基于AMS14C测年、有机碳、氮含量及其同位素等指标分析,探讨了冲绳海槽中南部OKT-3孔末次冰消期以来沉积物有机质来源及其对古海洋环境演化的响应。结果显示,OKT-3孔沉积物中有机质主要由中国大陆和中国台湾等陆源有机质,以及海洋自生...基于AMS14C测年、有机碳、氮含量及其同位素等指标分析,探讨了冲绳海槽中南部OKT-3孔末次冰消期以来沉积物有机质来源及其对古海洋环境演化的响应。结果显示,OKT-3孔沉积物中有机质主要由中国大陆和中国台湾等陆源有机质,以及海洋自生有机质组成。末次冰消期至全新世晚期(17.3~4 ka B.P.),中国大陆源有机质贡献逐渐下降,中国台湾源有机质贡献逐渐上升,表明海平面变化、黑潮变动是该阶段有机质来源的主要控制因素。4~1.5 ka期间,陆源有机质供给变化趋势与黑潮变动不一致,表明该时期陆源输入非黑潮单一控制,还可能受季风降雨等变化影响。值得注意的是,OKT-3孔海源有机质贡献在B-A和PB时期高、YD时期低,与北太平洋地区的生产力变化相似,反映了北太平洋中层水(NPIW)对海水表层生产力的控制作用,NPIW是连通冲绳海槽与北太平洋的重要纽带。展开更多
分析南黄海中部泥质区柱状样ZY1和ZY3中的生物标志物,来研究全新世沉积有机质的来源和运输过程的变化.根据海源生物标志物（菜子甾醇、甲藻甾醇和长链烯酮含量的总和（？PB,Phytoplankton Biomarker）和泉古醇（crenarchaeol））、陆源...分析南黄海中部泥质区柱状样ZY1和ZY3中的生物标志物,来研究全新世沉积有机质的来源和运输过程的变化.根据海源生物标志物（菜子甾醇、甲藻甾醇和长链烯酮含量的总和（？PB,Phytoplankton Biomarker）和泉古醇（crenarchaeol））、陆源生物标志物（烷醇（？n-alkanols）和土壤厌氧细菌生物标志物（br GDGTs））以及TMBR′和BIT指标,重建了全新世黄海海源有机质（marine organic matter,MOM）和陆源有机质（terrestrial organic matter,TOM）的沉积历史.结果表明海源有机质和陆源有机质的变化与陆地植被丰度、海洋浮游植物生产力和海洋环流系统的输运过程有关.受海洋环流系统不断增强的影响,全新世南黄海海源生物标志物含量呈增加趋势,指示了海源有机质输入的增多.陆源生物标志物含量变化波动较大,揭示了影响黄海陆源有机质埋藏的因素可能更复杂：早全新世（7200~6000cal a BP）陆源有机质输入量适中,由于环流系统还未形成,输运黄海陆源有机质有限,但仍存在河流输运的陆源有机质.中全新世（6000~3000cal a BP）陆源有机质含量较低,陆源有机质供应的减少和环流系统输运的增强共同导致陆源生物标志物含量减少,但是变化趋势比较稳定.晚全新世（3000cal a BP至今）南黄海陆源有机质增加,原因是尽管陆地有机质的供应减少,但由于环流系统增强,输运较多陆源有机质至南黄海中部.展开更多
Terrestrial organic matter(TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea(ECS) is important for understanding regional carbon c...Terrestrial organic matter(TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea(ECS) is important for understanding regional carbon cycle. A novel approach combining molecular proxies and compound-specific carbon isotopes is used to quantitatively constrain the origins and transport mechanisms of TOM in surface sediments from the ECS shelf. The content of terrestrial biomarkers of(C_(27)+C_(29)+C_(31)) n-alkanes(52 to 580 ng g^(-1)) revealed a seaward decreasing trend, the δ^(13)CTOC values(-20.6‰ to-22.7‰) were more negative near the coast, and the TMBR(terrestrial and marine biomarker ratio) values(0.06 to 0.40) also revealed a seaward decreasing trend. These proxies all indicated more TOM(up to 48%) deposition in the coastal areas. The Alkane Index, the ratio of C_(29)/(C_(29)+C_(31)) n-alkanes indicated a higher proportion of grass vegetation in the coastal area; While the δ13C values of C_(29) n-alkane(-_(29).3‰ to-33.8‰) indicated that terrestrial plant in the sediments of the ECS shelf were mainly derived from C_3 plants. Cluster analysis afforded detailed estimates of different-sourced TOM contributions and transport mechanisms. TOM in the Zhejiang-Fujian coastal area was mostly delivered by the Changjiang River, and characterized by higher %TOM(up to 48%), higher %C_3 plant OM(68%-85%) and higher grass plant OM(56%-61%); TOM in the mid-shelf area was mostly transported by aerosols, and characterized by low %TOM(less than 17%), slightly lower C_3 plant OM(56%-72%) and lower grass plant OM(49%-55%).展开更多
文摘基于AMS14C测年、有机碳、氮含量及其同位素等指标分析,探讨了冲绳海槽中南部OKT-3孔末次冰消期以来沉积物有机质来源及其对古海洋环境演化的响应。结果显示,OKT-3孔沉积物中有机质主要由中国大陆和中国台湾等陆源有机质,以及海洋自生有机质组成。末次冰消期至全新世晚期(17.3~4 ka B.P.),中国大陆源有机质贡献逐渐下降,中国台湾源有机质贡献逐渐上升,表明海平面变化、黑潮变动是该阶段有机质来源的主要控制因素。4~1.5 ka期间,陆源有机质供给变化趋势与黑潮变动不一致,表明该时期陆源输入非黑潮单一控制,还可能受季风降雨等变化影响。值得注意的是,OKT-3孔海源有机质贡献在B-A和PB时期高、YD时期低,与北太平洋地区的生产力变化相似,反映了北太平洋中层水(NPIW)对海水表层生产力的控制作用,NPIW是连通冲绳海槽与北太平洋的重要纽带。
文摘分析南黄海中部泥质区柱状样ZY1和ZY3中的生物标志物,来研究全新世沉积有机质的来源和运输过程的变化.根据海源生物标志物（菜子甾醇、甲藻甾醇和长链烯酮含量的总和（？PB,Phytoplankton Biomarker）和泉古醇（crenarchaeol））、陆源生物标志物（烷醇（？n-alkanols）和土壤厌氧细菌生物标志物（br GDGTs））以及TMBR′和BIT指标,重建了全新世黄海海源有机质（marine organic matter,MOM）和陆源有机质（terrestrial organic matter,TOM）的沉积历史.结果表明海源有机质和陆源有机质的变化与陆地植被丰度、海洋浮游植物生产力和海洋环流系统的输运过程有关.受海洋环流系统不断增强的影响,全新世南黄海海源生物标志物含量呈增加趋势,指示了海源有机质输入的增多.陆源生物标志物含量变化波动较大,揭示了影响黄海陆源有机质埋藏的因素可能更复杂：早全新世（7200~6000cal a BP）陆源有机质输入量适中,由于环流系统还未形成,输运黄海陆源有机质有限,但仍存在河流输运的陆源有机质.中全新世（6000~3000cal a BP）陆源有机质含量较低,陆源有机质供应的减少和环流系统输运的增强共同导致陆源生物标志物含量减少,但是变化趋势比较稳定.晚全新世（3000cal a BP至今）南黄海陆源有机质增加,原因是尽管陆地有机质的供应减少,但由于环流系统增强,输运较多陆源有机质至南黄海中部.
基金the Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology, Ministry of Land and Resources (No. MRE201301)the National Natural Science Foundation of China (No. 41506087)the ‘111’ Project (No. B13030)
文摘Terrestrial organic matter(TOM) is an important component of marine sedimentary OM, and revealing the origins and transport mechanisms of TOM to the East China Sea(ECS) is important for understanding regional carbon cycle. A novel approach combining molecular proxies and compound-specific carbon isotopes is used to quantitatively constrain the origins and transport mechanisms of TOM in surface sediments from the ECS shelf. The content of terrestrial biomarkers of(C_(27)+C_(29)+C_(31)) n-alkanes(52 to 580 ng g^(-1)) revealed a seaward decreasing trend, the δ^(13)CTOC values(-20.6‰ to-22.7‰) were more negative near the coast, and the TMBR(terrestrial and marine biomarker ratio) values(0.06 to 0.40) also revealed a seaward decreasing trend. These proxies all indicated more TOM(up to 48%) deposition in the coastal areas. The Alkane Index, the ratio of C_(29)/(C_(29)+C_(31)) n-alkanes indicated a higher proportion of grass vegetation in the coastal area; While the δ13C values of C_(29) n-alkane(-_(29).3‰ to-33.8‰) indicated that terrestrial plant in the sediments of the ECS shelf were mainly derived from C_3 plants. Cluster analysis afforded detailed estimates of different-sourced TOM contributions and transport mechanisms. TOM in the Zhejiang-Fujian coastal area was mostly delivered by the Changjiang River, and characterized by higher %TOM(up to 48%), higher %C_3 plant OM(68%-85%) and higher grass plant OM(56%-61%); TOM in the mid-shelf area was mostly transported by aerosols, and characterized by low %TOM(less than 17%), slightly lower C_3 plant OM(56%-72%) and lower grass plant OM(49%-55%).
