地学前缘 ›› 2010, Vol. 17 ›› Issue (4): 15-32.

• 论文 • 上一篇    下一篇

川主寺—黄龙左行走滑剪切断层和松潘—平武剪切转换构造体制

张家声, 黄雄南, 牛向龙, 刘峰   

  1. 中国地震局 地质研究所, 北京 100029
  • 收稿日期:2010-02-09 修回日期:2010-04-06 出版日期:2010-07-01 发布日期:2010-07-01
  • 作者简介:张家声(1946—),男,博士，研究员，博士生导师，构造地质学专业。Email: jszhang@public3.bta.net.cn
  • 基金资助:

    国家重点基础研究发展计划“973”项目(2008CB425703);科学技术部国际科技合作计划项目(2008DFA20700)

ChuanzhusiHuanglong strikeslip faults and a transpressional shear system in SongpanPingwu Area, Northwestern Sichuan, China.

 ZHANG  Jia-Qing, HUANG  Xiong-Na, NIU  Xiang-Long, LIU  Feng   

  1. Institute of Geology, China Earthquake Administration, Beijing 100029, China
  • Received:2010-02-09 Revised:2010-04-06 Online:2010-07-01 Published:2010-07-01

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摘要：

石炭系碳酸盐岩中大规模断层崖残留体是研究区新构造变动的显著地貌特征。相关摩擦滑动面的产状、擦痕线理定向及其运动学标志的野外观测数据表明,西起川主寺,东抵黄龙乡,中更新世(Q2)以来存在一条近东西走向的左行走滑断层。沿川主寺—黄龙左行走滑断层的位移在切错了近SN走向的岷山隆起后,向东追踪并改造先存的雪山逆冲断层,在黄龙乡以东通过3种方式发生了构造和位移转换,即(1)其前方北侧派生出一系列NE走向的左行剪切断裂;(2)沿走向位移逐渐减弱为顺层滑动;(3)其前方南侧转化为沿近SN向虎牙断裂的左旋斜冲。川主寺—黄龙断裂的构造几何学和运动学特征及其与岷江、虎牙冲断层的构造联系,支持一个左行剪切转换构造体制。松潘—平武地区的卫星遥感图像,1970—2008年的地震活动性,以及1991年以来4次GPS重复测量结果所建立的现今位移矢量场等证据表明,川主寺—黄龙左行走滑断裂系统是继东昆仑—岷江断裂组合之后发育起来的、现在仍然活动的剪切转换断裂构造,是青藏高原东缘东北角的典型地震构造样式之一,反映了青藏高原物质具有向东逃逸的趋势。

关键词: 川主寺&mdash, 黄龙, 断层崖, 擦痕线理, 地震构造, 转换断层

Abstract:

 Relics of faultage cliff in Carboniferous carbonate rocks are one of the distinct landforms resulted from neotectonic movement in the study area. Frictional traces and kinematic indicators on various fracture surfaces within the relics demonstrated that a nearly EW trending, left lateral strikeslip fault extending from Chuanzhusi in the west to Huanglong village in the east occurred since the MedioPleistocene. The recognized ChuanzhusiHuanglong strikeslip fault cut off an older SN trending Minjiang thrusting system, running eastwards, following and reworking the previous Xueshan Thrust Belt, and finally transforming itself into three alternating fault components: (1)growing into a group of NE trending shear bands at its northern side, (2)becoming interlayergliding at its front where the layering subparallel to the fault，and (3)transforming its movement sense to be an oblique down slip along a SN trending Huya thrust at its southern side. The geometry and kinematics of the ChuanzhusiHuanglong strikeslip fault and its regional tectonic relationships with the Minjiang and the Huya thrust system are in favor of a left lateral transform strikeslip fault system. The data derived from interpretation of satellite remote sensing images, the analysis of seismicity in 19702008 and the displacement vector field induced by GPS measurements that repeated four times since 1991 in the SongpanPingwu Area show that the ChuanzhusiHuanglong strikeslip fault system is an active transpressional shear belts developed following the eastern KunlunMinjiang transpressional shear fault system, and is one of the typical seismotectonic model in the northeastern corner of the QinghaiTibet Plateau, indicating the eastward escape of the Tibet Plateau materials.

Key words: ChuanzhusiHuanglong, faultage cliff, frictional traces, seismotectonic, transpressional shear belts

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