内蒙古查干敖包石英闪长岩锆石SHRIMP U-Pb年龄及其地质意义  

Zircon SHRIMP U-Pb age of quartz diorite in Qagan Obo of Inner Mongolia and its geological significance

作　　者：张万益[1] 聂凤军[1] 江思宏[1] 刘妍[1] 许东青[1] 郭灵俊[2] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]内蒙古自治区地质调查院,内蒙古呼和浩特010020

出　　处：《岩石矿物学杂志》2008年第3期177-184,共8页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目(40573025)

摘　　要：内蒙古查干敖包石英闪长岩位于西伯利亚板块南缘白音乌拉-东乌珠穆沁旗碱性花岗岩带东部,在时空分布上与查干敖包矽卡岩型铁-锌矿床关系密切。石英闪长岩中的岩浆结晶锆石SHRIMP U-Pb测年结果显示206Pb/238U加权平均年龄为237±6Ma(1σ),MSWD=0.63。根据野外地质调查和室内研究资料,并结合上述同位素年龄数据可以推测查干敖包石英闪长岩和铁-锌矿床形成于印支期,它们同属兴蒙造山带碰撞后拉张构造环境的产物。Located in the eastern part of the Baiyinwula-Dong Ujimqin Banner alkali granite belt on the southern edge of the Siberian plate, the Qagan Obo quartz diorite stock has an intimate temporal and spatial relationship with the Qagan Obo Fe-Zn deposit. SHRIMP magmatic zircon U-Pb dating of quartz diorite stock yields an age of 237 ± 6 Ma （1σ）, with the MSWD value being 0.63. Based on field geological investigation and laboratory data in combination with the result of zircon dating, it is suggested that the quartz diorite and its associated FeZn ore bodies were formed in Indosinian period. Both of them were formed in a post-collision extensional tectonic setting within the Xing＇ anling-Mongolia orogenic belt.

关 键 词：石英闪长岩 锆石SHRIMP U-PB测年 兴蒙造山带 印支期 查干敖包 内蒙古 

分 类 号：P597.3[天文地球—地球化学] P588.122[天文地球—地质学]