2016 Vol. 22, No. 3

Display Method:
THE ACTIVE TECTONICS AND REGIONAL CRUSTAL STABILITY FEATURES IN THE AREA OF YANGTZE RIVER ECONOMIC BELT
WU Zhong-hai, ZHOU Chun-jing, TAN Cheng-xuan, SUN Yu-jun, MA Xiao-xue
2016, 22(3): 379-411.
Abstract (254) HTML (167) PDF (2245KB)(57)
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Combining the new Remote sensing interpretation and the result of surface survey with the active faults data on the Yangtze River Economic Belt, we preliminarily summarized the active tectonic features in this area, and teased out the main active faults that directly and indirectly threating to crustal stability of important urban agglomerations, state-level new district and river-crossing channels at the Yangtze River Economic Belt region, then pointed out 32 important active faults along Chengdu-Shanghai region that belongings to the middle and lower reaches of Yangtze River Economic Belt, and the influenced major urban agglomerations and major projects. After teasing out the active faults, we put forward that the strong crustal deformation and seismicity of western Yangtze River Economic Belt are mainly controlled by "the Sichuan-Yunnan arc rotational-shear active tectonic system" at southeastern margin of Qinghai-Tibetan Plateau that formed under the action of the collision between Indian Plate and Eurasian Plate. But the middle-eastern area of Yangtze River Economic Belt is a "check board" active tectonic system that has the characteristics of conjugate strike slip fault which caused by the regional extrusion shearing deformation under the action of Indian Plate and Western Pacific Plate, 7 typical active faults' activity and their influences to the crustal stability of urban agglomeration required especially attentive. According to the features of regional active tectonic system, active faults and historic seismic activities, we preliminarily summarized the problems of future seismic hazard in this area, and the potential strong earthquake risk segment that needs to be focused on, then identified the importance of surveying the characteristics of geological relics of typical regional paleoearthquakes and paleoearthquake study. Further, the preliminary evaluation of regional crustal stability in the Yangtze River Economic Belt region showed that the unstable and sub-unstable regions are mainly concentrated in the western region, and the most of central-eastern regions are belong to the sub-stable and stable regions, but there are a few obvious sub-unstable regions along the Tanlu fault zone. Finally, we pointed out the main problems and challenges on the field surveying and evaluation of active tectonics and regional crustal stability, and the active fault identification and seismic risk evaluation of major city area in the Yangtze River Economic Belt.
CHARACTERISTICS OF SEISMIC ACTIVITY AND SEISMIC RISK PROBLEMS IN THE CENTRAL-EASTERN YANGTZE RIVER ECONOMIC BELT (SHANGHAI-CHONGQING SECTION)
ZHAO Gen-mo, WU Zhong-hai, LIU Jie
2016, 22(3): 412-420.
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In this paper, based on historical and instrumental seismic data, we focused on the characteristics of the seismic activity in the eastern part of Yangtze River Economic Belt, gave the division of seismic zone, discussed the problems of the earthquake in the city center area. Combining with regional seismic anomaly, we pointed out the great earthquake hazard information of the current eastern coastal and Tanlu belt, pointed out the problems and related suggestions on confronting the earthquake safety and earthquake prevention and disaster reduction.
LITHOSPHERIC THERMAL-RHEOLOGICAL STRUCTURE AND DEEP GEODYNAMICS IN THE YANGTZE RIVER ECONOMIC BELT
SUN Yu-jun, WU Zhong-hai, JIA Feng-qin
2016, 22(3): 421-429.
Abstract (226) HTML (106) PDF (1607KB)(24)
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Constructing the finite three-dimensional numerical model through Crust 2.0, under constraints of the surface temperature, deep inversion temperature and surface heat flow, we have calculated the thermal structure of the continental lithosphere beneath Yangtze River Economic Belt and adjacent regions. On the basis of 3D thermal structure, deriving surface strain rates from GPS observation, and selecting representative rock physical properties, we have calculated the strength and effective viscosity of the continental lithosphere. The results show that there is obvious lateral heterogeneity in the Yangtze River Economic Belt. The Sichuan basin has low temperature, high strength and high viscosity. In the same depth, temperature beneath the Sichuan basin is lower than ambient region for 100~300℃. Strength and viscosity is lower for 1~2 orders of magnitude. The transition zone of temperature, strength and viscosity has strong active tectonics. Combining with deep geophysical observation, the study proposed that the Pacific Plate subduction and India-Eurasia Plate collision played important roles in the deep dynamic process respectively in the eastern and western parts of the Yangtze River Economic Belt. The effective sphere reach the eastern and western boundaries of Sichuan basin, deep dynamic process may lead to the horizontal heterpgeneity of the lithosphere.
FAULTS AND EARTHQUAKES IN GUIZHOU
WANG Shang-yan
2016, 22(3): 430-438.
Abstract (522) HTML (115) PDF (1530KB)(41)
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Earthquakes in Guizhou were controlled and affected by (active) faults. The regional faults controlled the earthquake partition boundaries. Earthquakes usually occurred near faults or intersection area of many faults. Epicenters of the four earthquakes, M 6 or so, since 1819, were in intersection area of many faults. The M 6.5 earthquake that occurred on Jun. 8th, 1875, its epicenter was located at the Chuangjing anticline, intersection area of Kaiyuan-Pingtang fault and Yadu-Ziyun fault. The epicenter is located at the west of Luodian County, and is nealy Wangmo County and Ziyun County. Its longitude and latitude is 106°36'E and 25°18'N.
RESEARCH ON THE MAJOR ACTIVE FAULTS IN ZHENJIANG, JIANGSU AND THEIR LATE QUATERNARY ACTIVITIES
ZONG Kai-hong, ZONG Wen, KANG Cong-xuan, BAI Shi-biao
2016, 22(3): 439-453.
Abstract (251) HTML (101) PDF (1892KB)(28)
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Combined with a series of measures from geophysical exploration, drilling and trench, through surveying the geomorphology and interpreting the remote sensing image at Zhenjiang, Jiangsu province, we discussed the age of Quaternary strata at both sides of Zhenjiang fault, then confirmed the activity mechanism and activity time of the fault. Research showed that the faults formed in different periods divided by directions include NE-NEE, NW, nearly EW, nearly NS and strike thrust (eversed) faults associated with fold, etc. Strike thrust (eversed) faults and early nearly EW trending faults formed in the late Indosinian to early Yanshanian fold orogenesis, NE-NNE trending and NW trending faults are the largest faults, formed mainly in Yanshan regional fault blockperiod. Nearly SN and late nearly EW trending tectonics controlled the spacial distribution of the Cenozoic sedimentary depression, which formed in late Yanshanianto Himalayan period. The faults that have inheritance activities include Mufushan-jiaoshan fault, Maoshan fault (belt) and fault along the river since the Quaternary, they are the main fault tectonics to Shape the modern landscape. Combining the regularity of seismic occurrence at Zhenjiang region with the charactristics of stress field, we consider the last activity time of the fault tectonics in Zhenjiang region is Pleistocene, activity is weak at Holocene, and then tends to be stable.
THE MAJOR ACTIVE FAULTS AND REGIONAL CRUSTAL STABILITY ASSESSMENT IN THE AREA OF CITY GROUP IN CENTRAL YUNNAN
ZHOU Chun-jing, WU Zhong-hai, MA Xiao-xue, LI Jia-cun, WANG Ji-long
2016, 22(3): 454-477.
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Combining previous data, active fault remote sensing interpretation and geological field survey, we classify the active faults into four classes according the fault activity in city group of central Yunan. They are faults with very high activity rate, faults with high activity rate, faults with moderate activity rate and faults with low activity rate. It shows that there are thirteen main active faults zone in the study area, with an image of "5 longitudinal and 2 lateral" fault zones. The study of the active fault affection on the main project reveals that the active faults are the key geological factor that restricts the layout of the cities and the main projects. The regional crustal stability assessment is calculated by the three factors of faults, rocks and slopes. The result suggests that most areas of the city group of central Yunnan is "unstable", one-third of the city group area is "extremely unstable region", "unstable region" or "sub unstable region".
GEOLOGICAL CHARACTERISTICS OF THE MAIN ACTIVE FAULTS AND EARTHQUAKES IN HUNAN AND HUBEI AREAS, THE MIDDLE REACHES OF THE YANGTZE RIVER
LI Hao-min, WU Zhong-hai, WANG Hao-nan, WANG Guo-sheng
2016, 22(3): 478-499.
Abstract (414) HTML (309) PDF (1568KB)(61)
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In this paper, the predecessors' achievements were collected and combined with the historical and modern seismic data in Hunan and Hubei areas. The major active faults and historical earthquakes in the areas, characteristics of the main active earthquake-controlled fault system (belt), seismic activity and spatial and temporal distribution were summarized. Research results indicate that the trends of major active faults in this region are mainly of NE, NNE and NW. There are 6 main active fault systems from north to south, including NW trending Qinkun fault system, NE trending fault system in the east of Hubei, Jianghan-Dongting basin fault system, NE trending fault system from west Hubei to west Hunan, NE trending fault system in central and south Hunan, and NEE trending fault system in east of Hunan. Quaternary activities of Jianghan-Dongting basin fault system and NW trending Qinkun fault system are more significant. Seismic activity level in the "Two Lakes" area is relatively low, being in the relatively calm period of the third activity period. Combining modern medium-strong earthquakes data with characteristics of China's seismic intensity zoning, we believed that crust is unstable in the east and west boundaries of the south of Jianghan-Dongting basin, the Ezhou-Huanggang-Wuhan area and fault block uplift area in northwestern Hubei, with higher potential earthquake risk, which should be paid more attentions in the planning and construction of the urban agglomeration, protecting river embankment design and construction of major projects.
BASIC CHARACTERISTICS OF THE MAIN ACTIVE FAULTS AND SEISMIC ACTIVITIES IN PAN YANGTZE RIVER DELTA REGION
WANG Hao-nan, WU Zhong-hai, LI Hao-min
2016, 22(3): 500-516.
Abstract (335) HTML (417) PDF (1476KB)(60)
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On the basis of systematically collecting and sorting the data of predecessors' achievements, and combination of basic geology and remote sensing interpretation, we comprehensively analyzed and sorted out the main active faults and their activity in Pan-Yangtze River Delta region. According to the main regional faults and the activity of historical earthquakes, this paper further analyzed, and pointed out the potential focal region that needs special attention and region of relatively poor crustal stability in this area. The research results show that, there are 38 active faults with relatively strong activity, mainly being in the directions of northeast and northwest. The former mainly on right lateral strike slip activity, the later mainly on left lateral strike slip activity. Then east-west faults with poor activity followed. Furthermore, combining the information of historical earthquake activity, we find that the convergence position of the two groups of fault zone with different directions are often the sites of earthquake occurrence. The most prominent controlled earthquake faults are northeast-orientational Tanlu fault and northwest-orientational Wuxi-Suqian fault.
RECENT ACTIVE FEATURES OF WEIXI-QIAOHOU FAULT AND ITS RELATIONSHIP WITH THE HONGHE FAULT
CHANG Zu-feng, CHANG Hao, ZANG Yang, DAI Bo-yang
2016, 22(3): 517-530.
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According to geological and geomorphic field observations, in this paper, we mainly elaborate the late Quaternary active features of the Weixi-Qiaohou fault, and discuss its relationship with the Honghe fault. The fault have apparently dominated many late Cenozoic basins' development, showing dextral strike slip motion features as being documented by synchronous right-lateral dislocation of mountain ridges and rivers along it. It has displaced late Pleistocene to Holocene accumulations revealed by the exploratory trenches at Desheng and the site south of Changyi. Nearby Yanqu and Shiyan, there is a 3 km long, ~2.5 m high fault scarp on the river terraces and the alluvial fans. It is estimated the fault has a average rate of 1.8~2.4 mm/yr. horizontally and 0.3~0.35 mm/yr. vertically since late Pleistocene, based on displaced magnitude of the alluvial fans, gullies and river terraces. It is a significant link which connects with the Honghe fault in the south and with the Jingshajiang fault in the north. Since late Cenozoic, the Weixi-Qiaohou fault in kinematics is similar to the Honghe fault and the Jinshajiang fault, they having identical geological evolutionary history and tectonic deformation mechanism, accordingly, indicating that the Weixi-Qiaohou fault should be the northern segment of the Honghe fault. The Weixi-Qiaohou, Honghe, Jinshajiang as well as Deqin-Zhongdian fault composed of the western boundary of Sichuan-Yunnan active block all together.
THE MAIN ACTIVE FAULTS AND TECTONIC SYSTEM IN YONGSHENG AREA, NORTHWESTERN YUNNAN
HUANG Xiao-long, WU Zhong-hai, WU Kun-gang, ZHOU Chun-jing
2016, 22(3): 531-547.
Abstract (183) HTML (106) PDF (1898KB)(33)
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Yongsheng located in the northeast of Dali fault system and the north end of Chenghai-Binchuan fault zone. Faults in Yongsheng area have been strongly active since the Pliocene and with significantly tectonic geomorphology characteristics. According from 1:50000 active fault mapping, there are 14 faults in Yongcheng-Jinguan area. Jinguan Fault (F1), Yongsheng Fault (F2) and Muerping-Yangping Fault (F3) are the largest scale and with strongest activity among them. They belong to the first class branch faults of Chenghai-Binchuan fault zone, the others belong to the second class branch faults. Tectonic landform characteristic, geological bodies broken by fault and the results of striations statistics all indicate that faults in Yongsheng area normal fault activities was the predominance. According to the activity, faults in this area are divided in to five classes, including stronger, strong, medium, weak and weaker. Jinguan fault is the most active fault among them, the vertical movement rate up to 0.2~0.26 mm/a. The geometry, kinematics and dynamics features of the main faults in Yongsheng area have been discussed. The result shows that the faults in Yongsheng area make up an east protruding curved rotational shear tectonic system in the plane, and form a negative flower structure in profile which was very common among transtension fault system. The current activity of Chenghai-Binchuan fault zone is near EW extension is mainly caused by the near SN compressive stress. And it has a certain left lateral strike slip because of the superposition of the twisting action. The curved rotational shear tectonic system in Yongsheng area and the Northwest Yunnan rift zone are all form from arc belt clockwise in Sichuan-Yunnan and the strike slip puil apart process of Nandinghe fracture、Wanding fracture and Litang fracture.
REMOTE SENSING EVIDENCE OF THE SOUTH SEGMENT OF LONGMENSHAN FAULT ZONE EXTENDING TO SOUTHWEST AND ITS SEISMIC GEOLOGICAL SIGNIFICANCE
MA Xiao-xue, WU Zhong-hai, LI Jia-cun, ZHOU Chun-jing, LI Kai, WANG Ji-long
2016, 22(3): 548-567.
Abstract (185) HTML (58) PDF (2412KB)(23)
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Combining remote sensing imagery interpretation of active faults with Landsat ETM, Google Earth and ASTER GDEM image data, this paper analysed the spatial distribution and geometry and motion characteristics of the south section of Longmenshan tectonic belt. The results showed that Longmenshan tectonic belt occurred obvious fracture dispersion in the process of extending to the south. The tectonic zone gradually widened, developing 5 faults and many secondary faults. The southernmost of Longmenshan tectonic zone was stopped by Xianshuihe sinistral strike-slip fault. Activities of Luding fault, Tianquan fault, Lushan fault and Dayi-Mingshan fault are more obvious. The former two are south-extending branches of Beichuan-Yingxiu fault, the latter two are south-extending branches of Anxian-Guanxian fault. The tectonic deformation of south Longmenshan tectonic belt was dispersed to a plurality of secondary faults, resulting in surface activity signs of single fault weaken significantly. So the potential earthquake frequency and intensity of single fault will also be correspondingly smaller, but potential seismic source region will be more dispersed. According to the existing seismic geological data, we should pay attention to the crustal stability and strong earthquake risk in Ya'an and Luding areas in the future.
THE EFFECT OF 1668 TANCHENG M8.5 EARTHQUAKE ON THE SEISMIC ACTIVITY OF THE VICINITY FROM COSEISMIC AND POSTSEISMIC DEFORMATION
XU Hao, SUN Yu-jun, WU Zhong-hai
2016, 22(3): 568-576.
Abstract (253) HTML (111) PDF (1413KB)(14)
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The Tanlu fault zone is an important active fault zone in east China. Many great earthquakes have occurred along it. The 1668 M8.5 Tancheng earthquake is the largest recorded event. With the constraint of surface rupture, we get a coseismic rupture model based on the elastic dislocation theory. In addition, we calculate the coseismic, postseismic deformation and Coulomb stress change of this earthquake with a viscoelastic multilayered model. The results show that the rupture fault of the earthquake is adextral strike-slip fault, which has slight thrust. The coseismic displacement of this event is very large. The accumulated energy is released thoroughly. The coseismic rupture of the 1668 Tancheng earthquake increased the Coulomb stress on the northwest, northeast and southeast faults of Tanlu fault zone. The Coulomb stress increases further due to the postseismic deformation. After 350 years of the Tancheng earthquake, the Coulomb stress changes in Shanxian, Suqian and Rizhaoget to +1bar-+1MPa. When the mantle is imposed different viscosities, the duration time which the deformation and Coulomb changes become stable will be different. However, the stable values of them are generally same.
COMPREHENSIVE REMOTE SENSING ANALYSIS ON ACTIVITIES OF THE MAIN FAULTS IN JIUJIANG AND ADJACENT AREAS, JIANGXI
LI Kai, WU Zhong-hai, LI Jia-cun, ZHOU Chun-jing, MA Xiao-xue
2016, 22(3): 577-593.
Abstract (165) HTML (133) PDF (2111KB)(27)
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This paper summarized interpretation marks of the main active fault zone in Jiujiang and its adjacent areas to obtain the spatial distribution of the main active faults using the Landsat 8, Google Earth and other moderate-high resolution remote sensing images and ASTER GDEM data combined with previous studies. At the same time, the nature of the main active faults in the area and the Quaternary activity were discussed on the basis of seismic geological data. It is found that the spatial distribution of fault structures in this area is complex, with NE and NW oriented, and the main development active fault zones are divided into 4 fault systems, including Lujiang-Guangji fault system Huanggang-Poyang fault system, Jiujiang fault system and the east Poyang fault system. According to the landform dislocation, 3-D landforms and terrain information and historical earthquake data of the main active fault zones, the activity of faults are analyzed and classified.The activity of the main faults in this area are divided into 3 different levels, which are remarkable, moderately remarkable and general, then further discusses the relationship between earthquake and the regional seismic activity.
RESEARCH ON DETECTION AND ACTIVITY OF THE HENGGANG BRICKYARD FAULT IN RUICHANG CITY, JIANGXI PROVINCE
QI Xin, SHAO Chang-sheng, CHEN Zhou-feng, CHEN Li-de
2016, 22(3): 594-601.
Abstract (266) HTML (76) PDF (1438KB)(14)
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In the fault activity survey, we found much more fissures in the Henggang Brickyard in Ruichang City, Jiangxi province. The overall trend of the fissures is NE, the fissures distribute densely in a "cluster" shape, with length more than three hundreds. And filled by gray-white and light gray minerals Through the analysis, this paper considers that there is a north-east trend steep normal fault, with south-east strike and dip angle 60°~75°. Local trench excavation exposes that one of the fault planes diastrophism the Quaternary slope alluvial material, the fault occurrence is 155°∠71°, fault strike NE 65°, upside down, stagger distance up to 3 m (not reveal bottom). The fault is straight, we can clearly visible scratches on the fault plane, and five 1~2 m long scraping grooves with 5~20 m deep. These display the fault is left-lateral dip-slip. Through ESR to date the strata sediment from upper breakpoint, the age range is 0.27~0.42 Ma. Research showes that this fault is significantly active in Middle Pleistocene, it is a Middle Pleistocene active fault. It is analysed that the development of ground fissures in this area are controlled by the Henggang Brickyard fracture, the forming of fissures responded to the activity of Henggang Brickyard fracture in Quaternary.
CHARACTERISTICS OF THE FRACTURES IN YANGKOU AREA, RUDONG, JIANGSU PROVINCE AND ITS IMPLICATION
LI Yun, JIANG Yue-hua, YANG Guoqiang, JING Yang, YANG Hui
2016, 22(3): 602-609.
Abstract (115) HTML (52) PDF (1321KB)(15)
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Fracture characteristics in Rudong Yangkou area, Jiangsu province have been studied through various geophysical methods combined with geothermal drilling data in this paper. Results indicate that there are three fault systems in Yangkou area, including a NW-trending secondary fault system of Binhai fault, EW-trending Benchahe fault system and Haian-Hekou fault. The NW-trending secondary fault system contains four secondary faults, mainly distributed in the north of Yangkou area and Laobagang area. The faults are steeply NE-dipping, with dip angles range from 70° to 80°, and speculatively cut through the Neogene strata. The EW-trending Benchahe fault system contains three secondary faults, mainly distributed in the middle of Yangkou area. The faults are mainly north dipping, with dip angles range from 60° to 80°. Combined with previous seismogeological and geothermal data in Yangkou area, it is comprehensively speculated that Benchahe fault is active, which makes the Quaternary Holocene strata being cut off with minor displacement. The activity of Benchahe fault influences the safety in the construction and development of Yangkou Economic area. The EW-trending Haian-Hekou fault is south dipping with the dip angle about 70°, extending from haian to the south of Yangkou area and cut off the Paleogene strata. There is compatible corresponding relation between distribution characteristics of faults and geothermal resources in Yangkou area, which is of certain guiding significance for the geothermal resources exploitation in this region.
ANALYSIS ON CHARACTERISTICS OF TECTONIC STRESS FIELD AND THE GEODYNAMIC ENVIRONMENT IN THE YANGTZE RIVER ECONOMIC BELT
Cao Hai-bo, Fan Tao-yuan
2016, 22(3): 610-619.
Abstract (229) HTML (104) PDF (1288KB)(15)
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According to existing research results, the tectonic stress field in the Yangtze River Economic Belt is divided into different zones based on active blocks and characteristic of tectonic stress field, respectively as the North China stress zone, the Southern China stress zone and the Qinghai-Tibet plateau stress zone. The South China stress zone is the major part of the Yangtze River economic belt. Based on that, we established a two-dimensional finite element model according to the active faults and tectonic blocks in the Yangtze River Economic Belt to simulate the tectonic stress and to analyze the geodynamic environment of the Yangtze River Economic Belt. The result shows that the tectonic stress field of the Yangtze River Economic Belt is combined controlled by the India plate, Pacific plate and Philippines sea plate. Collision between India plate and the Eurasian plate determines the overall trend of the stress field, and local areas also are affected by the surrounding tectonic environment. Southeast China is effected by the stretching environment of Okinawa Trough produced by Philippines plate subducting to Eurasian plate, Southwest China is effected by the northward moving of the India plate inducing shear and tension of Burma plate and resulting of Sagaing fault and western of Burma central basin, material of eastern Qinghai-Tibet Plateau in the transverse extrusion process is controlled by the joint subduction of the Pacific plate and Philippines plate, and has important influence for the distribution characteristics of the crustal stress field in the Yangtze River Economic Belt.
THE MAIN CHARACTERISTICS AND EVOLUTION OF GEOTECTONICS IN JIANGSU PROVINCE
JIA Gen, XU Shi-yin, GUO Gang
2016, 22(3): 620-630.
Abstract (144) HTML (229) PDF (1299KB)(30)
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In this paper, we discussed the basic characteristics of geotectonics in Jiangsu Province by taking the theory of plate tectonics and continental dynamics as a guide, taking the formation and evolution of the continents and their margins as the main line, taking the rock construction combination as the basic analytical object, taking regional major geological events as an important clue, and combining with the analysis of regional deep faults and the main tectonic characteristics. We further expound the geotectonic evolution process in Jiangsu Province by combining with geodynamic setting and geological environmental evolution in different periods.
THE NEOTECTONIC RESTRICTS TO QUATERNARY DEPOSITION ENVIRONMENT EVOLUTION OF JIANGHAN BASIN
YANG Qing-xiong, TIAN Wang-xue, LI Qi-wen, KONG Ling-yao
2016, 22(3): 631-641.
Abstract (189) HTML (133) PDF (1418KB)(21)
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Through the transverse contrast of Quaternary strata, combining with the data of outcrop profiles in periphery area of Jianghan Basin and Quaternary drilling cores in sedimentary central area, we restored the sedimentary environment of Jianghan Basin in different period of Quaternary, and discussed the neotectonic characteristics and its control functions to Quaternary sedimentary environment evolution. The result shows that most part of Jianghan Basin is in a lift condition in early and Middle Pleistocene, the periphery of the basin is in a state of erosion. The amount of crust exercise is unequal in late Pleistocene, from north west to south central the basin is slowly rising and sinking. In Holocene, rising in periphery of basin and undulating terrain and sinking in low plain area are more significant, and the area of the lake reached the maximum in middle and late Holocene.
THE ORIGIN AND EVOLUTION OF QINGYI RIVER'S DEPOSITS AND TERRACES IN WEST SICHUAN, CHINA
WANG Ji-long, WU Zhong-hai, SUN Yu-jun, XU Hao, ZHOU Chun-jing, MA Xiao-xue
2016, 22(3): 642-658.
Abstract (326) HTML (139) PDF (1781KB)(36)
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Based on the analysis of previous research results, we analysed and summaried the gravel composition, gravel particle size and gravel direction of Mingshan-Qionglai and Danling-Simeng gravel layers related to ancient Qingyi River diversion in southwest of Longmenshan. Moreover, we discussed the characteristics of provenance region, origin and formation of the gravel layer. Combining with the latest survey and measurements to trunk stream terrace of Qingyi River, the distribution, height, structure and age of the terrace were sorted and summarized. We also used the satellite remote sensing image and Digital Elevation Model (DEM) to extract tectonic geomorphology and water features, finding that the terrain of Qingyi River basin descends in a cascade manner, the fold passed through it should be earlier than the Quaternary, the terraces of Qingyi River formed in Quaternary can be continuously contrasted, the terrace in Baoxing-Lushan section ever uplifted, that may be caused by the underlying thrust fault. Based on the characteristics of Qingyi River terraces, we made a comprehensive analysis on the system evolution, then put forward that the diversion of the river is caused by the multiple captures of the river, the local uplift at the southwest segment of Longmenshan caused by the blind thrust fault has created good structure conditions.
POSSIBLE SEISMIC CONTROL ON RIVER CHANNEL CHANGE IN THE LONGMENSHAN MOUNTAIN
LI Jian-feng, LIU Feng, WU Zhong-hai
2016, 22(3): 659-666.
Abstract (216) HTML (129) PDF (1464KB)(12)
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The 2008 Mw7.9 Wenchuan earthquake induced a large quantity of landslides whose materials entered the river channels. In some channel reach the seismic surface ruptures caused the co-seismic knick points across the channel of the Longmenshan Mountain. The river morphology and hydrodynamic condition may be changed. The field investigations show that co-seismic knick points disappeared rapidly, and meander cut-off would potentially occur in the near future. This suggests that the temporal increase in sediment input will not reduce the long-term fluvial transport capacity. A few years later, the rivers will reach a new state of eroion-transport-deposition. It is concluded that the seismic erosion events (landslide) and local hydrometerological conditions (heavy rainfall and flash flood) exert significant controls on the river channel change in the Longmenshan Mountain.
GEOLOGICAL EVOLUTION, NEOTECTONICS AND GENETIC MECHANISM OF THE POYANG LAKE BASIN
YANG Xiao-dong, WU Zhong-hai, ZHANG Hai-jun
2016, 22(3): 667-684.
Abstract (213) HTML (667) PDF (1781KB)(38)
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Combining with drilling and profile data, this paper synthesizes the sedimentary characteristics and tectonic activity characteristics of the Poyang Lake Basin and discusses the development and evolution of the basin in the tectonic background of East Asia, and also summarizes the main control faults structures and their characteristics in the basin as well as it's paleogeographic evolution in the Mesozoic and Cenozoic. Finally summarizes the main fracture of Quaternary activity and its relationship with seismic activity, and the genetic mechanism of the basin is discussed according to the existing data. Comprehensive study showed that, in the Mesozoic, the movement of Yanshan brought about a set of roughly parallel NE-SW trending fault zones in southeast of China, and resulted in the Poyang lake depression and the embryonic form of Poyang lake sedimentary basin. Then, with the change of the Ganjiang fault mode, Poyang lake basin has experienced a complex evolution process. Until the Quaternary, overall depression occurred in the middle of the basin and it continued to be deposited. After the mid Holocene, it evolved into the modern Poyang Lake.
GEOLOGICAL HAZARDS MONITORING AND APPLICATION IN MOUNTAINOUS TOWN OF THREE GORGES RESERVOIR
FENG Zhen, LI Bin, ZHAO Chao-ying, WANG Li, WANG Lei
2016, 22(3): 685-694.
Abstract (165) HTML (69) PDF (1526KB)(7)
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Regular geological hazards monitoring is very difficult in southwestern mountainous area, due to steep terrain, abundant plants, rainy and foggy weather. On the basis of geological hazards survey, a comprehensive monitoring network has been established. Regular geo-hazards monitoring devices, such as telescopic displacement meters and stressometers, are installed to monitor relative displacement of ground cracks and stress in base of perilous rock respectively. Static and real-time GPS, as well as corner reflector interferometry (CR-InSAR), are applied to monitor ground movement of perilous rocks. In order to obtain regional deformation, high coherence InSAR is adopted to investigate and detect geo-hazards. The Yangjiao monitoring network achieves high-resolution and real-time monitoring, and the methods applied are essentially in agreement with movement results.
FORMATION CONDITIONS AND SPATIAL DISTRIBUTION OF GEO-HAZARDS IN SOUTHERN URBAN AGGLOMERATION OF CHENGDU-CHONGQING ECONOMIC ZONE
WANG Dong-Hui, CHEN Xu-Yu, ZHU De-Ming, TIAN Kai
2016, 22(3): 695-705.
Abstract (172) HTML (62) PDF (1372KB)(14)
Abstract:
Based on the data analysis and field investigation, the spatial distribution characteristics of geological hazards in the south urban agglomeration of Chengdu-Chongqing Economic Zone are compared and analyzed. Study result shows that both of the formation conditions (topography, geological structure, lithology) and triggering condition (rainfall, seismic activity, human engineering activities) vary significantly from south to north, from west to East, leading to great difference of spatial distribution and characteristics of geological hazards. In the west part, the formation factors such as lithology and geological structure are very complex, the topography undulates greatly, and the seismic activity is frequent. As a result, the geological hazards take on the characteristics of larger magnitude, more debris flows, and linear distribution along the river and tectonic. In the south part, due to the wide distribution of carbonate rocks and intense mining activity, ground collapse becomes the main type of geological hazard. As far as the north part is concerned, the geological and lithology are simple and the terrain is flat, but the human engineering activities are the most intense of the urban agglomeration of south Sichuan Province, simpler type, larger quantity, smaller scale, wide distribution compose the main features of the geological hazards in this part.
TREND PREDICTION RESEARCH OF GEOLOGICAL HAZARD IN THE YANGTZE ECONOMIC ZONE BASED ON GRAY SYSTEM THEORY
CHEN Chun-li, HE Kai, WEN Ming-sheng, LIANG Hong-kun
2016, 22(3): 706-713.
Abstract (117) HTML (68) PDF (1225KB)(6)
Abstract:
The grey system theory is introduced to the trend prediction research of geological hazard. Modeling and prediction are taken with the case study of the trend of geological hazards in the Yangtze Economic Zone, and the precision is analyzed finally. The result shows that model GM(1, 1) can be used for trend prediction research of geological hazard and the gray system theory are useful. Based on the prediction we know that the annual number of geological hazards presents fluctuant descend tendency and serious disaster year maybe appear in the next 2 years. The results obtained may provide supportable information to the prevention and reduction department in the Yangtze Economic Zone.
A REVIEW ON THE COLLAPSE HAZARDS OF TOWER-SHAPED ROCK
HE Kai, CHEN Chun-li, FENG Zhen, LI Bin, Pan Li-bin
2016, 22(3): 714-724.
Abstract (261) HTML (86) PDF (1285KB)(18)
Abstract:
Through systematically sorting out the relative data of the collapse hazards of tower-shaped rock at home and abroad, we summarized three aspects of the tower-shaped rock (the influence factors of formation and stability, failure mode of collapse and application of damage theory) in Yangtze River Economic Belt and surrounding areas. Then we discussed the trend and hotspot issues of the collapse hazards of tower-shaped rock, offering theoretical preparation and reference for the next stages of the geological survey and research.
STABILITY ANALYSIS OF SUB-HORIZONTAL THICK-BEDDED SLOPE IN THREE GORGES RESERVIOR AREA: A CASE STUDY OF JIANCHUANDONG DANGEROUS ROCKMASS IN WUSHAN, CHONGQING
WANG Wen-pei, LI Bin, HUANG Bo-lin, ZHANG Nan, HAN Xiao
2016, 22(3): 725-732.
Abstract (185) HTML (71) PDF (1352KB)(4)
Abstract:
Taking Jianchuandong dangerous rockmass in Wushan for an example, based on analyzsis of geological conditions, displacement of base and stress monitoring data, we summarized the present deformation and stress state of the dangerous rockmass, then found that the strength of it remaining reduce. Meanwhile, using FLAC2D we set up four simulation conditions, including Initial natural, Initial saturation, critical sliding and destabilizing to research the rule of rock base and shale strip limestone when facing up rock slide. The results show that decreasing of base strength of argillaceous limestone will make dangerous rockmass in a state of critical sliding. Stability analysis of the above also provides a basis for further control of the design.
APPLICATION AND PROGRESS OF GROUND PENETRATING RADAR IN ACTIVE FAULT DETECTION
ZHANG Di, LI Jia-cun, WU Zhong-hai, REN Li-li
2016, 22(3): 733-746.
Abstract (183) HTML (93) PDF (1799KB)(15)
Abstract:
Combining with the recent research at home and abroad, the application of Ground Penetrating Radar in active fault detection was summed up and concluded. Three aspects on the application of GPR in active fault detection were put forward and reviewed:the application of GPR in urban active fault, the application of GPR in paleoearthquake and the interpretation of fault in the GPR profile, and an example of the method was illustrated to demonstrate the effectiveness of GPR method in Litang active. Finally, the existing problems of the application of GPR in active fault detection was put forward, and the direction of development and the prospect of this technology were also denoted.
APPLICATION OF HIGH RESOLUTION AIRBORNE LIDAR IN XIAOJIANG ACTIVE TECTONICS AND GEOLOGICAL DISASTER STUDY
LIU Yu-ping, LIANG Hong, CHENG Fi-fi
2016, 22(3): 747-759.
Abstract (134) HTML (92) PDF (2475KB)(13)
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By processing airborne LiDAR flight data of Jinsha River and Xiaojiang, we obtained high precision Digital Elevation Model (DEM) and Digital Surface Model (DSM). Using the digital terrain in geological structure interpretation, we may determine the distribution of active faults and the characteristics of tectonic geomorphology, delineating the range of the landslide and debris flow in Jinsha River and Xiaojiang, also estimating the area and volume of the landslide and debris flow. High precision airborne LiDAR data provides reliable information for such geological disaster warning.
RISK ASSESSMENT OF SEISMIC LANDSLIDE WITHIN SMALL REGION BASED ON MULTI-LEVEL PHYSICAL AND MECHANICAL PARAMETERS: A CASE STUDY OF SHIMIAN AND ADJACENT AREAS IN THE UPPER REACHES OF YANGTZE RIVER
SONG Zhi, NI Hua-yong, ZHOU Hong-fu, FENG Wei
2016, 22(3): 760-770.
Abstract (140) HTML (100) PDF (1590KB)(6)
Abstract:
Compared to the risk assessments of seismic landslide before, this paper achieves the landslide and collapse inventory, loose accumulated layer and the physical and mechanical parameters of rock soil mass of geological units by field survey, remote sensing interpretation and data collection. It makes an organic integration of landslide inventory, geological survey and regional Newmark displacement model. During three degrees of the landslide inventory, it can been seen that the physical and mechanical parameters get smaller gradually from the first degree to the third degree, which also inflects the importance of the landslide inventory for risk assessment and that it accords better with reality. The dangerous areas and regular under different peak acceleration are got by assessing the potential risk of geological hazard in Shimian City on the upper Yangzi River. Through the linear fitting of risks, when peak acceleration is 0.3, the dangerous areas increase greatly on the large scale that is the critical value of the regional devastating disaster. Meanwhile, the dangerous area gradually transit from that under the control of landslide inventory to that of slope, which shows the validity of the risk assessment under multi-level physical and mechanical parameters.
TOPOGRAPHIC CORRECTION OF GPR PROFILES BASED ON DIFFERENTIAL GPS
LI Shuang-fei, LI Jia-cun, ZHANG Di
2016, 22(3): 771-777.
Abstract (220) HTML (98) PDF (1359KB)(5)
Abstract:
As a new type of ground detection technology, Ground Penetrating Radar (GPR) has advantages of high resolution and fast survey and no damage in detection, especially in the exploration of shallow active fault. However, the result image of GPR is not consistent with the objective facts in undulated areas. This paper presents a new method to correct the topographic distortion of GPR image:GPR and GPS are combined to collect and record data at the same time, achieving time synchronization between the GPR data and GPS data. Specifically, through time shifting and linear interpolation method, taking a standard level for reference surface, converting the time-depth of GPR data, finally achieving topographic correction. Contrast the original GPR image and adjusted GPR image, it shows that the method can correctly express the distribution characteristics of underground medium, and it is helpful to interpret and position the underground target, especially in the shallow active fault detection program.
DISCOVERY OF BIOTITE MONZOLITE AND Ar-Ar THERMOCHRONOLOGY SIGNIFICANCE IN LINGLONG GOLD FIELD
SHEN Yu-ke, GUO Tao, YANG Yu-quan, CHEN Zheng-le, WEI Chang-shan, SUN Hua-shan
2016, 22(3): 778-793.
Abstract (357) HTML (199) PDF (1773KB)(12)
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The biotite monzolite that was discovered at 2170 meters below the surface in Linglong Gold Field in Jiaodong is not only used to find out the source of ore-forming material, but also is used to furnish new evidence for study the cause of mineralization of gold deposit. As the new rock types that was discovered in this area, Biotite monzonitichas the typical monzonitic texture under microscope. The non-metallic minerals composed the rock mainly are plagioclase, sodium feldspar, quartz, biotite and hornblende. It contains more metal minerals that mainly are pyrite and magnetitethan the other magmatic rocks in Northwest of Jiaodong. The biotite 40Ar-39Ar thermochronology indicate that the age of the formation of biotite monzonite is 123.7±1.5 Ma which was later than the time of formation of Linglong granite, Luanjiahe granite and Guojialing granites, and is very close with the age of the formation of Linglong Gold Deposit. Although it is not sure that the metal minerals in the gold ore bodies in Linglong gold field directly come from biotite monzonite, the result of analysis of the characteristics of their generation time demonstrate that the metal minerals and biotite monzonite form in the same period and come from the same originate. In the process of invasion of the Biotite monzonite magma, it supply ore-forming materials for the formation of gold mine, and provides energy and driving force for ore-forming elements and ore-forming fluid migration. It can be deduced that the gold mineralization is closely related with the intrusion of biotite monzonite
MINERALIZATION ZONATION OF MASSIVE SULFIDE DEPOSIT IN THE CHENGMENSHAN OREFIELD, JIANGXI PROVINCE, CHINA
LI Xu-hui, GAO Ren, MA Li-cheng, FU Bin
2016, 22(3): 794-802.
Abstract (283) HTML (266) PDF (1359KB)(12)
Abstract:
Chengmenshan ore field is located in the middle part of Middle-Lower Yangtze River Cu-Fe mineralization belt, China. It is a large comprehensive ore field with enriched in ore-forming elements of Cu, S, Pb, Zn, Mo, Au, Ag and Fe. The deposit is a trinity of massive sulfide-type, skarn-type and porphyry-type. Massive sulfide-type ore body is the largest one in the Chengmenshan ore field, and it accounted for 57% of total copper resources. Based on the investigation on geological characteristics, thickness and grade changes of ore body along the strike and tendency, it summarized the features of mineralization. It studied and discussed the controlling factors of mineralization enrichment about ore-forming temperature and geochemistry, genesis of mineral deposit, prospecting direction of the mine periphery. The mineralization of the orebody has zonality both horizontal and vertical direction. It roughly shows Mo, Cu, Zn, Pb, Ag, Au element mineralization zonality from hydrothermal center to outside, and TFe, Au, Ag, Pb, Zn, Cu element mineralization zonality from surface to down. In addition, the mineralization is different. It display inconformity both the ends of the orebody along the strike and leguminous shape along the tendency. In this paper, the zonality and difference mineralization identified the hydrothermal genesis and sedimentary origin respectively. It has preferable exploration prospect outside the orefield, especially the eastern periphery of mine.