Recently there has been growing interest in the physical properties of rocks. To interpret data on the geophysical fields observed near the Earth's surface, we must know the physical properties of the materials composing the interior. Moreover, the development of geophysical methods (in particular, electrical methods) is necessitating a multiple approach to the study of the physical properties of rocks and minerals. In connection with problems now appearing, the physical properties of rocks must be studied in the laboratory under var- ious thermodynamic conditions. Electrical methods of...

As a method of structure analysis, electron diffraction has its own spe- cial possibilities and advantages in comparison to the X -ray method for the study of finely dispersed minerals with layer or pseudolayer structures. How- ever, possibly because of the prior existence of the X-ray method, which found universal application in different fields and attracted the main efforts of spe- cialists, electron diffraction has been unevenly disseminated and developed in different countries. In particular, the oblique texture method, which gives very complete and detailed structural information, has...

Sixty years ago the Louisiana Geological Survey published "Rock Salt. Its Origin. Geological Occurrences and Economic Importance in the' State of Louisiana, Together with Brief Notes and References to All Known Salt Deposits and Industries of the World" (Bull., 7, 1908, 259 pp.) by G. D. Harris, assisted by G. D. Maury and L. Reineke. The volume which follows is an equally ambitious project, carved out as a labor of love by Stanley J. Lefond, who began the work when he was a geologist with Diamond Alkali Company, Cleve- land, Ohio, and finished it when he was a member of the geology staff of...

I was very happy to learn that Plenum Press has decided to publish an English edition of Chemistry of the Ionosphere. Although the book was largely intended for the Soviet reader in order to fill some gaps in Russian-language reviews on aeronomic problems, I hope that it may be useful to foreign specialists engaged in iono- spheric research as well. Naturally, during the time which has elapsed since the preparation of the Russian edition new studies have been published in the world literature on the problems dealt with in this book. The most important of these are noted in the ap- pendix to...

The founders of geology at the beginning of the last century were suspicious oflaboratories. Hutton's well-known dictum illustrates the point: "There are also superficial reasoning men . . . they judge of the great oper- ations of the mineral kingdom from having kindled a fire, and looked into the bottom of a little crucible. " The idea was not unreasonable; the earth is so large and its changes are so slow and so complicated that labo- ratory tests and experiments were of little help. The earth had to be studied in its own terms and geology grew up as a separate science and not as a branch...

The present volume seems to me to be a particularly im portant one for several reasons. Not least among these is the fact that it summarizes the work of two decades by G. S. Gorshkov, one of the world's leading volcanologists. In addition, it is the first general work of this length on the volcanism of what might be called a "narrow" island arc, a relatively simple megastructure as com pared with the "wide" arcs such as Japan and Indonesia. Finally, in this volume Gorshkov has summarized and cited extensive evi dence for his general ideas on the relation between volcanism and the earth's...

Radiography, the use of penetrating radiation to produce shadow images of the internal structure of materials, has been with us since Roentgen made his discovery of x rays in 1895. However, applications of radiography in the earth sciences and in the related field of soils engineering have, until recent ly, been slow to develop. Bruhl reported optimistically on applications in paleontology as early as 1896 and there have been additional reports through the years. However, very few paleontologists adopted the method and the significant literature is relatively restricted. In soil mechanics,...

In comparison with engineering, geology is a relatively new domain of know ledge. Man has been building almost from the moment he came down out of the trees or emerged from the caves. All of his structures were founded in or upon rock or soil. Before the end of what we call ancient history, he had learned a great deal about materials, mechanics, and structures. This empirical information had become an organized field of practical knowledge by the time of Leonardo da Vinci. Although both foundations and ma terials of construction were largely earthy, codified knowledge of neither one nor the...

In many areas of geophysics, geology, geochemistry, and mining, there is considerable interest in laboratory data on the physical properties of various types of rocks. Until recently, how- ever, only the mechanical properties of rocks had been studied in detail. The last few years have seen a relatively large amount of study of the electrical properties of rock samples and a need to organize the results of these studies has arisen. In"Electrical Properties of Rocks,"* E. 1. Parkhomenko reviewed and cataloged studies of electrical resistivity and the dielectric constant in rocks. In the...

In its classical sense "epigenesis" refers to all geological processes originating at or near the surface of the earth. It thus embraces all those phenomena which we associate with the land- scape; Perel'man has already written extensively on this subject. The landscape, in the physical sense, is controlled by the interac- tion of exogenic and endogenic agencies-on the one hand, the atmo- sphere, the wind, the rain, and other components of the weather, the forces of running water and the planetary controls of gravitational and tidal nature; and on the other hand the materials of the earth's...