The Yellow Sea(YS)environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current(YSWC),the East Asian Winter Monsoon(EAWM)and the Kuroshio Current(KC).We re...The Yellow Sea(YS)environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current(YSWC),the East Asian Winter Monsoon(EAWM)and the Kuroshio Current(KC).We report marine biomarker records of brassicasterol,dinosterol and C37 alkenones in core ZY1 and core ZY2 from the South Yellow Sea(SYS)to reconstruct the spatial/temporal variations and possible mechanisms of phytoplankton primary productivity and community structure changes during the Mid-late Holocene.The contents of the corresponding biomarkers in the two cores are similar,and they also reveal broadly similar temporal trends.From 6 kyr to 3 kyr,the biomarker contents in the two cores were relatively low with small oscillations,followed by a distinct increase at about 3 kyr indicating productivity increases caused by a stronger EAWM.The alkenone/brassicasterol ratio(A/B)is used as a community structure proxy,which also showed higher values in both cores since 3 kyr,indicating increased haptophyte contribution to total productivity.It is proposed that the YS community structure has been mainly influenced by the YSWC,with stronger YSWC influences causing an increase in haptophyte contribution since 3 kyr.Some differences of the biomarker records between ZY2 and ZY1 suggest spatial variations in response to YSWC and KC forcing.When the KC was intensified during the periods of 6 4.2 kyr and 1.7 0 kyr,the YSWC extended eastward,exerting more influence on core ZY1.On the other hand,when the KC weakened during 4.2 1.7 kyr,the YSWC extended westward,exerting more influence on the ZY2.展开更多
We present lipid biomarker records of two cores(ZY1 and ZY3) from the central South Yellow Sea mud area to investigate the changes in sources and transport processes of the sedimentary organic matter(OM) throughout th...We present lipid biomarker records of two cores(ZY1 and ZY3) from the central South Yellow Sea mud area to investigate the changes in sources and transport processes of the sedimentary organic matter(OM) throughout the Holocene. Based on the analysis of marine biomarker content(SPB(Phytoplankton Biomarker, total content of brassicasterol, dinosterol and C_(37)-alkenones) and crenarchaeol), and terrestrial biomarkers(Sn-alkanols and br GDGTs) as well as TMBR′ and BIT index values, the marine organic matter(MOM) and terrestrial organic matter(TOM) deposition history was reconstructed. Changes in TOM and MOM were related to variations in land vegetation density and marine productivity, as well as transport processes dominated by the oceanic circulation system. The marine biomarker contents from the South Yellow Sea have generally increased throughout the Holocene, indicating that the increased MOM contents were mainly controlled by the strengthening of the circulation system. The terrestrial biomarkers, on the other hand, were more variable, indicating more complex influence of TOM burial in the Yellow Sea. During the Early Holocene(7200–6000 cal yr BP), the moderate TOM input revealed by the terrestrial proxy records may result from abundant land source supply by strong river transport despite the lack of transport via circulation system. The Mid-Holocene(6000–3000 cal yr BP) was characterized by decreased terrestrial biomarker contents. The balance between the decrease in land source supply and increase of transportation by the current system of the TOM resulted in the lower but stable contents of TOM. During the Late Holocene(3000 cal yr BP to present), the TOM deposition in the South Yellow Sea increased as the current system was further enhanced and thus transported more TOM to the central South Yellow Sea, although the land supply of TOM was further reduced.展开更多
基金supported by the National Basic Research Program of China(973 Program 2010CB428901)the National Natural Science Foundation of China(Grant Nos.41221004,41020164005)the ‘111’ Project
文摘The Yellow Sea(YS)environmental and ecological changes during the Holocene are driven by the interactions between the Yellow Sea Warm Current(YSWC),the East Asian Winter Monsoon(EAWM)and the Kuroshio Current(KC).We report marine biomarker records of brassicasterol,dinosterol and C37 alkenones in core ZY1 and core ZY2 from the South Yellow Sea(SYS)to reconstruct the spatial/temporal variations and possible mechanisms of phytoplankton primary productivity and community structure changes during the Mid-late Holocene.The contents of the corresponding biomarkers in the two cores are similar,and they also reveal broadly similar temporal trends.From 6 kyr to 3 kyr,the biomarker contents in the two cores were relatively low with small oscillations,followed by a distinct increase at about 3 kyr indicating productivity increases caused by a stronger EAWM.The alkenone/brassicasterol ratio(A/B)is used as a community structure proxy,which also showed higher values in both cores since 3 kyr,indicating increased haptophyte contribution to total productivity.It is proposed that the YS community structure has been mainly influenced by the YSWC,with stronger YSWC influences causing an increase in haptophyte contribution since 3 kyr.Some differences of the biomarker records between ZY2 and ZY1 suggest spatial variations in response to YSWC and KC forcing.When the KC was intensified during the periods of 6 4.2 kyr and 1.7 0 kyr,the YSWC extended eastward,exerting more influence on core ZY1.On the other hand,when the KC weakened during 4.2 1.7 kyr,the YSWC extended westward,exerting more influence on the ZY2.
基金supported by the National Natural Science Foundation of China(Grant No.41221004)the Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology of the Ministry of Land and Resources(Grant No.MRE201301)+1 种基金the National Basic Research Program of China(Grant No.2010CB428901)the“111”Project(Grant No.B13030)
文摘We present lipid biomarker records of two cores(ZY1 and ZY3) from the central South Yellow Sea mud area to investigate the changes in sources and transport processes of the sedimentary organic matter(OM) throughout the Holocene. Based on the analysis of marine biomarker content(SPB(Phytoplankton Biomarker, total content of brassicasterol, dinosterol and C_(37)-alkenones) and crenarchaeol), and terrestrial biomarkers(Sn-alkanols and br GDGTs) as well as TMBR′ and BIT index values, the marine organic matter(MOM) and terrestrial organic matter(TOM) deposition history was reconstructed. Changes in TOM and MOM were related to variations in land vegetation density and marine productivity, as well as transport processes dominated by the oceanic circulation system. The marine biomarker contents from the South Yellow Sea have generally increased throughout the Holocene, indicating that the increased MOM contents were mainly controlled by the strengthening of the circulation system. The terrestrial biomarkers, on the other hand, were more variable, indicating more complex influence of TOM burial in the Yellow Sea. During the Early Holocene(7200–6000 cal yr BP), the moderate TOM input revealed by the terrestrial proxy records may result from abundant land source supply by strong river transport despite the lack of transport via circulation system. The Mid-Holocene(6000–3000 cal yr BP) was characterized by decreased terrestrial biomarker contents. The balance between the decrease in land source supply and increase of transportation by the current system of the TOM resulted in the lower but stable contents of TOM. During the Late Holocene(3000 cal yr BP to present), the TOM deposition in the South Yellow Sea increased as the current system was further enhanced and thus transported more TOM to the central South Yellow Sea, although the land supply of TOM was further reduced.
