陕西略阳铜厂铜矿床Sr,Pb同位素组成特征及其意义

结合岩体产出环境，时代及其与碧口火山岩的关系，认为铜厂石英闪长岩体是由碧口火山岩的局部熔融作用形成的。铜厂铜矿硫化物Ｐｂ同位素特征显示出以浅源的地壳铅为主，并与碧口火山岩铅同位素组成的壳源端员重合，指示矿质与碧田火山岩之间存在密切关系。由于岩体与火山岩的同源性，所以脉状铜矿石既可能来自岩体也可能来自围岩。

COMPOSITION CHARACTERISTICS OF Sr,Pb ISOTOPES AND IMPLICATIONS FOR MINERALZATION OF TONGCHANG COPPER DEPOSIT,LUEYANG,SHANXI PROVINCE

Based on occurrence geologic setting, and intrusion time of quartz diorite and relation with volcanic rocks.Tongchang quartz diorite is thought to be derived from Bikou Group volcanic rocks through partial melting processes. The Pb isotopic composition of sulfides of Tongchang copper deposit show sign of overlapping the end member component of the crust Pb isotopes of Bikou Group volcanic rocks. This indicates there exists the original affinity between mineralization material and Bikou Group volcanic rocks. The ore material was derived from Tongchang quartz diorite or volcanic rock strata because of the affinity of Tongchang intrusive rock and Bikou Group volcanic rocks. Rb Sr isotopic system of sulfides gives main ore forming time about 199 Ma.Initial Sr isotopic composition display enrichment of radiogenic Sr and indicate exotic fluid or matter was introduced during sulfide precipitation.Above evidence shows the characters of dynamically reformed mineralization.