文档介绍：第16卷第3期
2009年5月
地学前缘(中国地质大学(北京)；北京大学)
Earth Science Frontiers (Ch ina University of Geosciences(Beijing) ; Peking Uniear structur al belt. Based on the deformational sequence, deformed str ata, and re gional geology, the authors believe that t he time of D1, both in western and in central and eastern Dabashan curvilinear structural belt, is the late Triassic to the early Jurassic. It is possible that the deformation D1 was related to the collision between north China block and Yangtze block. On the other hand, t he geological rela tionship, geochronology and AFT data show that the main deformation time of D2, is about the late Jurassic to the early Cretaceous( 160 110 Ma). So the Dabashan curvilinear structur al belt recorded two phasesof deformation which were fo rmed during different tectonic settings. It is of great significance for the understanding of the evolut ion of Qinling orogen.
Key words: Qinling orogen; Dabashan curvilinear str uctural belt; Mesozoicdeformation; detachment deformation
摘要:大巴山构造带位于秦岭造山带南部，一直被认为是华北、扬子板块碰撞带前陆逆冲推覆构造带。研究表明，位于城口)房县断裂之南的大巴山弧形构造带，经历了两次明显的叠加变形过程。大巴山弧形构造带由轴向弧形延伸的线状褶皱与弧形弯曲的逆冲断层组成(D2),是南大巴山主期变形产物。弧形构造带西
收稿日期：200903-25;修回日期：2009 0520
基金项目：国家自然科学基金项目 (40830314, 40272097)
作者简介：胡健民(1959)),男,研究员，从事构造地质学、造山带与盆地构造、南极地质研究。 E mail: jianmin hu@ vip. sina. com
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# 胡健民,施炜,渠洪杰,等/地学前缘 (Earth Science Frontiers) 2009, 16 ( 3)
50 胡健民,施炜,渠洪杰,等/地学前缘 (Earth Science Frontiers) 2009, 16 ( 3)
段褶皱轴向为北北西）近南北向，叠加在先前轴向近东西向的开阔宽缓的褶皱（D1）之上,形成典型横跨叠加构造。弧形构造带中段和东段，褶皱轴向逐渐转变为近东西向。构造填图显示，在弧形带形成之前，发生过一期轴向北东到北北东向褶皱为主的变形（D1）。据变形序列、卷入的地层以及区域构造关系判断，西段与中、东段D1变形时代均为晚三叠世）早侏罗世，很可能与华北、扬子的碰撞相关。而相关的地质、同位素年代学及磷灰石裂变径迹资料显示，大巴山弧形构造带主期变形（D2）的变形时代为晚侏罗世）早白垩世（160 〜110 Ma）,所以大巴山弧形构造带记录了两期不同系统构造变形的叠加，这对研究秦岭造山带的演化，具有重要意义。
关键词：秦岭造山带；大巴山弧形构造带；中生代变形；滑脱拆离构造
中图分类号：P542 文献标志码：A 文章编号：1005 2321（2009） 03 0049 20
# 胡健民,施炜,渠洪杰,等/地学前缘 (Earth Science Fr