摘要
新疆西天山温泉县城南部温泉岩体群研究程度较低,本文在野外地质调查的基础上,通过精确的LA-ICP-MS锆石U-Pb定年研究,对温泉岩体群进行重新定位和解体。温泉岩体群中细粒二长花岗岩的锆石U-Pb年龄为884±6 Ma,定位为青白口纪;闪长岩、石英闪长岩、花岗闪长岩的锆石U-Pb年龄分别为465±3 Ma、464±3 Ma、452±3 Ma,定位为奥陶纪。这些年代学数据填补了本区岩体年龄资料的不足,限定了温泉岩体群的形成时限,表明该地区存在新元古代早期及早古生代两期重要的岩浆活动。通过对天山不同地区新元古代和奥陶纪岩浆岩年龄和岩石类型的对比研究,认为包括研究区在内的天山地区在新元古代早期参与了Rodinia超大陆的汇聚,并在早古生代奥陶纪进入消减机制的古亚洲洋演化阶段,这对认识天山地区区域构造演化具有重要的地质意义。
The Wenquan pluton group in the south of Wenquan County,western Tianshan has been little documented previously.Based on field geological survey,this work conducted accurate LA-ICP-MS zircon U-Pb dating to reposition and disintegrate this pluton group.The medium-to fine-grained monzonitic granite in the Wenquan pluton group yielded zircon U-Pb age of 884±6 Ma,belonging to the Qingbaikou Period.The diorite,quartz diorite and granodiorite yielded zircon U-Pb ages of 465±3 Ma,464±3 Ma and 452±3 Ma,respectively,belonging to the Ordovician.These chronological data fill the shortage of few pluton ages in this area,and limit the formation time of Wenquan pluton group.It is indicated that this area has undergone two important magmatic activities in the early Neoproterozoic and Early Paleozoic.This work also compared the ages and rock types of Neoproterozoic and Ordovician magmatic rocks in different areas of Tianshan.The Tianshan area,including the study area,participated in the convergence of the Rodinia supercontinent in the early Neoproterozoic and entered the paleo-Asian Ocean evolution of subduction mechanism in the Ordovician of Early Paleozoic,which is of great geological significance to understand the regional tectonic evolution.
作者
孟令华
马明永
崔庆岗
MENG Linghua;MA Mingyong;CUI Qinggang(Shandong Geological Prospecting Institute of Chemical Geology and Mine Bureau,Tai’an,Shandong 271000;Shandong Provincial Research Institute of Coal Geology Planning and Exploration,Jinan,Shandong 250104)
出处
《地质与勘探》
CAS
CSCD
北大核心
2022年第3期597-608,共12页
Geology and Exploration
基金
中央返还新疆两权价款项目(编号:T15-1-LQ17)资助。
