Rupture segmentation and slip partitioning of the mid-eastern part of the Kunlun Fault,north Tibetan

来源 :Science China(Earth Sciences) | 被引量 : 0次 | 上传用户:ttingting
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The Kunlun Fault,an active fault on the border between the Bayan Har and Kunlun-Qaidam blocks,is one of the major left lateral strike-slip faults in the Tibetan Plateau.Previous research has not reached a consensus on agreeable slip rates along much of its length and the slip rate gradient along the eastern part,both of which play critical roles in a range of models for the eastward extrusion and thickened crust of the Tibetan Plateau.New slip rates have been determined at sites along the eastern part of the Kunlun Fault by dating deposits and measuring atop displaced fluvial terrace risers.Field investigations and interpretation of satellite images reveal geometrical features of the fault and the late Quaternary offset,new earthquake ruptures and surface-rupturing segmentation,from which long-term slip rates and earthquake recurrence intervals on the fault are estimated.The tectonic geomorphology method has determined that the long-term horizontal slip rates on the Tuosuohu,Maqin and Maqu segments from west to east are 11.2±1,9.3±2,and 4.9±1.3 mm/a while their vertical slip rates are 1.2±0.2,0.7±0.1,and 0.3 mm/a in the late Quaternary.Results indicate that the slip rates regularly decrease along the eastern ~300 km of the fault from >10 to <5 mm/a.This is consistent with the decrease in the gradient such that at the slip rate break point is at the triple point intersection with the transverse fault,which in turn is transformed to the Awancang Fault.The vector decomposition for this tectonic transformation shows that the western and eastern branches of the Awancang Fault fit the slip-partitioning mode.The slip rate of the southwestern wall is 4.6 mm/a relative to the northeastern wall and the slip direction is 112.1°.The mid-eastern part of the Kunlun Fault can be divided into three independent segments by the A’nyêmaqên double restraining bend and the Xigongzhou intersection zone,which compose the surface rupture segmentation indicators for themselves as well as the ending point of the 1937 M7.5 Tuosuohu earthquake.The average recurrence interval of the characteristic earthquakes are estimated to be 500-1000 a,respectively.The latest earthquake ruptures occurred in AD 1937 on the western Tuosuohu segment,as compared to ~514-534 a BP on the Maqin segment,and ~1055 to 1524 a BP on the Maqu segment.This may indicate a unidirectional migration for surface rupturing earthquakes along the mid-eastern Kunlun Fault related to stress triggered between these segments.Meanwhile,the long-term slip rate is obtained through the single event offset and the recurrence interval,which turn out to be the same results as those determined by the offset tectonic geomorphology method,i.e.,the decreasing gradient corresponds to the geometrical bending and the fault’s intersection with the transverse fault.Therefore,the falling slip rate gradient of the mid-eastern Kunlun Fault is mainly caused by eastward extension of the fault and its intersection with the transverse fault. The Kunlun Fault, an active fault on the border between the Bayan Har and Kunlun-Qaidam blocks, is one of the major left lateral strike-slip faults in the Tibetan Plateau. Previous research has not reached a consensus on agreeable slip rates along much its length and the slip rate gradient along the eastern part, both of which play critical roles in a range of models for the eastward extrusion and thickened crust of the Tibetan Plateau. New slip rates have been determined at sites along the eastern part of the Kunlun Fault by dating deposits and measuring atop displaced fluvial terrace risers. Field investigations and interpretation of satellite images reveal geometrical features of the fault and the late Quaternary offset, new earthquake ruptures and surface-rupturing segmentation, from which long-term slip rates and earthquake recurrence intervals on the fault are estimated. The tectonic geomorphology method has determined that the long-term horizontal slip rates on the Tuosuohu, Maqin and Maqu segments from west to east are 11.2 ± 1,9.3 ± 2, and 4.9 ± 1.3 mm / a while their vertical slip rates are 1.2 ± 0.2, 0.7 ± 0.1, and 0.3 mm / a in the late Quaternary. Results indicate that the slip rates regularly decrease along the eastern ~ 300 km of the fault from> 10 to <5 mm / a. This is consistent with the decrease in the gradient such that at the slip rate break point is at the triple point intersection with the transverse fault , which in turn is transformed to the Awancang Fault. The vector decomposition for this tectonic transformation shows that the western and eastern branches of the Awancang Fault fit the slip-partitioning mode. The slip rate of the southwestern wall is 4.6 mm / a relative to the northeastern wall and the slip direction is 112.1 °. The mid-eastern part of the Kunlun Fault can be divided into three independent segments by the A’nyêmaqên double restraining bend and the Xigongzhou intersection zone, which compose the surface rupture segmentation indicators for themselves as well as the ending point of the 1937 M7.5 Tuosuohu earthquake.The average recurrence interval of the characteristic earthquakes are estimated to be 500-1000 a, respectively. the latest earthquake ruptures occurred in AD 1937 on the western Tuosuohu segment, as compared to ~ 514 -534 a BP on the Maqin segment, and ~ 1055 to 1524 a BP on the Maqu segment. This may indicate a unidirectional migration for surface rupturing earthquakes along the mid-eastern Kunlun Fault related to stress triggered between these segments. -term slip rate is obtained through the single event offset and the recurrence interval, which turn out to be the same result as those determined by the offset tectonic geomorphology method, ie, the decreasing gradient corresponds to the geometrical bending and the fault’s intersection with the transverse fault.Therefore, the falling slip rate gradient of the mid-eastern Kunlun Fault is mainly caused by eastward extension of the fault and its intersection with the transveness rse fault.
其他文献
32P探针杂交是病原微生物基因诊断应用最广泛的方法之一。在建立了人巨细胞病毒PCR、套式PCR的基础上,我们用613bpPCR外引物扩增产物制备了杂交探针,并与300bp内引物扩增产物进行转膜杂交,可将单纯琼脂
切除5只成年雄猫一侧L1~L5和L7~S2背根,保留L6背根为备用根。术后11d用两侧背角提取液大于50k组份进行实验。发现,手术组电泳迁移率为0.1的蛋白带内的蛋白含量明显增多,且其对鸡胚背根节神经突起生长的
我心目中的《贵州档案》——写在《贵州档案》创刊20周年之际@典延纯$山东海阳市档案局!原局长 My opinion of the “Guizhou archives” - written in the “Guizhou archi
期刊
主持人语正确理解马克思主义的接受美学,并将其方法论引入艺术史研究领域,这对于促进艺术史特别是美术史研究的深入开展具有重要的现实意义。胡光华辨析了西方一些美学家对马
DNA倍性并非直肠类癌的预后因素(英)\=FitzgeraldS,etal.DisColonRectum,1996;39(6):643 ̄648直肠类癌在直肠肿瘤中不足1%,其处理主要依据肿瘤的大小与浸润深度,但<1cm的类癌亦有转移,而>2cm或侵袭... DNA ploidy is not a prognostic factor for rec
本文就思维教学在初中英语口语教学中的具体运用对策与手段,展开细致的探讨研究,期望为初中英语口语教育质量的提升,以及学生英语表达与思维能力的培养,提供有益的参考。 In
阜阳市局 £4a 局长——_MINtkMMtgj’#lnH$B——q.M——D收束志不他只邀狲位J则【科校为先导推动地租工作.B为广为戳民U用凶盼引眯B.习.互们羹宽.互狈槽竺汹IAn.刊 办好杂志。必
强有力的微磁学计算机模拟和近年来提出的微磁学显微成像新技术,有助于深入理解亚微米级的磁化过程。概略介绍了微磁学模型的建立过程,及其在磁记录膜等磁性薄膜中的应用。最后
用识别人活化B细胞分化抗原5C5的单克隆抗体5C5和5C5-G1的混合物从人扁桃体细胞λgtll cDNA文库筛选到3个阳性克隆。其cDNA插入到质粒pUC18,经双链双脱氧测序法作核苷酸序列分析,知其中一个cDNA长613bp,另二个长467bp,后者与前者的前467bp完全重叠。613bp cDNA中有一个开放阅读框架,从103bp到429bp,共327bp。Northern印迹分析显示,此6
近年来研究表明DNA直接接种动物体内可诱导机体产生免疫反应,很可能成为预防感染的新型疫苗,即基因疫苗。含HCV基因重组质粒DNA的工程菌是否也有可能在预防HCV感染中发挥一定的作用?本文初步