Radiogenic, nucleogenic and fissiogenic noble gas compositions in early Archaean magmatic zircons from Greenland

Abstract

We report a full suite of radiogenic, nucleogenic and fissiogenic noble gas compositions obtained by step-heating experiments from early Archaean Greenland zircons. We estimated activation energy (Ea) of diffusion and closure temperatures (Tc) for radiogenic 4He* and fissiogenic 86Kr* and 136Xe* in zircons. These data demonstrate that the combined study of (U-Th)/He and (U-Th)/Kr-Xe can provide powerful geochronological information on cooling ages and crystallization ages from the same samples.