Zircon U-Pb geochronology and trace elements geochemistry of Hiltaba Suite in the north of Moonta-Wallaroo mining district, Yorke Peninsula, Gawler Craton, Australia

The Hiltaba Suite is widely developed in the Gawler Craton, South Australia, which is closely related to the IOCG deposits in the area. It is very important to find out the diagenetic age, diagenetic temperature and tectonic setting of the suite for the study of IOCG deposits. Zircon U-Pb dating of the augen granite collected from the north of the Moonta-Wallaroo mining district in the York Peninsula shows that the age is 1589 ±43 Ma, which is consistent with the magmatic event (1595~1575 Ma) of the Hiltaba Suite determined by previous geologists. According to zircon Ti thermometer, the diagenetic temperature of granite is 848~971℃, with an average of 878℃, which is close to that of A-type granite. The rare earth element patterns of zircon show the characteristics of LREE loss, HREE enrichment and left-dip, with obvious positive Ce anomaly and negative Eu anomaly, δCe varies widely (4.85~107.63) and δEu varies small (0.17~0.36). In the zircon Y-Yb/Dy and other discriminant diagrams, most of the samples fall within and near the within plate tectonic environment, and a few fall within and near the volcanic arc tectonic environment. In the zircon Hf-U/Yb and Y-Yb/Dy discriminant diagrams, the samples fall within the continental crust environment. Comprehensive analysis shows that the granite was formed in the tectonic setting of the evolution from the active continental margin to the intracontinental environment.