海洋地质与第四纪地质2026，Vol.46Issue(1)：44-53,10.DOI:10.16562/j.cnki.0256-1492.2025030701
中—晚更新世南大洋深部氧化还原条件指示的垂向流通状况:以IODP 374航次U1524A孔为例
Deepsea redox conditions in the Southern Ocean indicating vertical ventilation during the Middle-Late Pleistocene:A cause study from IODP Expedition 374 Hole U1524A
摘要
Abstract
The redox conditions in the deep ocean are important parameters for diagnosing carbon storage/release in abyssal waters.After correcting the oxygen consumption by organic matter,deep-sea redox conditions are regulated mainly by deep-water ventilation.However,in most available studies,the decoupling between lateral and vertical ventilation was often ignored,but instead used this indicator to suggest the overall or lateral ventilation intensity,which may not be correct in sea areas with developed vertical ventilation(such as the Southern Ocean).To address this issue,we reconstructed the productivity(opal/Ti),redox conditions(Mn/Ti and Mo/Ti ratios),and lateral current strength(ln(Zr/Rb))from International Ocean Discovery Program Hole U1524A in the Ross Sea,Antarctica,dated to the Middle-Late Pleistocene in a glacial-interglacial framework established through physical parameters.Results demonstrate distinct glacial patterns.The glacial periods were characterized by weaker oxidation(suboxic conditions),lower productivity,and stronger lateral currents compared to the interglacial periods that had stronger oxidation(oxic conditions),higher productivity,and weaker lateral current.Comparing these records with the record of the intensity of the Antarctic Circumpolar Current(ACC),which represents the vertical upwelling of deep water of the Circumpolar Deep Water(CDW),the vertical ventilation was proposed to be the dominate process of deep-sea redox condition.The specific mechanism is that during the glacial periods,the westerlies moved northward,while the ACC weakened and sea ice expanded,which collectively suppressed CDW upwelling.The reduced vertical ventilation diminished deep-sea oxidation and carbon release to the atmosphere,and consequently decreased the atmospheric pCO2.These findings demonstrate that the Southern Ocean deep-sea redox conditions in the Middle-Late Pleistocene reflected the vertical ventilation,underscoring the importance of distinguishing between vertical and lateral ventilation to properly interpret deep-sea redox signals.关键词
大气pCO2/生产力/冰期-间冰期旋回/上涌活动/底层水/罗斯海Key words
atmospheric pCO2/productivity/glacial-interglacial/upwelling/bottom water/Ross Sea分类
海洋科学引用本文复制引用
刘恒,郭景腾,肖文申,赵翔宇,熊志方,李铁刚..中—晚更新世南大洋深部氧化还原条件指示的垂向流通状况:以IODP 374航次U1524A孔为例[J].海洋地质与第四纪地质,2026,46(1):44-53,10.基金项目
国家自然科学基金项目"南大洋对北半球大冰期(NHG)大气pCO2降低的贡献:NHG成因的启示"(42076232),"南极罗斯海硅藻沉积变化机理及其与中更新世气候转型(MPT)的潜在关联"(42006075) （NHG）
泰山学者工程项目(TS20190963,TSQN202211265) （TS20190963,TSQN202211265）
