东天山西段路北铜镍矿基性岩体锆石U-Pb年代学对Ni-Cu找矿的启示

Zircon U-Pb Geochronology of the Lubei Cu-Ni Deposit in the Western Part of Eastern Tianshan and Its Implications for Ni-Cu Prospecting

路北铜镍矿床位于觉罗塔格构造带内,岩体走向受康古尔深大断裂控制,矿床规模达中型。含矿岩体侵入于下石炭统小热泉子组,围岩为安山岩与细砂岩,主要基性-超基性岩为橄榄岩、橄榄辉石岩、辉石岩、辉长岩等。岩体由中心向两侧基性程度逐渐降低,产状平缓,主要赋矿岩相为辉石橄榄岩相,矿体多呈似层状或透镜状。含矿角闪辉长岩中锆石LA-ICP-MSU-Pb定年为(282.9±2.4)Ma,与东天山地区黄山东、黄山、香山等典型铜镍矿床及基性-超基性岩体形成时代一致,为早二叠纪。认为路北矿床为东天山黄山-镜儿泉铜镍成矿带西延部分,该铜镍矿带向西具较大的铜镍找矿空间,康古尔深大断裂可能为该区重要的控岩控矿断裂。

The Lubei Cu Ni deposit is located in the Jueluotage structural belt.The strike of the rock mass is controlled by the Kanggur deep fault.At present,the scale of the deposit is medium.The ore bearing rocks intrude into the lower Carboniferous Xiaorequanzi formation,The main basic ultrabasic rocks are peridotite,olivine pyroxenite,pyroxenite and gabbro,The basic degree of the rock decreases gradually from the center to both sides,and the occurrence of the rock body is gentle,The main ore bearing lithofacies is pyroxene peridotite facies,and the ore bodies are mostly stratoid or len-ticular.Zircon La ICP MS U-Pb dating results of ore bearing hornblende gabbro are(282.9±2.4)Ma,It is consistent with the formation age of typical copper nickel deposits and basic ultrabasic rock bodies in Huangshan,Huangshan and Xiang-shan of Eastern Tianshan area,and formed in Early Permian.It is proved that Lubei deposit is the western extension of Huangshan jingerquan Cu Ni metallogenic belt in East Tianshan,In addition,the Kangguer deep fault may also be an im-portant rock and ore controlling fault in the area.