meetings of the Boston 

 Society of Natural History, discussed the problems of Biogenesis, 

 and evolved the working principles which have since guided the in- 



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