Chronology and Geochemistry of Jingbulake Complex Containing Cu-Ni Mineralization, West Tianshan Mountain, NW China

The Jingbulake complex containing Cu-Ni Mineralization in west Tianshan Mountain is located in the south of Yili block.The pyroxene diorite has a LA-ICP-MS zircon U-Pb isotope age of (414.8±0.9)Ma.The contents of REE has little change in all rocks,which have flat chondrite-normalized rare element or slight LREE enrichment pattern and that of La/Sm(1.07-2.62) and Mg^#(0.59-0.85).They are enriched in large ion lithophile elements,such as Cs,Ba,Sr,and show negative Nb-Ta 、Zr、Hf and Ti anomalies on mantle-normalized trace element diagrams.They have positive εNd values(+3.8-+6.3),which indicated a depleted mantle source.The genesis of the Jingbulake complex suggests subduction of the South Tianshan oceanic lithosphere beneath the YIli-Central Tianshan block.The subduction-related fluids triggered the melting of the mantle.The genesis of the rocks and mineralization caused by magmatic differentiation and slight crustal contamination.