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本文在前人对中国大陆及周边活动地块研究和划分的基础上，系统研究了6个Ⅰ级活动地块区和22个Ⅱ级活动地块之间共26个活动边界带的构造变形与强震活动，包括强震分布与活动边界带的关系，边界带构造活动速率与地震活动水平及强震复发期等的关系. 给出了边界带强震活动水平与构造活动速率之间的线性关系和强震复发期长短与构造活动速率的反向变化关系. 从而进一步揭示了中国大陆活动地块构造及其块体运动特征，以及块体边界带的构造变形对强震的控制作用. 相似文献
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本文依据深部地球物理场、区域大地构造、地表活动断裂、地震活动等，划分了中国大陆的地震构造带，同时分析了地震构造带的活动特征和孕震构造条件，在此基础上，具体地把地震构造带的概念应用于地震危险区分析之中，探讨了地震危险区及地震前兆异常与地震构造带的关系，本文提出以地震构造带研究作为地震监测和预报工作的基础，将地震构造带作为系统性的活动构造条件应用于地震危险区划分之中。 相似文献
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龙门山北段断裂活动特征 总被引：5，自引：0，他引：5
本文对第四纪地层形变、构造地貌、卫片影象、年代学样品鉴定，构造岩应力矿物、现今应力场、地震活动以及块体运动特征等进行了综合分析，认为龙门山北段断裂为中、晚更新世活动断裂，构造应力相对中南段弱，以蠕滑活动方式为主，孕育中强地震的可能性较小。 相似文献
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全球变暖、构造运动与沙漠化 总被引：8，自引：0，他引：8
采用统计分析与综合分析方法，研究了全球变暖、构造活动、地球（以及月球和行星）轨道效应、太阳活动等对降水的影响。认为构造活动、地震、气候变暖与降水或洪涝灾害有一定关系；地球的轨道效应是地球气候变化的重要因素，从而与旱涝相关；月球行星轨道效应和太阳活动均与旱涝有明显的对应关系。气候变冷和构造活动弱是沙漠化的主要原因，人类活动则加速了沙漠化的进程。 相似文献
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南海北部陆缘地震带基本特征及区域稳定性初步分析 总被引：3，自引：0，他引：3
讨论了南海北部陆缘断裂构造的格局及其活动性，提出南海北部陆缘地震带与邻区其它地震带有别的新观点，对该区各地震带的地震活动进行了探讨，分析了强震构造与活动断裂的关系。通过综合分析，将该区划分为强活动、中等活动和微弱活动三大区域。 相似文献
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运用波浪镶嵌构造观点，对临汾盆地的构造背景和地震活动规律进行了探讨，认为临汾盆地正好位于环太平洋波系和特提斯波系壳下次级构造隆起的叠加部位，其地震活动明显受这２大波系的控制，即临汾大地震是在２大波系构造同时强烈活动时发生的，单方向构造活动，不足以引发临汾大地震。认为临汾盆地大震活动的周期约４００年，其活跃期约１００年，平静期约３００年。 相似文献
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阿拉善活动块体的划分及归宿 总被引：15，自引：0，他引：15
通过对阿拉善地区地震活动图象呈现显著的条带状、新构造变形表现为块体的隆升和向北的掀斜、周缘的内部性质各异的断裂活动状况、结晶基底与基底内推覆和滑脱构造发育等构造特征的分析，以及与相邻块体的比较，论证了阿拉善活动块体的存在，对其边界作了厘定，并将其归属到华北亚板块，强调了阿拉善块体为一活动构造，其内部存在一个ＮＥ向的阿拉善地震带，归属于华北地震区。该地区的地震危险性不可低估。 相似文献
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2013年4月20日发生在龙门山南段的芦山MS7.0地震是继发生在龙门山中北段的汶川MS8.0地震之后的又一次强震。本文通过震后地表变形特征、余震分布、震源机制解、石油地震勘探剖面、历史地震数据等资料,结合前人对龙门山南段主干断裂、褶皱构造特征的研究以及野外实地考察,应用活动褶皱及"褶皱地震"的相关理论,初步分析芦山地震的发震构造模式。认为芦山地震为典型的褶皱地震,发震断裂为前山或山前带一隐伏断裂。构造挤压产生的地壳缩短大部分被褶皱构造吸收。认为龙门山南段前缘地区具有活褶皱-逆断层的运动学特征,表明龙门山逆冲作用正向四川盆地内部扩展。 相似文献
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发生在地球浅层的2008年汶川地震驱动了龙门山及前陆地区的地表同震垂向位移.根据冲断带-前陆盆地弹性挠曲模型理论,在进行弹性挠曲模拟反演的基础上,结合对深部地球物理特征(泊松比、电性结构)的分析,发现龙门山前陆盆地现今岩石圈有效弹性厚度(T_e)具有自东向西逐渐减薄的趋势,自川中地区的30~40 km减至龙门山地区的10~20 km.在对晚三叠世以来前陆盆地各阶段盆地结构进行刻画的基础上,进行弹性挠曲模拟反演,推断龙门山前陆盆地的前渊地区(四川盆地西部)岩石圈的T_e值自晚三叠世以来具有逐渐减薄的趋势.这可能与松潘一甘孜地块下方广泛存在的软流圈热物质对四川盆地西部岩石圈下部的长期加热而导致的熔融有关,反映了地球深部动力学过程与地球表层盆地演化之间的耦合关系. 相似文献
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Tang Rongchang Huang Zuzhi Qian Hong Gong Yu Wen Dehua Ma Senghao and Zhou RongjunSeismological Bureau of Sichuan Province Chengdu China 《中国地震研究》1997,(1)
Chengdu fault depression is an important Quaternary basin in the piedmont of Longmenshan mountain.Formation and evolution of the fault depression are entirely controlled by the Longmenshan piedmont fault and the Longquanshan fault.Since the late Quaternary,Chengdu fault depression has been subjected to an NW-SE oriented compression.Many NE or NNE trending faults inside the depression or near its margins show thrust slip,resulting in moderate and strong earthquakes along the piedmont Longmenshan fault,the western slop Longquanshan fault,and Pujiang-Xinjin-Chengdu-Deyang fault.It is indicated that three faults as mentioned above have the potential capability for the occurrence of moderate earthquakes. 相似文献
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WANG ErChie 《中国科学D辑(英文版)》2009,52(5):579-592
The giant earthquake (M
s=8.0) in Wenchuan on May 12, 2008 was triggered by oblique convergence between the Tibetan Plateau and the South China along
the Longmenshan fault belt. The Longmenshan fault belt marks an important component of the tectonic and geomorphological boundary
between the eastern and western part of China and has a protracted tectonic history. It was first formed as an intracontinental
transfer fault, patitioning the differential deformation between the Pacific and Tethys tectonic domains, initiated in late
Paleozoic-early Mesozoic time, then served as the eastern boundary of the Tibetan Plateau to accommodate the growth of the
plateau in Cenozoic. Its current geological and geomorphological frameworks are the result of superimposition of these two
tectonic events. In Late Triassic, the Longmenshan underwent left-slip oblique NW-SE shortening due to the clockwise rotation
of the Yangtze Block, which led to the flexural subsidence of the Sichuan foreland basin, but after that, the subsidence of
the Sichuan Basin seems no longer controlled by the tectonic activity of the Longmenshan fault belt. The Meosozoic tectonic
evolution of the Songpan-Ganzi fold belt differs significantly compared with that of the Yangtze Platform, featured by intensive
northeast and southwest shortening and resulted in the close of the Paleo-Tethys. Aerial photos taken immediately after main
shock of the giant May 12, 2008 earthquake have documented extensive rock fall and landslides that represent one of the most
destructive aspects of the earthquake. Both rock avalanches and landslides delivered a huge volume of debris into the middle
part of the Minjiang River, and formed many dammed lakes. Breaching of these natural dams can be catastrophic, as occurred
in the Diexi area along the upstream of the Minjiang River in the year of 1933 that led to devastating floodings. The resultant
flood following the breaching of these dams flowed through and out of the Longmenshan belt into the Chengdu Plain, bringing
a huge volume of sediments. The oldest alluvial deposits within the Chengdu Plain are estimated to be Late Miocene (8–13 Ma).
We suggest that the flooding that transported the course-grained sediments into the Chengdu Plain occurred in late Cenozoic,
resulted from both the climate and the historical earthquakes similar to the May 12 earthquake. Estimated age of the sediments
related to earthquakes and coeval shortening across the Chengdu Plain indicate that the eastern margin of the plateau became
seismically and tectonically active in Late Miocene.
Supported by Knowledge Innovation Project of Chinese Academy of Sciences (Grant No. KZCX2-YW-12), National Natural Science
Foundation of China (Grant Nos. 40672151, 40721003, 40472121 and 40830314) and PetroChina Company Limited 相似文献
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ZHAO HongGe LIU ChiYang WANG Feng WANG JianQiang LI Qiong YAO YaMing 《中国科学D辑(英文版)》2007,50(Z2):217-226
The Helan Mountain lies in the northwest margin of Ordos Basin and its uplift periods have close relations with the tectonic feature and evolution of the basin. There are many views on the uplift time of Helan Mountain, which is Late Triassic and Late Jurassic. It is concluded by the present strata, magmatic rock and hot fluid distribution that the Helan Mountain does not uplift in Late Triassic to Middle Jurassic but after Middle Jurassic. Through the research of the sedimentary strata and deposit rate in Yinchuan Graben which is near to the Helan Mountain, it is proved that the Helan Mountain uplifts in Eocene with a huge scale and in Pliocene with a rapid speed. The fission track analysis of apatite and zircon can be used to determine the precise uplift time of Helan Mountain, which shows that four stages of uplifting or cooling Late Jurassic to the early stage of Early Cretaceous, mid-late stage of Early Cretaceous, Late Cretaceous and since Eocene. During the later two stages the uplift is most apparent and the mid-late stage of Early Cretaceous is a regional cooling course. Together with several analysis ways, it is considered that the earliest time of Helan Mountain uplift is Late Jurassic with a limited scale and that Late Cretaceous uplift is corresponding to the whole uplift of Ordos Basin, extensive uplift happened in Eocene and rapid uplift in Pliocene. 相似文献
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THRUST OF THE SOUTHERN LONGMENSHAN FAULT IN THE LATE QUATERNARY REVEALED BY RIVER LANDFORMS 
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下载免费PDF全文 The Longmenshan fault zone is divided into three sections from south to north in the geometric structure. The middle and northern segments are mainly composed of three thrust faults, where the deformation of foreland is weak. The geometric structure of the southern segment is more complex, which is composed of six fault branches, where the foreland tectonic deformation is very strong. The Wenchuan MS8.0 earthquake occurred in the middle of the Longmenshan in 2008, activating the bifurcation of two branches, the Yingxiu-Beichuan and the Guixian-Jiangyou faults. In 2013, the Lushan MS7.0 earthquake occurred in the southern Longmenshan, whose seismogenic structure was considered to be a blind fault. After the Lushan earthquake, the seismic hazard in the southern Longmenshan has been widely concerned.
At present, the studies on active tectonics in the southern Longmenshan are limited to the Dachuan-Shuangshi and the Yanjing-Wulong faults. The Qingyi River, which flows across the southern Longmenshan, facilitates to study fault slip by the deformation of river terraces. Based on satellite imagery and high-resolution DEM analysis, we measured the fluvial terraces along the Qingyi river in detail. During the measurement, the Sichuan network GPS system (SCGNSS)was employed to achieve a precision of centimeter grade. Besides, the optical luminescence dating (OSL)method was employed to date the terraces' ages. And the late Quaternary activities of the six branch faults in the southern Longmen Shan were further analyzed.
The Gengda-Longdong, Yanjing-Wulong and the Xiao Guanzi faults (west branch of the Dachuan-Shuangshi fault)all show thrust slip and displaced the terrace T2. Their average vertical slip rates in the late Quaternary are 0.21-0.30mm/a, 0.12-0.21mm/a and 0.10-0.12mm/a, respectively. Since the Late Quaternary, vertical slip of the east branch of the Dachuan-Shuangshi fault was not obvious, and the arc-like Jintang tectonic belt was not active. Crustal shortening rate of the southern Longmenshan thrust fault zone in the late Quaternary is 0.48-0.77mm/a, which equals about half of the middle segment of the Longmenshan. Based on the previous study on the tectonic deformation of the foreland, we consider that the foreland fold belt in the southern Longmenshan area has absorbed more than half of the crustal shortening. The three major branch faults in the southern Longmenshan are active in the late Quaternary, which have risk of major earthquakes. 相似文献
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The crustal structures of the central Longmenshan along and its margins as related to the seismotectonics of the 2008 Wenchuan Earthquake 总被引：10，自引：0，他引：10
JIA ShiXu LIU BaoJin XU ZhaoFan LIU Zhi FENG ShaoYing ZHANG JianShi LIN JieYan TIAN XiaoFeng LIU QiaoXia &GUO WenBin 《中国科学:地球科学(英文版)》2014,57(4):777-790
In 2010, a 500-km-long wide-angle reflection/refraction seismic profile was completed, running northwest from the central Sichuan Basin. This profile orthogonally crosses the meizoseismal area of great Wenchuan earthquake of 12 May 2008, which occurred in the central part of the Longmenshan. The profile also passes through the northwestern Sichuan Plateau, along which a new deep seismic sounding observation system was set up that was much improved over previous datasets and enabled abundant observations to be recorded. Seismic wave phase records that reflect the structural characteristics of different tectonic blocks, especially the complicated phase features associated with the Wenchuan earthquake, were calculated and analyzed in detail. A 2D crustal P-wave velocity model for the orogenic belt in the central Longmenshan and its margins was determined, and crustal structure differences between the stable Sichuan Basin and the thickened northwestern Sichuan Plateau were characterized. Lithological variations within the upper and lower crust in the interior of the plateau, especially a great velocity decrease and plastic rheological properties associated with strong lithologic weakening in lower crust, were detected. From west to east in the lower crust beneath the orogenic belt lying between the Sichuan Basin and the northwestern Sichuan Plateau, a giant shovel-like upwelling is observed that dips gently in the lower part and at higher angles in the upper part; this is inferred to be related to the fault systems in the central Longmenshan. An upwelling in the upper-middle crust along the eastern margin of the orogenic belt is associated with steeply dipping thrusts that strongly uplift the upper crust and crystalline basement beneath a central fault system in the Longmenshan. The data, combined with an understanding of the regional tectonic stress field and previous geological results, enable a discussion of basin-and-range coupling, orogenic tectonics, the crustal fault system, and the seismogenic tectonic environment of the central Longmenshan along the eastern margin of the Qinghai-Tibet Plateau. 相似文献
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成都断陷区活动断裂带基本特征及其潜在地震能力的判定 总被引：4，自引：0，他引：4
成都断陷是龙门山前缘重要的第四纪构造盆地，龙门山前山断裂和龙泉山西坡断裂对断陷盆地的形成和演化有重要的控制作用。晚第四纪时成都断陷遭受北西－南东向的挤压，使断陷盆地边缘和内部的北东，北北东向断裂具逆冲运动性质，并导致龙门山前山断裂，龙泉山西坡断裂和蒲江－新津－成都－德阳断裂上中，强地震的发生，研究表明，上述３条断裂均具有发生中强地震的潜在能力。 相似文献
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龙泉山构造带是四川盆地内川西强烈断陷区和川中稳定隆起区之间的一条区域性断裂.2008年汶川地震后该断裂带未来的强震潜势备受关注.本文对该断裂带的展布、晚第四纪活动性、深部构造形成机制以及断裂带未来的地震危险潜势进行了讨论.断裂带北段位于德阳东侧龙泉山脉西缘;龙泉山脉中段的山体两翼存在断裂;断裂带的南段以向西倾斜的断裂为主.这些断裂在晚更新世以来曾有活动,前人阶地调查显现该断裂带全新世存在活动.考虑到该断裂带未来的地震潜势评估,值得对该断裂带的活动性及断裂带深部构造和运动方式开展进一步的调查. 相似文献