Deformation history of the Hengshan complex: Implications for the tectonic evolution of the Trans-North China Orogen
Deformation history of the Hengshan complex: Implications for the tectonic evolution of the Trans-North China Orogen
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DOI：
10.1016/j.jsg.2007.02.013
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发表时间：
2007-06
影响因子：
3.1
通讯作者：
Jian Zhang;Guochun Zhao;San-zhong Li;M. Sun;Shuwen Liu;S. Wilde;A. Kröner;C. Yin
中科院分区：
文献类型：
--
作者：
Jian Zhang;Guochun Zhao;San-zhong Li;M. Sun;Shuwen Liu;S. Wilde;A. Kröner;C. Yin
构造分析表明，恒山杂岩经历了5期（D1-D5）变形。D1幕形成小型等斜褶皱（F1）、贯通轴面叶理（S1）和矿物拉伸线理（L1）。D1织物经D2变形后进行再加工。与D2相对应的是北西向不对称褶皱和逆冲断层的发育。D_1和D_2均为地壳增厚的产物，与俯冲变质作用和峰期变质作用有关。D_2变形后，D_3发生压扭性右旋剪切作用，包括顶-NW向走滑剪切作用和北北东-南西西向右旋走滑剪切作用。持续的碰撞导致了朱家坊韧性剪切带（D4）的发育，这是一条横跨恒山杂岩的近东西向高应变带。D_5变形以F_5张开褶皱和伴生正断层为特征，可能与杂岩的折返作用有关。恒山杂岩的构造样式可以为最近提出的构造模式提供重要的见解，该模式认为东、西地块之间的海洋在东地块西缘之下经历了向东的俯冲，该海洋的闭合最终导致了两个地块之间的碰撞，形成了连贯的华北板块。
Structural analysis indicates that the Hengshan Complex underwent five distinct episodes of deformation (D1–D5). The D1episode formed small isoclinal folds (F1), penetrative axial planar foliations (S1) and mineral stretching lineations (L1). D1fabrics were reworked by following D2deformation. Associated with D2was the development of NW-verging asymmetric folds and accompanying thrust faults. Both D1and D2resulted from crustal thickening and coherent with prograde and peak metamorphism. D2deformation was followed by transpressional dextral shearing (D3), including top-to-NW oblique-slip shearing and NNE–SSW dextral strike-slip shearing. Ongoing collision led to development of the Zhujiafang ductile shear zone (D4), a near E–W trending high strain belt across the Hengshan Complex. D5deformation is characterized by F5open folds and associated normal faults, probably related to exhumation of the complex. Structural patterns of the Hengshan Complex can place important insights into a recently proposed tectonic model suggesting that an ocean between the Eastern and Western Blocks underwent eastward-directed subduction beneath the western margin of the Eastern Block, and closure of this ocean finally led to collision between the two blocks to form the coherent North China Craton.