胶东夏甸金矿成矿流体及成矿物质来源：H-O、He-Ar、Sr-Nd-Pb同位素证据

夏甸金矿是胶东金矿集区中一处大型焦家式矿床。文章在详尽的岩相学和矿相学研究基础上，对该矿床进一步开展了H-O同位素并首次开展了He-Ar和Sr-Nd-Pb同位素示踪研究，为该矿床成矿流体及成矿物质来源提供了新的制约。石英中流体包裹体的H-O同位素（δDV-SMOW=-102.3‰~-93.9‰，δ18OH2O=-0.2‰~1.6‰） 揭示出成矿流体主要为富集地幔流体，并有少许大气降水加入；黄铁矿中He-Ar同位素[3He/4/He=0.58×10− 6~1.90×10− 6 （0.42~1.36 Ra），40Ar/36Ar=724.7~1358.4]同样表明成矿流体以富集地幔流体为主导；矿石及蚀变岩的Nd-Pb同位素既不同于围岩花岗岩，也不同于基底变质岩，与胶东地区中生代软流圈地幔起源的玄武岩也相差甚远，而与胶东地区中生代富集岩石圈地幔起源的煌斑岩相一致，但它们的初始87Sr/86Sr比值明显高于煌斑岩，甚至高于围岩花岗岩。Sr-Nd-Pb同位素特征表明成矿流体及成矿物质来源于富集岩石圈地幔，并在其上升过程中与基底变质岩发生了相互作用。

H-O,He-Ar and Sr-Nd-Pb Isotopic Constraints on the Sources of Ore-Forming Fluids and Ore-Forming Materials in the Xiadian Gold Deposit,Jiaodong

The Xiadian gold deposit is a large Jiaojia-type gold deposit in Jiaodong district. On the basis of detailed petrographic andmineralogical studies, we carried out the H-O isotopes and the first He-Ar and Sr-Nd-Pb isotope tracing studies of the Xiadian golddeposit, which furnish the new constrains on the source of ore-forming fluids and materials. H-O isotopes of fluid inclusions in quartz（δDV-SMOW=-102.3‰~-93.9‰ ，δ18OH2O=-0.2‰~1.6‰）reveal that the ore-forming fluids is mainly composed of enriched mantlederivedfluidwithinvolvedalittlemeteoricwater.He-Arisotopeofpyrite[3He/4/He=0.58×10−6~1.90×10−6(0.42~1.36Ra),40Ar/36Ar=724.7~1358.4] also indicates that the ore-forming fluids are dominant by the enriched mantle-derived fluid. Nd-Pb isotopes of ore and alteredrocks are different either from those of the surrounding granites and the basement metamorphic rocks or from those of Mesozoicasthenosphere-derived basalts. Instead, they are consistent with those of Mesozoic lithospheric mantle-derived lamprophyres in theJiaodong district. However, their initial 87Sr/86Sr ratios are higher than those of the lamprophyres and even higher than the surroundinggranites. The Sr-Nd-Pb isotopic characteristics indicate that the ore-forming fluids and ore-forming materials were derived from theenriched lithospheric mantle with subsequent interacted with the basement metamorphic rocks during the ascending process.