The west block of the middle belt of TanLu fault belt is one of the areas where volcanic landforms are mainly distributed. This paper divides the volcanic landforms into four grades according to formation, morphology,...The west block of the middle belt of TanLu fault belt is one of the areas where volcanic landforms are mainly distributed. This paper divides the volcanic landforms into four grades according to formation, morphology, and ingredient of matter. Lava cones are divided into two types based on the force of top-support and the fluid form of magma: the arc-projecting type and spring-spilling type. Furthermore, the courses of development of volcanic landforms are divided into three stages according to the form and strength of volcanic activities.展开更多
The geometry of the Qianning-Kangding segment of the Xianshuihe fault zone is quite complex, and it is composed of four secondary-faults, i.e., the Yalahe fault, Selaha-Kangding fault, Zeduotang fault and Moxi fault. ...The geometry of the Qianning-Kangding segment of the Xianshuihe fault zone is quite complex, and it is composed of four secondary-faults, i.e., the Yalahe fault, Selaha-Kangding fault, Zeduotang fault and Moxi fault. On this segment, three strong earthquakes with M(7.0 occurred in 1725, 1786 and 1955, respectively. Based on a study of fault landform and geochronology (14C and Thermoluminesense), this paper documents the average horizontal slip rates during the late-Quaternary on all the secondary-faults of the Qianning-Kangding segment as follows: Yalahe fault: (2.0(0.2) mm/a; Selaha-Kangding fault: (5.5(0.6) mm/a; Zeduotang fault: (3.6(0.3) mm/a; Moxi fault: (9.9(0.6) mm/a. The results from the investigation of surface ruptures of historical earthquakes, coseismic-slip and paleo-earthquakes show that the strong-earthquake recurrence intervals are thousands of years on the Yalahe fault, and 230 to 350 years on the Selaha-Kangding and Zeduotang faults. In the next one hundred years, the recurrence of a strong-earthquake on these faults appears impossible. However, the strong-earthquake recurrence interval on the Moxi fault is about 300 years. Up to now, it has been 214 years since the last earthquake (magnitude 7) occurred in 1786, therefore, this fault is now approaching the condition favorable for the next strong earthquake recurrence.展开更多
Located on the western of Sichuan, the east border of Tibet plateau, Xianshuihe fault is a significant strong earthquake zone. From Huiyuansi pull\|apart basin in Qianning, Xianshuihe fault can be divided two segments...Located on the western of Sichuan, the east border of Tibet plateau, Xianshuihe fault is a significant strong earthquake zone. From Huiyuansi pull\|apart basin in Qianning, Xianshuihe fault can be divided two segments\|NW section and SE section: the construction of the former is single and a main fault; the construction of the latter is complex and composed by three parallel faults, its main fault is named as Selaha—Kangding fault, which distributes along Jinlongsi, Sehala, Mugecuo and Kangding. Yalahe fault, located at the NE direction of the main fault, and Zeduotang fault, located at the SW direction of the main fault, are all secondary faults, which are 9～13km away from the main fault. At the south of Kangding, the segment of Xianshuihe fault is a single main section, called as Moxi fault. On the basis of recent researching results, this paper mainly discusses the slip rate and recurrence interval of strong earthquake of the SE segment (Qianning—Kangding) on Xianshuihe.展开更多
Eastern Hunan-western Jiangxi, the main distribution domain of the Luoxiao MountainRange, is one of the key districts of the Circum-Pacific tectonically active belt in China, in whichNNE-trending en echelon strike-sli...Eastern Hunan-western Jiangxi, the main distribution domain of the Luoxiao MountainRange, is one of the key districts of the Circum-Pacific tectonically active belt in China, in whichNNE-trending en echelon strike-slip faulting since Cenozoic time has obviously controlled thefundamental framework of the modern land forms. Based on the study of tectonic evolution and ac-tive strike-slip faults, this paper discusses the forms, types and combinations of the modern tec-tonic land forms in this region.展开更多
The Longling-Ruili fault is an important active fault in Southwestern China, striking generally northeast. The fault controls the development of the sedimentary series and magmatic action on its two sides, as well as ...The Longling-Ruili fault is an important active fault in Southwestern China, striking generally northeast. The fault controls the development of the sedimentary series and magmatic action on its two sides, as well as the development of the Longling basin, Mangshi basin and the Zhefang basin along it. Due to limited Quaternary sediments and harsh natural conditions, the study of late Quaternary fault activity on the northern segment of the Longling-Ruili fault is lacking and the time of the newest faulting and the Quaternary slip rate are not clear at present. Based on the interpretation of remote images, quantitative geomorphologic deformation measurements and dating of young terrace deposits and alluvial fans, this paper obtains some new results as follows. The northern segment of the Longling-Ruili fault is a Holocene dextral strike-slip fault with some component of a normal slip. The terrace T1 composing mainly of alluvial deposits formed during 4ka B. P. was offset by the northern segment of the Longling-Ruili fault and its left-lateral and its vertical displacements are 8m - 12m and 2m, respectively. The late Pleistocene alluvial fan was displaced with a left-lateral and vertical displacement of 70m and lgm, respectively. The strike-slip rate of the Longling-Ruili fault is 2.2mm/a 2.5mm/a and the vertical slip rate is 0.6mm/a since the late Pleistocene epoch. The strike-slip rate of the Longling-Ruili fault is 1.8mm/a - 3.0mm/a and vertical slip rate is 0.5mm/a during the Holocene epoch. The proportion of horizontal to vertical displacement is about 4： 1, which means that the vertical slip rate on the northern segment of the Longling-Ruili fault is about 25 % of the horizontal slip rate. The left-lateral slip rate in the late Holocene is consistent with the GPS measurement. The strike slip rate is of great consistency in different time scales since the late Pleistocene epoch, indicating that the activity of the Longling-Ruili fault is of great stability.展开更多
Systematic research of the characteristics of late Quaternary activity of the middle part of Kouquan fault has been done through conducting 1∶50000 geologic mapping combining with remote sensing interpretation of spo...Systematic research of the characteristics of late Quaternary activity of the middle part of Kouquan fault has been done through conducting 1∶50000 geologic mapping combining with remote sensing interpretation of spot imaging, field validating and chronology research of the research area. Studies suggest that the middle part of Kouquan fault has had strong activity since the late Quaternary which controls the tectonic evolvement of the nearby mountains and Datong basin. The recent activity of this fault has faulted the sandy gravel layers of T1 terrace and the lower part of dark loessial soils over the terrace on the north of Chanfang village. The maximum vertical displacement is over 3m in the area between Xiaoyukou village and Louzikou village, and to the south of Dayukou village and the north of Emaokou village, the displacement decreases to 0.5m and 0.25m respectively. Based on the recent faulted landforms and combined with dating, we determined the age of recent activity of the fault in the research area to be between 7.71ka B.P. to 3.00 ka B.P. Discussions are made on this in combination with previous research.展开更多
Based on fault geometric features,composite pattern,faulting land-forms and seismic data,this paper discussed the activity behavior along the northern segment of the Anninghe fault(from Xichang to Shimian)since the La...Based on fault geometric features,composite pattern,faulting land-forms and seismic data,this paper discussed the activity behavior along the northern segment of the Anninghe fault(from Xichang to Shimian)since the Late Pleistocene.The fault can be divided into three active segments by discrepancies of their activity:the segment from Xichang to Mianning,the segment from Mianning to Zimakua,and the segment from Zimakua to Tianwan.The southern segment has the background of occurrence of great earthquakes,but the middle and the northern segments can generate strong and moderate events respectively.According to the features of quartz from fault gouges by scanning electron microscopy(SEM),this paper discussed the movement features along the fault and indicated the stick-slipping feature on the segment from Xichang to Zimakua,the creeping feature on the segment from Jiziping to Tianwan and the transitional feature on the segment in between.展开更多
文摘The west block of the middle belt of TanLu fault belt is one of the areas where volcanic landforms are mainly distributed. This paper divides the volcanic landforms into four grades according to formation, morphology, and ingredient of matter. Lava cones are divided into two types based on the force of top-support and the fluid form of magma: the arc-projecting type and spring-spilling type. Furthermore, the courses of development of volcanic landforms are divided into three stages according to the form and strength of volcanic activities.
基金Chinese Joint Seismological Science Foundation (95-07-0425).
文摘The geometry of the Qianning-Kangding segment of the Xianshuihe fault zone is quite complex, and it is composed of four secondary-faults, i.e., the Yalahe fault, Selaha-Kangding fault, Zeduotang fault and Moxi fault. On this segment, three strong earthquakes with M(7.0 occurred in 1725, 1786 and 1955, respectively. Based on a study of fault landform and geochronology (14C and Thermoluminesense), this paper documents the average horizontal slip rates during the late-Quaternary on all the secondary-faults of the Qianning-Kangding segment as follows: Yalahe fault: (2.0(0.2) mm/a; Selaha-Kangding fault: (5.5(0.6) mm/a; Zeduotang fault: (3.6(0.3) mm/a; Moxi fault: (9.9(0.6) mm/a. The results from the investigation of surface ruptures of historical earthquakes, coseismic-slip and paleo-earthquakes show that the strong-earthquake recurrence intervals are thousands of years on the Yalahe fault, and 230 to 350 years on the Selaha-Kangding and Zeduotang faults. In the next one hundred years, the recurrence of a strong-earthquake on these faults appears impossible. However, the strong-earthquake recurrence interval on the Moxi fault is about 300 years. Up to now, it has been 214 years since the last earthquake (magnitude 7) occurred in 1786, therefore, this fault is now approaching the condition favorable for the next strong earthquake recurrence.
文摘Located on the western of Sichuan, the east border of Tibet plateau, Xianshuihe fault is a significant strong earthquake zone. From Huiyuansi pull\|apart basin in Qianning, Xianshuihe fault can be divided two segments\|NW section and SE section: the construction of the former is single and a main fault; the construction of the latter is complex and composed by three parallel faults, its main fault is named as Selaha—Kangding fault, which distributes along Jinlongsi, Sehala, Mugecuo and Kangding. Yalahe fault, located at the NE direction of the main fault, and Zeduotang fault, located at the SW direction of the main fault, are all secondary faults, which are 9～13km away from the main fault. At the south of Kangding, the segment of Xianshuihe fault is a single main section, called as Moxi fault. On the basis of recent researching results, this paper mainly discusses the slip rate and recurrence interval of strong earthquake of the SE segment (Qianning—Kangding) on Xianshuihe.
文摘Eastern Hunan-western Jiangxi, the main distribution domain of the Luoxiao MountainRange, is one of the key districts of the Circum-Pacific tectonically active belt in China, in whichNNE-trending en echelon strike-slip faulting since Cenozoic time has obviously controlled thefundamental framework of the modern land forms. Based on the study of tectonic evolution and ac-tive strike-slip faults, this paper discusses the forms, types and combinations of the modern tec-tonic land forms in this region.
基金sponsored by the Science and Technology Development Program of the Ministry of Railways(2008G027B),the People's Republic of Chinathe National Key Technology R&D Program(2006BAC13B)103),China
文摘The Longling-Ruili fault is an important active fault in Southwestern China, striking generally northeast. The fault controls the development of the sedimentary series and magmatic action on its two sides, as well as the development of the Longling basin, Mangshi basin and the Zhefang basin along it. Due to limited Quaternary sediments and harsh natural conditions, the study of late Quaternary fault activity on the northern segment of the Longling-Ruili fault is lacking and the time of the newest faulting and the Quaternary slip rate are not clear at present. Based on the interpretation of remote images, quantitative geomorphologic deformation measurements and dating of young terrace deposits and alluvial fans, this paper obtains some new results as follows. The northern segment of the Longling-Ruili fault is a Holocene dextral strike-slip fault with some component of a normal slip. The terrace T1 composing mainly of alluvial deposits formed during 4ka B. P. was offset by the northern segment of the Longling-Ruili fault and its left-lateral and its vertical displacements are 8m - 12m and 2m, respectively. The late Pleistocene alluvial fan was displaced with a left-lateral and vertical displacement of 70m and lgm, respectively. The strike-slip rate of the Longling-Ruili fault is 2.2mm/a 2.5mm/a and the vertical slip rate is 0.6mm/a since the late Pleistocene epoch. The strike-slip rate of the Longling-Ruili fault is 1.8mm/a - 3.0mm/a and vertical slip rate is 0.5mm/a during the Holocene epoch. The proportion of horizontal to vertical displacement is about 4： 1, which means that the vertical slip rate on the northern segment of the Longling-Ruili fault is about 25 % of the horizontal slip rate. The left-lateral slip rate in the late Holocene is consistent with the GPS measurement. The strike slip rate is of great consistency in different time scales since the late Pleistocene epoch, indicating that the activity of the Longling-Ruili fault is of great stability.
基金jointly funded by the National Natural Science Foundation ( Grant No. 40972143)the Key Research Project of the 11th "Five-year Plan"of China Earthquake Administration( 1520945024)
文摘Systematic research of the characteristics of late Quaternary activity of the middle part of Kouquan fault has been done through conducting 1∶50000 geologic mapping combining with remote sensing interpretation of spot imaging, field validating and chronology research of the research area. Studies suggest that the middle part of Kouquan fault has had strong activity since the late Quaternary which controls the tectonic evolvement of the nearby mountains and Datong basin. The recent activity of this fault has faulted the sandy gravel layers of T1 terrace and the lower part of dark loessial soils over the terrace on the north of Chanfang village. The maximum vertical displacement is over 3m in the area between Xiaoyukou village and Louzikou village, and to the south of Dayukou village and the north of Emaokou village, the displacement decreases to 0.5m and 0.25m respectively. Based on the recent faulted landforms and combined with dating, we determined the age of recent activity of the fault in the research area to be between 7.71ka B.P. to 3.00 ka B.P. Discussions are made on this in combination with previous research.
文摘Based on fault geometric features,composite pattern,faulting land-forms and seismic data,this paper discussed the activity behavior along the northern segment of the Anninghe fault(from Xichang to Shimian)since the Late Pleistocene.The fault can be divided into three active segments by discrepancies of their activity:the segment from Xichang to Mianning,the segment from Mianning to Zimakua,and the segment from Zimakua to Tianwan.The southern segment has the background of occurrence of great earthquakes,but the middle and the northern segments can generate strong and moderate events respectively.According to the features of quartz from fault gouges by scanning electron microscopy(SEM),this paper discussed the movement features along the fault and indicated the stick-slipping feature on the segment from Xichang to Zimakua,the creeping feature on the segment from Jiziping to Tianwan and the transitional feature on the segment in between.
