The Inaccessible Earth: Integrated View of its Structure and Composition - Softcover

Brown, G. C.; Mussett, A. E.

Softcover

ISBN 10: 041248160X ISBN 13: 9780412481604

Publisher: Chapman and Hall, 1993

Synopsis

In the dozen years since the first edition appeared, there has been a great advance in understanding of the Earth's deep interior. This is not because there have been breakthroughs in understanding, or even many changes of ideas, but largely because of many small advances, often the result of improved tech- niques. This has led to a complete revision of the book. For instance, we have a much better idea of how the cloud of gas that formed the Solar Nebula evolved into the Sun and the planets, and of the chemical processes that accompanied its evolution and determined the mix of elements in the Earth. We have a better understanding of convection and how plates are an essential part of it, and how it is accompanied by chemical processes that have extracted the materials to build continents. Although the major variation within the Earth is radial, improved geophysical and geochemical techniques have made progress in investigating and under- standing the lateral heterogeneities, and it is encouraging that when geochemists and geophysicists talk about lateral heterogeneities they can sometimes be referring to the same thing. Plumes have become very fashionable as the cause of hot-spot magmatism and associated geochemical anomalies, probably origi- nating at the base of the mantle (though clear evidence for their existence is lacking).

About this title

Synopsis

This is the second edition of a treatment of the origin, structure and internal composition of the Earth, synthesizing the geological, chemical and physical knowledge bearing on the Earth's inaccessible interior. It seeks answers to questions about the Earth's origin, evolution and dynamics, producing an integrated account of these subjects suitable for students and teachers in the earth sciences. Why do we think that the centre of the Earth is a nickel-iron alloy; or that the crust evolves by processes at subduction zones and by vertical plumes rising through the mantle; or that the Earth's magnetic field is generated by some form of convection in the molten outer core? The evidence comes from many disciplines ranging from geology to nuclear physics, but the contributions of geophysics and geochemistry are particularly important and have been given equal weight, while mathematics has been kept to a minimum. The text traces the evolution of the earth's layered structure and explains how its density at depth is deduced from seismic and gravitational data.

Density is the prime constraint on chemical composition which is deduced also by reference to new theories of stellar evolution and planetary accretion, combined with evidence from the solar system and meteorites. With this information as background, the second half of the text goes on to describe the probable composition and physical state of the present-day core, mantle and crust. In the second edition, more emphasis is placed on the effects of heat and gravity on dynamic processes at all levels in the Earth. Effects such as stresses in tectonic plates, mantle convection and the geomagnetic dynamo are re-examined in the light of improved understanding. Finally, geological evidence is used to construct a model for the evolutionary history of the Earth's continental crust.

Edition details

• Publisher: Chapman and Hall
• Publication date: 1993
• Language: English
• ISBN 10: 041248160X
• ISBN 13: 9780412481604
• Binding: Paperback
• Edition number: 2
• Number of pages: 287