Regularities of rare-earth element distribution in the sedimentary shell and in the crust of the earth

After summarizing the vast analytical material it was possible to establish the differences in rare-earth element (REE) distribution in geosynclines and on platforms. It is shown that the heavier REE composition in sediments of geosynclines and the lighter one in sediments of platforms was initially created by processes of endogenic differentiation and then inherited by sedimentary series of these zones. On the basis of the calculation of the REE content in rocks of various shells of the Earth crust the increase of the role of heavy lanthanides into the depths of the crust is shown. The obtained estimate of REE abundance in the lithosphere led to the conclusion that the crust of our planet, despite the repeated reworking of its matter by sedimentary processes, metamorphism and granitization, has inherited features peculiar to products of tholeiitic magmatism—the most widely spread type of mantle fusion.