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Mantle transition zone structure beneath the Central Asian Orogenic Belt

Science China Earth Sciences 2020年第4期63卷 548-560页

作者： Jing HE qingju wu Key Laboratory of Crustal Dynamics Institute of Crustal DynamicsChina Earthquake AdministrationBeijing 100085China Key Laboratory of Seismic Observation and Geophysical Imaging Institute of GeophysicsChina Earthquake AdministrationBeijing 100081China

Over the past decades, there have been hot debates in the geodynamic community regarding to the deep evolution mechanisms of Cenozoic volcanism in the Central Asian Orogenic Belt(CAOB). Of all the constraints available, high resolution structure of upper mantle discontinuities, especially the discontinuities at depths of 410 km(D410) and 660 km(D660), is of the most important, which may provide reliable clues on the magma channel as well as its evolution. In this work, we adopt the common conversion point stacking technique with teleseismic radial P-wave receiver functions to examine the D410 and D660 discontinuities. The primary results exhibit that the major characteristics of the mantle transition zone(MTZ) obtained by different velocity models are largely consistent. Obviously elevated D410 and slightly depressed D660 are observed beneath the Hannuoba Volcano, suggesting possible delamination of the local lithosphere deposited at the D410. This process may induce upwelling of the asthenospheric materials filling the space left by the delaminated lithosphere, and subsequently trigger volcanic eruptions. Strong depressions are observed at both D410 and D660 depths beneath west of the Dariganga Volcano, and the depression of D660 is more pronounced. It leads to the apparently thickened MTZ, indicating the presence of cold material at the D660. This cold material is speculated as a stagnant slab from the subducted Pacific Plate or the remains of a detached island arc system from the collision and formation of the CAOB. Slightly thinner MTZ is found beneath the Hentey Mountains and the Middle Gobi Volcano. Apparently, this thinner MTZ is not significant enough to support the existence of high thermal anomalies,which may rule out the possibility of large-scale hot material upwelling from either the local MTZ or even the lower mantle.

关键词： Central Asian Orogenic Belt Cenozoic Volcano Mantle transition zone Receiver function

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Moho反射波噪声干涉方法及其在青藏高原东北缘地壳结构成像的应用初探

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地球与行星物理论评（中英文） 2025年第2期56卷 167-181页

作者：马小军吴庆举宁夏回族自治区地震局银川750001 中国地震局地球物理研究所北京100081

基于南北地震带北段布设的密集流动地震台阵的连续波形记录,采用台阵噪声干涉技术获得了青藏高原东北缘Moho面PmP反射波,利用已有的区域三维地壳速度模型,采用沉积层校正方法建立研究区域的三维地壳初始模型,进而对噪声互相关函数进行... 详细信息

基于南北地震带北段布设的密集流动地震台阵的连续波形记录,采用台阵噪声干涉技术获得了青藏高原东北缘Moho面PmP反射波,利用已有的区域三维地壳速度模型,采用沉积层校正方法建立研究区域的三维地壳初始模型,进而对噪声互相关函数进行基准面校正,然后采用共中心点叠加方法获得了研究区的地壳厚度分布.结果显示,青藏高原东北缘及周边不同块体地壳厚度差异显著,沿青藏高原北东向的扩展方向,地壳厚度逐渐变薄.祁连造山带中、西段地壳厚度约55~65 km,西秦岭造山带地壳厚度从西至东从53 km左右减小至42 km上下,阿拉善块体地壳厚度约50 km,鄂尔多斯块体西缘地壳厚度约40~45 km.六盘山断裂、海原断裂与天景山断裂附近呈现局部的地壳增厚,并且出现脉冲状Moho面反射震相,表明断裂带附近可能存在速度跃变较大的Moho面结构.祁连山北缘断裂出现叠置的反射震相,推测下地壳的逆冲形成了此类Moho结构.

关键词：青藏高原东北缘噪声干涉技术 Moho面反射波基准面校正地壳厚度

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Structure of the mantle transition zone in the central and western parts of the North China Craton using the receiver function 3D Kirchhoff migration method

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Science China Earth Sciences 2024年第9期67卷 2783-2795页

作者： Min ZHU qingju wu Jieyuan NING Ruiqing ZHANG Institute of Geophysics China Earthquake AdministrationBeijing 100081China Institute of Theoretical and Applied Geophysics Peking UniversityBeijing 100871China

Using data from the regional broadband dense temporary array deployed by the ChinArray project,we applied the three-dimensional(3D)Kirchhoff migration method of the teleseismic P-wave receiver function to investigate discontinuity structures of the mantle transition zone(MTZ)in the central and western parts of the North China Craton(NCC)using a highresolution 3D velocity model of the East Asian *** results show that the 410-km discontinuity beneath the Datong Volcano is depressed by~10 km,indicating the presence of a high-temperature anomaly near the depth of 410 km,which is likely related to small-scale mantle upwelling caused by the dehydration of the stagnant Pacific Plate in the *** upwelling of hot material provides a heat source for surface magmatic *** the Bohai Bay Basin,significant subsidence of the 660-km discontinuity is observed,and the transition zone here is extensively ***’s suggested that the anomalies in this region are related to the stagnation of the Pacific slab in the *** the thickness of the transition zone west of the North-South Gravity Lineament appears normal,we propose that the subducting front of the Pacific slab did not cross the gravity lineament in the *** comparison,the small-scale subsidence of the 660-km discontinuity and the thickening of the MTZ observed north of the Hannuoba Volcano likely indicate that the slab crossed the gravity lineament at its turning point and remained in the ***,a local thickening of the MTZ is observed in the Dabie orogenic belt of the Qinling *** is believed to be a combined effect of lithospheric delamination into the transition zone in the lower Yangtze region and the stagnation of the Pacific Plate.

关键词： North China Craton Mantle transition zone Receiver function migration Datong Volcano

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Differential patterns of SH and P wave velocity structures in the transition zone beneath northwestern Tibet

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Science China Earth Sciences 2011年第10期54卷 1551-1562页

作者： ZHANG RuiQing wu qingju LI YongHua ZENG RongSheng Institute of Geophysics China Earthquake Administration Beijing 100081 China

Triplicate waveform modeling is used to resolve SH （Vs） and P （Vp） wave velocity structures in the upper mantle transition zone （TZ） beneath northwestern （NW） Tibet. Focal depth move out stacking is proposed to enhance the identification of triplicate phases, and can be used to test consistency of our data. Our results show that the Vs and Vp structures are decorrelated, and that a large Vs jump occurred across the 660-km discontinuity, with a small Vs gradient above it. Conversely, the Vp model is characterized by a relatively small contrast across the discontinuity, accompanied by a high Vp gradient in the TZ. There seem no significant depth anomalies of the 660-kin discontinuity in both models. The seismic structures in TZ beneath NW Tibet are similar to recent studies beneath the central Qiangtang and western Lhasa terrains. Taking the lower TZ structures under India as references, Vs is normal but Vp appears slightly high, and thus a high ratio of Vp/Vs was indicated beneath NW Tibet. Combined results with experiment information from mineral studies, we suggest that the differential anomalies of Vp and Vs can be attributed to a chemical heterogeneity, such as increased A1 content in the lower TZ. Considering the tectonic evolution of Tibet, the chemical heterogeneity may be associated with subduction or detachment of the Tethys oceanic slab.

关键词： mantle transition zone seismic velocity northwestern Tibet

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Crustal and upper mantle structure and deep tectonic genesis of large earthquakes in North China

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Science China Earth Sciences 2017年第5期60卷 821-857页

作者： WANG ChunYong wu qingju DUAN YongHong WANG ZhiShuo LOU Hai Key Laboratory of Seismic Observation and Geophysical Imaging China Earthquake Administration Beijing 100081 China Institute of Geophysics China Earthquake Administration Beijing 100081 China Research Center of Geophysical Exploration China Earthquake Administration Zhengzhou 450002 China Earthquake Administration of Henan Province Zhengzhou 450016 China

From the 1960 s to 1970 s, North China has been hit by a series of large earthquakes. During the past half century,geophysicists have carried out numerous surveys of the crustal and upper mantle structure, and associated studies in North *** have made significant progress on several key issues in the geosciences, such as the crustal and upper mantle structure and the seismogenic environment of strong earthquakes. Deep seismic profiling results indicate a complex tectonic setting in the strong earthquake areas of North China, where a listric normal fault and a low-angle detachment in the upper crust coexist with a high-angle deep fault passing through the lower crust to the Moho beneath the hypocenter. Seismic tomography images reveal that most of the large earthquakes occurred in the transition between the high-and low-velocity zones, and the Tangshan earthquake area is characterized by a low-velocity anomaly in the middle-lower crust. Comprehensive analysis of geophysical data identified that the deep seismogenic environment in the North China extensional tectonic region is generally characterized by a low-velocity anomalous belt beneath the hypocenter, inconsistency of the deep and shallow structures in the crust, a steep crustalal-scale fault,relative lower velocities in the uppermost mantle, and local Moho uplift, etc. This indicates that the lithospheric structure of North China has strong heterogeneities. Geologically, the North China region had been a stable craton named the North China Craton or in brief the NCC, containing crustal rocks as old as ～3.8 Ga. The present-day strong seismic activity and the lower velocity of the lower crust in the NCC are much different from typical stable cratons around the world. These findings provide significant evidence for the destruction of the NCC. Although deep seismic profiling and seismic tomography have greatly enhanced knowledge about the deep-seated structure and seismogenic environment, some fundamental iss

关键词： North China Craton Crust and upper mantle structure Deep seismic sounding profile Deep seismic reflection profile Broadband seismic array Seismogenic environment

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Focal depths for moderate-sized aftershocks of the Wenchuan M_S8.0 earthquake and their implications

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Science China Earth Sciences 2008年第12期51卷 1694-1702页

作者： ZHANG RuiQing wu qingju LI YongHua DING ZhiFeng ZENG RongSheng Institute of Geophysics China Earthquake AdministrationBeijing 100081China

Sliding-window cross-correlation method is firstly adopted to identify sPn phase, and to constrain focal depth from regional seismograms, by measuring the time separation between sPn and Pn phases. We present the focal depths of the 17 moderate-sized aftershocks (MS≥5.0) of the Wenchuan MS8.0 earth-quake, using the data recorded by the regional seismic broadband networks of Shaanxi, Qinghai, Gansu, Yunnan and Sichuan. Our results show focal depths of aftershocks range from 8 to 20 km, and tend to cluster at two average depths, separate at 32.5°N, i.e., 11 km to the south and 17 km to the north, indicating that these aftershocks are origin of upper-to-middle crust. Combined with other results, we suggest that the Longmenshan fault is not a through-going crustal fault and the Pingwu-Qingchuan fault may be not the northward extension of the Longmenshan thrust fault.

关键词： Wenchuan MS8.0 earthquake aftershocks sPn phase

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Inversion of teleseismic waves at Shidao Seismographic Station

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Acta Oceanologica Sinica 2006年第5期25卷 63-73页

作者： RUAN Aiguo LI Jiabiao HAO Tianyao wu qingju XU Yi Key Laboratory of Submarine C eosciences of State Oceanic Administration Hangzhou 310012 China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100101 China Institute of Geophysics China Seismological Bureau Beijing 100081 China

Teleseismic datasets at the Shidao Seismographic Station, located in the northwestern South China Sea, are used to determine the earth anisotropy and the vertical distribution pattern of the shear wave velocity by inversion approaches. The rotated correction function is applied to analyzing high quality SeS records from five earthquakes at distance of 25°-35° to obtain shear wave splitting parameters of the lithosphere. The result from the deepest earthquake among the five events indicates that the polarization of the fast shear wave is N94°E, which means the direction of extensional stress or the moving of the upper mantle mass in Xisha Islands is nearly west to east and confirms that the crust in this region is a transitional one and the driving force beneath the crust is from the moving mass consistent with the Eurasian plate. The anisotropy effective thickness is estimated about 100 km based on the time delay of 1.3 s between the fast and slow shear waves. The receiver function is applied to analyzing high quality P wave records from nine earthquakes at distance of 20°- 60° to obtain the vertical distribution pattern of shear wave velocity beneath the station. The result indicates that the crust could be divided into three layers： the uppermost crust （5 km above） is a velocity gradient zone consisting of several small layers, where the shear wave velocity increases from 1.5 to 3.5 km/s gradually; the 5 - 16 km depth interval also consiss of several small layers of which the mean velocity is about 3.8 km/s; and the lower crust （ 16.0 - 26. 5 km） is an obvious low velocity layer with a velocity of about 3.6 km/s. The buried depth of the Moho discontinuity is 26.5 kin, the mean velocity of the layers beneath the Moho is about 4.7 km/s and there is an obvious low velocity layer just beneath the Moho. Moreover, analysis of the arrival time of converted waves and the swinging variation of velocity around the initial model suggests that smaller layers in the model mayb

关键词： South China Sea S wave splitting receiver function S wave velocity structure waveform inversion

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Upper mantle SH velocity structure beneath Qiangtang Terrane by modeling triplicated phases

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Chinese Science Bulletin 2008年第20期53卷 3211-3218页

作者： ZHANG RuiQing wu qingju LI YongHua ZENG RongSheng Institute of Geophysics China Earthquake Administration Beijing 100081 China

我们嘘由比较地区性的距离在西方的 Qiangtang 岩层下面为上面的披风抑制波浪速度结构有合成震动图的地震 triplicated 波形，基于中介，事件(∼220 km ) 由 INDEPTH-III 地震数组记录了。ATIP 模型揭示一个低速度的异例与直到在在在上... 详细信息

我们嘘由比较地区性的距离在西方的 Qiangtang 岩层下面为上面的披风抑制波浪速度结构有合成震动图的地震 triplicated 波形，基于中介，事件(∼220 km ) 由 INDEPTH-III 地震数组记录了。ATIP 模型揭示一个低速度的异例与直到在在在上面的披风的 410 km 的深度上面的 190 270 km 和一个相对小的速度坡度的深度的 −4% 变化，它与以前的结果一致。在有另外的地质的研究的联合，我们建议最高的岩流圈的深度是 190 km，变瘦的大规模岩石圈都不发生在西方的 Qiangtang 岩层，除以外， Qiangtang 岩层作为稳定的欧亚大陆有一样的有点上面的披风结构。

关键词：剪切速度结构三重相转变带上地幔岩层西藏高原

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Three-dimensional crustal P-wave velocity structure in the Yangbi and Eryuan earthquake regions, Yunnan, China

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Earthquake Science 2021年第4期34卷 358-366页

作者： Jia Jia qingju wu Fuyun Wang Geophysical Exploration Center China Earthquake AdministrationZhengzhou 450002China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

A magnitude 5.5 earthquakes occurred in Eryuan County,Dali Bai Autonomous Prefecture,Yunnan Province,China,on March *** a magnitude 5.0 earthquake occurred in the same place on April 17,2013,i.e.,45 days ***,on May 21,2021,multiple earthquakes,one with magnitude 6.4 and several at 5.0 or above,occurred in Yangbi County,Dali Bai Autonomous Prefecture,Yunnan Province,*** of these occurred in the Weixi-QiaohouWeishan fault *** this study,1,874 seismic events in Yangbi and Eryuan counties were identified by automatic micro-seismic identification technology and the first arrivals were picked up *** this,a total of 11,968 direct P-wave absolute arrivals and 73,987 high-quality Pwave relative arrivals were collected for joint inversion via the double difference tomography *** was done to obtain the regional three-dimensional fine crustal P-wave velocity *** results show that the travel time residuals before and after inversion decreased from the initial–0.1–0.1 s to–0.06–0.06 *** upper crust in the study area,which exhibited a low-velocity anomaly,corresponded to the basin region;this indicated that the low-velocity anomaly in the shallow part of the study area was affected by the *** also showed some correlation between the distribution of the earthquakes and velocity structure,as there was a lowvelocity body Lv1 with a wide distribution at depths ranging from 15–20 km in the Yangbi and Eryuan earthquake *** addition,earthquakes occurred predominantly in the highlow velocity abnormal transition *** low-velocity body in the middle and lower crust may be prone to concentrating upper crustal stress,thus leading to the occurrence of earthquakes.

关键词： Yangbi and Eryuan earthquakes double difference tomography three-dimensional P-wave velocity structure Weixi-Qiaohou-Weishan fault.

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A review of geophysical studies on the Mongolian Plateau

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Earthquake Science 2024年第3期37卷 224-240页

作者： Lei Zhang Zhouchuan Huang Xiaodong Song qingju wu SinoProbe Laboratory School of Earth and Space SciencesPeking UniversityBeijing 100871China Hebei Hongshan National Observatory on Thick Sediments and Seismic Hazards Peking UniversityBeijing 100871China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

The Mongolian Plateau in Central Asia is an intracontinental tectonic system far from active plate *** its distance from these boundaries,the plateau is characterized by intense crustal deformation accompanied by voluminous Cenozoic volcanism and active modern ***,the intraplate deformation mechanism has long been debated owing to the scarcity of observations and contradictions between different *** recent years,growing geophysical studies have been conducted on the Mongolian Plateau,providing constraints on its lithospheric structure and ***,we review the geophysical research on the Mongolian Plateau over the last decade,including seismological,geodetic,gravity,magnetotelluric,and geodynamic *** review aims to(a)describe crustal and mantle structures based on multiscale seismic images;(b)describe deformation patterns based on seismic anisotropy,focal mechanisms,and global positioning system(GPS)observations;and(c)discuss the mechanisms behind intraplate deformation,volcanism,and seismic activity across the Mongolian *** images show that the crustal structure of the plateau has significant east-west *** blocks in the western Mongolian Plateau have thick crusts,including the Altai Mountains,Hovsgol Rift,and Hangay *** lithospheric deformation across the Mongolian Plateau has strong lateral variation,with NE-SW shortening in the Altai Mountains and W-E or NW-SE shear deformation in the Hangay Dome region and the eastern *** varied deformation may result from the superposition of multiple mechanisms,including far-field stress in the Altai Mountains,mantle upwelling,and mantle flow in the Hangay Dome ***,it is difficult to identify the geodynamics of the formation of the entire Mongolian Plateau because the deformation is too complicated,and the present models are not sufficient and are always ***,this review encompasses recent advances in seismic observa

关键词： Mongolian Plateau Central Asia seismic tomography crust-mantle structure intraplate deformation

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