Geochemistry Of Volcanic Rocks In Huangtupo VMS Cu Polymetallic Deposit In Eastern Tianshan, Xinjiang

Valcanogenic massive sulfide deposit (VMS) or volcanica-hosted masisivesulfide (VHMS) refers to a polymetallic deposit hosted by volcanic rocks and iscomprised of massive sulfide lenses or sheets and an underlying discordant stringerzone, which is also an important source of copper, zinc and lead. VMS deposit hasclosely associations in spatial-temporal distribution and the tectonomagmatic withhosted volcanic rocks. The Huangtupo Cu-Zn deposit, located in the Odivirionsubmarine volcanic district in the Klatage area in the eastern Tianshan orogenic belt,northwestern China. Many uncertainties on the host volcanic rocks, such as thedistribution, the origin and evolution of magmas, tectonic envorionment and thecontrolling to deposit constrain understand to the genesis of deposit, and prevent theexploration VMS deposit in Kalatage and eastern Tianshan.In this paper, petrographic, chronological and geochemical analyses have beencarried out on the volcanic rocks hosted Huangtupo Cu-Zn polymetallic deposit, Weconstructed their precise age, discussed their petrogenesis and magma source regions,as well as the tectonic evolution. Some conclusions have been drawn:1、 The volcanic rocks crops out in the Huangtupo Cu-Zn polymetallic ore areacomposed andesite, basalt-andesite, tuff and volcanic breccia. LA-ICP-MS analysesof zircons from andesite of the Kalatage formation yield weighted mean206Pb/238Uages of425.6Ma, which indicated that the Kalatage Fm. was formed during the LateOrdivician.2、Andesite and dacite have similar characteristics with obvious enrichment ofLREE and HFSE, obvious negative anomaly of Ti, P, Sr, Ba and Eu. The andecite anddacite were likely resulted from same primary magma. The primary magma may havebeen derived from a mixture of mantle metasomatized by fluids and melts releasedfrom the subducted slab. During the cooling of magmas, they underwent crystallization differentiation of pyroxenes and plagioclase.3、The volcanic rocks hosted Huangtupo Cu-Zn polymetallic deposit are formedin setting associated with subduction and volcanism provided materials and fluids forthe iron deposits.