Geochemistry of the Jingbulake Cu-Ni-(PGE) sulphide bearing mafic-ultra mafic intrusion, South Tianshan, NW China, tectonic and ore-forming processes implication

摘要

The South Tianshan orogenic belt, the southwestern extension of the Central Asian orogenic belt, separates the Yili-Central Tianshan block to the north from the Tarim block to the south. This belt is marked by a Proterozoic metamorphic complex, ophiolites, granitoids, mafic intrusions and younger high pressure - low temperature metamorphic rocks. The 430 Ma Jingbulake mafic intrusion in this belt is a zoned body composed of gabbro-diorite, olivine gabbro, and wehrlite. Pyroxenite locally intrudes all of these rocks but is most abundant along the boundaries between different rocks. The olivine gabbros and wehrlites contain disseminated sulfide mineralization and a sulfide orebody intrudes the pyroxenite.