CRUSTAL EVOLUTION OF THE CAPRICORN OROGEN (WA): INSIGHT FROM A PROVENANCE STUDY OF ITS MAJOR MESOPROTEROZOIC SEDIMENTARY BASINS
To do so more than 3000 detrital zircons were analysed and studied with a new approach to the traditional provenance study. The zircon U-Pb isotopes and trace elements were measure on a recently developed Laser-Ablation Split Stream – ICPMS facility (LASS-ICPMS) at the Curtin University. The U-Pb age data were visually and statistically compared with published data, through stacked cumulative probability plots, Kolmogorov-Smirnov test probabilities and multidimensional scaling plots (MDS), with the aim to reveal potential source terrains and sediment transportation patterns. The outcomes were then analysed under the light of the geochemical signature of the detrital zircons through: (i) chemical discrimination diagrams with rock types compositional fields (ii) chemical discrimination diagrams containing compositional fields established on geochemical data, analysed in the same way, from magmatic zircons selected for some granite suites of the Capricorn. The elemental matching between detrital and magmatic zircons constrained distinct sources for the sediments that would be otherwise invisible within the U-Pb age modes. Moreover, this methodology set a new base for provenance study, where a higher detail in the distinction of source terrains can be achieved.