Mineralogical Characteristics and Their Implications of the Labaxi Chromite Deposit in the West Junggar Region, Xinjiang

The Mayile ophiolite belt, a significant ophiolite zone in the western Junggar region, has revealed multiple clues of chromite mineralization, though no major prospecting breakthroughs have been achieved. This study employs mineral geochemical methods to analyze the properties of the protolith, physicochemical conditions, and tectonic setting of the recently discovered Labaxi chromite occurrence. The results indicate that the chromite formed at a temperature of approximately 1260°C, a pressure of about 3.06 GPa, a mantle oxygen fugacity of around FMQ - 4.94 log units, and a mantle melting degree of about 45.63 %. It is concluded that the Labaxi chromite corresponds to a forearc basin environment. The mineral chemical composition of the high-chromium chromite spinel in this area is similar to that of the Luobusa chromite deposit and is likely formed by boninitic melt/rock interactions in a subduction zone setting. It shows distinct differences from typical high-aluminum chromite deposits in the western Junggar region, such as those in Sartohay, Jingyu, and Tangbale, indicating considerable potential for further exploration.