The isotopic constitution of terrestrial rocks and meteorites

Abstract

The lecture cites numerous data on the isotoplc constitution of sulfur, oxygen, carbon and light gases in iron, stone iron and stone meteorites. A comparison is made between the isotopic consitution of these elements in meteorites and in different rocks of the earth's crust. An analysis of these data leads the author to a number of important conclusions in the realms of geochemistry and cosmochemistry. Considering that the fractionation of isotopes in the earth's crust is the result of differentiation of terrestrial matter, the author concludes that no such differentiation occurred in the meteoritic material (in which no fractioning of isotopes is observed) and that, therefore, all meteorites must have formed by accretion of particles of primordial cosmic dust.