The temporal distribution of the diagnostic biofabrics in the Lower and Middle Ordovician in North China distinctly illustrates that the sedimentary systems on the paleoplate have been changed markedly as consequences...The temporal distribution of the diagnostic biofabrics in the Lower and Middle Ordovician in North China distinctly illustrates that the sedimentary systems on the paleoplate have been changed markedly as consequences of the Great Ordovician Biodiversification Event （GOBE）. The pre-GOBE sedimentary systems deposited in Tremadoc display widespread microbialite and flat-pebble conglomerates, and a less extent of bioturbation. Through the transitional period of early Floian, the sedimentary systems in the rest of the Early and Mid- Ordovician change to GOBE type and are characterized by intensive bioturbation and vanishing flat-pebble conglomerates and subtidal microbial sediments. The irreversible changes in sedimentary systems in North China are linked to the GOBE, which conduced the increase in infaunal tiering, the expansion of infaunal ecospace, and the appearance of new burrowers related to the development of the Paleozoic Evolutionary Fauna during the Ordovician biodiversification. Thus, changes in sedimentary systems during the pivotal period of the GOBE were consequences of a steep diversification of benthic faunas rather than the GOBE＇s environmental background.展开更多
The Hirnantia Fauna is a globally-represented,cool water brachiopod fauna that originated and flourished in shallow marine environments at intermediate to low latitudes after the first episode of the end-Ordovician ma...The Hirnantia Fauna is a globally-represented,cool water brachiopod fauna that originated and flourished in shallow marine environments at intermediate to low latitudes after the first episode of the end-Ordovician mass extinction.It was well-developed,widely distributed,long in stratigraphical range,and complex in palaeoecological differentiation on the Upper Yangtze Platform of the South China paleoplate,where it has been extensively studied.Qualitative and quantitative analyses show that the FAD of the Hirnantia Fauna in South China becomes stratigraphically higher from nearshore to offshore localities on the Yangtze Platform,while the range of the fauna becomes shorter whereas the taxonomic diversity increases.Over its stratigraphical range the diversity of the Hirnantia Fauna at nearshore localities consistently decreases,but trends in the opposite direction at offshore,deeper water localities.The fauna was represented by different communities,subcommunities or associations with changing environmental factors(such as water depth and substrate) at different localities or horizons.展开更多
1 Introduction As one of the major groups in the Great Ordovician Biodiversification Event(GOBE),cephalopods may have played a critical role in the marine ecosystem in late Cambrian and Ordovician.Among the few predat...1 Introduction As one of the major groups in the Great Ordovician Biodiversification Event(GOBE),cephalopods may have played a critical role in the marine ecosystem in late Cambrian and Ordovician.Among the few predators in the Ordovician,cephalopods are typified by their big sizes and the development of swimming ability.展开更多
A robust stratigraphic framework and a coherent depositional ramp model for the Zitai,Dawan,Meitan and Ningkuo formations of Floian–Darriwilian age(Early–Middle Ordovician)in the Yangtze(Daoba,Xiangshuidong,Daling,G...A robust stratigraphic framework and a coherent depositional ramp model for the Zitai,Dawan,Meitan and Ningkuo formations of Floian–Darriwilian age(Early–Middle Ordovician)in the Yangtze(Daoba,Xiangshuidong,Daling,Gudongkou and Honghuayuan sections)and Jiangnan regions(Nanba section)was created based on lithofacies and major element analysis.Three siliciclastic(LF1–3)and six carbonate(LF4–9)lithofacies are recognized representing sediments that were deposited in mixed siliciclastic and carbonate ramp environment.The intensity of mixed sedimentation and terrigenous input were evaluated using the elemental proxies Intensity of Mixed sedimentation(IM)and Aluminum Accumulation Rate(Al AR),as well as their mean values during certain time intervals.Mixed sediments are most well-developed along the marginal Yangtze region,strongly impacted by recurrent influx of westerly derived terrigenous materials in response to global eustatic changes and regional tectonic movements,shaping the gently southeast-dipping morphology.Regular terrigenous influx resulted in periods of enhanced primary productivity on the Yangtze Ramp as evidenced by matching biodiversity peaks in planktonic organisms,i.e.,chitinozoans and acritarchs.Brachiopods and other shelly fauna were also able to proliferate as new niches developed along the gently dipping ramp floor with substrate changes.The biodiversification patterns suggest that terrigenous influx controlled in part by regional tectonics played a more important role than previously thought in the development of Great Ordovician Biodiversification Event in South China.展开更多
Project No.591.The Early to Middle Palaeozoic Revolution Countries involved:Argentina,Australia,Austria,Belgium,Canada,Czech Republic,Denmark,Estonia,France,Germany,Iran,Italy,Lithuania,New Zealand,Norway,People’s Re...Project No.591.The Early to Middle Palaeozoic Revolution Countries involved:Argentina,Australia,Austria,Belgium,Canada,Czech Republic,Denmark,Estonia,France,Germany,Iran,Italy,Lithuania,New Zealand,Norway,People’s Republic of China,Poland,Portugal,Russia,Saudi Arabia,Spain,Sweden,Turkey,United Kingdom,USA Project leaders:Bradley D.Cramer(USA),ÞivileÞigaitë(Lithuania),Thijs R.A.Vanderbroucke(France),Kathleen Histon(Italy),Renbin Zhan(China),Guillermo L.Albanesi(Argentina),Michael J.Melchin(Canada),Mikael Calner(Sweden)Duration:2011-2015 Contact:Bradley D.Cramer Kansas Geological Survey Department of Geology University of Kansas 1930 Constant Avenue Lawrence,Kansas 66047 USA Tel:+16147461334 Fax:+17858645317 E-mail:cramerbd@gmail.com Website:in process The presence of at least eight major perturbations to the global carbon cycle in roughly 40 million years demonstrates that the Late Ordovician to Early Devonian interval was among the climatically least stable episodes of Earth history.Following the Great Ordovician Biodiversification Event(GOBE)and prior to the Devonian Terrestrial Revolution,this interval represents a unique opportunity to study in detail the cause-andeffect relationships of significant global planetary change within a biologically fully populated ocean-atmosphere-biosphere system but prior to the development of a significant global terrestrial biosphere.展开更多
IGCP 503‘Ordovician Palaeogeography and Palaeoclimate’was established in 2004 primarily to identify the main drivers,both biological and geological,of the Great Ordovician Biodiversification Event.From the outset of...IGCP 503‘Ordovician Palaeogeography and Palaeoclimate’was established in 2004 primarily to identify the main drivers,both biological and geological,of the Great Ordovician Biodiversification Event.From the outset of the project it was clear that this event was part of a larger-scale,long-term,multifaceted process that included the end Ordovician extinction and Silurian recovery,if not more.IGCP 503 thus developed a major network that included scientists whose interests spanned the entire Lower Palaeozoic and encompassed a range of disciplines from classical palaeontology and palaeoecology through isotope geochemistry to climate modelling.展开更多
基金support for thisstudy was provided by the National Natural ScienceFoundation of China(no.:40472008,40825006)the Ministry of Science and Technology of China(no.:2006CB806402)the State Key Laboratory ofPalaeobiology and Stratigraphy(no.:LPS20081103)
文摘The temporal distribution of the diagnostic biofabrics in the Lower and Middle Ordovician in North China distinctly illustrates that the sedimentary systems on the paleoplate have been changed markedly as consequences of the Great Ordovician Biodiversification Event （GOBE）. The pre-GOBE sedimentary systems deposited in Tremadoc display widespread microbialite and flat-pebble conglomerates, and a less extent of bioturbation. Through the transitional period of early Floian, the sedimentary systems in the rest of the Early and Mid- Ordovician change to GOBE type and are characterized by intensive bioturbation and vanishing flat-pebble conglomerates and subtidal microbial sediments. The irreversible changes in sedimentary systems in North China are linked to the GOBE, which conduced the increase in infaunal tiering, the expansion of infaunal ecospace, and the appearance of new burrowers related to the development of the Paleozoic Evolutionary Fauna during the Ordovician biodiversification. Thus, changes in sedimentary systems during the pivotal period of the GOBE were consequences of a steep diversification of benthic faunas rather than the GOBE＇s environmental background.
基金supported by Chinese Academy of Sciences (Grant No. KZCX2-YW-Q05-01)National Natural Science Foundation of China (Grant No. 40825006)Ministry of Science and Technology of China (Grant Nos. 2006CB806402,2006FY120300-5)
文摘The Hirnantia Fauna is a globally-represented,cool water brachiopod fauna that originated and flourished in shallow marine environments at intermediate to low latitudes after the first episode of the end-Ordovician mass extinction.It was well-developed,widely distributed,long in stratigraphical range,and complex in palaeoecological differentiation on the Upper Yangtze Platform of the South China paleoplate,where it has been extensively studied.Qualitative and quantitative analyses show that the FAD of the Hirnantia Fauna in South China becomes stratigraphically higher from nearshore to offshore localities on the Yangtze Platform,while the range of the fauna becomes shorter whereas the taxonomic diversity increases.Over its stratigraphical range the diversity of the Hirnantia Fauna at nearshore localities consistently decreases,but trends in the opposite direction at offshore,deeper water localities.The fauna was represented by different communities,subcommunities or associations with changing environmental factors(such as water depth and substrate) at different localities or horizons.
基金supported by the Chinese Academy of Sciences(Grant Nos.XDB26000000,XDB10010100)the Ministry of Science and Technology of China(Grant Nos.2013FY111000,2017ZX05036-001-004)+1 种基金the National Natural Science Foundation of China(Grant No.41772005)IGCP project 653’The Onset of the Great Ordovician Biodiversification Event’.
文摘1 Introduction As one of the major groups in the Great Ordovician Biodiversification Event(GOBE),cephalopods may have played a critical role in the marine ecosystem in late Cambrian and Ordovician.Among the few predators in the Ordovician,cephalopods are typified by their big sizes and the development of swimming ability.
基金funded by National Natural Science Foundation of China(Grant Nos.42102130,41972011)Natural Science Foundation of Jiangsu Province(Grant No.BK20191101)+2 种基金Chinese Academy of Sciences(Grant No.XDB26000000)China Scholarship Council(Grant No.202004910207)State Key Laboratory of Palaeobiology and Stratigraphy。
文摘A robust stratigraphic framework and a coherent depositional ramp model for the Zitai,Dawan,Meitan and Ningkuo formations of Floian–Darriwilian age(Early–Middle Ordovician)in the Yangtze(Daoba,Xiangshuidong,Daling,Gudongkou and Honghuayuan sections)and Jiangnan regions(Nanba section)was created based on lithofacies and major element analysis.Three siliciclastic(LF1–3)and six carbonate(LF4–9)lithofacies are recognized representing sediments that were deposited in mixed siliciclastic and carbonate ramp environment.The intensity of mixed sedimentation and terrigenous input were evaluated using the elemental proxies Intensity of Mixed sedimentation(IM)and Aluminum Accumulation Rate(Al AR),as well as their mean values during certain time intervals.Mixed sediments are most well-developed along the marginal Yangtze region,strongly impacted by recurrent influx of westerly derived terrigenous materials in response to global eustatic changes and regional tectonic movements,shaping the gently southeast-dipping morphology.Regular terrigenous influx resulted in periods of enhanced primary productivity on the Yangtze Ramp as evidenced by matching biodiversity peaks in planktonic organisms,i.e.,chitinozoans and acritarchs.Brachiopods and other shelly fauna were also able to proliferate as new niches developed along the gently dipping ramp floor with substrate changes.The biodiversification patterns suggest that terrigenous influx controlled in part by regional tectonics played a more important role than previously thought in the development of Great Ordovician Biodiversification Event in South China.
文摘Project No.591.The Early to Middle Palaeozoic Revolution Countries involved:Argentina,Australia,Austria,Belgium,Canada,Czech Republic,Denmark,Estonia,France,Germany,Iran,Italy,Lithuania,New Zealand,Norway,People’s Republic of China,Poland,Portugal,Russia,Saudi Arabia,Spain,Sweden,Turkey,United Kingdom,USA Project leaders:Bradley D.Cramer(USA),ÞivileÞigaitë(Lithuania),Thijs R.A.Vanderbroucke(France),Kathleen Histon(Italy),Renbin Zhan(China),Guillermo L.Albanesi(Argentina),Michael J.Melchin(Canada),Mikael Calner(Sweden)Duration:2011-2015 Contact:Bradley D.Cramer Kansas Geological Survey Department of Geology University of Kansas 1930 Constant Avenue Lawrence,Kansas 66047 USA Tel:+16147461334 Fax:+17858645317 E-mail:cramerbd@gmail.com Website:in process The presence of at least eight major perturbations to the global carbon cycle in roughly 40 million years demonstrates that the Late Ordovician to Early Devonian interval was among the climatically least stable episodes of Earth history.Following the Great Ordovician Biodiversification Event(GOBE)and prior to the Devonian Terrestrial Revolution,this interval represents a unique opportunity to study in detail the cause-andeffect relationships of significant global planetary change within a biologically fully populated ocean-atmosphere-biosphere system but prior to the development of a significant global terrestrial biosphere.
文摘IGCP 503‘Ordovician Palaeogeography and Palaeoclimate’was established in 2004 primarily to identify the main drivers,both biological and geological,of the Great Ordovician Biodiversification Event.From the outset of the project it was clear that this event was part of a larger-scale,long-term,multifaceted process that included the end Ordovician extinction and Silurian recovery,if not more.IGCP 503 thus developed a major network that included scientists whose interests spanned the entire Lower Palaeozoic and encompassed a range of disciplines from classical palaeontology and palaeoecology through isotope geochemistry to climate modelling.
