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Colluvial wedges associated with pre-historical reverse faulting paleoearthquakes

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Chinese Science Bulletin 2000年第17期45卷 1598-1604页

作者： Qidong Deng peizhen zhang China Seismol Bur Inst Geol Beijing 100029 Peoples R China

Colluvial wedges collapsed from fault scarp can also be used to study reverse faulting paleoearthquakes. Generating processes of reverse faulting colluvial wedges are much more complex than those associated with normal faulting earthquakes. Reverse faulting colluvial wedge is also in triangle shape, and dies away from the fault. Contact between the fault and the colluvial wedge may be a simple straight reverse fault or a combination of an erosive surface in the upper part and a reverse fault in the lower part. Contents and grain sizes increase near the fault and along the base of a colluvial wedge. Based on examples from the piedmont reverse fault and fold along the northern Tainshan, we studied characteristics of reverse faulting colluvial wedges, and discussed the generating processes of reverse faulting colluvial wedges. Reverse faulting generates an unstable scarp hanging in the air immediately after an earthquake. Fallen material deposits along the base of newly formed fault scarp. Erosive

关键词： colluvial wedge paleoearthquake fault rupture active reverse fault.

Drainage Responses to the Activity of the Langshan Range-Front Fault and Tectonic Implications

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Journal of Earth Science 2018年第1期29卷 193-209页

作者： Shaopeng Dong peizhen zhang Huiping zhang Wenjun Zheng Huixian Chen Key Laboratory of Active Tectonics and Volcano Institute of Geology China Earthquake Administration Beijing 100029 China State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China School of Earth Science and Geological Engineering Sun Yan-Sen University Cruangzhou 510275 China Map Supervision Center of SBSM Beijing 100830 China

Langshan, a monoclinic mountain, which started to uplift since Oligocene, bounds the northwest margin of the Hetao Basin. The continuous activity of the active normal Langshan range- front fault forms the typical basin-and-range landform in Langshan area and controls the landform evolution of Langshan. Langshan is an ideal place to study relationship between quantitative geomor- phological index and active deformation. According to study on knickpoints, fitting on longitudinal channel profiles and steepness index, we demonstrate that the main controlling factors on distribution of normalized steepness index of channels are not climate （precipitation）, lithology, sediment flux, but tectonic factor, or the activity of Langshan range-front fault. The short channels in southeast flank, whose lengths are shorter than 16 km, may be still in the non-steady status. If not considering these short channels, the distribution of normalized steepness index along the Langshan range-front fault appears like M-shape pattern, while the normalized steepness index in the middle section is higher than those at both ends. This pattern is well consistent with geometrical segmentation model of the Langshan range-front fault. Combining previous active tectonic research on Langshan range-front fault, which demonstrates the Langshan range-front fault has been in the stage of linkup, we reasonably infer the Langshan range-front fault now is the result of linkup of both fault which continuously bilaterally ex- tended independently. Our tectonic geomorphological study also supports the conclusion that the Langshan range-front fault has been in the stage of linkup. The formation of several knickpoints due to tectonic factor may have been caused by slip-rate variation because of linkup of both independent faults. Based on cognition above, we also proposed the geological and geomorphological evolutionary model of the Langshan range-front fault since Oligocene.

关键词： Langshan range-front fault Hetao Basin steepness index Langshan geomorphological evolutionary model.

Paleoearthquake rupture behavior and recurrence of great earthquakes along the Haiyuan fault, northwestern China

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Science China Earth Sciences 2005年第3期48卷 364-375页

作者： zhang peizhen MIN Wei DENG Qidong MAO Fengying State Key Laboratory of Earthquake Dynamics Institute of Geology China Seismological Bureau Beijing 100029 China State Key Laboratory of Earthquake Dynamics Institute of Geology China Seismological Bureau Beijing 100029 China State Key Laboratory of Earthquake Dynamics Institute of Geology China Seismological Bureau Beijing 100029 China State Key Laboratory of Earthquake Dynamics Institute of Geology China Seismological Bureau Beijing 100029 China

The Haiyuan fault is a major seismogenic fault in north-central China where the 1920 Haiyuan earthquake of magnitude 8.5 occurred, resulting in more than 220000 deaths. The fault zone can be divided into three segments based on their geometric patterns and associated geomorphology. To study paleoseismology and recurrent history of devastating earthquakes along the fault, we dug 17 trenches along different segments of the fault zone. Although only 10 of them allow the paleoearthquake event to be dated, together with the 8 trenches dug previously they still provide adequate information that enables us to capture major paleoearthquakes oc- curring along the fault during the past geological time. We discovered 3 events along the eastern segment during the past 14000 a, 7 events along the middle segment during the past 9000 a, and 6 events along the western segment during the past 10000 a. These events clearly depict two temporal clusters. The first cluster occurs from 4600 to 6400 a, and the second occurs from 1000 to 2800 a, approximately. Each cluster lasts about 2000 a. Time period between these two clus- ters is also about 2000 a. Based on fault geometry, segmentation pattern, and paleoearthquake events along the Haiyuan fault we can identify three scales of earthquake rupture: rupture of one segment, cascade rupture of two segments, and cascade rupture of entire fault (three segments). Interactions of slip patches on the surface of the fault may cause rupture on one patch or ruptures of more than two to three patchs to form the complex patterns of cascade rupture events.

关键词： paleoearthquake event, recurrent interval, earthquake rupture pattern, temporal clustering, slip patch interaction.

Cenozoic tectonic evolution of regional fault systems in the SE Tibetan Plateau

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Science China Earth Sciences 2022年第4期65卷 601-623页

作者： Yang WANG Yuejun WANG peizhen zhang Jinjiang zhang Bo zhang Jing LIU-ZENG Renjie ZHOU Weitao WANG Huiping zhang zhangjun LI Guangdong Provincial Key Laboratory of Geodynamics and Geohazards School of Earth Sciences and EngineeringSun Yat-Sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China The Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China School of Earth and Environmental Sciences The University of QueenslandSt Lucia QLD 4072Australia State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

The SE Tibetan Plateau,tectonically situated in the eastern India-Eurasia oblique convergence zone,has experienced multiple stages of deformation since the *** major tectonic boundaries—the Ailaoshan-Red River,ChongshanLincang-Inthanon,and Gaoligong-Mogok shear zones—delineate the first-order tectonic framework in this *** most striking structural features in the block interiors are a series of NW-and NE-trending fault systems,such as the Dayingjiang,Longlin-Ruili,Nantinghe,Red River,Weixi-Qiaohou,and Lancang-Genma faults,which have conjugate geometric *** this study,we review these structures’geometric and kinematic characteristics and deformation histories.A synthesis of existing geological observations,geomorphological analyses,and chronological data reveals three major Cenozoic tectonothermal events,including crustal shortening,strike-slip shearing,and kinematic *** boundary structures controlled the tectonic extrusion of plateau material during the early Oligocene-early *** the mid-late Miocene,NW-and NE-trending fault systems mostly experienced diachronous slip-sense *** onset and spatial trend of regional kinematic reversal are constrained by existing chronologic *** with geophysical and geodetic observations,the activity and geodynamic drivers of the major fault systems and regional deformation styles are explored,revealing that the SE Tibetan Plateau underwent a transition from discrete(lateral block extrusion)to diffuse deformation in the mid-late *** intracontinental crustal deformation and its coupling with dynamic processes at depth during the plateau growth are discussed in the context of the IndiaEurasia convergence.

关键词： Cenozoic SE Tibetan Plateau tectonic boundary conjugate fault system tectonic evolution

The effect of altimetry data in estimating the elastic thickness of the lithosphere in the western Pacific Ocean

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Geodesy and Geodynamics 2021年第5期12卷 315-322页

作者： Zheng Gong peizhen zhang Wenjun Zheng Dongli zhang Binbin Xu Guangdong Provincial Key Laboratory of Geodynamics and Geohazards School of Earth Sciences and EngineeringSun Yat-Sen UniversityGuangzhou510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519082China

The elastic thickness of the lithosphere(Te)is a key parameter used to describe the strength of the *** is usually estimated by a spectral analysis between gravity and *** previous research on the estimation of Te,altimetry data were used on both the gravity data and topography data,which could lead to *** study described in this paper analyzed the effects of using gravity anomalies derived from different data sources on the estimation of Te,Taking the western Pacific region as an example,this study analyzed the impact of the repeated presence of altimetry satellite data on the calculation of the effective elastic thickness and found that if gravity anomalies and topography model both contain altimetry satellite data,they systematically overestimate effective *** a uniform area,the difference in Te can reach up to 30%.For a Te distribution,the difference can reach up to about16%.After eliminating this effect,the effective elastic thickness of the western Pacific region was found to be 10 km,and the statistical results of the effective elastic thickness distribution showed that the effective elastic thickness of the lithosphere in most areas of the western Pacific is about 12 *** paper shows the importance of choosing the appropriate gravity model in evaluating the elastic thickness of lithosphere in the oceans.A figure of Te at seamounts with loading ages demonstrates that Te in the western Pacific is generally distributed within the 100-300℃isotherm depth and does not increase with loading age.

关键词： The elastic thickness of lithosphere The western Pacific Ocean Altimetry data Spectral analysis

Lushan M_S7.0 earthquake:A special earthquake occurs on curved fault

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Chinese Science Bulletin 2013年第28期58卷 3483-3490页

作者： zhang ZhuQi WANG WeiTao REN ZhiKun zhang peizhen FANG LiHua WU JianPing Institute of Geology State Key Laboratory of Earthquake DynamicsChina Earthquake Administration Institute of Geophysics China Earthquake Administration

Relocation result shows that the aftershocks of the Lushan MS7.0 earthquake spatially distribute in a shape like"half bowl",indicating that the rupture structure of the mainshock is a highly curved *** analysis reveals that a laterally varied dislocation pattern occurs on this curved fault even though a single relative horizontal movement controls slip on this *** slip prevails on curved ***,significant normal slip is predicted near the edge of north ***,the north flank features left-lateral slip while the south flank contrarily features right-lateral *** relative scope of aftershock distribution implies inadequate breaking of the curved fault during the mainshock,calling for the attention to potential earthquake risk on the neighboring portions of the coseismic rupture due to significant increase of the coseismic Coulomb *** stress modeling also reveals that it is unnecessary for the stress on ruptured part to be unloaded following the earthquakes on the curved *** coseismic stress loading on ruptured elements unveils the specialty of faulting for the Lushan earthquake and we conclude that this specialty is due to the highly curved fault geometry.

关键词：弯曲故障地震发生庐山地震空间分布库仑应力左旋走滑地震断层运动学分析

Initiation and recession of the fluvial knickpoints:A case study from the Yalu River-Wangtian'e volcanic region,northeastern China

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Science China Earth Sciences 2011年第11期54卷 1746-1753页

作者： zhang HuiPing zhang peizhen FAN QiCheng State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

Initiation and recession of the knickpoints are significant boundary condition for processes of fluvial system. The distribution and recession rates of knickpoints contain information that provides a fundamental understanding of geomorphic processes. In the Yalu River-Wangtian＇e volcanic region of northeastern China, broadly distributed fiat lava terrain provides an ideal site to study the recession of fluvial knickpoints because knickpoints and waterfalls are well preserved here. Here we describe the distribution of knickpoints in the Yalu River-Wangtian＇e volcanic region by combining DEM analysis and numerical modeling Furthermore, we present a knickpoint celerity model, derived from stream-power incision model, to relate knickpoint recession rate to drainage area. We calibrate important empirical coefficients with our knickpoint celerity model; the best fit erosion coefficient （K） is 1.32×10^-8, and the best fit drainage area exponent （m） is 0.69. Error analysis indicates a close correspondence between synthetic and real knickpoints. Finally, we show that knickpoint recession rates in the Yalu River-Wangtian＇e volcanic region are -1-10 mm/a during the early stages of transient incision, and that the present rates are -1-6 mm/a. Our recession rate results are in good agreement with previous findings from the Aso Volcano and volcanoes near Boso Peninsula （Japan）, which have a similar geologic history to the Yalu River-Wangtian＇e volcanic region. Our present effort provides new insight into landscape evolution in the Yalu River-Wangtian＇e volcanic region in northeastern China.

关键词： Yalu River-Wangtian'e volcanic region knickpoint knickpoint celerity model landscape evolution

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Dextral strike-slip of Sanguankou-Niushoushan fault zone and extension of arc tectonic belt in the northeastern margin of the Tibet Plateau

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Science China Earth Sciences 2016年第5期59卷 1025-1040页

作者： LEI QiYun zhang peizhen ZHENG WenJun CHAI Chizhang WANG WeiTao DU Peng YU JingXing State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China Earthquake Administration of Ningxia Hui Autonomous Region Yinchuan 750001 China

The kinematic characteristics of the Sanguankou-Niushoushan fault（SGK-NSSF） are of great significance to the understanding of the extension of the arc tectonic belt in the northeastern margin of the Tibet Plateau. Using field surveys and various data collection methods, including large-scale geological mapping, measurement of typical topographies, and dating of sedimentary strata, it was determined that the SGK-NSSF exhibits obvious dextral strike-slip characteristics and thus is not a sinistral strike-slip fault, as believed by previous researchers. The results of this study show that the geological boundaries for the Paleozoic, Mesozoic, and Cenozoic eras were all dextrally dislocated by the fault, with the faulted displacements being similar. The maximum strike-slip displacement of the fault, after elimination of topographic effects, was found to be 961±6 m. The Sanguankou fault at the northern section exhibits obvious characteristics of more recent activities, with a series of small gullies having undergone synchronized dextral writhing after traversing the fault. The average horizontal slip rate of the fault since the late Quaternary was determined to be approximately 0.35 mm/a. The pre-existing fold structures formed during the late Pliocene were dislocated by the fault and became ex situ, indicating that dextral strike-slip of the fault could not have occurred prior to the late Pliocene. The maximum displacements and average slip rates were used to estimate the onset time of the dextral strike-slip activities of the fault as being after 2.7 Ma. In this study, the understanding of previous researchers concerning the extension in the northeastern margin of the Tibet Plateau was combined with analyses of the successive relationships between fold deformations and fault activities. This led to the finding that the extension in the northeastern margin of the Tibet Plateau reached the vicinity of the SGK-NSSF during the late Pliocene（~2.7 Ma）, causing regional uplif

关键词： Northeastern margin of Tibet Plateau Sanguankou-Niushoushan fault Dextral strike-slip Tectonic interactions between blocks Arc tectonic belt

Formation of the Yazi Spring Stream and its significance on tectonics-climate on the northern slope of Kunlun Mountains

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Chinese Science Bulletin 2005年第18期50卷 2063-2068页

作者： CHANG Hong zhang peizhen AN Zhishen WANG Xulong QIANG Xiaoke FU Chaofeng State Key Laboratory of Loess and Quaternary Geology. Institute of Earth Environment Chinese Academy of Sciences. Xi'an 710075. China Graduate School of Chinese Academy of Sciences. Beijing 100039.China State Key Laboratory of Seismic Dynamics. China Earthquake Administration. Beijing 100029 China

The sequences of fluvial terraces in the Yazi Spring Stream are signs of the stepwise uplift of the Kunlun Mountains in the northern part of the Tibetan Plateau since the Late Pleistocene. Geomorphic and sedimentary features of the terraces reveal that they have resulted from the phased tectonic uplift and the consequent river incision in the northern plateau. Using the method of Single-aliquot Regenerative-dose (SAR) Protocol and Radiocarbon 14C dating, the deposit ages of three-grade terraces were ob- tained, which are 57.5, 12.8 and 5.7 kaBP, respectively. The features and ages of terraces reveal that the incision rate of the stream accelerated at the beginning of the Holocene. The incision rate changed suddenly at 12.8 KaBP, from 0.43±0.07 mm/a to 1.59±0.55 mm/a. This implicates that uplift of the Kunlun Mountains is intensive at the first onset of the Holo- cene, corresponding to the obvious change of slip-rate on the Altyn Tagh Fault. But its uplift rate is much lower than that of the latter, which suggests that growth of the northern mar- gin of the Tibetan Plateau is stronger than its interior.

关键词：青藏高原昆仑山脉激励发光沉淀特征地球科学