The Earth's crust and upper mantle / Земная кора и верхняя мантия

Amonп the major results of the Upper Mantle Project, two are especially significant. First, it has been clearly demonstrated that the earth is not radially symmetric: important lateral inhomogeneities exist in the uppermost 700 kilometers. Second, it is now clear that large-scale motions of the upper parts of the earth are taking place now and have taken place in the past. These two ideas may well be coupled: the inhomogeneities may be the evidence for the driving mechanism for the motions; the motions, in turn, may provide the process whereby the inhomogeneities are produced. These results, the details and full significance of which were unforeseen at the beginning of the Upper Mantle Project, led to a clearer understanding of the essential interrelation of geophysical and geological phenomena. Thus, they are in large part responsible for the decision of the International Union of Geodesy and Geophysics and the International Union of Geological Sciences jointly to propose a long-range program of studies of the solid earth—beginning in 1972 under the sponsorship of the International Council of Scientific Unions—with ‘dynamics of the earth’s interior’ as a principal focal theme.

The Earth's Crust and Upper Mantle was prepared under the auspices of the International Upper Mantle Committee. It is designed to give a broad survey of modern developments in solid earth studies, with emphasis on the interrelation of geophysical, geochemical, and geological observations. Thus, the monograph serves not only as a review of achievements during the period of the Upper Mantle Project but also underscores the relations of these developments, with their uncertainties, to the future studies of the earth’s interior. <...>