Studies related to the earth and planets along with their surroundings are of great concern for modern scientists. Global geodynamics as represented by plate tectonics has now become one of the most powerful tools by which we can study the causes of earthquakes, volcanic eruptions, mountain formation and the like. Various missions sent out to space, manned or of the moon, Mars, Venus and unmanned, brought out geoscientific features other planets. Earthquake prediction that was the business of astrologers and fortune-tellers some twenty years ago, has now grown up to be an important science. A number of destructive earthquakes were successfully forecast in the People's Republic of China. In the light of the above-mentioned and other accomplishments in geosciences, we feel that it is a good thing to publish a series of monographs which review selected topics of earth and planetary sciences. We are of course well aware of the fact that similar monographs have been and will be published from overseas publishers. The series, which we plan to publish, will therefore stress Japanese work. But we hope that the series will also include review articles by distinguished overseas authors.