In order to determine the tectonic framework of the Late Paleozoic sedimentary basin of the studied area in Inner Mongolia, horizontal derivative, vertical derivative, total gradient modulus, tilt angle, and Euler dec...In order to determine the tectonic framework of the Late Paleozoic sedimentary basin of the studied area in Inner Mongolia, horizontal derivative, vertical derivative, total gradient modulus, tilt angle, and Euler deconvolution methods were used to process the high-precision gravity data. Four major faults and six secondary faults have been identified according to the horizontal fault position information provided by the first four methods, and the fault depth information were obtained using the Euler deconvolution method. The interpreted faults were identified as the main basin-controlling structures in the study area, which was helpful for deepening the understanding of the basin's structure, as well as providing important references for delineating hidden polymetallic ore veins.展开更多
Recent paleontological, paleomagnetic and carbon isotopic investigations have provided new evidence supporting placement of the Chinese terrestrial Paleocene-Eocene boundary at the base of the Lingcha Formation in the...Recent paleontological, paleomagnetic and carbon isotopic investigations have provided new evidence supporting placement of the Chinese terrestrial Paleocene-Eocene boundary at the base of the Lingcha Formation in the Hengyang Basin, Hunan Province, and within the upper part of the Nomogen Formation in the Erlian Basin, Inner Mongolia. Based on mammalian and ostracod biostratigraphic data, the boundary can also be roughly correlated with the contacts between the Baoyue and Huayong formations in the Sanshui Basin of Guangdong, the Qingjiang and Xinyu formations of Jiangxi, the Fourth Formation of the Funing Group and the Dainan Formation in northern Jiangsu, and the Dabu and Shisanjianfang formations in the Turfan Basin of Xinjiang.展开更多
plane with the strike of 127°, the dip of 79° and the rake of 171°. The rupture process inversion result of MS=7.9 earthquake shows that the total rupture duration is about 37 s, the scalar moment tenso...plane with the strike of 127°, the dip of 79° and the rake of 171°. The rupture process inversion result of MS=7.9 earthquake shows that the total rupture duration is about 37 s, the scalar moment tensor is M0=0.97 × 1020 N·m. Rupture mainly occurred on the shallow area with 110 km long and 30 km wide, the location in which the rupture initiated is not where the main rupture took place, and the area with slip greater than 0.5 m basically lies within 35 km deep middle-crust under the earth surface. The maximum static slip is 3.6 m. There are two distinct areas with slip larger than 2.0 m. We noticed that when the rupture propagated towards northwest and closed to the area around the MS=7.3 hypocenter, the slip decreased rapidly, which may indicate that the rupture process was stopped by barriers. The consistence of spatial distribution of slip on the fault plane with the distribution of aftershocks also supports that the rupture is a heterogeneous process owing to the presence of barriers.展开更多
文摘In order to determine the tectonic framework of the Late Paleozoic sedimentary basin of the studied area in Inner Mongolia, horizontal derivative, vertical derivative, total gradient modulus, tilt angle, and Euler deconvolution methods were used to process the high-precision gravity data. Four major faults and six secondary faults have been identified according to the horizontal fault position information provided by the first four methods, and the fault depth information were obtained using the Euler deconvolution method. The interpreted faults were identified as the main basin-controlling structures in the study area, which was helpful for deepening the understanding of the basin's structure, as well as providing important references for delineating hidden polymetallic ore veins.
基金supported by the Basic Work Program (2006FY120300-15)the Major Basic Research Projects (2006CB806400) of the Ministry of Science and Technology of Chinathe National Natural Science Foundation of China (40532010)
文摘Recent paleontological, paleomagnetic and carbon isotopic investigations have provided new evidence supporting placement of the Chinese terrestrial Paleocene-Eocene boundary at the base of the Lingcha Formation in the Hengyang Basin, Hunan Province, and within the upper part of the Nomogen Formation in the Erlian Basin, Inner Mongolia. Based on mammalian and ostracod biostratigraphic data, the boundary can also be roughly correlated with the contacts between the Baoyue and Huayong formations in the Sanshui Basin of Guangdong, the Qingjiang and Xinyu formations of Jiangxi, the Fourth Formation of the Funing Group and the Dainan Formation in northern Jiangsu, and the Dabu and Shisanjianfang formations in the Turfan Basin of Xinjiang.
基金The Specialized Funds for National Key Basic Study (G1998040704), the Dual Project of China Earthquake Admini-stration (9691309020301) and National Natural Science Foundation of China (46764010).
文摘plane with the strike of 127°, the dip of 79° and the rake of 171°. The rupture process inversion result of MS=7.9 earthquake shows that the total rupture duration is about 37 s, the scalar moment tensor is M0=0.97 × 1020 N·m. Rupture mainly occurred on the shallow area with 110 km long and 30 km wide, the location in which the rupture initiated is not where the main rupture took place, and the area with slip greater than 0.5 m basically lies within 35 km deep middle-crust under the earth surface. The maximum static slip is 3.6 m. There are two distinct areas with slip larger than 2.0 m. We noticed that when the rupture propagated towards northwest and closed to the area around the MS=7.3 hypocenter, the slip decreased rapidly, which may indicate that the rupture process was stopped by barriers. The consistence of spatial distribution of slip on the fault plane with the distribution of aftershocks also supports that the rupture is a heterogeneous process owing to the presence of barriers.
