Strong deformed sediments investigated in the Hoh Xil basin may contain detailed records for early Tertiary crustal shortening in northern Tibet (Fig.1A). Sedimentary sequences in the basin consist of the Fenghuoshan ...Strong deformed sediments investigated in the Hoh Xil basin may contain detailed records for early Tertiary crustal shortening in northern Tibet (Fig.1A). Sedimentary sequences in the basin consist of the Fenghuoshan Group, the Yaxicuo Group, and the early Miocene Wudaoliang Group from lower to upper. Magnetostratigraphic research has indicated the Eocene to early Oligocene ages for the Fenghuoshan and Yaxicuo Groups (Liu, et al., 2000). Total 29 lithological sections with 20487 7m thick were measured spread all over the 101000km\+2 Hoh Xil basin, the largest Tertiary sedimentary basin in the hinterland of the Tibetan plateau, to reveal the prototype basin and its evolution processes. They include 17 sections with 14925 3m thick of the Fenghuoshan Group, 8 sections with 4273 5m thick of the Yaxicuo Group, and 4 sections with 1284 9m thick of the Wudaoliang Group.展开更多
Geological studies indicate that Qinghai\|Tibet plateau crust has shortened at least 2500km and the thickness was increased to 60～70km in the past 45Ma. Different researchers advocate different views to explain the s...Geological studies indicate that Qinghai\|Tibet plateau crust has shortened at least 2500km and the thickness was increased to 60～70km in the past 45Ma. Different researchers advocate different views to explain the shortening according to their studies.( Tapponnier,1977;Chang et al,1986;England et al,1986;Murphy,1997;Y.Pan,1999),however it is still unresolved on how much shortening in upper crustal especially in Qiangtang terrain.Qiangtang terrain is located in the center of Qinghai\|Tibet plateau, the tectonic deformation has been resulted from intracontinental convergence and collision of India plate with Eurasian plate.The deformation style of Qiangtang terrain shows east\|west\|trending folds and thrusts which formed in the shallow tectonic level during collisional\|intracontinental period. The folds type is characterized by nonpenetrative\|foliation parallel fold, the hinges have the same trend with the thrusts. These traits are favourable for restoring the balanced cross\|section and measuring the shortening. The balanced reconstruction is based on line balancing on three different stratigraphic sections (A,B and C)across the Northern Qiangtang basin in the area between 85°E and 87°E.The sections are all north\|south\|trending in accordance with the moving direction of thrusts.展开更多
Finite strain patterns of rocks The structural styles and crustal shortening in the northern margin of Qinghai—Tibet plateau are examined by systematic finite strain measurements. The finite strain patterns in this a...Finite strain patterns of rocks The structural styles and crustal shortening in the northern margin of Qinghai—Tibet plateau are examined by systematic finite strain measurements. The finite strain patterns in this area are of following characteristics:① The orientation of & principal axes of strain ellipsoid varies regularly in regard to different tectonic locations. In fact, most of the measured X axes are parallel to the regional structure lines, striking east\|west or approximately east\|west with some X axes trending northeast\|southwest. The measured Z\|axes are approximately at right angle to the regional structure lines, trending north\|northeast or north\|northwest.② The Flinn parameter k is higher in the northern and southern margins of the basin than that in the basin center, indicating that the margins of basin experienced extensional strain and the middle of basin undergo strain.③ Rocks of different age possess different strain state and show k value of 1～2 for Tertiary rocks, 3～4 for Jurassic—Cretaceous rocks. The k value of the basement rocks is the highest of all.展开更多
It is one of hot issues in Tibetan research that is to study the mode,process and kinetics of the crustal shortening during Mesozoic-Cenozoic.In this paper, on the basis of systematic collection,analysis and research ...It is one of hot issues in Tibetan research that is to study the mode,process and kinetics of the crustal shortening during Mesozoic-Cenozoic.In this paper, on the basis of systematic collection,analysis and research of the existing data and results from Himalayas,Lhasa and Qiangtang terranes,we conducted the balanced cross-section study.In the north Qiangtang,the line-balanced cross-section展开更多
As a part of INDEPTH 3/GEODEPTH geological surface investigations were carried out during two field campaigns in 1998 and 1999. The working area covers a roughly N\|S (30～36°N) tren ding, 200km wide belt through...As a part of INDEPTH 3/GEODEPTH geological surface investigations were carried out during two field campaigns in 1998 and 1999. The working area covers a roughly N\|S (30～36°N) tren ding, 200km wide belt through the Lhasa Terrane and Qiangtang Terrane at a longitude of 88～90°E. Field geology was focused on geological mapping, structural measurements, and extensive sampling for the purpose of fission track geochronology. Additionally a total number of 742 orientated palaeomagnetic samples were drilled at 73 sites. Most of the samples were taken in fine\|grained sediments of Cretaceous, Eocene, and Neogene age. Five sites were drilled in acid to intermediate volcanics.A first sequence of measurements has been applied on a set of specimen. Most of the chosen formations (>80%) have acquired stable remanences which are carried by hematite and magnetite. As an example for the characteristic demagnetising behaviour of fine\|grained probable Cretaceous sandstones see Fig.1a. The unblocking temperature of 650℃ allows to identify hematite as remanence carrier.. Although single sites show well\|defined mean directions (e.g. site 76B: α 95 =3 8; k =185 8) the distribution among several site means of one formation could scatter (Fig.1b). It has to be checked carefully if rotations of single crustal elements are responsible for this effect. There is evidence to assume the detected characteristic remanences to be primary—further analysis including fold tests will be performed after the data set has increased.展开更多
The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic -Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision si...The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic -Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision since～55 Ma have been well recorded.Based on the latest progress in high-resolution stratigraphy,a technique of balanced section was applied to six pieces of northeast-southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began展开更多
The Late Cenozoic fold\|and\|thrust zone along the northwestern margin of the Tarim Basin and the adjacent Tian Shan of Central Asia is an actively deforming part of the India\|Asia collision system. This deformation ...The Late Cenozoic fold\|and\|thrust zone along the northwestern margin of the Tarim Basin and the adjacent Tian Shan of Central Asia is an actively deforming part of the India\|Asia collision system. This deformation zone has two remarkable oppositely vergence arcuate fold\|and\|thrust systems (Kepingtage and Kashi\|Atushi fold\|and\|thrust belts) reaching from east of Keping to west of Kashi. This shape is manifested by structure, topography and seismicity. From north to south, this deformation zone is characterized by four main kinematic elements: (1) a hanging\|wall block (Maidan fault and Tuotegongbaizi\|Muziduke thrust system) that represents the Cenozoic reactivation of a late Paleozoic thrust system; (2) an imbricated thrust stack (Kepingtage\|Tashipeshake thrust system) where slices of Tarim platform sediments are thrust south toward the basin; (3) the Kashi\|Atushi fold\|and\|thrust system where thrusting and folding verge toward the Tian Shan; (4) a foot\|wall block (Tarim craton) that dips gently northwest below the sediment\|filled southern Tian Shan basin and generally has little internal deformation.展开更多
The southeastern edge of the Tibetan plateau is marked by several thrust sheets trending roughly in E\|W direction. The Yanyuan thrust sheet is bounded by three arcuate thrust belts, marked by high mountain ranges wit...The southeastern edge of the Tibetan plateau is marked by several thrust sheets trending roughly in E\|W direction. The Yanyuan thrust sheet is bounded by three arcuate thrust belts, marked by high mountain ranges with the Jinhe belt on the north, the Qianhe belt on the south and the Ninglang belt on the west. Within the Yanyuan thrust belt are sedimentary cover rocks of the Yangtze platform, with ages ranging from Sinian to Triassic. In the north, the thrust sheet is overlain by the Muli thrust sheet along the Jinhe belt, while in the south, it is underlain by the Kangdian paleoland along the Qianhe belt. The youngest rocks on the foot wall are late Eocene to Oligocene in age, indicating that the thrusting occurred in the late Tertiary. The top of the Yanyuan thrust belt is truncated by a flat erosion surface similar to that on the plateau to the north. Along a north\|dipping normal fault bordering the Yanyuan basin on the south, the erosion surface is tilted to the south against Triassic rocks. The basin is filled with coal\|bearing clastic sediments of Pliocene and early Pleistocene age, which gives the timing of the normal faulting. Based on the faulting pattern, we propose that the southeastern edge of the Tibetan plateau underwent a large amount of N\|S shortening and uplift along the Yanyuan thrust sheet in the late Tertiary, while the subsequent normal faulting that had occurred along the Yanyuan basin during the Pliocene and Pliocene can be interpreted to have accommodated gravitational collapse of the crust.展开更多
The quantitative analysis of uplift process of the Qinghai—Tibet plateau is a key to deepen the study of uplift mechanism and dynamic model, for this, numerical simulate was done to the whole process of uplift of the...The quantitative analysis of uplift process of the Qinghai—Tibet plateau is a key to deepen the study of uplift mechanism and dynamic model, for this, numerical simulate was done to the whole process of uplift of the Qinghai—Tibet plateau.1 Geological model According to the tectonic evolution and lithospheric structure, continental crust in the Qinghai—Tibet plateau in profile is divided into sedimentary cover, crystalline rock formation and lower crust and composed of Kunlun, Bayan Har, Qiangtang, Gangdise and Himalaya blocks on the plane. Layer or block is bounded the detachment layer or large fault. On the basis of the uplift characteristics, the calculated time limit is in the Cenozoic since 65Ma, roughly four stages, i.e., 65 to 40Ma, 40 to 20Ma, 20 to 3Ma and 3Ma to now. Mesh profile used Yadong—Golmud Geoscience transect.展开更多
The study was to investigate the effect of reducing central sympathetic nervous tone with clonidine on cardiomyocyte contraction,and further to analyze the influence of reducing the central sympathetic nervous tone on...The study was to investigate the effect of reducing central sympathetic nervous tone with clonidine on cardiomyocyte contraction,and further to analyze the influence of reducing the central sympathetic nervous tone on response of β1 and β2-AR in aged ventricular myocytes.Sprague-Dawley rats were randomly divided into three groups:adult group,aged group and aged group with clonidine.展开更多
临时语(nonce word)的定义是,“为某一特定场合而创造的词语”(a word coined for a particular occasion)。构成临时语的方式很多,有词缀法(affixation)、转化法(conversion)、合成法(composition or compounding)、拼缀法(blending)...临时语(nonce word)的定义是,“为某一特定场合而创造的词语”(a word coined for a particular occasion)。构成临时语的方式很多,有词缀法(affixation)、转化法(conversion)、合成法(composition or compounding)、拼缀法(blending)、逆成法(backformation)和缩略法(shortening)。展开更多
文摘Strong deformed sediments investigated in the Hoh Xil basin may contain detailed records for early Tertiary crustal shortening in northern Tibet (Fig.1A). Sedimentary sequences in the basin consist of the Fenghuoshan Group, the Yaxicuo Group, and the early Miocene Wudaoliang Group from lower to upper. Magnetostratigraphic research has indicated the Eocene to early Oligocene ages for the Fenghuoshan and Yaxicuo Groups (Liu, et al., 2000). Total 29 lithological sections with 20487 7m thick were measured spread all over the 101000km\+2 Hoh Xil basin, the largest Tertiary sedimentary basin in the hinterland of the Tibetan plateau, to reveal the prototype basin and its evolution processes. They include 17 sections with 14925 3m thick of the Fenghuoshan Group, 8 sections with 4273 5m thick of the Yaxicuo Group, and 4 sections with 1284 9m thick of the Wudaoliang Group.
文摘Geological studies indicate that Qinghai\|Tibet plateau crust has shortened at least 2500km and the thickness was increased to 60～70km in the past 45Ma. Different researchers advocate different views to explain the shortening according to their studies.( Tapponnier,1977;Chang et al,1986;England et al,1986;Murphy,1997;Y.Pan,1999),however it is still unresolved on how much shortening in upper crustal especially in Qiangtang terrain.Qiangtang terrain is located in the center of Qinghai\|Tibet plateau, the tectonic deformation has been resulted from intracontinental convergence and collision of India plate with Eurasian plate.The deformation style of Qiangtang terrain shows east\|west\|trending folds and thrusts which formed in the shallow tectonic level during collisional\|intracontinental period. The folds type is characterized by nonpenetrative\|foliation parallel fold, the hinges have the same trend with the thrusts. These traits are favourable for restoring the balanced cross\|section and measuring the shortening. The balanced reconstruction is based on line balancing on three different stratigraphic sections (A,B and C)across the Northern Qiangtang basin in the area between 85°E and 87°E.The sections are all north\|south\|trending in accordance with the moving direction of thrusts.
文摘Finite strain patterns of rocks The structural styles and crustal shortening in the northern margin of Qinghai—Tibet plateau are examined by systematic finite strain measurements. The finite strain patterns in this area are of following characteristics:① The orientation of & principal axes of strain ellipsoid varies regularly in regard to different tectonic locations. In fact, most of the measured X axes are parallel to the regional structure lines, striking east\|west or approximately east\|west with some X axes trending northeast\|southwest. The measured Z\|axes are approximately at right angle to the regional structure lines, trending north\|northeast or north\|northwest.② The Flinn parameter k is higher in the northern and southern margins of the basin than that in the basin center, indicating that the margins of basin experienced extensional strain and the middle of basin undergo strain.③ Rocks of different age possess different strain state and show k value of 1～2 for Tertiary rocks, 3～4 for Jurassic—Cretaceous rocks. The k value of the basement rocks is the highest of all.
文摘It is one of hot issues in Tibetan research that is to study the mode,process and kinetics of the crustal shortening during Mesozoic-Cenozoic.In this paper, on the basis of systematic collection,analysis and research of the existing data and results from Himalayas,Lhasa and Qiangtang terranes,we conducted the balanced cross-section study.In the north Qiangtang,the line-balanced cross-section
文摘As a part of INDEPTH 3/GEODEPTH geological surface investigations were carried out during two field campaigns in 1998 and 1999. The working area covers a roughly N\|S (30～36°N) tren ding, 200km wide belt through the Lhasa Terrane and Qiangtang Terrane at a longitude of 88～90°E. Field geology was focused on geological mapping, structural measurements, and extensive sampling for the purpose of fission track geochronology. Additionally a total number of 742 orientated palaeomagnetic samples were drilled at 73 sites. Most of the samples were taken in fine\|grained sediments of Cretaceous, Eocene, and Neogene age. Five sites were drilled in acid to intermediate volcanics.A first sequence of measurements has been applied on a set of specimen. Most of the chosen formations (>80%) have acquired stable remanences which are carried by hematite and magnetite. As an example for the characteristic demagnetising behaviour of fine\|grained probable Cretaceous sandstones see Fig.1a. The unblocking temperature of 650℃ allows to identify hematite as remanence carrier.. Although single sites show well\|defined mean directions (e.g. site 76B: α 95 =3 8; k =185 8) the distribution among several site means of one formation could scatter (Fig.1b). It has to be checked carefully if rotations of single crustal elements are responsible for this effect. There is evidence to assume the detected characteristic remanences to be primary—further analysis including fold tests will be performed after the data set has increased.
文摘The Qaidam Basin,located in the northern margin of the Qinghai-Tibet Plateau,is a large Mesozoic -Cenozoic basin,and bears huge thick Cenozoic strata.The geologic events of the Indian-Eurasian plate-plate collision since～55 Ma have been well recorded.Based on the latest progress in high-resolution stratigraphy,a technique of balanced section was applied to six pieces of northeast-southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began
文摘The Late Cenozoic fold\|and\|thrust zone along the northwestern margin of the Tarim Basin and the adjacent Tian Shan of Central Asia is an actively deforming part of the India\|Asia collision system. This deformation zone has two remarkable oppositely vergence arcuate fold\|and\|thrust systems (Kepingtage and Kashi\|Atushi fold\|and\|thrust belts) reaching from east of Keping to west of Kashi. This shape is manifested by structure, topography and seismicity. From north to south, this deformation zone is characterized by four main kinematic elements: (1) a hanging\|wall block (Maidan fault and Tuotegongbaizi\|Muziduke thrust system) that represents the Cenozoic reactivation of a late Paleozoic thrust system; (2) an imbricated thrust stack (Kepingtage\|Tashipeshake thrust system) where slices of Tarim platform sediments are thrust south toward the basin; (3) the Kashi\|Atushi fold\|and\|thrust system where thrusting and folding verge toward the Tian Shan; (4) a foot\|wall block (Tarim craton) that dips gently northwest below the sediment\|filled southern Tian Shan basin and generally has little internal deformation.
文摘The southeastern edge of the Tibetan plateau is marked by several thrust sheets trending roughly in E\|W direction. The Yanyuan thrust sheet is bounded by three arcuate thrust belts, marked by high mountain ranges with the Jinhe belt on the north, the Qianhe belt on the south and the Ninglang belt on the west. Within the Yanyuan thrust belt are sedimentary cover rocks of the Yangtze platform, with ages ranging from Sinian to Triassic. In the north, the thrust sheet is overlain by the Muli thrust sheet along the Jinhe belt, while in the south, it is underlain by the Kangdian paleoland along the Qianhe belt. The youngest rocks on the foot wall are late Eocene to Oligocene in age, indicating that the thrusting occurred in the late Tertiary. The top of the Yanyuan thrust belt is truncated by a flat erosion surface similar to that on the plateau to the north. Along a north\|dipping normal fault bordering the Yanyuan basin on the south, the erosion surface is tilted to the south against Triassic rocks. The basin is filled with coal\|bearing clastic sediments of Pliocene and early Pleistocene age, which gives the timing of the normal faulting. Based on the faulting pattern, we propose that the southeastern edge of the Tibetan plateau underwent a large amount of N\|S shortening and uplift along the Yanyuan thrust sheet in the late Tertiary, while the subsequent normal faulting that had occurred along the Yanyuan basin during the Pliocene and Pliocene can be interpreted to have accommodated gravitational collapse of the crust.
文摘The quantitative analysis of uplift process of the Qinghai—Tibet plateau is a key to deepen the study of uplift mechanism and dynamic model, for this, numerical simulate was done to the whole process of uplift of the Qinghai—Tibet plateau.1 Geological model According to the tectonic evolution and lithospheric structure, continental crust in the Qinghai—Tibet plateau in profile is divided into sedimentary cover, crystalline rock formation and lower crust and composed of Kunlun, Bayan Har, Qiangtang, Gangdise and Himalaya blocks on the plane. Layer or block is bounded the detachment layer or large fault. On the basis of the uplift characteristics, the calculated time limit is in the Cenozoic since 65Ma, roughly four stages, i.e., 65 to 40Ma, 40 to 20Ma, 20 to 3Ma and 3Ma to now. Mesh profile used Yadong—Golmud Geoscience transect.
文摘The study was to investigate the effect of reducing central sympathetic nervous tone with clonidine on cardiomyocyte contraction,and further to analyze the influence of reducing the central sympathetic nervous tone on response of β1 and β2-AR in aged ventricular myocytes.Sprague-Dawley rats were randomly divided into three groups:adult group,aged group and aged group with clonidine.
文摘临时语(nonce word)的定义是,“为某一特定场合而创造的词语”(a word coined for a particular occasion)。构成临时语的方式很多,有词缀法(affixation)、转化法(conversion)、合成法(composition or compounding)、拼缀法(blending)、逆成法(backformation)和缩略法(shortening)。
