Cosmochemical and geochemical fractionations

Next we will examine unstable isotopes in some detail. The chronologic information they provide, coupled with knowledge of cosmochemical and geochemical fractionations, are powerful tools in understanding nebular and planetary processes. 

Young ED, Galy A, Nagahara H (2002) Kinetic and equilibrium mass-dependent isotope fractionation laws in nature and their geochemical and cosmochemical significance. Geochim Cosmochim Acta 66 1095-1104... 

Thiemens MH, Heidenreich JE (1983) The mass independent fractionation of oxygen - A novel isotope effect and its cosmochemical implications. Science 219 1073-1075 Thiemens MH, Jackson T, Zipf EC, Erdman PW, van Egmond C (1995) Carbon dioxide and oxygen isotope anomalies in the mesophere and stratosphere. Science 270 969-972 Thode HG, Monster J (1964) The sulfur isotope abundances in evaporites and in ancient oceans. In Vinogradov AP (ed) Proc Geochem Conf Commemorating the Centenary of V I Vernadsku s Birth, vol 2, 630 p... 

FIGURE 3.9 The geochemical/ cosmochemical fractionation diagram for the Earth showing the various estimates of primitive mantle composition discussed in the text. The elliptical shaded area is the field for Cl chondrites and the analyses in Table 3.1 are plotted as weight ratios, for the chondritic model (C), the pyrolite model (P) and the peridotite-chondrite model (PC). 

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