About 75% water-inrush accidents in China are caused by geological structure such as faults, therefore, it is necessary to investigate the water-inrush mechanism of faults to provide references for the mining activity...About 75% water-inrush accidents in China are caused by geological structure such as faults, therefore, it is necessary to investigate the water-inrush mechanism of faults to provide references for the mining activity above confined water. In this paper, based on the fluid-solid coupling theory, we built the stress-seepage coupling model for rock, then we combined with an example of water-inrush caused by fault, studied the water-inrush mechanism by using the numerical software COMSOL Mutiphysics, analyzed the change rule of shear stress, vertical stress, plastic area and water pressure for stope with a fault, and estimated the water-inrush risk at the different distances between working faces and the fault. The numerical simula- tion results indicate that: (1) the water-inrush risk will grow as the decrease of the distance between working face and the fault; (2) the failure mode of the rock in floor with fault is shear failure; (3) the rock between water-containing fault and working face failure is the reason for water-inrush.展开更多
We apply three methods to relocate 599 earthquake events that occurred from August 2004 to August 2005 in the northeastern Tianshan Mountains area ( 85°30' ~ 88°30'E,43°00' ~ 44°40...We apply three methods to relocate 599 earthquake events that occurred from August 2004 to August 2005 in the northeastern Tianshan Mountains area ( 85°30' ~ 88°30'E,43°00' ~ 44°40' N ) by using travel times recorded by regional seismic network and 10 portable seismic stations deployed around the Urumqi city. By comparing the reliability of different results,we determined a suitable location method,and an improved 1-D crustal velocity model of the study area. The uncertainty of earthquake location is significantly reduced with combined data of seismic network and portable stations. The relocated events are clearly associated with regional tectonics of the northeastern Tianshan Mountains area, and are also in agreement with the existence of active faults imaged by deep seismic reflection profile. The relocated seismicity discovers some potential traces of buried active faults,which need to be validated further.展开更多
The seismotectonic environment and seismic activity in Southwest China region were studied based on new data and new results obtained during the Eighth and Ninth Five-Year Plans, the seismic areas and zones and potent...The seismotectonic environment and seismic activity in Southwest China region were studied based on new data and new results obtained during the Eighth and Ninth Five-Year Plans, the seismic areas and zones and potential seismic source zones were determined, and the relation between seismic activity parameters and ground motion attenuation was determined. Finally the seismic ground motion zoning maps of the Pangxi region was compiled by using the multi-parameter and multi-scheme method.展开更多
Fractal geometry is increasingly becoming a useful tool for modeling and quantifying the complex patterns of natural phenomena. The Earth's topography is one of these phenomena that have fractal characteristics. T...Fractal geometry is increasingly becoming a useful tool for modeling and quantifying the complex patterns of natural phenomena. The Earth's topography is one of these phenomena that have fractal characteristics. This paper investigates the relative sensitivity of topography to active tectonics using ASTER Global Digital Elevation Model. The covering divider method was used for direct extraction of surface fractal dimension(D surf) to estimate the roughness-surface of topography with aid of geographic information system(GIS)techniques. This evaluation let us highlight the role of the geomorphic and tectonic processes on the spatial variability of fractal properties of natural landforms.Geomorphic zones can be delineated using fractal dimension mapping in which variability of surface fractal dimension reflects the roughness of the landform surface and is a measure of topography texture. Obtained results showed this method can be a quick and easy way to assess the distribution of land surface deformation in different tectonic settings. The loose alluvial deposits and irregularities derived by tectonic activity have high fractal dimensions whereas the competent formations and higher wavelength folded surfaces have lower fractal dimensions.According to the obtained results, the Kazerun Fault Zone has a crucial role in the separation of the Zagros Mountain Ranges into the different lithological,geomorphological and structural zones.展开更多
The fields of structural geology and tectonics have witnessed great progress over the last decade and are poised for further expansion in the future. One of the significant breakthroughs is the establishment of the ...The fields of structural geology and tectonics have witnessed great progress over the last decade and are poised for further expansion in the future. One of the significant breakthroughs is the establishment of the 'Beyond Plate Tectonics Theory' where a combination of conceptual models and numerical modeling on plume tectonics and plate tectonics has enabled new insights into the structural and tectonic architecture and processes in the deep interior and deep sea. This paper synthesizes developments of structural geology and tectonics from a macroscopic perspective in deep interior and deep sea. Four key techniques are also reviewed: satellite altimetry for surface structures in deep-sea multi-beam sea-floor mapping; tomography for tectonics of the deep interior; diverse modeling approaches and software for unfolding dynamic evolution; and techniques for HT/HP experiments on material rheology and in situ component measurements.展开更多
Deep and shallow tectonic data in Shenyang and its relationship with seismic activity shows that the NE trending faults developed on the surface control the formation and development of the fault-uplift and fault-depr...Deep and shallow tectonic data in Shenyang and its relationship with seismic activity shows that the NE trending faults developed on the surface control the formation and development of the fault-uplift and fault-depression. The uplift and depression of the bedrock at a depth of 7km underground are'consistent with the surface structure. 12 planar listric normal faults have developed above a depth of 18km -20km and two deep faults have developed in the lower crust. Because of the deep incision and new activities, the surface Wanggangpu-Xinehengzi fault and Yongle-Qingshuitai fault, which correspond to the deep F3 fault and F6 fault, might be related to seismic activity in Shenyang.展开更多
Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and su...Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn: (1) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicheng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them. The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture——seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.展开更多
We obtained the 2-D P-wave velocity structure of the lithosphere in the eastern North China Craton, Shanxi fault subsidence zone, and Yinchuan-Hetao fault subsidence zone by ray tracking technology based on six groups...We obtained the 2-D P-wave velocity structure of the lithosphere in the eastern North China Craton, Shanxi fault subsidence zone, and Yinchuan-Hetao fault subsidence zone by ray tracking technology based on six groups of clearly identified crustal phases and one group of lithospheric interface reflection phases from seismic recording sections of 21 shots along the 1300-km-long Yancheng-Baotou deep seismic wide-angle reflection/refraction profile. The results indicate significant differ- ences between the lithospheric structure east and west of the Taihang Mountains, which is a gravity-gradient zone as well as a zone of abrupt change in lithospheric thickness and a separation zone of different rock components. East of the Taihang Mountains, the Mesozoic and Cenozoic lithospheric structure of the North China Craton has undergone strong reformation and destruction, resulting in the lithosphere thickness decreasing to 70-80 km. The North China Basin has a very thick Cenozoic sedimentary cover and the deepest point of crystalline basement is about 7.0 kin, with the crustal thickness decreasing to about 31.0 kin. The crystalline basement of the Luxi uplift zone is relatively shallow with a depth of 1.0-2.0 km and crustal thickness of 33.0-35.0 km. The Subei Basin has a thicker Cenozoic sedimentary cover and the bottom of its crystalline basement is at about 5.0-6.0 km with a crustal thickness of 31.0-32.0 km. The Tanlu fault is a deep fracture which cuts the lithosphere with a significant velocity structure difference on either side of the fault. The Tanlu fault plays an important role in the lithospheric destruction in the eastern part of the North China Craton. West of the Taihang Mountains, the crustal thickness increases sig- nificantly. The crust thickness beneath the Shanxi fault depression zone is about 46 km, and there is a low-velocity structure with a velocity of less than 6.1 km s-~ in the upper part of the middle crust. Combined with other geophysical study results, our data shows that the lithospheric destruction at the Shaanxi-Shanxi fault depression zone and the Yinchuan-Hetao rift surround- ing the Ordos block is non-uniform. The lithosphere thickness is about 80-90 km in the Datong-Baotou area, 75-137 km at the Dingxiang-Shenmu region, and about 80-120 km in the Anyang-Yichuan area. The non-uniform lithospheric destruction may be related to the ancient tectonic zone surrounding the Ordos block. This zone experienced multi-period tectonic events in the long-term process of its tectonic evolution and was repeatedly transformed and weakened. The weakening level is related to the interactions with the Ordos block. The continental collision between the Cenozoic India and Eurasia plates and N-E thrust- ing by the Qinghai Tibet Plateau block is causing further reformation and reduction of the lithosphere.展开更多
Development of Xiong'an New District(XND) is integral to the implementation of the Beijing-Tianjin-Hebei(BTH) Integration Initiative. It is intended to ease the non-capital functions of Beijing, optimize regional ...Development of Xiong'an New District(XND) is integral to the implementation of the Beijing-Tianjin-Hebei(BTH) Integration Initiative. It is intended to ease the non-capital functions of Beijing, optimize regional spatial patterns, and enhance ecosystem services and living environment in this urban agglomeration. Applying multi-stage remote sensing(RS) images, land use/cover change(LUCC) data, ecosystem services assessment data, and high-precision urban land-cover information, we reveal the regional land-cover characteristics of this new district as well as across the planned area of the entire BTH urban agglomeration. Corresponding ecological protection and management strategies are also proposed. Results indicated that built-up areas were rapidly expanding, leading to a continuous impervious surface at high density. Urban and impervious surface areas(ISAs) grew at rates 1.27 and 1.43 times higher than that in the 2000 s, respectively, seriously affecting about 15% area of the sub-basins. Construction of XND mainly encompasses Xiongxian, Rongcheng, and Anxin counties, areas which predominantly comprise farmland, townships and rural settlements, water, and wetland ecosystems. The development and construction of XND should ease the non-capital functions of Beijing, as well as moderately control population and industrial growth. Thus, this development should be included within the national ‘sponge city' construction pilot area in early planning stages, and reference should be made to international low-impact development modes in order to strengthen urban green infrastructural construction. Early stage planning based on the existing characteristics of the underlying surface should consider the construction of green ecological patches and ecological corridors between XND and the cities of Baoding, Beijing, and Tianjin. The proportion of impervious surfaces should not exceed 60%, while that of the core area should not exceed 70%. The development of XND needs to initiate the concept of ‘planning a city according to water resource amount' and incorporate rainwater collection and recycling.展开更多
基金Supported by the National Basic Research Program of China (2010CB226800) the National Natural Science Foundation of China (50904065) the Program for New Century Excellent Talents in University (NCET-09-0728)
文摘About 75% water-inrush accidents in China are caused by geological structure such as faults, therefore, it is necessary to investigate the water-inrush mechanism of faults to provide references for the mining activity above confined water. In this paper, based on the fluid-solid coupling theory, we built the stress-seepage coupling model for rock, then we combined with an example of water-inrush caused by fault, studied the water-inrush mechanism by using the numerical software COMSOL Mutiphysics, analyzed the change rule of shear stress, vertical stress, plastic area and water pressure for stope with a fault, and estimated the water-inrush risk at the different distances between working faces and the fault. The numerical simula- tion results indicate that: (1) the water-inrush risk will grow as the decrease of the distance between working face and the fault; (2) the failure mode of the rock in floor with fault is shear failure; (3) the rock between water-containing fault and working face failure is the reason for water-inrush.
基金supported by the Basic Research Project of Institute of Earthquake Science,CEA (2012IES010103)the National Natural Science Foundation of China (41204037)
文摘We apply three methods to relocate 599 earthquake events that occurred from August 2004 to August 2005 in the northeastern Tianshan Mountains area ( 85°30' ~ 88°30'E,43°00' ~ 44°40' N ) by using travel times recorded by regional seismic network and 10 portable seismic stations deployed around the Urumqi city. By comparing the reliability of different results,we determined a suitable location method,and an improved 1-D crustal velocity model of the study area. The uncertainty of earthquake location is significantly reduced with combined data of seismic network and portable stations. The relocated events are clearly associated with regional tectonics of the northeastern Tianshan Mountains area, and are also in agreement with the existence of active faults imaged by deep seismic reflection profile. The relocated seismicity discovers some potential traces of buried active faults,which need to be validated further.
文摘The seismotectonic environment and seismic activity in Southwest China region were studied based on new data and new results obtained during the Eighth and Ninth Five-Year Plans, the seismic areas and zones and potential seismic source zones were determined, and the relation between seismic activity parameters and ground motion attenuation was determined. Finally the seismic ground motion zoning maps of the Pangxi region was compiled by using the multi-parameter and multi-scheme method.
基金the Research Council of Shiraz University which has supported the project
文摘Fractal geometry is increasingly becoming a useful tool for modeling and quantifying the complex patterns of natural phenomena. The Earth's topography is one of these phenomena that have fractal characteristics. This paper investigates the relative sensitivity of topography to active tectonics using ASTER Global Digital Elevation Model. The covering divider method was used for direct extraction of surface fractal dimension(D surf) to estimate the roughness-surface of topography with aid of geographic information system(GIS)techniques. This evaluation let us highlight the role of the geomorphic and tectonic processes on the spatial variability of fractal properties of natural landforms.Geomorphic zones can be delineated using fractal dimension mapping in which variability of surface fractal dimension reflects the roughness of the landform surface and is a measure of topography texture. Obtained results showed this method can be a quick and easy way to assess the distribution of land surface deformation in different tectonic settings. The loose alluvial deposits and irregularities derived by tectonic activity have high fractal dimensions whereas the competent formations and higher wavelength folded surfaces have lower fractal dimensions.According to the obtained results, the Kazerun Fault Zone has a crucial role in the separation of the Zagros Mountain Ranges into the different lithological,geomorphological and structural zones.
基金Funding Sources:Marine 863 Project (No.2009AA093401)Projects of the National Natural Science Foundation of China (Nos.41072152,90814011 and 41190072)
文摘The fields of structural geology and tectonics have witnessed great progress over the last decade and are poised for further expansion in the future. One of the significant breakthroughs is the establishment of the 'Beyond Plate Tectonics Theory' where a combination of conceptual models and numerical modeling on plume tectonics and plate tectonics has enabled new insights into the structural and tectonic architecture and processes in the deep interior and deep sea. This paper synthesizes developments of structural geology and tectonics from a macroscopic perspective in deep interior and deep sea. Four key techniques are also reviewed: satellite altimetry for surface structures in deep-sea multi-beam sea-floor mapping; tomography for tectonics of the deep interior; diverse modeling approaches and software for unfolding dynamic evolution; and techniques for HT/HP experiments on material rheology and in situ component measurements.
基金sponsored by the Active Fault Detecting Subprogram (2007-2230) of the"Chinese Digital Earthquake Observation Network"of the Tenth"Five-year Plan",China
文摘Deep and shallow tectonic data in Shenyang and its relationship with seismic activity shows that the NE trending faults developed on the surface control the formation and development of the fault-uplift and fault-depression. The uplift and depression of the bedrock at a depth of 7km underground are'consistent with the surface structure. 12 planar listric normal faults have developed above a depth of 18km -20km and two deep faults have developed in the lower crust. Because of the deep incision and new activities, the surface Wanggangpu-Xinehengzi fault and Yongle-Qingshuitai fault, which correspond to the deep F3 fault and F6 fault, might be related to seismic activity in Shenyang.
文摘Study of seismic activity in the Kuqa area enables us to infer some possible active faults in basement from the epicentral distribution on different profiles. The relations between active faults in the basement and surface structures are analyzed and the difference between sedimentary cover and basement in their deformation characteristics and the genesis are discussed. The following conclusions have been drawn: (1) the epicentral distribution indicates that, the east Qiulitag and south and north Qiulitag deep faults in the basement correspond to the east and west Qiulitag anticlines, respectively. Moreover, deep faults also exist beneath the Yiqiklik and Yaken anticlines. It indicates that the formation of surface structures is controlled by deep structures; (2) A NE-trending strike-slip fault develops along the line from the western termination of Yiqiklik structure to Dongqiu Well 5 and a NW-trending active fault on the western side of Baicheng. The two active faults across the tectonic strike are the main causes for tectonic segmentation of the Kuqa depression and possibly the cause for the middle segment (Kuqa-Baicheng) of the depression to be more shortened than both its eastern and western terminations; (3) The difference between the sedimentary cover and basement in their deformation characteristics depends mainly on the different properties of media between them. The lithospheric strength of the basement in the basin is fairly high, which determines the basement deformation to be mainly of brittle fracture——seismic activity. While the strength of sedimentary cover is low, where there exist weak thin layers, such as coal and gyps. Under the effect of strong tectonic compression, the sedimentary rocks may undergo strong viscous or plastic flow deformation; meanwhile, an aseismic detachment may take place along the weak layers.
基金supported by the National Natural Science Foundation of China(Grant Nos.91214205,41174052)the Special Scientific Research of Seismologic Industry(Grant No.200908001)
文摘We obtained the 2-D P-wave velocity structure of the lithosphere in the eastern North China Craton, Shanxi fault subsidence zone, and Yinchuan-Hetao fault subsidence zone by ray tracking technology based on six groups of clearly identified crustal phases and one group of lithospheric interface reflection phases from seismic recording sections of 21 shots along the 1300-km-long Yancheng-Baotou deep seismic wide-angle reflection/refraction profile. The results indicate significant differ- ences between the lithospheric structure east and west of the Taihang Mountains, which is a gravity-gradient zone as well as a zone of abrupt change in lithospheric thickness and a separation zone of different rock components. East of the Taihang Mountains, the Mesozoic and Cenozoic lithospheric structure of the North China Craton has undergone strong reformation and destruction, resulting in the lithosphere thickness decreasing to 70-80 km. The North China Basin has a very thick Cenozoic sedimentary cover and the deepest point of crystalline basement is about 7.0 kin, with the crustal thickness decreasing to about 31.0 kin. The crystalline basement of the Luxi uplift zone is relatively shallow with a depth of 1.0-2.0 km and crustal thickness of 33.0-35.0 km. The Subei Basin has a thicker Cenozoic sedimentary cover and the bottom of its crystalline basement is at about 5.0-6.0 km with a crustal thickness of 31.0-32.0 km. The Tanlu fault is a deep fracture which cuts the lithosphere with a significant velocity structure difference on either side of the fault. The Tanlu fault plays an important role in the lithospheric destruction in the eastern part of the North China Craton. West of the Taihang Mountains, the crustal thickness increases sig- nificantly. The crust thickness beneath the Shanxi fault depression zone is about 46 km, and there is a low-velocity structure with a velocity of less than 6.1 km s-~ in the upper part of the middle crust. Combined with other geophysical study results, our data shows that the lithospheric destruction at the Shaanxi-Shanxi fault depression zone and the Yinchuan-Hetao rift surround- ing the Ordos block is non-uniform. The lithosphere thickness is about 80-90 km in the Datong-Baotou area, 75-137 km at the Dingxiang-Shenmu region, and about 80-120 km in the Anyang-Yichuan area. The non-uniform lithospheric destruction may be related to the ancient tectonic zone surrounding the Ordos block. This zone experienced multi-period tectonic events in the long-term process of its tectonic evolution and was repeatedly transformed and weakened. The weakening level is related to the interactions with the Ordos block. The continental collision between the Cenozoic India and Eurasia plates and N-E thrust- ing by the Qinghai Tibet Plateau block is causing further reformation and reduction of the lithosphere.
基金Key Project of Beijing Natural Science Foundation,No.8171004
文摘Development of Xiong'an New District(XND) is integral to the implementation of the Beijing-Tianjin-Hebei(BTH) Integration Initiative. It is intended to ease the non-capital functions of Beijing, optimize regional spatial patterns, and enhance ecosystem services and living environment in this urban agglomeration. Applying multi-stage remote sensing(RS) images, land use/cover change(LUCC) data, ecosystem services assessment data, and high-precision urban land-cover information, we reveal the regional land-cover characteristics of this new district as well as across the planned area of the entire BTH urban agglomeration. Corresponding ecological protection and management strategies are also proposed. Results indicated that built-up areas were rapidly expanding, leading to a continuous impervious surface at high density. Urban and impervious surface areas(ISAs) grew at rates 1.27 and 1.43 times higher than that in the 2000 s, respectively, seriously affecting about 15% area of the sub-basins. Construction of XND mainly encompasses Xiongxian, Rongcheng, and Anxin counties, areas which predominantly comprise farmland, townships and rural settlements, water, and wetland ecosystems. The development and construction of XND should ease the non-capital functions of Beijing, as well as moderately control population and industrial growth. Thus, this development should be included within the national ‘sponge city' construction pilot area in early planning stages, and reference should be made to international low-impact development modes in order to strengthen urban green infrastructural construction. Early stage planning based on the existing characteristics of the underlying surface should consider the construction of green ecological patches and ecological corridors between XND and the cities of Baoding, Beijing, and Tianjin. The proportion of impervious surfaces should not exceed 60%, while that of the core area should not exceed 70%. The development of XND needs to initiate the concept of ‘planning a city according to water resource amount' and incorporate rainwater collection and recycling.