Ore-control structural and geochronologic constrain in Shalagang antimony deposit in southern Tibet, China
西藏沙拉岗锑矿控矿构造及成矿时代约束

The Shalagang Sb deposit is located at 40km southeast of the Ranba complex dome at the Northern Himalaya area in China. At least four mineralization styles are recognized in Northern Himalaya: (1) Au deposits; (2) Sb-Au deposits; (3) Sb deposits and (4) Pb-Zn (Ag, Sb) deposits. Shalagang is one of representative vein type antimony deposits that have stibnite as the only mineral of economic interest. The country rocks are consisted of slate, siltstone, and silicalite of Lower Cretaceous Jiabula Formation, gabbro and diorite dike. The main ore bodies are controlled by E-W striking faults and N-S striking faults. The E-W striking faults are low angle and shallow lever interlayer fault, and were in activity during pre-mineralization and post-mineralization. The N-S striking faults are high angle faults. It cut the E-W faults, diorites and gabbros, and connected the deep lever ore-forming fluids with the shallow lever faults, resulting in stibnite deposition along the E-W faults and N-S faults. The place, where E-W striking faults jointed with N-S striking faults, has stronger alteration and Sb mineralization along these faults. Larger economic ore body could exist along these jointed faults. Zircon SHRIMP U-Pb analysis showing that the age of diorite is around 23.6Ma, indicated that the N-S striking faults and Sb-mineralization within it, which cut the diorite, are formed later than 23.6Ma.