Zircon/rock partition coefficient of REEs in the acidic rocks of the Dar Gaz district: Implication to determination of oxygen fugacity and zircon crystallization temperature

This research focused on zircon/rock partition coefficients of REEs in the acidic rocks of the Dar Gaz district, located in the southeast of the Kerman Province, in order to determination of oxygen fugacities and zircon crystallization temperatures. Zircon/rock partition coefficients were determined in three different types of acidic rocks including plagiogranite intrusions, plagiogranitic dikes and granitic dikes (two samples from each rock type) in the Dar Gaz district. Partition coefficient results determined based on the composition of the host granitoids and the zircon grain composition indicate that the patterns of the trace elements in zircon grains are controlled by the liquid composition at the moment of crystallization and are magmatic type. Zircon/rock partition coefficients indicate LREE depletion and HREE enrichments consistent with host rocks and magmatic zircons. Ti-in-zircon temperatures range from 707 to 1046 ºC. Zircon crystallization temperature, oxygen fugacity and Ce4+/Ce3+ ratios decrease from plagiogranite intrusions toward plagiogranitic dikes indicate that plagiogranite intrusions formed by hydrous partial melting of gabbro cumulates. The plagiogranite dikes formed by more fractionation of this felsic melt. Finally granitic dikes are probably formed by fractionation of a felsic melt produced by partial melting of sedimentary material.