云南中甸普朗斑岩铜矿成因探讨

The Genesis in Yunnan of Zhongdian Pulang Porphyry Copper Deposit

普朗斑岩铜矿位于义敦岛弧带南段,产于印支-燕山早期普朗复式斑(玢)岩中。主要岩性由石英闪长玢岩、石英二长斑岩和花岗闪长斑岩组成,岩石化学和地球化学特征显示为碱性岩石系列I型花岗岩。成矿流体具高盐度和成矿温度150～300℃变化。硫同位素δ34SCDT为-2.23‰～3.75‰,来源于深源岩浆。矿床的构造作用、液压致裂作用和蚀变脉体形成等成矿机理经历了一个复杂过程。成岩和成矿作用的时间大致为235～206Ma,具多阶段性,其中石英-辉钼成矿阶段为(213±3.8)Ma,成岩和成矿时代主体为印支期。矿床蚀变由中心向外依次为硅化钾化带—绢英岩化带—青磐岩(角岩)化带的面型蚀变特征。成因类型属岛孤斑岩型铜矿床。

The Pulang porphyry copper deposit located in the Yidun arc with the southern section,produced in the Indo-porphyry in the early Yanshan Pulang duplex. Main rocks from the quartz diorite porphyry、quartz monzonite porphyry and composed of granodiorite porphyry,the feature of petrochemistry and geochemistry show alkaline rock series of I-type granite. Ore-forming fluids high salinity and forming temperature from 150 to 300 ℃. Sulfur isotope δ^34SCDT：-2.23‰～3.75‰,from deep magma.The metallogenic mechanism of the construction of the role of deposit、hydraulic fracturing and the formation of alteration veins etc undergone a complex process. Diagenesis and mineralization time is roughly 235 ～ 206 Ma.with a multi-stage,and the one quartz-molybdenite mineralization stage for （213 ± 3.8） Ma,nThe principal age of diagenesis and mineralization is the Indo-Chinese epoch. Alteration outward from the center were：K of silicified zone-sericite alteration zone-propylitic alteration zone（hornfels）of face alteration features.The genetic type is the island arc porphyry copper deposit.