The Study Of Geological Characteristics Of Naruo Copper (Gold) Deposit In Gaize, Tibet

Duolong ore concentration area is located in the west of the Bangonghu-Nujiangmetallogenic belt,caused high attention characterized by large scale,diverse types,mature study. Naruo copper(gold) deposit is asignificant prospecting breakthroughporphyry deposit in Bangonghu-Nujiang metallogenic belt. This paper selects Naruodeposit as the research object which have relatively low research degree in this oreconcentration area.In a detailed study on geological characteristics of deposit based onsystem understand the stratas, structures, magmatic rocks.Naruo copper (gold)orebodies occurred in granite diorite porphyry and feldspar quartz sandstone.In2013,copper (gold) orebodyoccurred in concealed explosive breccia have been found inwest of mining area. The ore bodyextends about1300m in lengthand500mindeep.There are two concentration centers on the space caused by Cu, Au elementscorrespond to ore-bearing porphyry and concealed explosive breccia. The ore fabric，mineralsparagenetic association，mineral component，vein types and hydrothermalalterationsimilar totypical porphyry deposit.The metallogenic epoch can be divided tothree periods which are magmatic metallogenic period,hydrothermal metallogenicperiod andepigenetic metallogenic period.LA-ICP-MS zircon U-Pb isotopic dating indicate that the ore-bearing granitediorite porphyry formed at119.62±0.64Ma. Isotope determination of molybdeniteRe-Os reveal the Re-Os model ages range from116.6to118.5Ma and weightedaverage age is117.62±2.3Ma,which represent the Naruocopper (gold) mineralizationage.Rock geochemical characteristics of ore-bearing rock are similar to arcgranites,characterized by relatively high silicon, rich potassium, peraluminouscharacteristics.REE elements show are characterized by LREE enriched， notobviousnegative δEu； chondrite-normalized REE distribution patterns show thedistribution pattern of right-wing gently inclined.Trace elements aregeneralenrichedwithlarge ion lithophile elements (LILE:such as Rb,Ba,K,Sr) andlively highfield-strength elements (such as U,Th),depleted in other high field-strengthelements(HFSE:such asNb,Ta,Zr,Hf,Ti).Comprehensive research that the metallogenesis of Naruo deposit is agreement with other porphyry deposits in Duolongore concentration area. These deposits are theproducts oftectono-magmatic-metallogenic activities formed at the same tectonicbackground. The Naruodeposit is a island arc copper (gold) deposit formed in Tethysoceanic crust plate northward dive to south Qiangtangplate and the island arcenvironment fluid produced by oceanic crust dehydration effect replacement of partialmelting of wedgemantle.