Abundant well-preserved Late Jurassic-Early Cretaceous radiolarian fossils were extracted from 31 bedded green chert samples collected from Zhilong section,Gyangse,southern Tibet.This
Qilian orogenic belt is a typical orogenic belt formed by polycyclic collisions between the North China plate and Qaidam microplate. Qilian ocean originated from the rift of the late Proterozoic Rodinia continent(Pang...Qilian orogenic belt is a typical orogenic belt formed by polycyclic collisions between the North China plate and Qaidam microplate. Qilian ocean originated from the rift of the late Proterozoic Rodinia continent(Pangea\|850), evolved through rift basin and became an archipelagic ocean in the Caledonian stage. The Lower Proterozoic strata in Qilian area are mid\|high\|rank metamorphic rocks that constitute the metamorphic basement of the area. The “Huangyuan Movement" (in South Qilian and Central Qilian) and "Alashan Movement" (in North Qilian) in the latest Late Proterozoic formed a regional unconformity. The middle Proterozoic in the area are mudstones and carbonate rocks with stromatolites and ooids. The Qingbaikou System of the upper Proterozoic in the North Qilian and Corridor region is also mudstone and carbonate rock with stromatolites. The Qingbaikou System in Central Qilian is sandstones and mudstones. There are alkaline and tholeiite in the Sinian System in North Qilian and Corridor. The contact between Qingbaikou System and Sinian System is a regional unconformity (Quanji Movement). Qilian ocean began to rift away in Caledonian tectonic stage on the Pre\|Sinian basement.展开更多
Most of the massive sulfide deposits (VMS) occurring from Precambrian to Cenozoic throughout the world has been subsequently metamorphosed at various grades. Thus, all the original textures have been either completely...Most of the massive sulfide deposits (VMS) occurring from Precambrian to Cenozoic throughout the world has been subsequently metamorphosed at various grades. Thus, all the original textures have been either completely destroyed or strongly modified. However, there are a very few examples, rather younger deposits such as late Cretaceous Turkish VMS deposits and Miocene Kuroko deposits of Japan in which representative and original ore textures are preserved. The Turkish massive sulfide deposits are mainly Cu-Zn-Pb-type and entirely hosted by Late Cretaceous felsic volcanic rocks within a paleoarc geotectonic setting.展开更多
The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin,Gansu,are described here.The assemblage consists of 16 species of 13 genera belonging to 7 families,including one new species and on...The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin,Gansu,are described here.The assemblage consists of 16 species of 13 genera belonging to 7 families,including one new species and one taxon previously unknown from China.Among them 5 genera are Oligocene holdovers and 11 genera/species are known to make their first appearances in Early Miocene,indicating an Early Miocene age for the Gucheng Fauna.The absence of Oligocene survivors such as Tataromys,Yindirtemys,Eucricetodon and Tachyoryctoides,which usually occur in the Xiejian age of Early Miocene,and the presence of newcomers Protalactaga,Megacricetodon and Gobicricetodon,that made their first appearance only in the Shanwangian age of late Early Miocene,suggest that the Gucheng Fauna is of a later age of Early Miocene.The new species,Sinolagomys guchengensis,showing more derived morphology than in S.ulunguensis,seems to support an assessment of the fauna in Shanwangian age.Thus,the Gucheng Fauna may belong to late Early Miocene Shanwangian,partially equivalent to MN 3/4 of the European land mammal zonation.Ecological analysis of the fauna indicates that the palaeoecological condition of the Gucheng area might still be a predominantly arid shrub-steppe in late Early Miocene.展开更多
Jehol Biota in western Liaoning and northern Hebei has been a hot topic of global concern,a large number of exquisite fossils were found in Yixian group Sihetun,such as Sinosauropteryx,Protarchaeopteryx, Caudipteryx a...Jehol Biota in western Liaoning and northern Hebei has been a hot topic of global concern,a large number of exquisite fossils were found in Yixian group Sihetun,such as Sinosauropteryx,Protarchaeopteryx, Caudipteryx and Confuciusornis.Scientists consider the discovering of Sinosauropteryx discovered so far as the earliest ancestor of birds.According to the dates of root layer,we can see warm and humid,lakes展开更多
The Cretaceous is a typical period for studying the greenhouse climate and the earth system interactions, and the world’s most extensive terrestrial strata are mainly in East Asia, especially in China. Continental se...The Cretaceous is a typical period for studying the greenhouse climate and the earth system interactions, and the world’s most extensive terrestrial strata are mainly in East Asia, especially in China. Continental sediments can effectively reflect the paleo-climate change, but the previous studies of the Late Cretaceous paleo-climate, based on the combined characteristics of continental climate-sensitive sediments, were barely found in China. To obtain the Late Cretaceous paleo-climate characteristics of China, the distribution characteristics of different continental climate-sensitive sediment types in the early, middle and Late Cretaceous in China were studied in detail. According to the distribution and combination characteristics and types of continental climate-sensitive sediments, seven climate types can be divided: 1) warm-humid and warm-dry climate;2) hot and dry climate;3) hot-dry and arid climate;4) hot-dry and semiarid climate;5) hot-dry and hot-wet climate;6) hot-dry and warm-humid climate;7) hot-dry and warm-dry climate. The results show that in the early Late Cretaceous, the hot and dry climate was the most widespread, followed by warm-humid and warm-dry climate, but the climate was drier than the paleo-climate of the previous study of Early Cretaceous. Hot and dry climate zone became wider in the Coniacian and Maastrichtian;furthermore, it covered Xinjiang to the east of China from east to west after the Santonian Period. The hot-dry and semiarid climate zone was nearly latitudinally distributed from the northwest to the southeast and it shows a further increase in aridification. Global geological events, paleogeographic features and regional tectonic evolution had significant impacts on the paleoclimate of China in the Late Cretaceous, such as global eruptive events of volcanoes led to the temperature increase in China in the early Late Cretaceous;coastal mountain ranges in southeastern China led to the drying of the Late Cretaceous climate in southern China;Xuefeng Mountains, Wuling Mountains, Nanling Mountains and Tai-hang Mountains were the dividing line between the hot and dry climate zone and hot-dry and arid climate zone in the early Late Cretaceous, and Altun Mountains were the dividing line between the southeastern section of the hot and dry climate zone in western China in the middle Late Cretaceous.展开更多
We examined sediment samples from twenty-four stations in the Indo-Pacific warm pool(IPWP)region. Our objective is to provide a better understanding of changes in the IPWP and related tropical climatic phenomena such ...We examined sediment samples from twenty-four stations in the Indo-Pacific warm pool(IPWP)region. Our objective is to provide a better understanding of changes in the IPWP and related tropical climatic phenomena such as East Asian-Australian monsoon and El Ni(?)o-Southern Oscillation(ENSO),through improving spatial coverage of proxy records.In order展开更多
The Pamir plateau may have been a westward continuation of Tibet plateau.Meanwhile,the Rushan-Pshart suture is correlative to the Bangong-Nujiang suture of Tibet,and the Central Pamir is the lateral equivalent of the ...The Pamir plateau may have been a westward continuation of Tibet plateau.Meanwhile,the Rushan-Pshart suture is correlative to the Bangong-Nujiang suture of Tibet,and the Central Pamir is the lateral equivalent of the Qiangtang Block.We present the first detailed LA-ICPMS zircon U-Pb chronology,major and trace element,and Lu-Hf isotope geochemistry of Taxkorgan two-mica monzogranite to illuminate the Tethys evolution in central Pamir.LA-ICPMS zircon U-Pb dating shows that two-mica monzogranite is emplaced in the Cretaceous(118 Ma).Its geochemical features are similar to S-type granite,with enrichment in LREEs and negative Ba,Sr,Zr and Ti anomalies.All the samples show negative zirconεHf(t)values ranging from 17.0 to 12.5(mean 14.5),corresponding to crustal Hf model(TDM2)ages of 1906 to 2169 Ma.It is inferred that these granitoids are derived from partial melting of peliticmetasedimentary rocks analogous to the Paleoproterozoic Bulunkuole Group,predominantly with muscovite schists component.Based on the petrological and geochemical data presented above,together with the regional geology,this work provides new insights that Bangong Nujiang Ocean closed in Early Cretaceous(120114 Ma).展开更多
Clay mineral analyses of the Middle Jurassic through the Early Cretaceous sedimentary rocks from the Guangyuan-Jian’ge section,Sichuan Basin (southwestern China)were undertaken in this article, which is aiming to rec...Clay mineral analyses of the Middle Jurassic through the Early Cretaceous sedimentary rocks from the Guangyuan-Jian’ge section,Sichuan Basin (southwestern China)were undertaken in this article, which is aiming to reconstruct the palaeoclimate of the area.Relative contents of the four clay minerals, smectite(25.8%-1.0%-46.8%),kaolinite(31.0%- 12.5%-12.6%),illite(31.3%-68.0%-28.0%)and chlorite(11.8%-8.5%-12.6%),as the target clay minerals,illite crystalline index(0.26-0.31-0.27)and chemical index(0.62-0.66-0.79)are used as indicator of paleoclimate.It is indicated that changes of展开更多
In the late Qing Dynasty and the early R epublic of China,foreign invasion made China suffer from an unprecedented humiliation,and the W estern powers initiated a commercial intrusion by forcing China to sign unequal ...In the late Qing Dynasty and the early R epublic of China,foreign invasion made China suffer from an unprecedented humiliation,and the W estern powers initiated a commercial intrusion by forcing China to sign unequal treaties and open treaty ports. From this perspective,a deep exploration is made to study the corresponding influence and its function. The rule shows that the developing route of national politics,economy and culture can determine the trend of the development of overseas Chinese problem; in addition,it objectively reflects that the social nature is vital to overseas Chinese problem.展开更多
文摘Abundant well-preserved Late Jurassic-Early Cretaceous radiolarian fossils were extracted from 31 bedded green chert samples collected from Zhilong section,Gyangse,southern Tibet.This
文摘Qilian orogenic belt is a typical orogenic belt formed by polycyclic collisions between the North China plate and Qaidam microplate. Qilian ocean originated from the rift of the late Proterozoic Rodinia continent(Pangea\|850), evolved through rift basin and became an archipelagic ocean in the Caledonian stage. The Lower Proterozoic strata in Qilian area are mid\|high\|rank metamorphic rocks that constitute the metamorphic basement of the area. The “Huangyuan Movement" (in South Qilian and Central Qilian) and "Alashan Movement" (in North Qilian) in the latest Late Proterozoic formed a regional unconformity. The middle Proterozoic in the area are mudstones and carbonate rocks with stromatolites and ooids. The Qingbaikou System of the upper Proterozoic in the North Qilian and Corridor region is also mudstone and carbonate rock with stromatolites. The Qingbaikou System in Central Qilian is sandstones and mudstones. There are alkaline and tholeiite in the Sinian System in North Qilian and Corridor. The contact between Qingbaikou System and Sinian System is a regional unconformity (Quanji Movement). Qilian ocean began to rift away in Caledonian tectonic stage on the Pre\|Sinian basement.
文摘Most of the massive sulfide deposits (VMS) occurring from Precambrian to Cenozoic throughout the world has been subsequently metamorphosed at various grades. Thus, all the original textures have been either completely destroyed or strongly modified. However, there are a very few examples, rather younger deposits such as late Cretaceous Turkish VMS deposits and Miocene Kuroko deposits of Japan in which representative and original ore textures are preserved. The Turkish massive sulfide deposits are mainly Cu-Zn-Pb-type and entirely hosted by Late Cretaceous felsic volcanic rocks within a paleoarc geotectonic setting.
文摘The micromammal fossils collected from the Shangzhuang Formation of the Linxia Basin,Gansu,are described here.The assemblage consists of 16 species of 13 genera belonging to 7 families,including one new species and one taxon previously unknown from China.Among them 5 genera are Oligocene holdovers and 11 genera/species are known to make their first appearances in Early Miocene,indicating an Early Miocene age for the Gucheng Fauna.The absence of Oligocene survivors such as Tataromys,Yindirtemys,Eucricetodon and Tachyoryctoides,which usually occur in the Xiejian age of Early Miocene,and the presence of newcomers Protalactaga,Megacricetodon and Gobicricetodon,that made their first appearance only in the Shanwangian age of late Early Miocene,suggest that the Gucheng Fauna is of a later age of Early Miocene.The new species,Sinolagomys guchengensis,showing more derived morphology than in S.ulunguensis,seems to support an assessment of the fauna in Shanwangian age.Thus,the Gucheng Fauna may belong to late Early Miocene Shanwangian,partially equivalent to MN 3/4 of the European land mammal zonation.Ecological analysis of the fauna indicates that the palaeoecological condition of the Gucheng area might still be a predominantly arid shrub-steppe in late Early Miocene.
文摘Jehol Biota in western Liaoning and northern Hebei has been a hot topic of global concern,a large number of exquisite fossils were found in Yixian group Sihetun,such as Sinosauropteryx,Protarchaeopteryx, Caudipteryx and Confuciusornis.Scientists consider the discovering of Sinosauropteryx discovered so far as the earliest ancestor of birds.According to the dates of root layer,we can see warm and humid,lakes
基金A project funded by National Natural Science Foundation of China(41572093)Central Young College Teachers Fund Project (3142020002)Supported by the Fundamental Research Funds for the Central Universities(3142021004)。
文摘The Cretaceous is a typical period for studying the greenhouse climate and the earth system interactions, and the world’s most extensive terrestrial strata are mainly in East Asia, especially in China. Continental sediments can effectively reflect the paleo-climate change, but the previous studies of the Late Cretaceous paleo-climate, based on the combined characteristics of continental climate-sensitive sediments, were barely found in China. To obtain the Late Cretaceous paleo-climate characteristics of China, the distribution characteristics of different continental climate-sensitive sediment types in the early, middle and Late Cretaceous in China were studied in detail. According to the distribution and combination characteristics and types of continental climate-sensitive sediments, seven climate types can be divided: 1) warm-humid and warm-dry climate;2) hot and dry climate;3) hot-dry and arid climate;4) hot-dry and semiarid climate;5) hot-dry and hot-wet climate;6) hot-dry and warm-humid climate;7) hot-dry and warm-dry climate. The results show that in the early Late Cretaceous, the hot and dry climate was the most widespread, followed by warm-humid and warm-dry climate, but the climate was drier than the paleo-climate of the previous study of Early Cretaceous. Hot and dry climate zone became wider in the Coniacian and Maastrichtian;furthermore, it covered Xinjiang to the east of China from east to west after the Santonian Period. The hot-dry and semiarid climate zone was nearly latitudinally distributed from the northwest to the southeast and it shows a further increase in aridification. Global geological events, paleogeographic features and regional tectonic evolution had significant impacts on the paleoclimate of China in the Late Cretaceous, such as global eruptive events of volcanoes led to the temperature increase in China in the early Late Cretaceous;coastal mountain ranges in southeastern China led to the drying of the Late Cretaceous climate in southern China;Xuefeng Mountains, Wuling Mountains, Nanling Mountains and Tai-hang Mountains were the dividing line between the hot and dry climate zone and hot-dry and arid climate zone in the early Late Cretaceous, and Altun Mountains were the dividing line between the southeastern section of the hot and dry climate zone in western China in the middle Late Cretaceous.
文摘We examined sediment samples from twenty-four stations in the Indo-Pacific warm pool(IPWP)region. Our objective is to provide a better understanding of changes in the IPWP and related tropical climatic phenomena such as East Asian-Australian monsoon and El Ni(?)o-Southern Oscillation(ENSO),through improving spatial coverage of proxy records.In order
基金Project(41802103)supported by the National Natural Science Foundation of ChinaProject(2017YFC0601403)supported by the National Key R&D Program of China
文摘The Pamir plateau may have been a westward continuation of Tibet plateau.Meanwhile,the Rushan-Pshart suture is correlative to the Bangong-Nujiang suture of Tibet,and the Central Pamir is the lateral equivalent of the Qiangtang Block.We present the first detailed LA-ICPMS zircon U-Pb chronology,major and trace element,and Lu-Hf isotope geochemistry of Taxkorgan two-mica monzogranite to illuminate the Tethys evolution in central Pamir.LA-ICPMS zircon U-Pb dating shows that two-mica monzogranite is emplaced in the Cretaceous(118 Ma).Its geochemical features are similar to S-type granite,with enrichment in LREEs and negative Ba,Sr,Zr and Ti anomalies.All the samples show negative zirconεHf(t)values ranging from 17.0 to 12.5(mean 14.5),corresponding to crustal Hf model(TDM2)ages of 1906 to 2169 Ma.It is inferred that these granitoids are derived from partial melting of peliticmetasedimentary rocks analogous to the Paleoproterozoic Bulunkuole Group,predominantly with muscovite schists component.Based on the petrological and geochemical data presented above,together with the regional geology,this work provides new insights that Bangong Nujiang Ocean closed in Early Cretaceous(120114 Ma).
文摘Clay mineral analyses of the Middle Jurassic through the Early Cretaceous sedimentary rocks from the Guangyuan-Jian’ge section,Sichuan Basin (southwestern China)were undertaken in this article, which is aiming to reconstruct the palaeoclimate of the area.Relative contents of the four clay minerals, smectite(25.8%-1.0%-46.8%),kaolinite(31.0%- 12.5%-12.6%),illite(31.3%-68.0%-28.0%)and chlorite(11.8%-8.5%-12.6%),as the target clay minerals,illite crystalline index(0.26-0.31-0.27)and chemical index(0.62-0.66-0.79)are used as indicator of paleoclimate.It is indicated that changes of
基金the staged achievement of The Project supported by the Special Foundation for High-level Scientists of Guangdong Province(Grant No.11200-52010005)The Construction Project of Philosophy and Social Sciences in Guangdong Province(Grant No.GD12XHQ01)
文摘In the late Qing Dynasty and the early R epublic of China,foreign invasion made China suffer from an unprecedented humiliation,and the W estern powers initiated a commercial intrusion by forcing China to sign unequal treaties and open treaty ports. From this perspective,a deep exploration is made to study the corresponding influence and its function. The rule shows that the developing route of national politics,economy and culture can determine the trend of the development of overseas Chinese problem; in addition,it objectively reflects that the social nature is vital to overseas Chinese problem.
