Plate tectonic theory has revolutionized the study of the history of our planet. It is now becoming increasingly apparent that processes deep within the Earth's mantle and core strongly influence plate movements, and it is to these processes that the author addresses himself. Having discussed the origin, composition, structure and physical properties of the Earth, the book turns to discuss the key role that interactions between the mantle and core play in magmatic and tectonic processes. Other important issues discussed are the nature and existence of mantle plumes and convection cells, and...

This book deals with the particular case of reversals of the Earth's magnetic field. These have played a major role in the development of plate tectonics and in establishing a geological time scale. The magnetism of rocks is discussed in some detail with a warning of possible misinterpretations of the record. The latest observational results and theories are reviewed with special attention to the structure and geometry of the transition field. Changing conditions at the core-mantle boundary, their effect on reversals, the generation of plumes and the possible correlation of reversals with...

Reversals of the Earth's magnetic field have played a major role in establishing plate tectonics and a geological time scale.

The subject of geomagnetic micropulsations has developed extremely rapidly and it is difficult to know when is an appropriate time to pause and assess the sum total of our knowledge-both observational and theoretical. There has in recent years been a tremendous increase in both the quantity and quality of data and also many theoretical ad vances in our understanding of the phenomenon. Undoubtedly there will be further progress in both areas but it seems worthwhile now to review both our knowledge and our ignorance. This book was essen tially completed by the end of April 1969 and tries to...