沉积学报2023，Vol.41Issue(6)：1714-1738,25.DOI:10.14027/j.issn.1000-0550.2023.102
晚新生代日本海古生产力演化
Late Cenozoic Paleo-productivity Evolution of the Japan Sea:A review
摘要
Abstract
[Significance]Surface ocean primary productivity and biological pump processes are key components in the global ocean carbon cycle.As one of the major marginal seas in the northwest Pacific,the long-term evolution of Late Cenozoic paleo-productivity in the Japan Sea is closely linked to regional tectonics,East Asian monsoon/wester-lies,oceanic currents,global climate and sea-level changes.Thus,the Japan Sea provides an excellent window into the Earth's systems.[Progress and Conclusions]A benefit from the series of International Ocean Drilling Programs(DSDP Exp.31,ODP Exp.127/128 and IODP Exp.346)and consequent post-expedition research has been the re-markable increase in knowledge of the paleo-oceanography of the Japan Sea,especially in the reconstruction of paleo-productivity.Continuous cores obtained from IODP 346 were used to study the impact of long-term dust input on ocean productivity and the global carbon cycle,and to test the role of the"iron hypothesis"on a tectonic time scale.The commonly used proxies of paleo-productivity in the Japan Sea include trace elements,biomarkers,biogenic com-ponents and isotope compositions of sediments,and the species and genera of microfossils.On a geological time scale,surface ocean primary productivity in the Japan Sea basically depends on the main nutrients(N,P,Si)and trace nutrients(Fe,Mn,Co,Zn,Cu,etc.)necessary for plankton.Nutrients are mainly carried to the Japan Sea by wind dust,volcanic activity,surface ocean currents and deep currents.Consequently,volcanic activity,East Asian monsoons and westerlies,ocean current evolution,global climate and sea-level change directly or indirectly affect the supply of nutrients and therefore alter the level of primary productivity in the Japan Sea.On a tectonic time scale,the long-term evolution of the paleo-productivity in the Japan Sea and its driving mechanisms(e.g.,the contribution of wind dust,volcanic iron fertilization and ocean currents)are still unclear;regional tectonic evolution,opening and closing of sea channels,global climate and sea-level changes,volcanic activity and changes in Asian dust input may be crucial.Sediments in the Japan Sea are highly diatomaceous(with 20%-70%diatoms)and rich in organic car-bon(0.4%-4.9%)since the Late Miocene,reflecting high primary productivity and organic carbon burial.This peri-od also corresponds to global climate cooling with increased dust flux.However,preliminary comparison between the dust flux and paleo-productivity shows that increased dust has had no perceptible impact on the paleo-productivity in the Japan Sea.The reason may be that when the inner water nutrient conditions(which are controlled by regional tec-tonic evolution and global sea-level change)dominated primary productivity,the impact of dust input on paleo-pro-ductivity was masked.Volcanic deposits in the Japan Sea were more common in the Quaternary,but diatom deposits are significantly absent during this period;this may indicate that volcanic iron fertilization did not obviously promote the paleo-productivity of diatoms.On orbital and millennial scales,Japan Sea sediments are characterized by alternat-ing dark and light layers,and surface productivity was generally weakened during glacial periods and increased during interglacial periods,mainly due to the concomitant changes in nutrient supply caused by seawater exchange and strati-fication conditions.At present,reconstructions of the paleo-productivity of the Japan Sea mainly focus on the Late Quaternary(especially since the Last Glacial),but are lacking at the tectonic scale in the Late Cenozoic.[Prospect]Calcareous biological deposits are lacking in the Japan Sea,but diatomaceous fossils may show great potential value in further studies.In future research,it is recommended that novel systematic proxies(for example,stable isotopes and species assemblages of diatoms)be developed to reconstruct the long-term evolution history of Late Cenozoic pa-leo-productivity in the Japan Sea.It is also necessary to deeply explore the relationship between surface ocean prima-ry productivity,regional tectonic evolution and global climate change.关键词
日本海/古生产力/古海洋/古气候/国际大洋钻探计划Key words
Japan Sea/paleo-productivity/paleo-oceanography/paleoclimatology/International Ocean Drilling Program分类
海洋科学引用本文复制引用
程宇龙,万世明..晚新生代日本海古生产力演化[J].沉积学报,2023,41(6):1714-1738,25.基金项目
国家自然科学基金项目(42125602,42076052)National Natural Science Foundation of China,No.42125602,42076052 （42125602,42076052）
