Single zircon U-Pb geochronology of the Limpopo Belt by secondary ion mass spectrometry

Tsunogae, T. and Yurimoto, H. (1995)@Geochemical Journal, 29, 197-205.


Abstract

Single zircon U-Pb chronology was applied to understanding of evolution of an Archean metamorphic belt. High mass resolution (M/M = ca. 6000) obtained by a commercial instrument of secondary ion mass spectrometry was sufficient to determine Pb/U values of zircon crystal. U-Pb ages of zircons from the Limpopo Belt, southern Africa, cluster around 3200 Ma for the Central Zone and 2800 Ma for the Northern Marginal Zone. The gap in age between the two zones can be explained by different timing of peak metamorphism or by differential resetting of zircon U-Pb system owing to their discrete metamorphic P-T histories.