According to buried depth, the Yellow Rver's Paleochannels can be divided into ground Paleochannels (buried depth 0-8m) and shallowburied Paleochannels theried depth 8-50m). Each of them can be roughly divided int...According to buried depth, the Yellow Rver's Paleochannels can be divided into ground Paleochannels (buried depth 0-8m) and shallowburied Paleochannels theried depth 8-50m). Each of them can be roughly divided into three major Paleochannel belts, stretching Parallel with each other from SW to NE. Sedimentary layers of the paleochannels were mainly made up by sand levee of meanders or natural leavee deposits, and the flooding sedments were found bebeen the layers. The paleochannels in North Shadong Plain were formed in three stags; stage I (buried depth 50-15m) in later period of late Pleistocene-early period of Holocene, stag II (20-8m) in earlymiddle period of HOlocene; and stag III (8-0m) in midddle-late period of Holocene.展开更多
Quantitative morphologic analysis of shallowly buried, dendritic channel systems in the continental shelf off the abandoned Huanghe River （Yellow River） mouth has been made based on interpretation of high resolution...Quantitative morphologic analysis of shallowly buried, dendritic channel systems in the continental shelf off the abandoned Huanghe River （Yellow River） mouth has been made based on interpretation of high resolution seismic profiles, with the attempt to estimate the paleo-hydrologic parameters when the incised-channels formed, then assess the paleoenvironment. The results indicate that the buried channel systems were formed about 44 cal ka BP when the shelf was subaerially exposed and subsequently drowned and filled during the Holocene transgression with the sea level rise continuously. The study area has experienced the processes from fluvial and estuarine to fully marine.展开更多
The fluctuation pattern of China’s civilization can be ascribed to climate change and historical geopolitical variations. The ancient Silk Road served as the most prosperous route connecting East Asia and Europe duri...The fluctuation pattern of China’s civilization can be ascribed to climate change and historical geopolitical variations. The ancient Silk Road served as the most prosperous route connecting East Asia and Europe during Han Dynasty(206 BC–220 AD) and Sui-Tang Dynasties(581–907 AD), but was deserted in Wei, Jin, Northern and Southern dynasties(220–580 AD), of which the Tarim Basin was a key area. However, our understanding about the decline of the route during this period remains limited. Here, we present an ~7-year resolution record based on optically stimulated luminescence(OSL) age-depth model(ca. 120 BC–750 AD) from Luntai(LT) profile, about 5 km from the modern Tarim River, which fed the ancient oases, to assess the potential causes on the documented decline of the ancient Silk Road between Late Han and Sui dynasties. In this study, five episodes of hydrological change were identified by combining grain size, magnetic susceptibility, geochemistry and TOC/TN contents. Our reconstruction reveals that cold and wet climate dominated at 120 BC–50 AD and 550–750 AD, respectively, indicated by strong hydrodynamic conditions. Relatively warm and humid climate occurred at 120–550 AD, between Eastern Han and Sui-Tang dynasties, indicating a better and more suitable local environment. A comparison between the studied region and other areas of China demonstrates that the paleoclimatic variations in eastern and western China exhibit rough discrepancies, and the hydrological conditions in arid region is inconsistent with the decline of ancient Silk Road in the northern Tarim Basin. We suggest that political and societal factors are the key issues that caused the interruption of Silk Road during Wei, Jin, Northern and Southern dynasties, such as the co-occurrence of societal crises, turmoil and division in eastern China, rather than the deteriorating climatic condition in the northern Tarim basin.展开更多
Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have develope...Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have developed,of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui,Hebei Province,with a total length of 3 km,a dominant strike of NE78°,and nearly upright in the shallow layer.The surface damage observed in this fissure primarily manifests as beaded pits,and its activity shows distinct segmentation characteristics.On the trench profiles,the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to-3 m.An evident flexure is observed in the strata at depths ranging from-4.5 to-7 m.The drilling profile reveals that there is an absence of dislocations in the deeper strata.Nonetheless,the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area,underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure.Firstly,the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults.The interplay of the regional stress field,fault block movement,and fault activity played pivotal roles in driving the development of this paleochannel.Secondly,the paleochannel exerts a controlling influence on the development location and severity of the fissure.During pumping,the confined aquifer within the paleochannel undergoes water loss and compression,resulting in the formation of a surface subsidence funnel.When the tensile stress surpasses the soil's tensile strength at the funnel's edge,the soil fractures give rise to a ground fissure.Finally,large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture,emerge,and expand.This paper provides a heretofore generally unknown example,promotes research on the mechanisms of paleochannel-controlled fissures,and has guiding significance for disaster prevention and reduction in this area.展开更多
Keriya River,one of the ancient Four Green Corridors in the Tarim Basin,recording the changes of climate-environment and the ancient Silk Road of the region.According to the archaeological data,historical materials an...Keriya River,one of the ancient Four Green Corridors in the Tarim Basin,recording the changes of climate-environment and the ancient Silk Road of the region.According to the archaeological data,historical materials and paleoclimates information,its eeo-environment and climate have taken great changes since the 1.09 Ma B.P,especially during the recent 2,000 years,many famous ancient cities having been abandoned and the south route of the Silk Road has been moved southward.This study illustrates the capability of the remote sensing data(radar data,topographic data and optical images)and historical materials,in mapping the ancient drainage networks.A major paleodrainage system of Keriya River has linked the Kunlun Mountains to the Tienshan Mountains,possibly as far back as the early Pleistocene.The Keriya River will have important implications for not only the understanding of the paleoenvironments and paleoclimates of Tarim Basin from the early Pleistocene to the Holocene,but also the changes of the Silk Road.展开更多
A landslide that probably dates to the end of the Pleistocene has been found in Sierra County. The feature consists of three sub-parallel segments, covering an area about 8 km wide and 10 km long. The head of the slid...A landslide that probably dates to the end of the Pleistocene has been found in Sierra County. The feature consists of three sub-parallel segments, covering an area about 8 km wide and 10 km long. The head of the slide deposits consists of a northeast-trending paleochannel forming an inverted topography. The paleochannel deposits contain many boulders with sizes up to 1.5 meter diameter, indicating flow rate as high as 100 m3/s. The paleochannel ridge is mostly underlain by the hidden lateral contact of the Cretaceous Crevasse Canyon Formation and by the Tertiary Love Ranch and is sharply defined by Yoast Draw valley that cuts a water gap through the 25 m high inverted ridge. The landslide body consists of Love Ranch Formation overlain by a substantial cover of Quaternary fanglomerate. A series of northwest-trending faults have influenced the landslide. The broad western upslope segment of the slide has been washed away, leaving only trace evidence of a landslide. A low slide plane angle of less than 1% slope suggests a seismic trigger.展开更多
文摘According to buried depth, the Yellow Rver's Paleochannels can be divided into ground Paleochannels (buried depth 0-8m) and shallowburied Paleochannels theried depth 8-50m). Each of them can be roughly divided into three major Paleochannel belts, stretching Parallel with each other from SW to NE. Sedimentary layers of the paleochannels were mainly made up by sand levee of meanders or natural leavee deposits, and the flooding sedments were found bebeen the layers. The paleochannels in North Shadong Plain were formed in three stags; stage I (buried depth 50-15m) in later period of late Pleistocene-early period of Holocene, stag II (20-8m) in earlymiddle period of HOlocene; and stag III (8-0m) in midddle-late period of Holocene.
基金The National Natural Science Foundation of China under grant No. 40876034the National Basic Research Program under grant No. 1212010611401
文摘Quantitative morphologic analysis of shallowly buried, dendritic channel systems in the continental shelf off the abandoned Huanghe River （Yellow River） mouth has been made based on interpretation of high resolution seismic profiles, with the attempt to estimate the paleo-hydrologic parameters when the incised-channels formed, then assess the paleoenvironment. The results indicate that the buried channel systems were formed about 44 cal ka BP when the shelf was subaerially exposed and subsequently drowned and filled during the Holocene transgression with the sea level rise continuously. The study area has experienced the processes from fluvial and estuarine to fully marine.
基金This research was supported by the States Key Program of National Natural Science of China (grants No. 40830420)the Special Funds Projects for Basic Scientific Research Business Expenses of Mineral Resources, Research Institutes in Chinese Academy of Geological Sciences (No. KK1924)the National Key R&D Program of China (grants No. 2018YFA0606401)
文摘The fluctuation pattern of China’s civilization can be ascribed to climate change and historical geopolitical variations. The ancient Silk Road served as the most prosperous route connecting East Asia and Europe during Han Dynasty(206 BC–220 AD) and Sui-Tang Dynasties(581–907 AD), but was deserted in Wei, Jin, Northern and Southern dynasties(220–580 AD), of which the Tarim Basin was a key area. However, our understanding about the decline of the route during this period remains limited. Here, we present an ~7-year resolution record based on optically stimulated luminescence(OSL) age-depth model(ca. 120 BC–750 AD) from Luntai(LT) profile, about 5 km from the modern Tarim River, which fed the ancient oases, to assess the potential causes on the documented decline of the ancient Silk Road between Late Han and Sui dynasties. In this study, five episodes of hydrological change were identified by combining grain size, magnetic susceptibility, geochemistry and TOC/TN contents. Our reconstruction reveals that cold and wet climate dominated at 120 BC–50 AD and 550–750 AD, respectively, indicated by strong hydrodynamic conditions. Relatively warm and humid climate occurred at 120–550 AD, between Eastern Han and Sui-Tang dynasties, indicating a better and more suitable local environment. A comparison between the studied region and other areas of China demonstrates that the paleoclimatic variations in eastern and western China exhibit rough discrepancies, and the hydrological conditions in arid region is inconsistent with the decline of ancient Silk Road in the northern Tarim Basin. We suggest that political and societal factors are the key issues that caused the interruption of Silk Road during Wei, Jin, Northern and Southern dynasties, such as the co-occurrence of societal crises, turmoil and division in eastern China, rather than the deteriorating climatic condition in the northern Tarim basin.
基金funded by the National Science Foundation of China(Nos.2022XAGG0400,42207202,42293351)the Open Fund of the Key Laboratory of Earth Fissures Geological Disaster,Ministry of Natural Resources,Geological Survey of Jiangsu Province,China(No.EFGD20240604)+2 种基金the Open Fund of the Observation and Research Station of Ground Fissure and Land Subsidence,Ministry of Natural Resources(No.GKF2024-06)the Fundamental Research Funds for the Central Universities of China University of Geosciences,Beijing(No.2-9-2021-014)the Fundamental Research Funds for the Central Universities of Chang'an University(No.300102264501-01)。
文摘Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have developed,of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui,Hebei Province,with a total length of 3 km,a dominant strike of NE78°,and nearly upright in the shallow layer.The surface damage observed in this fissure primarily manifests as beaded pits,and its activity shows distinct segmentation characteristics.On the trench profiles,the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to-3 m.An evident flexure is observed in the strata at depths ranging from-4.5 to-7 m.The drilling profile reveals that there is an absence of dislocations in the deeper strata.Nonetheless,the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area,underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure.Firstly,the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults.The interplay of the regional stress field,fault block movement,and fault activity played pivotal roles in driving the development of this paleochannel.Secondly,the paleochannel exerts a controlling influence on the development location and severity of the fissure.During pumping,the confined aquifer within the paleochannel undergoes water loss and compression,resulting in the formation of a surface subsidence funnel.When the tensile stress surpasses the soil's tensile strength at the funnel's edge,the soil fractures give rise to a ground fissure.Finally,large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture,emerge,and expand.This paper provides a heretofore generally unknown example,promotes research on the mechanisms of paleochannel-controlled fissures,and has guiding significance for disaster prevention and reduction in this area.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China(Grant No.41271427)and the National Key Technology R&D Program(Grant No.2012BAH27B05).
文摘Keriya River,one of the ancient Four Green Corridors in the Tarim Basin,recording the changes of climate-environment and the ancient Silk Road of the region.According to the archaeological data,historical materials and paleoclimates information,its eeo-environment and climate have taken great changes since the 1.09 Ma B.P,especially during the recent 2,000 years,many famous ancient cities having been abandoned and the south route of the Silk Road has been moved southward.This study illustrates the capability of the remote sensing data(radar data,topographic data and optical images)and historical materials,in mapping the ancient drainage networks.A major paleodrainage system of Keriya River has linked the Kunlun Mountains to the Tienshan Mountains,possibly as far back as the early Pleistocene.The Keriya River will have important implications for not only the understanding of the paleoenvironments and paleoclimates of Tarim Basin from the early Pleistocene to the Holocene,but also the changes of the Silk Road.
文摘A landslide that probably dates to the end of the Pleistocene has been found in Sierra County. The feature consists of three sub-parallel segments, covering an area about 8 km wide and 10 km long. The head of the slide deposits consists of a northeast-trending paleochannel forming an inverted topography. The paleochannel deposits contain many boulders with sizes up to 1.5 meter diameter, indicating flow rate as high as 100 m3/s. The paleochannel ridge is mostly underlain by the hidden lateral contact of the Cretaceous Crevasse Canyon Formation and by the Tertiary Love Ranch and is sharply defined by Yoast Draw valley that cuts a water gap through the 25 m high inverted ridge. The landslide body consists of Love Ranch Formation overlain by a substantial cover of Quaternary fanglomerate. A series of northwest-trending faults have influenced the landslide. The broad western upslope segment of the slide has been washed away, leaving only trace evidence of a landslide. A low slide plane angle of less than 1% slope suggests a seismic trigger.
