The Conference recorded in this volume was held on the occasion of the dedication of the Cecil and Ida Green Building. This new building houses the Center for the Earth Sciences ofthe Massachusetts Institute of Technology, comprising the Departments of Meteorology and of Geology and Geophysics.
The annals of science do not frequently honor a man of industry, as the faculty in earth sciences at M.I.T. have done in choosing to dedicate this volume to Cecil H. Green, geophysicist and alumnus of the Institute.

In 1915, when the first edition of this text-book appeared, the author had had ten years' experience in teaching Historical Geology in the Sheffield Scientific School of Yale University. Since then he has continued his interest in the subject, teaching it until 1920, and has made almost daily annotations in his table copy of the first edition concerning the newer facts as they appeared in publications. It soon became a perplexing problem to know what to eliminate so as to keep the book within bounds, as one intended for  eginners in Geology rather than for matured geologists.

This book has been written to bring up to date The Interior of the Earth, published in 1971 following the plate tectonic revolution. Plate tectonic theory has now been widely accepted as a unifying theory for the origin ofthe Earth’s major surface features, and the broad viewpoint taken in 1971 has been vindicated. The last ten years, however, has been a period of continuing rapid advance in earth sciences. The structure of the Earth’s interior has become much better defined. A new understanding ofthe physical processes within the Earth which permit the escape of heat from the deep interior, drive the geomagnetic dynamo and cause the plate motions, is emerging. Consequently, much of the original text has had to be re-written to produce this new book.

This book was inspired when I began to teach California geology at the college level and found there were no books suitable for such a course. All the books on the market either were grossly out of date or didn’t discuss the modern understanding of California tectonics. California has one of the most amazing and complex histories of any state in the United States, and so the simplistic approaches of the books currently on the market do not do it justice.

The Earth is our familiar home, yet the geological processes which underlie our tenure on it can seem intimidatingly vast, ancient, and sometimes even alien—certainly beyond everyday human experience. Our planet’s origins and upheavals have fascinated humans for millennia, but only recently have we developed a clear understanding of how the Earth actually works.
Many people alive today were born at a time when no one knew where Earth’s constituents came from, why continents move, how diamonds are made, what causes earthquakes, when life started, or whether geological processes occur elsewhere in the Universe. We now know a great deal about all these things, and geology is expanding at breakneck speed.Long before it had a name, geology was a crucial part of human knowledge. Even before agriculture, humans needed to know where water was wrung from the ground, where the best tool-stones could be found, and how to choose a stable, safe campsite. This knowledge expanded with the advent of farming and settlements around ten thousand years ago—working the land where minerals in the soil would make crops and beasts thrive, carving irrigation channels and trackways into the ground, and hewing stones to build the new villages and cities. <...>

Принципы геологии: исследование того, в какой степени прежние изменения поверхности Земли можно объяснить причинами, действующими в настоящее время.