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Science China Earth Sciences 2011年第11期54卷 1730-1745页

作者： LI ChenXia XU XiWei WEN XueZe zheng rongzhang CHEN GuiHua YANG Hu AN YanFen GAO Xiang Institute of Geology China Earthquake Administration National Center of Active Fault Studies Beijing 100029 China Lanzhou Seismological Institute of China Earthquake Administration Lanzhou 730000 China Earthquake Administration of Sichuan Province Chengdu 610041 China

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 Ma- qu 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＇nyemaqen double restraining bend and the Xigongzhou intersection zone, which compose the surface rupture segmentation indicators for t

关键词： mid-eastern Kunlun Fault slip rate surface rupture segmentation slip partition paleoearthquake Tibetan Plateau

Average slip-rate and recent large earthquake ruptures along the Garzê-Yushu fault

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Science China Earth Sciences 2003年第Z2期46卷 276-288页

作者： WEN Xueze (闻学泽) XU Xiwei (徐锡伟) zheng rongzhang (郑荣章) XIE Yingqing (谢英情) WAN Chuang (万创) Seismological Bureau of Sichuan Province Chengdu 610041 China Institute of Geology China Seismological Bureau Beijing 100029 China Institute of Geology China Seismological Bureau Beijing 100029 China Seismological Bureau of Yunnan Province Kunming 650041 China Seismological Bureau of Sichuan Province Chengdu 610041 China

Our field investigation obtains new evidence of the later Quaternary activity and recent large earthquake ruptures of the Garzê-Yushu fault. The average left-lateral slip-rate along the fault is determined to be (12 ± 2) mm/a for the last 50000 years from both offset landforms and ages of the correlative sediments. This result is very close to the estimated average left-lateral slip-rate for the Xianshuihe fault, suggesting that the horizontal movement along the northern boundary of the Sichuan-Yunnan active tectonic block and the northeastern boundary of the Qiangtang active tectonic block has been basically harmonious during the later Quaternary period. Remains of ground ruptures of recent large earthquakes have been discovered along all 3 segments of the fault, of which, the 1896 rupture on the northwestern segment is at least 70 km long, and its corresponding earthquake could be of moment magnitude 7.3. The latest rupture on the middle segment of the fault has a length of about 180 km, and was produced by an unknown-age large earthquake that could have a moment magnitude of about 7.7. Along the southeastern segment of the fault, the latest unknown-age rupture is about 65 km long and has a maximum left-lateral coseismic displacement of 5.3 m, and its corresponding earthquake is estimated to be as large as about 7.3 of moment magnitude. Based on relevant investigation, an inference has been drawn that the later two large earthquakes probably occurred in 1854 and 1866, respectively. These demonstrate that the individual segments of the studied Garzê-Yushu fault are all able to produce large earthquakes.

关键词： Garzê-Yushu fault, average slip-rate, earthquake rupture, earthquake timing.

Pattern of latest tectonic motion and its dynamics for active blocks in Sichuan-Yunnan region, China

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Science China Earth Sciences 2003年第Z2期46卷 210-226页

作者： XU Xiwei (徐锡伟) WEN Xueze (闻学泽) zheng rongzhang (郑荣章) MA Wentao (马文涛) SONG Fangming (宋方敏) YU Guihua (于贵华) Institute of Geology China Seismological Bureau Beijing 100029 China Seismological Bureau of Sichuan Province Chengdu 610041 China Institute of Geology China Seismological Bureau Beijing 100029 China Institute of Geology China Seismological Bureau Beijing 100029 China Institute of Geology China Seismological Bureau Beijing 100029 China Institute of Geology China Seismological Bureau Beijing 100029 China

Based on the concept of "active blocks" and spatial distribution of historical earthquakes with surface ruptures as well as major and subordinate active faults. The Sichuan-Yunnan region can be divided into four first-order blocks. They are the Markam block (I), the Sichuan-Yunnan rhombic block (II), Baoshan-Pu'er block (III), and Mizhina-Ximeng block (IV). Cut by sub-ordinate NE-trending active faults, the Sichuan-Yunnan rhombic block (II) can be further divided into two sub-blocks: the northwestern Sichuan sub-block (II1) and the middle Yunnan sub-block (II2), while the Baoshan- Pu'er block (III) can be further divided into three sub-blocks: Baoshan sub-block (III1), Jinggu sub-block (III2), and Mengla sub-block (III3). A quantitative study of offset landforms is carried out and the basic types of active faults and their long-term slip rates along the major boundaries of active blocks of different orders in the Sichuan-Yunnan region are determined, through slip vector analysis, the motion states of the active blocks are clarified and the deformation coordination on the block margins is discussed. It is suggested that the tectonic motion of the blocks in this region is a complex or superimposition of three basic types of motions: southeastward sliding, rotating on vertical axis, and uplifting. The Markam block (I), the northwestern Sichuan sub-block (II1), and middle Yunnan sub-block (II2) have a southeastward horizontal sliding rate of 1-5 mm/a, clockwise rotating angular rate of 1.4-4(/Ma, and uplifting rate of about 1 mm/a. The Baoshan-Pu'er (III) and Mizhina-Ximeng (IV) blocks have also been extensively clockwise rotated. This pattern of motion is a strain response to the collision between the Indian and Eurasian plates and the localized deformation and differential slip on the block margins associated with the northward motion of the Indian Plate. Because a set of transverse thrusts between the blocks absorbs and transforms some components of eastward or south

关键词： Sichuan-Yunnan region, active fault, active block, block rotation, tectonic motion.

Research on the Effects of the Contents of Radioactive Elements on Granularity and Climate Change:An Example of SZK1 and SZK2 Drill Holes Strata in the Fuzhou Basin

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Earthquake Research in China 2006年第4期20卷 469-478页

作者： zheng rongzhang Xu Xiwei Li Jianping State Key Laboratory of Earthquake Dynamics Institute of Geology CEA Beijing 100029 China Center for Active Tectonic Studies ＆ Institute of Geology CEA Beijing 100029 China

Based on the content of radioactive elements (U, Th, K) of strata in two drill holes in the Fuzhou basin, and combined with the result of spore_pollen analysis, the relationship between radioactivity and lithology and deposit environments is discussed and the results show that the content of radioactive substances is related to the granularity and lithology in sediment, and it is higher in argillaceous sediment (e.g. silt and clay), lower in sand sediment and in the middle in gravels between the above two kinds of sediment. The content of radioactive substances is also related to paleoclimate. A warm and humid environment is propitious to the deposition of radioactive substances, while a cool and dry climate is just the reverse.

关键词： U-Th-K radioactive elements Granularity Paleoenvironment Drill hole Fuzhou Basin

Sedimentary and tectonic evolution of the Banquan pull-apart basin and implications for late Cenozoic dextral strike-slip movement of the Tanlu Fault Zone

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Science China Earth Sciences 2023年第4期66卷 797-820页

作者： Peng SHU Xiwei XU Shaoying FENG Baojin LIU Kang LI Paul TAPPONNIER Xiaojuan DENG Guihua CHEN Nuan XIA Hongtai XU Jingjing QIN Fubing HE Yan MA rongzhang zheng State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China Anhui Earthquake Agency Hefei 230031China Mengcheng National Geophysical Observatory Anhui Earthquake AgencyMengcheng 233500China National Institute of Natural Hazard Ministry of Emergency Management of the People’s Republic of ChinaBeijing 100085China Geophysical Exploration Center China Earthquake AdministrationZhengzhou 450002China Seismic Hazard Mitigation Center of Shandong Province(Engineering Seismology Research Center of Shandong Province) Ji’nan 250014China Beijing Institute of Geological Survey Beijing 100195China

The Banquan Basin is a pull-apart basin with the largest scale and the most prominent structure due to dextral slip of the Tanlu Fault Zone(TLFZ) in late Cenozoic. The depositional history of the basin records the start time and evolution of the right-lateral strike-slip movement of the TLFZ. This paper studies the sedimentary and tectonic evolution of the Banquan Basin by seismic reflection exploration, borehole detection and cosmogenic nuclide chronology. We analyze the coupling relationship between the pull-apart basin and the strike-slip fault and discuss the start time and tectonic significance of the right-lateral strikeslip of the TLFZ. Our study indicates that the Banquan Basin has undergone three evolutionary stages: weak rifting during the pre-pull-apart period, strong extension during the syn-pull-apart period and subsidence during the post-pull-apart period. This implies that the TLFZ, which controls the evolution of the basin, experienced an evolutionary process of weak activity,intensified activity and migration of activity toward the central basin. The sedimentary filling of the basin has strong response to the episodic pull-apart and extension of the basin. Lying upon the basement of the basin, a thin layer of Miocene mudstone slowly accumulated due to local rifting before the strong pull-apart event. Along with the dextral slipping and pull-apart process, the basin was filled with alluvial fan facies, fluvial facies and floodplain facies strata from bottom to top. The latest tectonic movement of the TLFZ in the North China Block in late Cenozoic was dominated by episodic dextral strike-slip motion, and this deformation pattern started at 4.01±1.27 Ma. The latest tectonic deformation in North China since late Cenozoic was governed by eastward extrusion and tectonic orogenesis of the eastern margin of the Qinghai-Xizang Plateau since late Miocene. The eastward thrusting of the Liupanshan fault zone and sinistral shearing of the Qinling fault zone led

关键词： Banquan Basin Strike-slip movement Pull-apart basin Tanlu Fault Zone North China Plain Start time

Average slip rate, earthquake rupturing segmentation and recurrence behavior on the Litang fault zone, western Sichuan Province, China

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Science China Earth Sciences 2005年第8期48卷 1183-1196页

作者： XU Xiwei1, WEN Xueze2, YU Guihua1, zheng rongzhang1, LUO Haiyuan2 & zheng Bin2 1. Institute of Geology, China Earthquake Administration, Beijing 100029, China 2. Earthquake Administration of Sichuan Province, Chengdu 610041, China Institute of Geology China Earthquake Administration Beijing China Earthquake Administration of Sichuan Province Chengdu China

The Litang fault zone (LFZ) is an active fault zone within the northwestern Sichuan sub-block. Field investigation reveals new evidence for its late Quaternary offset, neoteric earthquake ruptures and surface-rupturing segmentation, from which long-term slip-rates, char-acteristic earthquake magnitudes and recurrence intervals on the fault zone are estimated. This study shows that the LFZ consists of three subordinate faults, and they are the northern Maoyaba fault, Litang fault and Kangga-Dewu fault, respectively. All of them are dominated by left-lateral strike-slip with reverse dip-slip component on different segments. Based on offset landforms and ages of relevant deposits collected from seven sites, it is estimated that the average left-lateral slip-rate on the LFZ reaches 4.0±1.0 mm/a in the past 14 ka BP, and vertical (reverse) dip-slip rate in the range of 0.1―1.8 mm/a. Three subordinate faults are independent earthquake rup-turing segments, on which the maximum moment magnitude of the characteristic earthquakes is estimated to be 7.0―7.3, and their average recurrence interval to be 500―1000 a. The latest earthquake ruptures occurred 119±2 years ago on the northern Maoyaba fault, about 1890 AD on the Litang fault, and in 1948 AD on the Kangga-Dewu fault, and this may indicate a unidirectional migration for surface rupturing earthquakes along the Litang fault zone, related to stress trigger-ing between the segments.

关键词： Litang fault zone, slip rate, earthquake rupturing segmentation, recurrence interval.

Division of Buried Late Quaternary Strata of the Fuzhou Basin

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Earthquake Research in China 2006年第3期20卷 316-325页

作者： zheng rongzhang Chen Guihua Xu Xiwei Zhu Jinfang Huang Zonglin Li Jianping State Key Laboratory of Earthquake Dynamics Institute of Geology CEA Beijing 10029 China Center for Active Tectonic Studies ＆ Institute of Geology CEA Beijing 100029 China Earthquake Administration of Fujian Province Fuzhou 350013 China

Based on detailed logging of fourteen drill holes, combined with the results of other researchers, the preliminary summarization on sedimentary characteristics of the late Pleistocene of the Fuzhou basin is done. The deposition of Fuzhou basin began from about 56.5ka BP and the sediments are composed of gravel, sand, clay and silt, which show a depositional sequence with granularity becoming smaller from the lower to the upper and a big lateral variation of lithology. There are three silt layers in late Quaternary strata of Fuzhou basin. The first and second layers were developed during the middle and late Holocene, the deposition time is about 7.86ka BP to 1.44 ka BP and they are the results of ＂Changle Transgression＂. The third was developed during the late of late Pleistocene and the deposition time is from 44ka BP to 20ka BP and it is the result of ＂Fuzhou Transgression＂. The buried late Quaternary sediments in Fuzhou basin can be divided into upper Pleistocene series and Holocene series, which include four formations from old to new. They are the Longhai formation （ Q3p 1）, Dongshan formation （Qhd）, Changle formation （Qhc） and Jiangtian formation （Qhj）, respectively. The Longhai formation can be divided into three members and belongs to the Pleistocene series, other three formations belong to the Holocene series.

关键词： Strata division Late Quaternary Fuzhou basin

Active Fault Exploration and Seismic Hazard Assessment in Fuzhou City

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Earthquake Research in China 2005年第3期19卷 224-239页

作者： Zhu Jinfang Huang Zonglin Xu Xiwei zheng rongzhang Fang Shengmin Bai Denghai Wang Guangcai Min Wei Wen Xueze Han Zhujun Earthquake Administration ot Fujian Province Fuzhou 350003 China Institute of Gcology China Earthquake Administration Beijing 100029 China Geophysical Exploration Center CEA Zhengzhou 450002 China Earthqnke Administration of Sichuan Province Chengdu 610041 China

It has been proven by a number of earthquake case studies that an active fault-induced earthquake beneath a city can be devastating. It is an urgent issue for seismic hazard reduction to explore the distribution of active faults beneath the urban area and identify the seismic source and the risks underneath. As a pilot project of active fault exploration in China, the project, entitled “Active fault exploration and seismic hazard assessment in Fuzhou City”, started in early 2001 and passed the check before acceptance of China Earthquake Administration in August 2004. The project was aimed to solve a series of scientific issues such as fault location, dating, movement nature, deep settings, seismic risk and hazard, preparedness of earthquake prevention and disaster reduction, and etc. by means of exploration and assessment of active faults by stages, i.e., the preliminary survey and identification of active faults in target area, the exploration of deep seismotectonic settings, the risk evaluation of active seismogenic faults, the construction of geographic information system of active faults, and so on. A lot of exploration methods were employed in the project such as the detection of absorbed mercury, free mercury and radon in soil, the geological radar, multi-channel DC electrical method, tsansient electromagnetic method, shallow seismic refraction and reflection, effect contrast of explored sources, and various sounding experiments, to establish the buried Quaternary standard section of the Fuzhou basin. By summing up, the above explorations and experiments have achieved the following results and conclusions ：

关键词： fuzhou city active fault exploration seismic hazard assessment seismotectonics

滇东、滇西地区主要河流低阶地地貌面的年代学研究

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地震地质 2000年第3期22卷 265-276页

作者：计凤桔郑荣章李建平尹金辉中国地震局地质研究所北京100029

在流水沉积物热释光测年适用性和测年数据可靠性研究的基础上 ,对滇东、滇西地区几条主要河流的低阶地进行了系统采样和多方法的综合测年 ,获得了该区主要河流低阶地沉积物的堆积年代及其阶地面的形成时代 ,该区I级支流T1阶地堆积于 4 5... 详细信息

在流水沉积物热释光测年适用性和测年数据可靠性研究的基础上 ,对滇东、滇西地区几条主要河流的低阶地进行了系统采样和多方法的综合测年 ,获得了该区主要河流低阶地沉积物的堆积年代及其阶地面的形成时代 ,该区I级支流T1阶地堆积于 4 50 0～ 110 0 0aB .P .,其阶地地貌面形成于 4 50 0～ 50 0 0aB .P .;T2 阶地堆积于 90 0 0～ 2 2 0 0 0aB .P .,该级地貌面形成于 90 0 0～ 10 0 0 0aB .P .;主流T1阶地的堆积年龄为 90 0 0～ 170 0 0aB .P .,阶地面形成于 90 0 0～ 10 0 0 0aB .P .;T2 阶地的沉积年龄为 150 0 0～ 4 50 0 0aB .P .,阶地地貌面形成于 150 0 0aB .P .左右。同时 ,通过阶地堆积时期古气候、古环境的分析 ,探讨了该区低阶地地貌面的成因。

关键词：热释光测年阶地堆积年龄阶地地貌面年代学