黑龙江省铜山铜矿床英云闪长岩锆石U-Pb年龄及地球化学特征  

Zircon U-Pb dating and geochemistry of ore-bearing tonalite in Tongshan copper deposit, Heilongjiang Province

作　　者：刘军[1] 周振华[1] 何哲峰[2,3] 欧阳荷根[1] 

机构地区：[1]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质博物馆,北京100034 [3]中国地质大学,北京100083

出　　处：《矿床地质》2015年第2期289-308,共20页Mineral Deposits

基　　金：中国地质调查局地质调查项目(12120113093600);国家自然科学基金项目(41172081)联合资助

摘　　要：铜山矿床是位于大兴安岭北段多宝山矿田中的一个大型铜矿床。文章对该矿区含矿英云闪长岩进行了详细的LA-MC-ICP-MS锆石U-Pb定年、主量元素、微量元素及同位素地球化学研究。锆石U-Pb定年结果表明,英云闪长岩侵位于(461±1)Ma。岩石显示埃达克质岩的地球化学特征,具有高w(Si O2)(62.5%~64.53%)和w(Al2O3)(14.77%~17.7%),高w(Sr)(394×10-6~804×10-6),低w(Y)(7.78×10-6~10.3×10-6)和w(Yb)(0.8×10-6~1.04×10-6),轻稀土元素富集,重稀土元素亏损,无明显Eu异常。锆石εHf(t)值介于11.6~13.5。金属硫化物的δ34S值为-1.3‰^-0.4‰,206Pb/204Pb、207Pb/204Pb和208Pb/204Pb值分别为17.591~18.453、15.449~15.551和37.280~37.999。这些特征表明,铜山矿床英云闪长岩形成于大陆边缘弧环境,是加厚下地壳部分熔融的产物。成矿物质主要来自于英云闪长岩及多宝山组火山岩。The Tongshan deposit is a large copper deposit located in the Duobaoshan orefield within the northern Da Hinggan Mountains. This paper reports LA-MC-ICP-MS zircon U-Pb age, major and trace elements, and iso- topic geochemistry of the ore-related tonalite in the Tongshan deposit. LA-MC-ICP-MS zircon U-Pb dating yielded the crystallization age of （461 ± 1 ） Ma for the tonalite. The tonalite shows characteristics of adakitic affinity, i.e., high SiOz（62.5% -- 64.53% ）, A1203（14.77%--17.7% ） and Sr （394 × 10-6- 804 × 10-6）, low Y （7.78 × 10- 6 ~ 10.3 × 10- 6） and Yb （0.8× 10- 6 ~ 1.04 × 10-6）, slight Eu anomalies, rich light rare- earth elements and depleted heavy rare-earth elements. The zircon Hf isotope analysis shows EI-If （ t ） values of 11.6 to 13.5. ~34S values of sulfides are between - 1.3%0 and - 0.4%0, similar to data associated with mag-matic-hydrothermal systems. 206pb/204pb, 207pb/204pb and 208pb/204pb ratios vary from 17. 591 to 18. 453, 15.449 to 15.551, and 37.280 to 37.999, respectively. The tonalite was formed in a continental marginal arc setting, and originated from partial melting of the thickened lower crust. The ore-forming materials were de- rived from the volcanic rocks of the Duobaoshan Formation and tonalite.

关 键 词：地球化学 锆石U-PB定年 HF同位素 硫铅同位素 英云闪长岩 铜山矿床 

分 类 号：P618.41[天文地球—矿床学] P597[天文地球—地质学]