Structural geology / Структурная геология

Emphasis in this book has been placed on principles, methods, and technique. The structure of specific areas is not discussed, except for the purpose of illustrating principles. The writer has intentionally refrained from a treatment of the more speculative phases of geotectonics because he believes that such subjects can be intelligently studied only by geologists with a broad background in many fields of geology.

The indecisiveness of some of the criteria used in structural geology may cause dismay to some students. It is better, however, for the reader to realize the difficulties of structural geology and to understand at the outset that such a subject can never be treated with mathematical precision. The structural geologist must be proficient in weighing and balancing the evidence.

The laboratory exercises—many of which can be done outside the laboratory—included at the end of the book were prepared originally by the writer. They gradually evolved into their present form through the efforts of a succession of able assistants, including Randolph W. Chapman, Jarvis B. Hadley, Robert P. Sharp, and Walter S. White. The author's present assistant, George E. Moore, is largely responsible for the descriptive text that accompanies the laboratory problems.

Some instructors may prefer to make extensive use of the Geologic Folios published by the United States Geological Survey. It seemed inadvisable, however, to base the exercises too directly on such folios, because the folios available differ greatly in different institutions. Four of the laboratory problems may be removed from the book and submitted to the instructor.

The writer is indebted to several colleagues who have read and criticized parts of the original manuscript and have given valuable advice that was utilized in the final revision: Professor Francis Birch, Chapters 2 and 19; Professor L. Don Leet, Chapter 19; Professor Robert L. Nichols, Chapter 17. Dr. John Eric read much of the manuscript and made many pertinent suggestions.

The author is indebted to the following for photographs which are reproduced in the book: Dr. Barnum Brown, Dr. W. F. Jenks, Mr. Bradford Washburn, Mr. Herbert Wright, Mr. Donald Everhart, and Dr. Katharine Fowler-Billings. Professor A. K. Lobeck assisted in obtaining some of these pictures. All the figures were drawn by Mr. Edward A. Schmitz.

The following publishers have kindly granted permission to use illustrations, usually modified to some extent: Reinhold Publishing Company, successor to The Chemical Catalog Company, Fig. 1; Geophysics, Fig. 277; McGraw-Hill Book Company, Figs. 107 and 108; American Institute of Mining and Metallurgical Engineers, Fig. 302; American Association of Petroleum Geologists, Figs. 203, 204, 205, 206, 207, 278, 283, 290, 294, and 295.