The magnetostratigraphic sampling was carried out respectively in the inside part (14 cm away from the section surface along the bed) and outside part (5 cm away from the section surface along the bed) with no interva...The magnetostratigraphic sampling was carried out respectively in the inside part (14 cm away from the section surface along the bed) and outside part (5 cm away from the section surface along the bed) with no interval at the same bed (Bed 27) which the paleobiology boundary (PBB) of A and D sections lies in of Meishan, Changxing. This research shows that the deep samples suffered slighter secondary magnetization than the shallow ones did and in comparison with D section ’s samples, the samples of A section sustained slighter secondary magnetization. On the bases of the data, the secondary magnetization influence of which is relatively weak, this paper obtains the conclusion that the bed, in which the paleobiology boundary lies, lies within the reverse polarity subzone.展开更多
30 July–14 August 2011,Novosibirsk,Russia Numerous Neoproterozoic sedimentary basins were developed on the Siberian Craton,and the Siberian successions play an important role in the Neoproterozoic biostratigraphy,che...30 July–14 August 2011,Novosibirsk,Russia Numerous Neoproterozoic sedimentary basins were developed on the Siberian Craton,and the Siberian successions play an important role in the Neoproterozoic biostratigraphy,chemostratigraphy,basin dynamics,and petroleum exploration.To take advantage of Siberia’s rich geological and paleobiological heritages.展开更多
The Ediacaran to Cambrian transition witnessed great biological and environmental turnovers from the Precambrian to Phanerozoic.These changes are also reflected by the fossil records during that time.However,the fossi...The Ediacaran to Cambrian transition witnessed great biological and environmental turnovers from the Precambrian to Phanerozoic.These changes are also reflected by the fossil records during that time.However,the fossil distribution was highly heterogenous.While diverse fossils were constantly found from the shallow shelf including restricted basins,reports from deep-water areas,which are characterized by chert-dominated formations straddling the Ediacaran-Cambrian boundary,were scarce.Among them was the Liuchapo Formation that has been considered barren.In this study,a fossiliferous assemblage was found from the Liuchapo Formation in east Guizhou Province,South China.This assemblage comprises Palaeopascichnus jiumenensis,Horodyskia minor,multicellular algae that possibly related with red algae,cyanobacteria,sponge spicules,small shelly fossils,membrane structures of uncertain affinity,and fossils with structures resemble the Ediacaran Megasphaera.Palaeopascichnus and Horodyskia have been widely reported and abundant in the Liuchapo Formation and equivalents,while the others have seldomly,or never,been found from this formation or,more widely,the deep-water chert of transitional interval.The discovery not only contributes to the rare paleontological records preserved in deep-water sediments,but also expanded the geographic distribution of the fossils,providing new materials of biological diversity during this critical interval.展开更多
A new species of the probable calcareous alga Amsassia,A.koreanensis,is recognized from the Duwibong Formation(Middle Ordovician,Darriwilian)of the Taebaeksan Basin in mid-eastern Korea.This is the first report of the...A new species of the probable calcareous alga Amsassia,A.koreanensis,is recognized from the Duwibong Formation(Middle Ordovician,Darriwilian)of the Taebaeksan Basin in mid-eastern Korea.This is the first report of the genus from the Korean Peninsula,expanding its geographical range to the eastern Sino-Korean Block.The new species also occurs in the Xiazhen Formation(Upper Ordovician,Katian)at Zhuzhai in the South China Block.Amsassia koreanensis is the smallest species of this modular genus,having a maximum module diameter of 0.28 ram.Module increase is by bipartite,tripartite and quadripartite types of longitudinal axial fission,but unlike other species of the genus,quadripartite fission is common.The types of fission are comparable to those in some Tetradiida(now Prismostylales,florideophycean rhodophyte algae),although the processes of fission are different.The distribution of A.koreanensis further strengthens the biogeographical connection between the Sino-Korean and South China blocks,suggesting that these two paleocontinents were located closer together during the Middle to Late Ordovician than previously speculated.展开更多
The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated...The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated either by actively metabolizing cells of anaerobic microbes and aerobic halophilic archaea or by their inactive biomass.Aerobic halophilic bacteria are widely distributed in(proto-)dolomite-depositing evaporitic environments and their biomass might serve as a template for the crystallization of protodolomite.To test this hypothesis,carbonation experiments were conducted using dead biomass of an aerobic halophilic bacterium(Exiguobacterium sp.strain JBHLT-3).Our results show that dead biomass of JBHLT-3 can accelerate Mg2+uptake in carbonate mineral precipitates.In addition,the amount of Mg incorporated into Ca-Mg carbonates is proportional to the concentration of biomass.High Mg-calcite is produced with 0.25 or 0.5 g/L biomass,whereas protodolomite forms with 1 g/L biomass.This is confirmed by the main Raman peak of Ca-Mg carbonates,which shifts towards higher wavenumbers with increased Mg substitution.Microbial cells and their imprints are preserved on the surface of high Mg-calcite and protodolomite.Hence,this study furthers our understanding of the dolomitization within buried and dead microbial mats,which provides useful insights into the origin of ancient dolomite.展开更多
Compte Rendu,Deuxieme Congres pour l’avancement desetudes de Stratigraphie Carbonifere,Heerlen,septembre 1935,publie sous la redaction de W.J.Jongmans,tom,Ⅰ-Ⅲ,1937 1937.Gebrs.Van Aelst-Maestricht.
Geobiology is a new discipline on the crossing interface between earth science and life science, and aims to understand the in- teraction and co-evolution between organisms and environments. On the basis of the latest...Geobiology is a new discipline on the crossing interface between earth science and life science, and aims to understand the in- teraction and co-evolution between organisms and environments. On the basis of the latest international achievements, the new data presented in the Beijing geobiology forum sponsored by Chinese Academy of Sciences in 2013, and the papers in this special issue, here we present an overview of the progress and perspectives on three important frontiers, including geobiology of the critical periods in Earth history, geomicrobes and their responses and feedbacks to global environmental changes, and geobiology in extreme environments. Knowledge is greatly improved about the close relationship of some significant biotic events such as origin, radiation, extinction, and recovery of organisms with the deep Earth processes and the resultant envi- ronmental processes among oceans, land, and atmosphere in the critical periods, although the specific dynamics of the co-evolution between ancient life and paleoenvironments is still largely unknown. A variety of geomicrobial functional groups were found to respond sensitively to paleoenvironmental changes, which enable the establishment of proxies for paleoenvi- ronmental reconstruction, and to play active roles on the Earth environmental changes via elemental biogeochemical cycles and mineral bio-transforrnations, but to be deciphered are the mechanisms of these functional groups that change paleoenvi- ronmental conditions. Microbes of potential geobiology significance were found and isolated from some extreme environments with their biological properties partly understood, but little is known about their geobiological functions to change Earth envi- ronments. The biotic processes to alter or modify the environments are thus proposed to be the very issue geobiology aims to decipher in the future. Geobiology will greatly extend the temporal and spatial scope of biotic research on Earth and beyond. It has great potential of application in the domains of resource exploration and global change. To achieve these aims needs coor- dinative multidisciplinary studies concerning geomicrobiology and related themes, database and modeling of biogeochemical cycles, typical geological environments, and coupling of biological, physical, and chemical processes.展开更多
文摘The magnetostratigraphic sampling was carried out respectively in the inside part (14 cm away from the section surface along the bed) and outside part (5 cm away from the section surface along the bed) with no interval at the same bed (Bed 27) which the paleobiology boundary (PBB) of A and D sections lies in of Meishan, Changxing. This research shows that the deep samples suffered slighter secondary magnetization than the shallow ones did and in comparison with D section ’s samples, the samples of A section sustained slighter secondary magnetization. On the bases of the data, the secondary magnetization influence of which is relatively weak, this paper obtains the conclusion that the bed, in which the paleobiology boundary lies, lies within the reverse polarity subzone.
文摘30 July–14 August 2011,Novosibirsk,Russia Numerous Neoproterozoic sedimentary basins were developed on the Siberian Craton,and the Siberian successions play an important role in the Neoproterozoic biostratigraphy,chemostratigraphy,basin dynamics,and petroleum exploration.To take advantage of Siberia’s rich geological and paleobiological heritages.
基金supported by the Natural Science Foundation of China(No.41430101)。
文摘The Ediacaran to Cambrian transition witnessed great biological and environmental turnovers from the Precambrian to Phanerozoic.These changes are also reflected by the fossil records during that time.However,the fossil distribution was highly heterogenous.While diverse fossils were constantly found from the shallow shelf including restricted basins,reports from deep-water areas,which are characterized by chert-dominated formations straddling the Ediacaran-Cambrian boundary,were scarce.Among them was the Liuchapo Formation that has been considered barren.In this study,a fossiliferous assemblage was found from the Liuchapo Formation in east Guizhou Province,South China.This assemblage comprises Palaeopascichnus jiumenensis,Horodyskia minor,multicellular algae that possibly related with red algae,cyanobacteria,sponge spicules,small shelly fossils,membrane structures of uncertain affinity,and fossils with structures resemble the Ediacaran Megasphaera.Palaeopascichnus and Horodyskia have been widely reported and abundant in the Liuchapo Formation and equivalents,while the others have seldomly,or never,been found from this formation or,more widely,the deep-water chert of transitional interval.The discovery not only contributes to the rare paleontological records preserved in deep-water sediments,but also expanded the geographic distribution of the fossils,providing new materials of biological diversity during this critical interval.
基金supported by a grant from 2015 Research Fund of Andong National University
文摘A new species of the probable calcareous alga Amsassia,A.koreanensis,is recognized from the Duwibong Formation(Middle Ordovician,Darriwilian)of the Taebaeksan Basin in mid-eastern Korea.This is the first report of the genus from the Korean Peninsula,expanding its geographical range to the eastern Sino-Korean Block.The new species also occurs in the Xiazhen Formation(Upper Ordovician,Katian)at Zhuzhai in the South China Block.Amsassia koreanensis is the smallest species of this modular genus,having a maximum module diameter of 0.28 ram.Module increase is by bipartite,tripartite and quadripartite types of longitudinal axial fission,but unlike other species of the genus,quadripartite fission is common.The types of fission are comparable to those in some Tetradiida(now Prismostylales,florideophycean rhodophyte algae),although the processes of fission are different.The distribution of A.koreanensis further strengthens the biogeographical connection between the Sino-Korean and South China blocks,suggesting that these two paleocontinents were located closer together during the Middle to Late Ordovician than previously speculated.
基金jointly supported by the National Natural Science Foundation of China(Nos.42272046,42072336 and 41772362)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB26000000)+1 种基金the 111 Project of China(No.BP0820004)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUGCJ1703)。
文摘The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated either by actively metabolizing cells of anaerobic microbes and aerobic halophilic archaea or by their inactive biomass.Aerobic halophilic bacteria are widely distributed in(proto-)dolomite-depositing evaporitic environments and their biomass might serve as a template for the crystallization of protodolomite.To test this hypothesis,carbonation experiments were conducted using dead biomass of an aerobic halophilic bacterium(Exiguobacterium sp.strain JBHLT-3).Our results show that dead biomass of JBHLT-3 can accelerate Mg2+uptake in carbonate mineral precipitates.In addition,the amount of Mg incorporated into Ca-Mg carbonates is proportional to the concentration of biomass.High Mg-calcite is produced with 0.25 or 0.5 g/L biomass,whereas protodolomite forms with 1 g/L biomass.This is confirmed by the main Raman peak of Ca-Mg carbonates,which shifts towards higher wavenumbers with increased Mg substitution.Microbial cells and their imprints are preserved on the surface of high Mg-calcite and protodolomite.Hence,this study furthers our understanding of the dolomitization within buried and dead microbial mats,which provides useful insights into the origin of ancient dolomite.
文摘Compte Rendu,Deuxieme Congres pour l’avancement desetudes de Stratigraphie Carbonifere,Heerlen,septembre 1935,publie sous la redaction de W.J.Jongmans,tom,Ⅰ-Ⅲ,1937 1937.Gebrs.Van Aelst-Maestricht.
基金supported by the project on Strategy Development of Geobiology and Astrobiology from Chinese Academy of Sciences, National Basic Research Program of China (Grant No. 2011CB808800)National Natural Science Foundation of China (Grant No. 41330103)the "111" Program from Ministry of Education of China (Grant No. B08030)
文摘Geobiology is a new discipline on the crossing interface between earth science and life science, and aims to understand the in- teraction and co-evolution between organisms and environments. On the basis of the latest international achievements, the new data presented in the Beijing geobiology forum sponsored by Chinese Academy of Sciences in 2013, and the papers in this special issue, here we present an overview of the progress and perspectives on three important frontiers, including geobiology of the critical periods in Earth history, geomicrobes and their responses and feedbacks to global environmental changes, and geobiology in extreme environments. Knowledge is greatly improved about the close relationship of some significant biotic events such as origin, radiation, extinction, and recovery of organisms with the deep Earth processes and the resultant envi- ronmental processes among oceans, land, and atmosphere in the critical periods, although the specific dynamics of the co-evolution between ancient life and paleoenvironments is still largely unknown. A variety of geomicrobial functional groups were found to respond sensitively to paleoenvironmental changes, which enable the establishment of proxies for paleoenvi- ronmental reconstruction, and to play active roles on the Earth environmental changes via elemental biogeochemical cycles and mineral bio-transforrnations, but to be deciphered are the mechanisms of these functional groups that change paleoenvi- ronmental conditions. Microbes of potential geobiology significance were found and isolated from some extreme environments with their biological properties partly understood, but little is known about their geobiological functions to change Earth envi- ronments. The biotic processes to alter or modify the environments are thus proposed to be the very issue geobiology aims to decipher in the future. Geobiology will greatly extend the temporal and spatial scope of biotic research on Earth and beyond. It has great potential of application in the domains of resource exploration and global change. To achieve these aims needs coor- dinative multidisciplinary studies concerning geomicrobiology and related themes, database and modeling of biogeochemical cycles, typical geological environments, and coupling of biological, physical, and chemical processes.
