皖南祁门地区东源钨钼矿区花岗闪长斑岩SHRIMP锆石U-Pb年龄和Hf同位素特征

江家等系列花岗闪长斑岩是皖南祁门县东源钨钼矿区含矿岩体的组成部分,位于东源花岗闪长岩的西侧。对江家和方村花岗闪长斑岩进行的SHRIMP锆石U-Pb测年结果表明,江家、方村花岗闪长斑岩的结晶年龄为149~152Ma,与富钨的东源花岗闪长岩相近。岩石地球化学和锆石Hf同位素分析显示,江家等系列花岗闪长斑岩源区具有复杂的多成分端元,其中老锆石核的正εHf值反映了成岩岩浆对晋宁期岩浆岩的继承,震荡岩浆环带的负εHf值（-39.5~-2.86）指示源区的主要成分为古老的地壳物质,有少量地幔物质的混染。全岩锆石饱和温度（737~913°C）显示岩浆组成中有幔源物质的贡献。

SHRIMP zircon U-Pb dating and characteristics of Hf isotopes of the granodiorite porphyries in the Dongyuan W-Mo ore district,Qimen area,southern Anhui

Granodiorites in Jiangjia and neighboring areas are ore-bearing rock components of the Dongyuan W-Mo deposit in southern Anhui.The zircon SHRIMP U-Pb data show that these rock bodies were formed at 149~152 Ma,almost at the same time with the formation of the Dongyuan W-rich granodiorite.The whole-rock chemical and zircon Hf isotopic data indicate that these magma sources have complex multi-component end-members.CL images reveal that the young zircons occur as new grains or rims of homogeneous structure with magmatic zoning,whereas most of the old ages occur in cores or as single xenocrysts in Neoproterozoic granodiorites,showing that the magmatic source contained considerable amounts of components of early igneous rocks.Young magmatic zircon zones in the granodiorites samples are heterogeneous in εHf（t） values（-39.5~-2.86）,probably indicating the mixture between crust and mantle materials during the formation of the magma,with old crustal rocks being the main source.Zircon Hf isotopic data and bulk-rock zircon saturation temperature（737~913°C） indicate that mantle-derived materials probably played a role in the generation of the granodiorites.