新疆哈巴河地区托库孜巴依金矿区两类含矿脉岩LA-ICP-MS锆石U-Pb年龄及其地质意义  

LA-ICP-MS zircon U-Pb ages of two types of ore-bearing dykes in the Tuokuzibayi gold ore district in Habahe area of Xinjiang and their geological significance

作　　者：周能武[1,2] 郭新成 何桂林 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]新疆地勘局第十一地质大队,新疆昌吉831100

出　　处：《地质通报》2012年第5期707-715,共9页Geological Bulletin of China

基　　金：新疆地矿局第十一地质大队自有探矿权项目<新疆哈巴河县哲兰德金矿普查>

摘　　要：新疆阿勒泰南缘托库孜巴依金矿属造山带型金矿,经历了沟弧盆体系、碰撞造山和后碰撞伸展多个演化阶段。矿区内辉长闪长岩脉和花岗斑岩脉较常见,且与金矿化关系密切。采用原位激光剥蚀同位素质谱(LA-ICP-MS)法对2期脉岩进行锆石U-Pb定年,获得花岗斑岩脉侵位年龄384.1Ma±1.5Ma和384.7Ma±1.2Ma,属中泥盆世弧前盆地演化阶段的产物;获得辉长闪长岩脉年龄295.3Ma±3.0Ma,应代表后碰撞伸展期辉长闪长岩脉的结晶年龄。2期脉岩的侵位往往继承了早期的构造部位和后期强韧性剪切的部位,均代表一期金矿化作用。The Tuokuzibayi orogenic-type gold ore belt was formed by multi-stage evolution,which included complete forearc-arc-backarc system,collisional orogeny and post-collisional extensional tectonic activities.The Tuokuzibayi dykes include two intrusive phases,i.e.,the granite-porphyry dyke phase and the diorite dyke phase,both of which are associated with Au mineralization.LA-ICP-MS U-Pb zircon analyses suggest that the granite-porphyry dykes were formed at 384.1±1.5 Ma and 384.7±1.2 Ma,suggesting their generation in a Middle Devonian fore-arc basin setting,whereas the diorite dyke was formed at 295.3±3.0 Ma,implying its generation in a post-collisional extensional setting.The emplacement of these two types of dykes that respectively represented a gold mineralization stage commonly inherited the previous tectonic position and later strong ductile shearing position.

关 键 词：含矿脉岩 LA-ICP-MS锆石U-PB定年 托库孜巴依金矿区 额尔齐斯构造带 

分 类 号：P597.3[天文地球—地球化学] P588.13[天文地球—地质学]