Mesozoic strike-slip movement of the Dunhua-Mishan Fault Zone in NE China: A response to oceanic plate subduction
Mesozoic strike-slip movement of the Dunhua-Mishan Fault Zone in NE China: A response to oceanic plate subduction
复制标题
中国东北敦化-密山断裂带中生代走滑运动对大洋板块俯冲的响应
DOI：
10.1016/j.tecto.2017.12.024
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发表时间：
2018
期刊：
影响因子：
2.9
通讯作者：
Shiye Xiao
中科院分区：
文献类型：
--
作者：
Cheng Liu;Guang Zhu;Shuai Zhang;Chengchuan Gu;Yunjian Li;Nan Su;Shiye Xiao
东北向敦化-密山断裂带是中国东北地区大陆规模的郯庐左旋断裂带的两个分支之一。这里提供的现场数据表明，CA。1000公里长的DMFZ记录了两个阶段的左旋断裂。两期断裂活动所产生的构造分别为NE-SW向韧性剪切带和脆性断裂。糜棱岩显微构造和石英c轴组构表明韧性剪切带的变形温度为450 °C-500 °C。结合本研究中分析的14个火成岩样品的新锆石U-Pb年龄与该地区的地质相结合，表明这些剪切带形成于早白垩世最早期。这一阶段的左旋位移代表了DMFZ的初始形成，响应于郯庐断裂带向北扩展到中国东北。一个阶段的早白垩世裂谷其次是第二阶段的左行断层在102-96马，我们的新的U-Pb年龄为相关的火成岩证明。结合我们的新数据与以前的研究结果表明，DFMZ记录了一个四阶段的白垩纪演化历史，其中最初的左行断裂在早白垩世开始让位于裂谷在早白垩世的其余部分。随后是第二阶段的左行断层在晚白垩世开始和第二阶段的局部裂谷在其余的晚白垩世。DMFZ的白垩纪演化记录了太平洋边缘中国东北大陆的同步构造演化。两期区域性南北向挤压作用产生两期DMFZ内左旋断裂作用，两期区域性伸展作用产生两期裂谷作用。这两次挤压事件是Izanagi和太平洋板块快速低角度俯冲的结果，而两阶段伸展则是由这些板块各自的回滚引起的。早白垩世初蒙古-鄂霍次克洋的最终闭合，加强了中国东北地区的同步挤压作用，导致了郯庐断裂带向北的扩展。
The NE-striking Dunhua–Mishan Fault Zone (DMFZ) is one of two branches of the continental-scale sinistral Tan–Lu Fault Zone in NE China. The field data presented here indicate that the ca. 1000 km long DMFZ records two phases of sinistral faulting. The structures produced by these two phases of faulting include NE–SW-striking ductile shear belts and brittle faults, respectively. Mylonite-hosted microstructures and quartzc-axis fabrics suggest deformation temperatures of 450 °C–500 °C for the ductile shear belts. Combining new zircon U–Pb dates for 14 igneous rock samples analyzed during this study with the geology of this region indicates these shear belts formed during the earliest Early Cretaceous. This phase of sinistral displacement represents the initial formation of the DMFZ in response to the northward propagation of the Tan–Lu Fault Zone into NE China. A phase of Early Cretaceous rifting was followed by a second phase of sinistral faulting at 102–96 Ma, as evidenced by our new U–Pb ages for associated igneous rocks. Combining our new data with the results of previous research indicates that the DFMZ records a four-stage Cretaceous evolutionary history, where initial sinistral faulting at the beginning of the Early Cretaceous gave way to rifting during the rest of the Early Cretaceous. This was followed by a second phase of sinistral faulting at the beginning of the Late Cretaceous and a second phase of local rifting during the rest of the Late Cretaceous. The Cretaceous evolution of the DMFZ records the synchronous tectonic evolution of the NE China continent bordering the Pacific Ocean. Two phases of regional N–S compression generated the two phases of sinistral faulting within the DMFZ, whereas two-stage regional extension generated the two phases of rifting. The two compressive events were the result of the rapid low-angle subduction of the Izanagi and Pacific plates, whereas the two-stage extension was caused by the roll-back of these respective plates. The final closure of the Mongol–Okhotsk Ocean at the beginning of the Early Cretaceous intensified the synchronous compression in NE China, causing the northward propagation of the Tan–Lu Fault Zone.