Quaternary Activity of the Beihewan Fault in the Southeastern Beishan Wrench Belt, Western China: Implications for Crustal Stability and Intraplate Earthquake Hazards North of Tibet
Quaternary Activity of the Beihewan Fault in the Southeastern Beishan Wrench Belt, Western China: Implications for Crustal Stability and Intraplate Earthquake Hazards North of Tibet
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中国西部北山扳手带东南部北河湾断裂第四纪活动：对西藏北部地壳稳定性和板内地震灾害的影响
DOI：
10.1029/2018jb017209
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发表时间：
2019-12
期刊：
影响因子：
--
通讯作者：
Shuqing Miao（苗树青）
中科院分区：
文献类型：
--
作者：
Haibo Yang（杨海波）;Xiaoping Yang（杨晓平）;Yan Zhan（詹艳）;Dickson Cunningham;Lingqiang Zhao（照凌强）;Xiangyu Sun（孙翔宇）;Zongkai Hu（胡宗凯）;Xiongnan Huang（黄雄南）;Weiliang Huang（黄伟亮）;Shuqing Miao（苗树青）
本文提供了中国西部北山地块东南缘北河湾断裂晚第四纪活动的证据。现场观测和分析无人机衍生的DEMS和谷歌地球图像显示，在以前被认为是构造不活跃的地区，有一条约10公里长的活动断层痕迹。错位地貌和沟槽暴露表明，断裂以走滑为主，局部逆冲或正常位移。自全新世以来，左旋运动和逆冲的平均速率估计分别为~2.69 mm/a和~0.35 mm/a。最近一次地表破裂事件自6.2-8.6ka以来产生了约2.5m的走滑偏移量，估计M=6.3-6.9。新的大地电磁资料的模拟和二维反演表明，BHWF是一个穿透下地壳的亚垂直低阻带。现有的地质和地球物理证据不支持BHWF与河西走廊更南边的阿尔金-塔格-南山断裂系统之间的地下联系。对BHWF以西和以东的高分辨率卫星图像进行了仔细检查，发现了其他第四纪地表断层崖、压力脊、偏置排水沟和截断的岩性走向带。总体而言，这些特征构成了沿北山东南部和河西走廊北部边界的一条以前未被识别的150公里长的左行变形带，我们称之为北山东南扳带。北山东南部沿BHWF的第四纪活动的认识。扭动带挑战了长期以来的假设，即北山地区是西藏北部晚新生代印欧亚变形场内的一个相对稳定的构造不活跃的块体。
We present evidence for the Late Quaternary activity of the Beihewan Fault (BHWF), along the.southeastern margin of the Beishan block, western China. Field observations and analysis of UAV‐derived.DEMs and Google Earth images reveal an ~10‐km‐long active fault trace in a region previously.considered tectonically inactive. Offset landforms and trench exposures reveal that the fault is dominantly.strike‐slip, with local thrust or normal displacements. Average rates of left‐lateral motion and thrusting since.the Holocene are estimated to be ~2.69 and ~0.35 mm/a, respectively. The most recent surface‐rupturing.event generated ~2.5 m of strike‐slip offset since 6.2–8.6 ka; with estimated M = 6.3–6.9. Modeling and.two‐dimensional inversion of new magnetotelluric data indicate that the BHWF is a subvertical.low‐resistivity zone that penetrates into the lower crust. Existing geological and geophysical evidence do not.support subsurface linkage between the BHWF and Altyn Tagh–Jinta‐Nanshan Fault system further south in.the Hexi Corridor. Close examination of high‐resolution satellite imagery west and east of the BHWF.reveals other Quaternary surface fault scarps, pressure ridges, offset drainages, and truncated lithological.strike belts. Collectively, these features constitute a previously unrecognized 150‐km‐long sinistral deforming.belt along the southeastern Beishan and northern Hexi Corridor boundary that we call the Southeast Beishan.Wrench Belt. Recognition of Quaternary activity along the BHWF within the larger Southeast Beishan.Wrench Belt challenges long‐held assumptions that the Beishan region is a relatively stable and tectonically.inactive block within the Late Cenozoic Indo‐Eurasian deformation field north of Tibet.
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DOI：
10.5194/egusphere-egu21-12517
发表时间：
2019-04
期刊：
--
影响因子：
--
作者：
Nimrod Wieler;A. Mushkin;Huiping Zhang;E. Shelef;A. Sagy;Z. Ren;F. Huang;Jinrui Liu;P. Shi
通讯作者：
Nimrod Wieler;A. Mushkin;Huiping Zhang;E. Shelef;A. Sagy;Z. Ren;F. Huang;Jinrui Liu;P. Shi
影响因子：
8.3
作者：
C. B. Ramsey;E M Scott;J. van der Plicht
通讯作者：
C. B. Ramsey;E M Scott;J. van der Plicht
影响因子：
3
作者：
Xi-wei Xu;R. Yeats;Gui-hua Yu
通讯作者：
Xi-wei Xu;R. Yeats;Gui-hua Yu
影响因子：
4.2
作者：
Peizhen Zhang;P. Molnar;Xi-wei Xu
通讯作者：
Peizhen Zhang;P. Molnar;Xi-wei Xu
影响因子：
2.8
作者：
V. Godard;R. Cattin;J. Lavé
通讯作者：
V. Godard;R. Cattin;J. Lavé