秦岭中段印支期花岗质岩浆作用与造山过程  

Indosinian Granitoids and Orogenic Processes in the Middle Segment of the Qinling Orogen,China

作　　者：刘树文[1] 杨朋涛[1] 李秋根[1] 王宗起[2] 张万益[1] 王伟[1] 

机构地区：[1]北京大学造山带与地壳演化教育部重点实验室,北京100871 [2]中国地质科学院矿产资源研究所,北京100037

出　　处：《吉林大学学报（地球科学版）》2011年第6期1928-1943,共16页Journal of Jilin University：Earth Science Edition

基　　金：'十二.五'国家科技支撑计划项目(2011BAB04B05);'十一.五'国家科技支撑计划项目(2006BAB01A11)

摘　　要：据新测得的41个样品的秦岭中段花岗质岩石锆石U-Pb同位素年龄数据,结合近期发表的秦岭花岗岩年代学和岩石成因的研究资料,将秦岭中段印支期花岗质岩浆作用分为早期(248～216Ma)、中期(215～201Ma)和晚期(200～195Ma)3个阶段。早期阶段形成于勉略洋闭合过程,发育于洋壳向北俯冲到浅表地壳碰撞过程;中期阶段形成于扬子克拉通北缘与华北克拉通南缘北秦岭岛弧杂岩的同碰撞到造山带垮塌过程;晚期阶段形成于碰撞后造山带拆沉作用。因此,秦岭中段印支期花岗质岩浆作用较为完整地记录了造山带的演化过程。Using recent research results and previously published data of chronology and petrogenesis,the authors have divided the Indosinian granitoid magmatism into three stages in the middle segment of the Qinling orogen.The early stage of the magmatism is attributed to the northward subduction of oceanic slab coupled with the closure of the Mianxian-Lueyang ocean during 248-216 Ma.The middle stage of the magmatism occurred in the period from the collision between the northern margin of the Yangtze Craton and the North Qiling arc complex zone to the collapse of the orogen during 215-200 Ma.The late stage of the magmatism is considered to have resulted from the delamination of the orogenic root in the post-collision period during 200-195 Ma.Therefore,the Indosinian granitoid magmatism perfectly registered the evolutionary processes of the Qinling orogenic belt.

关 键 词：秦岭中段 印支期 花岗岩 造山带演化 

分 类 号：P588.1[天文地球—岩石学] P542.2[天文地球—地质学]