青海东昆仑托克妥Cu-Au(Mo)矿床含矿斑岩成因:锆石U-Pb年代学和地球化学约束  

The Genesis of the Ore-Bearing Porphyry of the Tuoketuo Porphyry Cu-Au(Mo)Deposit in the East Kunlun,Qinghai Province:Constraints from Zircon U-Pb Geochronological and Geochemistry

作　　者：夏锐[1,2] 卿敏[2] 王长明[1] 李文良[2] 

机构地区：[1]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [2]武警黄金地质研究所,河北廊坊065000

出　　处：《吉林大学学报（地球科学版）》2014年第5期1502-1524,共23页Journal of Jilin University：Earth Science Edition

基　　金：国家"973"计划项目(2009CB421008);北京市优秀博士学位论文指导老师科研项目(20111141501);武警黄金指挥部专项基金项目(HJ12-03)

摘　　要：东昆仑造山带是我国斑岩型矿床的重要成矿区之一。对东昆仑托克妥Cu-Au（Mo）矿床含矿斑岩利用原位LA-ICP-MS锆石U-Pb测年和地球化学分析方法,探讨该地区岩体成因以及岩浆作用与成矿作用的深部约束机制。东昆仑托克妥Cu-Au（Mo）矿床含矿二长花岗斑岩年龄为（232.49±0.93）Ma,花岗闪长斑岩年龄为（232.6±1.2）Ma,处于东昆仑碰撞造山阶段。含矿斑岩为二长花岗斑岩和花岗闪长斑岩,具有富硅（w（SiO2）=63.11%~71.78%）、高钾（w（K2O）=2.62%~3.61%）、高镁（w（MgO）=0.52%~1.89%）、低钛（w（TiO2）=0.26%~0.53%）和偏铝质（A/CNK=1.05~1.10）的特征,富集大离子亲石元素Rb、Ba、K和Pb等,亏损高场强元素Nb、Ta、Ti和P,属于高钾钙碱性系列的I型花岗岩。研究认为,托克妥Cu-Au（Mo）矿床形成于大陆动力体制下的伸展背景,与阿尼玛卿洋壳岩石圈北向俯冲碰撞有关的俯冲板片断离有关。The East Kunlun orogenic belt is one of the important areas of porphyry deposits in China.The authors report situ zircon U-Pb age and whole-rock geochemistry data for the ore-bearing porphyry in the Tuoketuo Cu-Au（Mo）deposit,which contrainted the processes of magmatism andmineralization.Zircon U-Pb dating indicates that the ore-bearing porphyries were emplaced at 232 Ma.These ore-bearing porphyry rocks have high SiO2contents（63.11%-71.78%）,high K contents（2.62%-3.61%）,high MgO contents（0.52%-1.89%）,and low Ti2 O contents（0.26%-0.53%）contents,with aluminum saturation index（A/CNK）of 1.05-1.10.They are enriched in LILEs（Rb,Ba,K and Pb）,depleted in HFSEs（Nb,Ta,Ti and P）,metaluminous and high K calc-alkaline,ranging from granodiorite to monzogranite in I rock type.It is suggested that the Tuoketuo Cu-Au（Mo）deposit is possibly related to extensional regime,which result from the break-off of the slab during the northward subduction of Animaqing Ocean lithosphere.

关 键 词：锆石U-Pb年代学 地球化学 斑岩型Cu-Au(Mo)矿床 托克妥 青海 

分 类 号：P618.41[天文地球—矿床学] P618.51[天文地球—地质学]