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龙门山冲断带分段-分带性构造格局及其差异变形特征 被引量:129
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作者 李智武 刘树根 +3 位作者 陈洪德 刘顺 郭兵 田小彬 《成都理工大学学报(自然科学版)》 CAS CSCD 北大核心 2008年第4期440-454,共15页
龙门山冲断带地处青藏高原东缘,介于松潘-甘孜褶皱带与四川盆地之间,由一系列走向北东、倾向北西的逆冲断层及其所夹的岩片组成。分段-分带性构造格局是龙门山冲断带的基本特点和重要特色。龙门山自西向东发育有4条主干断裂:茂县-汶川... 龙门山冲断带地处青藏高原东缘,介于松潘-甘孜褶皱带与四川盆地之间,由一系列走向北东、倾向北西的逆冲断层及其所夹的岩片组成。分段-分带性构造格局是龙门山冲断带的基本特点和重要特色。龙门山自西向东发育有4条主干断裂:茂县-汶川断裂、北川-映秀-五龙断裂、安县-都江堰(原称"灌县")-双石断裂和广元-大邑-雅安(隐伏)断裂。由这些主干断裂分隔,龙门山冲断带沿倾向表现出明显的分带性变形特征,以其典型构造特征自西向东称为弧形韧性变形带、基底冲断-同劈理褶皱带、同心褶皱-叠瓦冲断带、前陆扩展变形带和前陆坳陷带,它们自西向东显示层次渐浅、韧性递减、脆性渐强的变形特点。龙门山冲断带沿走向以北川-安县与卧龙-怀远一线为界可三分为北段、中段和南段,北段以出露轿子顶基底杂岩和唐王寨向斜及其前缘叠瓦冲断系为主要特征,中段以出露彭灌基底杂岩及其前缘发育飞来峰为典型特征,南段以出露五龙、宝兴基底杂岩及其前缘发育飞来峰为典型特征。自北东向南西,龙门山冲断带沿走向具有构造起始和定型时期渐晚、脆性渐强、前陆卷入变形的程度渐强、新生代隆升渐快和活动性增强的变化趋势。 展开更多
关键词 龙门山 冲断带 构造分带性 构造分段性 差异变形
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Active Tectonics of the Longmen Shan Region on the Eastern Margin of the Tibetan Plateau 被引量:38
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作者 ZHOU Rongjun LI Yong +4 位作者 Alexander L.DENSMORE Michael A. ELLIS HE Yulin LI Yongzhao LI Xiaogang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第4期593-604,共12页
There is a massive amount of geomorphic evidence for active tectonics in the Longmen Shan at the eastern margin of the Tibetan plateau. We have surveyed some typical geomorphic markers including the Wenchuan-Maowen, B... There is a massive amount of geomorphic evidence for active tectonics in the Longmen Shan at the eastern margin of the Tibetan plateau. We have surveyed some typical geomorphic markers including the Wenchuan-Maowen, Beichuan-Yingxiu and Pengxian-Guanxian faults, terrace offsets, scarps, fault-controlled saddles, dextral shutter ridges, dextral channel offsets, graben, shatter belts, and pull-apart basins. Electron spin resonance (ESR) and thermoluminescence(TL) ages were obtained using silty sand taken from below the surface of the sediments. According to these data, we calculated the rates of thrusting and strike-slip, and the results indicate that Cenozoic tectonic shortening at the plateau margin is minor with the rate of thrusting less than 1.10 mm/a and the rate of strike-slipping less than 1.46 mm/a. The Longmen Shan is a zone of NNE-trending dextral shear with slip-dip ratio of 6:1-1.3:1. From NW to SE, the thrust component becomes smaller, whereas the strike-slip component becomes larger. 展开更多
关键词 TECTONICS strike-slip thrusting Late Cenozoic longmen Shan Tibetan plateau
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Deep Background of Wenchuan Earthquake and the Upper Crust Structure beneath the Longmen Shan and Adjacent Areas 被引量:12
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作者 LI Qiusheng GAO Rui +5 位作者 WANG Haiyan ZHANG Jisheng LU Zhanwu LI Pengwu GUAN Ye HE Rizheng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第4期733-739,共7页
By analyzing the deep seismic sounding profiles across the Longmen Shan, this paper focuses on the study of the relationship between the upper crust structure of the Longmen Shan area and the Wenchuan earthquake. The ... By analyzing the deep seismic sounding profiles across the Longmen Shan, this paper focuses on the study of the relationship between the upper crust structure of the Longmen Shan area and the Wenchuan earthquake. The Longmen Shan thrust belt marks not only the topographical change, but also the lateral velocity variation between the eastern Tibetan Plateau and the Sichuan Basin. A low-velocity layer has consistently been found in the crust beneath the eastern edge of the Tibetan Plateau, and ends beneath the western Sichuan Basin. The low-velocity layer at a depth of -20 km beneath the eastern edge of the Tibetan Plateau has been considered as the deep condition for favoring energy accumulation that formed the great Wenchuan earthquake. 展开更多
关键词 the longmen Shan deep seismic sounding profile upper crust structure Wenchuan Earthquake
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Tectonic Evolution of the Middle Frontal Area of the Longmen Mountain Thrust Belt,Western Sichuan Basin,China 被引量:11
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作者 JIN Wenzheng TANG Liangjie +3 位作者 YANG Keming WAN Guimei Lü Zhizhou YU Yixin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第1期92-102,共11页
By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt, China, we concluded that it had experienced five tectonic stages: (1) the formation stage (T3x) of the miniatur... By analyzing the balanced cross sections and subsidence history of the Longmen Mountain thrust belt, China, we concluded that it had experienced five tectonic stages: (1) the formation stage (T3x) of the miniature of Longmen Mountain, early Indosinian movement, and Anxian tectonic movement created the Longmen Mountain; (2) the stable tectonic stage (J1) where weaker tectonic movement resulted in the Longmen Mountain thrust belt being slightly uplifted and slightly subsiding the foreland basin; (3) the intense tectonic stage (J2-3), namely the early Yanshan movement; (4) continuous tectonic movement (K-E), namely the late Yanshan movement and early Himalayan movement; and (5) the formation of Longmen Mountain (N-Q), namely the late Himalayan movement. During those tectonic deformation stages, the Anxian movement and Himalayan movement played important roles in the Longmen Mountain's formation. The Himalayan movement affected Longmen Mountain the most; the strata thrust intensively and were eroded severely. There are some klippes in the middle part of the Longmen Mountain thrust belt because a few nappes were pushed southeastward in later tectonic deformation. 展开更多
关键词 balanced cross section shortening rate subsidence history longmen Mountain thrust belt Sichuan basin
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Meso-Cenozoic Tectonic Events Recorded by Apatite Fission Track in the Northern Longmen-Micang Mountains Region 被引量:9
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作者 LEI Yongliang JIA Chengzao +3 位作者 LI Benliang WEI Guoqi CHEN Zhuxin SHI Xin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第1期153-165,共13页
There is a cross-cutting relationship between the E-W trending structures and the NE- trending structures in the northern Longmen-Micang Mountains region, which reflects possible regional tectonic transition and migra... There is a cross-cutting relationship between the E-W trending structures and the NE- trending structures in the northern Longmen-Micang Mountains region, which reflects possible regional tectonic transition and migration. Apatite fission track (AFT) analyses of 15 samples collected from this area yield apparent ages varying from 30.3±4.2 Ma to 111.7±9.0 Ma and confined-track-lengths ranging from 10.6±0.3 pm to 12.4±0.1 μm. Four specific groups were identified on the basis of the Track Age Spectrum Calculation (TASC) patterns, i.e., 143-112 Ma, 93.6-88 Ma, 42-40 Ma and -25.6 Ma. These age groups correspond to the spatial distributions of datasets and may represent four tectonic events. Together with the regional deformation patterns, the four age groups are interpreted to indicate tectonic superposition, transition and migration during the Meso-Cenozoic with the following possible order: (1) the Micang Mountains belt was dominated by the E-W trending structure during 143-112 Ma; (2) the contraction of the Longmen Mountains belt from the NW to the SE during 93.6-88 Ma led to the superposition of the NE-trending structures over the E-W trendinding structures; (3) dextral strike-slip shear dominated the Longmen Mountains belt at 42-40 Ma; (4) westward migration of the active tectonic belt occurred from 93.6-25.6 Ma in a break-back sequence in the northern Longmen Mountains belt. The Late Cenozoic tectonics in the northern Longmen Mountains belt are characterized by the dextral strike-slip shear and the occurrence of westward break-back sequence of deformations. As a result, north-south differences in deformations along the Longmen Mountains belt were intensified since the Miocene time and strains were mainly accumulated in the hinterland of the Longmen Mountains instead of being propagated to the foreland basin. 展开更多
关键词 apatite fission track tectonic events longmen Mountains Micang Mountains Meso-Cenozoic
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Seismogenic Structure around the Epicenter of the May 12,2008 Wenchuan Earthquake from Micro-seismic Tomography 被引量:7
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作者 AN Meijian FENG Mei +5 位作者 DONG Shuwen LONG Changxing ZHAO Yue YANG Nong ZHAO Wenjin ZHANG Jizhong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第4期724-732,共9页
A three-dimensional local-scale P-velocity model down to 25 km depth around the main shock epicenter region was constructed using 83821 event-to-receiver seismic rays from 5856 aftershocks recorded by a newly deployed... A three-dimensional local-scale P-velocity model down to 25 km depth around the main shock epicenter region was constructed using 83821 event-to-receiver seismic rays from 5856 aftershocks recorded by a newly deployed temporary seismic network. Checkerboard tests show that our tomographic model has lateral and vertical resolution of -2 km. The high-resolution P-velocity model revealed interesting structures in the seismogenic layer: (1) The Guanxian-Anxian fault, Yingxiu-Beichuan fault and Wenchuan-Maoxian fault of the Longmen Shan fault zone are well delineated by sharp upper crustal velocity changes; (2) The Pengguan massif has generally higher velocity than its surrounding areas, and may extend down to at least -10 km from the surface; (3) A sharp lateral velocity variation beneath the Wenchuan-Maoxian fault may indicate that the Pengguan massif's western boundary and/or the Wenchuan-Maoxian fault is vertical, and the hypocenter of the Wenchuan earthquake possibly located at the conjunction point of the NW dipping Yingxiu-Beichuan and Guanxian-Anxian faults, and vertical Wenchuan-Maoxian fault; (4) Vicinity along the Yingxiu- Beichuan fault is characterized by very low velocity and low seismicity at shallow depths, possibly due to high content of porosity and fractures; (5) Two blocks of low-velocity anomaly are respectively imaged in the hanging wall and foot wall of the Guanxian-Anxian fault with a -7 km offset with -5 km vertical component. 展开更多
关键词 Wenchuan earthquake seismogenic structure micro-seismic tomography Pengguan massif longmen Shan fault zone
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Differential Tectonic Deformation of the Longmen Mountain Thrust Belt,Western Sichuan Basin,China 被引量:6
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作者 TANG Liangjie YANG Keming +3 位作者 JIN Wenzheng WAN Guimei LüZhizhou YU Yixin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2009年第1期158-169,共12页
Field investigation and seismic section explanation showed that the Longmen Mountain Thrust Belt has obvious differential deformation: zonation, segmentation and stratification. Zonation means that, from NW to NE, th... Field investigation and seismic section explanation showed that the Longmen Mountain Thrust Belt has obvious differential deformation: zonation, segmentation and stratification. Zonation means that, from NW to NE, the Longmen Mountain Thrust Belt can be divided into the Songpan- Garz~ Tectonic Belt, ductile deformation belt, base involved thrust belt, frontal fold-thrust belt, and foreland depression. Segmentation means that it can be divided into five segments from north to south: the northern segment, the Anxian Transfer Zone, the center segment, the Guanxian Transfer Zone and the southern segment. Stratification means that the detachment layers partition the structural styles in profile. The detachment layers in the Longmen Mountain Thrust Belt can be classified into three categories: the deep-level detachment layers, including the crust-mantle system detachment layer, intracrustal detachment layer, and Presinian system basal detachment layer; the middle-level detachment layers, including Cambrian-Ordovician detachment layer, Silurian detachment layer, etc.; and shallow-level detachment layers, including Upper Triassic Xujiahe Formation detachment layer and the Jurassic detachment layers. The multi-level detachment layers have a very important effect on the shaping and evolution of Longmen Mountain Thrust Belt. 展开更多
关键词 differential deformation detachment layer segmentation STRATIFICATION transfer zone zonation longmen Mountain Thrust Belt
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The Seismogenic Structure of the 2010 Suining Ms 5.0 Earthquake and its Geometry,Kinematics and Dynamics Analysis 被引量:6
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作者 LU Renqi HE Dengfa +4 位作者 JOHN Suppe MA Yongsheng GUAN Shuwei SUN Yanpeng GAO Jinwei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第6期1277-1285,共9页
In January 2010, the Suining Ms5.0 earthquake occurred in central Sichuan Basin, with the epicenter in Moxi-Longnvsi structural belt and a focal depth of 10 km. Based on structural interpretations of seismic profiles ... In January 2010, the Suining Ms5.0 earthquake occurred in central Sichuan Basin, with the epicenter in Moxi-Longnvsi structural belt and a focal depth of 10 km. Based on structural interpretations of seismic profiles in this area, we recognized a regional detachment fault located at a depth of 9-10 km in the Presinian basement of the Suining area, transferring its slipping from NW to SE orientation. This detachment fault slipped from NW to SE, and underwent several shears and bends, which caused the basement to be rolled in and the overlaying strata fold deformation. It formed a fault-bend fold in the Moxi area with an approximate slip of 4 km. Correspondingly, the formation of the Moxi anticline is related to the detachment fault. With the earthquake's epicenter on the ramp of the detachment fault, there is a new point of view that the Suining earthquake was caused by re-activation of this basement detachment fault. Since the Late Jurassic period, under the influence of regional tectonic stress, the detachment fault transfered its slip from the Longmen Mountains (LMS) thrust belt to the hinterland of the Sichuan Basin, and finally to the piedmont zone of southwest Huayingshan (HYS), which indicates that HYS might be the final front area of the LMS thrust belt. 展开更多
关键词 Suining Ms5.0 earthquake Seismic interpretation Detachment fault Moxi anticline longmen Mountains Sichuan Basin
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Impact of vegetation restoration on hydrological processes in the middle reaches of the Yellow River,China 被引量:4
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作者 XIN Zhong-bao YU Xin-xiao 《Forestry Studies in China》 CAS 2009年第4期209-218,共10页
Sediment discharge from the Yellow River originates mainly from the drainage area between Hekouzhen and Longmen, i.e., the Helong area. Spatial-temporal variations of the vegetation cover in this area during the 1981-... Sediment discharge from the Yellow River originates mainly from the drainage area between Hekouzhen and Longmen, i.e., the Helong area. Spatial-temporal variations of the vegetation cover in this area during the 1981-2007 period have been investigated using GIMMS and SPOT VGT NDVI data. We have also analyzed the interannual variations in vegetation cover and changes in annual runoff and sediment discharge, the consequences from precipitation change and the Grain for Green Project (GGP). The results show that vegetation cover of the Helong area has increased during the 1981-2007 period. The northwestern part the Helong area, where the flat sandy lands are covered by grass, has experienced the largest increase. The region where the vegetation cover has declined is largely found in the southern and southeastern Helong area, which is a gullied hilly area or forested. Although precipitation was relatively low during the 1999-2007 period, the vegetation cover showed a significant increase in the Helong area, due to the implementation of the GGP. During this period, the most significant improvement in the vegetation cover occurred mainly in the gullied hilly areas of the Loess Plateau, such as the drainage basins of the Kuyehe and Tuweihe rivers and the middle and lower reaches of the Wudinghe and Yanhe rivers. A comparison of the average annual maximum NDVI between the earlier (1998-2002) stage and the next five years (2003-2007) of the GGP indicates that the areas with increases of 10% and 20% in NDVI account for 72.5% and 36.4% of the total area, respectively. Interannual variation of annual runoff and sediment discharge shows a declining trend, especially since the 1980s, when the decrease became very obvious. Compared with the 1950-1969 period, the average runoff during the 1980-2007 period was reduced by 34.8 × 10^8 m3 and the sediment discharge by 6.4 ×10^8 t, accounting for 49.4% and 64.9% of that in the 1950-1969 period, respectively. There is a positive correlation between the annual maximum NDVI 展开更多
关键词 middle reaches of the Yellow River Hekouzhen to longmen area (Helong area) vegetation restoration Grain forGreen Project (GGP) runoff and sediment
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Application of the Material Balance Method in Paleoelevation Recovery: A Case Study of the Longmen Mountains Foreland Basin on the Eastern Margin of the Tibetan Plateau 被引量:4
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作者 YAN Zhaokun LI Yong +6 位作者 LI Haibing DONG Shunli ZHAO Guohua LI Jingbo LI Fensheng YAN Liang ZHENG Lilong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第2期598-609,共12页
We applied the material balance principle of the denudation volume and sedimentary flux to study the denudation-accumulation system between the Longmen Mountains (Mts.) and the foreland basin. The amount of sediment... We applied the material balance principle of the denudation volume and sedimentary flux to study the denudation-accumulation system between the Longmen Mountains (Mts.) and the foreland basin. The amount of sediment in each sedimentation stage of the basin was estimated to obtain the denudation volume, erosion thickness and deposit thickness since the Late Triassic Epoch, to enable us to recover the paleoelevation of the provenance and the sedimentary area. The results show the following: (1) Since the Late Triassic Epoch, the elevation of the surface of the Longmen Mts. has uplifted from 0 m to 2751 m, and the crust of the Longmen Mts. has uplifted by 9.8 km. Approximately 72% of the materials introduced have been denuded from the mountains. (2) It is difficult to recover the paleoelevation of each stage of the Longmen Mts. foreland basin quantitatively by the present-day techniques and data. (3) The formation of the Longmen Mts. foreland basin consisted of three stages of thrust belt tectonic load and three stages of thrust belt erosional unload. During tectonic loading stages (Late Triassic Epoch, Late Jurassic-Early Cretaceous, Late Cretaceous-Miocene), the average elevation of Longmen Mts. was lower (approximately 700-1700 m). During erosional unloading stages (Early and Middle Jurassic, Middle Cretaceous and Jiaguan, Late Cenozoic), the average elevation of Longmen Mts. was high at approximately 2000-2800m. 展开更多
关键词 longmen Mountains foreland basin material balance method paleoelevation recovery the eastern margin of the Tibetan Plateau
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Tectono–sedimentary Evolution of the Late Triassic Xujiahe Formation in the Sichuan Basin 被引量:4
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作者 LUO Liang JIA Dong +2 位作者 QI Jiafu WEI Guoqi DENG Fei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第6期1554-1568,共15页
The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although t... The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although the Late Triassic Xujiahe Formation is assumed to represent the commencement of continental deposition in the Sichuan Basin,little research is available on the details of this particular stratum.Sequence stratigraphic analysis reveals that the Xujiahe Formation comprises four third-order depositional sequences.Moreover,two tectono-sedimentary evolution stages,deposition and denudation,have been identified.Typical wedge-shaped geometry revealed in a cross section of the southern Sichuan Basin normal to the Longmen Shan fold-thrust belt is displayed for the entire Xujiahe Formation.The depositional extent did not cover the Luzhou paleohigh during the LST1 to LST2 (LST,TST and HST mean Iowstand,transgressive and highstand systems tracts,1,2,3 and 4 represent depositional sequence 1,2,3 and 4),deltaic and fluvial systems fed sediments from the Longmen Shan belt,Luzhou paleohigh,Hannan dome,and Daba Shan paleohigh into a foreland basin with a centrally located lake.The forebulge of the western Sichuan foreland basin was located southeast of the Luzhou paleohigh after LST2.According to the principle of nonmarine sequence stratigraphy and the lithology of the Xujiahe Formation,four thrusting events in the Longmen Shan fold-thrust belt were distinguished,corresponding to the basal boundaries of sequences 1,2,3,and 4.The northern Sichuan Basin was tilted after the deposition of sequence 3,inducing intensive erosion of sequences 3 and 4,and formation of wedge-shaped deposition geometry in sequence 4 from south to north.The tilting probably resulted from small-scale subduction and exhumation of the western South China block during the South and North China block collision. 展开更多
关键词 Xujiahe Formation tectono-sedimentary DENUDATION longmen Shan Sichuan Basin
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The Deep Geophysical Structure of the Middle Section of the Longmen Mountains Tectonic Belt and its Relation to the Wenchuan Earthquake 被引量:4
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作者 YU Nian WANG Xuben +3 位作者 HU Xiangyun CAI Xuelin KAN Aike ZHAO Ning 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第2期483-497,共15页
Investigation of the deep geophysical structure of the Longmen Mountains tectonic belt and its relation to the Wenchuan Earthquake is important for the study of earthquakes.By using magnetotelluric sounding profiles o... Investigation of the deep geophysical structure of the Longmen Mountains tectonic belt and its relation to the Wenchuan Earthquake is important for the study of earthquakes.By using magnetotelluric sounding profiles of the Luqu-Zhongjiang and Anxian-Suining; seismic sounding profiles of the Sichuan Maowen-Chongqing Gongtan,the Qinghai Huashi Gorge-Sichuan Jianyang,and the Batang-Zizhong; and magnetogravimetric data of the Longmen Mountains region,the deep geophysical structure of the Songpan-Ganzi block,the western Sichuan foreland basin,and the Longmen Mountains tectonic belt and their relation was discussed.The eastward extrusion of the Qinghai-Tibet Plateau thrusts the Songpan-Ganzi block upon the Yangtze block,which obstructs the eastward movement of the Qinghai-Tibet Plateau.The Maoxian-Wenchuan,Beichuan-Yingxiu,and Anxian-Guanxian faults of the Longmen Mountains fault belt dip to northwest with different dip angles and gradually converge in the deeper parts.Geophysical structure suggests that an intracrustal low-velocity,low-resistivity,and high-conductivity layer is common between the middle and upper crust west of the Longmen Mountains tectonic belt but not in the upper Yangtze block.The Sichuan Basin has a thick low-resistance sedimentary layer on a stable high-resistance basement; moreover,there are secondary paleohighs and depression structures at the lower part of the western Sichuan foreland basin with characteristic of high magnetic anomalies,whereas the Songpan-Ganzi block has a high resisitivity cover of upper crust and continues to a low-resistance layer.Considering the Longmen Mountains tectonic belt as the boundary,there are Bouguer gravity anomalies of "one belt between two zones." Thus,we infer that there is a corresponding relation between the inferred crystalline basement of the Songpan block and the underlying basin basement of the Longmen Mountains fault belt.Furthermore,there may be an extensive ancient Yangtze block,which is west of the Ruoergai block.In addition,the crust-mantle du 展开更多
关键词 longmen Mountains tectonic belt Wenchuan earthquake magnetotelluric sounding seismic sounding Songpan-Ganzi folded belt Qinghai-Tibet plateau
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Interpreting the Coseismic Uplift and Subsidence of the Longmen Shan Foreland Basin System during the Wenchuan Earthquake by a Elastic Flexural Model 被引量:4
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作者 YAN Zhaokun LI Yong +4 位作者 SHAO Chongjian ZHOU Rongjun YAN Liang ZHAO Guohua YAN Binglei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第2期555-566,共12页
The coseismic surface uplift of the Longmen Shan(LMS) created an instantaneous topographic load over the western margin of the Sichuan Basin, where surface subsidence, decreasing eastward, has been measured using se... The coseismic surface uplift of the Longmen Shan(LMS) created an instantaneous topographic load over the western margin of the Sichuan Basin, where surface subsidence, decreasing eastward, has been measured using several methods, such as GPS, SAR and levelling. Using an elastic flexural model, we aim to interpret the coseismic surface uplift and subsidence, and constrain the effective lithospheric elastic thickness(Te) of the Sichuan Basin. Using different effective elastic thickness values for the Sichuan Basin, a series of subsidence curves were computed by the elastic flexure model equation for a broken elastic plate. The curves, produced by models using an effective elastic thickness of 30–40 km, provided the best fit to the general pattern of observed coseismic subsidence of the Sichuan Basin. However, the calculated subsidence(-40–70 cm) at the front of the LMS is evidently lower than the observed values(-100 cm), suggesting that the effective elastic thickness therein should be lower. These results indicate that the lithospheric strength may decrease westward from the Sichuan Basin to the LMS. 展开更多
关键词 flexural model longmen Shan Wenchuan Earthquake coseismic uplift and subsidence foreland basin system
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The Coupling Relationship between the Uplift of Longmen Shan and the Subsidence of Foreland Basin,Sichuan,China 被引量:4
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作者 LI Yong YAN Liang +5 位作者 SHAO Chongjian WANG Zhengjiang YAN Zhaokun YU Qian ZHOU Rongjun LI Haibin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第2期379-395,共17页
Depending on the analysis of the coeval sedimentary geometry and subsidence mechanism in the Longmen Shan foreland basin, three models about the coupling relationship between Longmen Shan uplift and foreland basin sub... Depending on the analysis of the coeval sedimentary geometry and subsidence mechanism in the Longmen Shan foreland basin, three models about the coupling relationship between Longmen Shan uplift and foreland basin subsidence since the Indosinian have been proposed:(1) crustal shortening and its related wide wedge-shaped foreland basin,(2) crustal isostatic rebound and its related tabular foreland basin, and(3) lower crustal flow and its related narrow wedge-shaped foreland basin. Based on the narrow wedge-shaped foreland basin developed since 4 Ma, it is believed that the narrow crustal shortening and tectonic load driven by lower crustal flow is a primary driver for the present Longmen Shan uplift and the Wenchuan(Ms 8.0) earthquake. 展开更多
关键词 coupling relationship foreland basin subsidence longmen Shan uplift eastern margin of Tibetan Plateau SICHUAN China Proto-Tethys
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龙门地下热水的开发与利用前景分析 被引量:6
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作者 李宏伟 罗锐 《中国煤田地质》 2005年第6期26-28,共3页
通过多年的地质勘探、研究与开发,对龙门地热资源的发育特征有了较深入的了解。龙门地热田热储层为富含温热水的Э2+3碳酸盐岩,属水热型地热田中的温热水型热储,温热水的补给来自大气降水,在径流的过程中、受本区构造的控制,经深循环加... 通过多年的地质勘探、研究与开发,对龙门地热资源的发育特征有了较深入的了解。龙门地热田热储层为富含温热水的Э2+3碳酸盐岩,属水热型地热田中的温热水型热储,温热水的补给来自大气降水,在径流的过程中、受本区构造的控制,经深循环加热而成。经检测,龙门温热水中锶及偏硅酸含量都达到了天然饮用矿泉水标准,具有较高的开发价值于利用前景。 展开更多
关键词 地下热水 天然饮用矿泉水 温热水型热储 开发利用前景 龙门
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Slope Seismic Response Monitoring on the Aftershocks of the Wenchuan Earthquake in the Mianzhu Section 被引量:6
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作者 WANG Yunsheng LUO Yonghong +4 位作者 WANG Fuhai WANG Dong MA Xiao LI Shun DENG Xi 《Journal of Mountain Science》 SCIE CSCD 2012年第4期523-528,共6页
Previous investigations have shown that the seismic response of slopes during the Wenchuan earthquake was highly variable. The present study tries to give an answer to the question: Which are the main factors affecti... Previous investigations have shown that the seismic response of slopes during the Wenchuan earthquake was highly variable. The present study tries to give an answer to the question: Which are the main factors affecting the seismic response degree of slopes? With the support of the China Geological Survey Bureau, we set 3 monitoring sections in Jiulong slope, Mianzhu city, China with the aim to record the site response of the slope during the affershoeks of the Wenehuan earthquake. After the Wenchuan earthquake, which happened on 12 May 2008, 30 aftershocks have been recorded in these monitoring points. We analyzed 11 records, with magnitudes ranging from ML = 4.6 to ML = 3.1. The amplification factors of the horizontal compound PGA and 3D compound PGA have been determined for the 3 points at different elevations on the slope. Results showed that the dynamic response of the slope on the earthquake was controlled by factors such as topography and the thickness of the Quaternary overburden. 展开更多
关键词 Seismic response SLOPE MONITORING longmen Mountains AFTERSHOCKS Wenchuanearthquake
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中国四川龙门山地区泥盆系牙形石 被引量:5
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作者 蒋武 胡祖修 郑家凤 《微体古生物学报》 CSCD 北大核心 1996年第2期195-205,216-218,共11页
龙门山地区泥盆系地层发育,厚度大,一般为2000-40000m,最厚达5000m以上,化石丰富,门类众多。主要有腕足类、珊瑚、双壳类、三叶虫、头足类、竹节石和层孔虫等。碳酸盐岩地层中发现了大量的牙形石。作者对桂溪、雁... 龙门山地区泥盆系地层发育,厚度大,一般为2000-40000m,最厚达5000m以上,化石丰富,门类众多。主要有腕足类、珊瑚、双壳类、三叶虫、头足类、竹节石和层孔虫等。碳酸盐岩地层中发现了大量的牙形石。作者对桂溪、雁门坝和硫铁矿三条剖面中的牙形石做了系统工作,在雁门坝和硫铁矿剖面中,发现了丰富的Palmatolepis(蹼刺)。经分析研究,将该区泥盆系划分出13个牙形石带和组合。在此基础上,对泥盆系的地层单元及下、中、上泥盆统之间的界线进行了划分,对该区泥盆纪的古生物地理进行了分析。 展开更多
关键词 牙形石 泥盆系 龙门山 四川
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Crustal Uplift in the Longmen Shan Mountains Revealed by Isostatic Gravity Anomalies along the Eastern Margin of the Tibetan Plateau 被引量:3
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作者 LI Yong YAN Zhaokun +4 位作者 ZHOU Rongjun YAN Liang DONG Shunli SHAO Chongjian Svirchev LAURENCE 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第1期56-73,共18页
This study examines the relationship between high positive isostatic gravity anomalies (IGA), steep topography and lower crustal extrusion at the eastern margin of the Tibetan Plateau. IGA data has revealed uplift a... This study examines the relationship between high positive isostatic gravity anomalies (IGA), steep topography and lower crustal extrusion at the eastern margin of the Tibetan Plateau. IGA data has revealed uplift and extrusion of lower crustal flow in the Longmen Shan Mountains (the LMS). Firstly, The high positive IGA zone corresponds to the LMS orogenic belt. It is shown that abrupt changes in IGA correspond to zones of abrupt change of topography, crustal thickness and rock density along the LMS. Secondly, on the basis of the Airy isostasy theory, simulations and inversions of the positive IGA were conducted using three-dimensional bodies. The results indicated that the LMS lacks a mountain root, and that the top surface of the lower crust has been elevated by 11 km, leading to positive IGA, tectonic load and density load. Thirdly, according to Watts's flexural isostasy model, elastic deflection occurs, suggesting that the limited (i.e. narrow) tectonic and density load driven by lower crustal flow in the LMS have led to asymmetric flexural subsidence in the foreland basin and lifting of the forebulge. Finally, based on the correspondence between zones of extremely high positive IGA and the presence of the Precambrian Pengguan-Baoxing complexes in the LMS, the first appearance of erosion gravels from the complexes in the Dayi Conglomerate layer of the Chengdu Basin suggest that positive IGA and lower crustal flow in the LMS took place at 3.6 Ma or slightly earlier. 展开更多
关键词 isostatic gravity anomalies crustal uplift longmen Shan Mountains lower crustal flow foreland basin the eastern margin of the Tibetan Plateau
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洛阳新辑石刻所见唐代中原之佛教 被引量:4
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作者 张乃翥 《中原文物》 北大核心 2008年第5期81-93,共13页
本文所辑洛阳地区新近出土的九件石刻文物,总体上反映了中古时期当地佛教寺院参与社会人文事态的广泛。此中显示的龙门地区出土石刻文物的密集,则折射出盛唐前后这一地区佛教人文活动的繁盛。
关键词 洛阳 龙门 浮图 经幢 墓志
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Pn-wave velocity and anisotropy of the western Sichuan and Longmen Mountain region,China 被引量:2
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作者 Xu Yi Li ZhiWei +2 位作者 Huang RunQiu Liu JianHua Liu JinSong 《Science China Earth Sciences》 SCIE EI CAS 2010年第11期1665-1670,共6页
Pn-wave velocity and anisotropy beneath the western Sichuan and adjacent region are inverted by a tomography method using arrival data from earthquakes recorded by the Sichuan Earthquake Network. It is followed by an ... Pn-wave velocity and anisotropy beneath the western Sichuan and adjacent region are inverted by a tomography method using arrival data from earthquakes recorded by the Sichuan Earthquake Network. It is followed by an analysis of the uppermost mantle structure of the Longmen Mountain region and the deep tectonics of the Ms8.0 earthquake in Wenchuan. Our results reveal a prominent velocity contrast across the Longmenshan fault: low velocities in the Songpan-Ganzi mountain range and high velocities in the Sichuan basin. They indicate that the Songpan-Ganzi mountain range is underlain by a weak uppermost mantle, which is easy to create ductile flow, whereas the Sichuan basin has a mechanically strong uppermost mantle. These features reflect a difference of the lithospheric mantle beneath tectonically active mountain range and stable basin. The boundary between the high and low velocities is coincident with the Longmenshan fault. Bordered by Wenchuan, the northern part of the boundary is parallel to the fault belt and aftershock distribution, but the southern part of the boundary deviates from the fault belt and is bent toward the Sichuan basin. The Ms8.0 earthquake in Wenchuan is located at the flexural part between them, where a strong heterogeneity is shown in the velocity variation across and parallel to the boundary. This area is reasonably believed as a potential location for regional stress accumulation and release in the Longmen Mountain region, reflecting a prominent character in the deep structure around Wenchuan. Pn-wave anisotropy reveals the mantle flow that is consistent with the eastward movement of the Tibetan Plateau. This process provided deep dynamic sourse for tectonic deformation in the Longmen Mountain region and for the occurrence of the Wenchuan Ms8.0 earthquake, but it is clearly affected by the strong lithosphere of the Sichuan basin. There is no correlation between the Pn-wave anisotropy and the Longmenshan fault, hence, this fault system is only restricted within the crust. However, the man 展开更多
关键词 western SICHUAN longmen MOUNTAIN Pn velocity ANISOTROPY WENCHUAN earthquake
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