Fractionation of Zr and Hf in cassiterite
1983; Elsevier BV; Volume: 40; Issue: 1-2 Linguagem: Inglês
10.1016/0009-2541(83)90087-6
ISSN1872-6836
Autores Tópico(s)Geochemistry and Elemental Analysis
ResumoAnalytical data on Zr and Hf in cassiterite samples from various genetic types of deposits are reported. Two genetic groups of cassiterites can be distinguished by their Zr/Hf ratios, which are ∼5 and ∼30 for samples from pegmatites and hydrothermal vein mineralizations, respectively. Relating these Zr/Hf ratios to those in zircons and common rocks (∼43), it is derived that the difference of α(Zr) − α(Hf) is ∼0.2, assuming a Rayleigh fractionation model. It is proposed to make use of the Zr/Hf ratio as a geochemical indicator of the mode of formation of the cassiterite in cases when this is not clear from the geologic setting such as in placer deposits.
Referência(s)