Sea floor spreading and continental drift / Спрединг и движение континентов

Studies of the magnetic anomalies paralleling ocean ridges have furnished partisans of continental drift with decisive arguments. To take stock of this important question, my colleague Thellier and I decided in the early summer of 1967 to make it the subject of the annual seminar on Earth physics for the school year 1967-68. Although research was still developing rapidly, the General Assembly of the International Union of Geodesy and Geophysics held in Switzerland in September, particularly some of the meetings in Zurich under the auspices of the International Committee for the Upper Mantle, appeared to confirm that we had made no important omissions. At the conclusion of the seminar, where I had been responsible for most of the lectures, I resolved to write the present volume for the non-specialized scientific reader. The project turned out to be a good deal more ambitious than I had thought. It is quite an undertaking nowadays to try to survey a rapidly growing subject, first of all because of the difficulty of gathering material; publication delays are now nearing one year, with the result that specialists communicate largely through a selective distribution of reports, as well as verbally in frequent colloquia. I warmly thank those who helped me in getting unpublished literature, especially Xavier Le Pichon. Even so, some essential work came to my knowledge only lately. Finally, from the viewpoint of this Series, the subject here dealt with is certainly Living Science, and seems ripe for exposition without too much fear that premature interpretations may be rapidly superseded, for the probable lines of development are fairly clear.
It may appear that not much would be needed to make the book into an introduction to original research by adding to the already long bibliography, giving the principles behind some of the calculations, and tempering each assertion with a statement on the conditions of its validity. But in fact this would have taken me far afield to satisfy a restricted public without perhaps answering the particular questions which always occur to enquirers from another discipline. For despite the number of general surveys published every year, scientists who can use it still prefer the timehonored method of consulting a university colleague or quizzing a neighbor at a colloquium when they need information on some particular aspect not in their field. The book has been kept relatively small then, for these reasons, and I hope that its readers will find as much interest in the wonderful recent discoveries about the ocean floor as I did in coming to know them fully.<...>