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Paleo-export production and terrigenous sedimentation in the Southern Ocean.

机译：南大洋的古出口产品和陆源沉积。

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As a result of the opening of important seaways (Tasmanian Seaway and Drake Passage) and the subsequent formation of the Antarctic Circumpolar Current during the Cenozoic, the Southern Ocean became an important feature of the climate system in terms of ocean circulation and carbon dioxide exchange between the surface ocean and the atmosphere. Therefore, it is vital that we understand the Southern Ocean's role in either forcing or amplifying climate changes of the Cenozoic, either through physical processes such as changes in ocean circulation and sea-ice extent or through changes in the biological carbon pump, particularly export production.; The purpose of this research is to evaluate changes in export production and terrigenous provenance in the Southern Ocean near the Eocene-Oligocene boundary and on glacial/interglacial time scales using major and minor element bulk sediment geochemical proxies. The major findings of this research suggest (1) down core P/Ti ratios match records of reactive P concentrations, suggesting that the two different P-based proxies are comparable in the Southern Ocean; (2) AIM ratios and Ba concentrations suggest the Drake Passage was open or opening at 32.8 Ma; (3) elemental ratios of P and Ba across the Eocene-Oligocene boundary suggest an interval of elevated export production, which supports previous observation based on microfossils assemblages that primary productivity was higher during this time interval; (4) export production across the entire southeastern Atlantic Ocean was maximum during some glacial terminations, which is contrary to other finding suggesting that productivity increased north of the Antarctic Polar Front (APF) during glacial intervals and increased south of the APF during interglacial intervals; and (5) comparisons of the timing between records of export production and atmospheric CO2 from ice cores, suggest that Southern Ocean productivity was not responsible for glacial CO2 drawdown.
机译：由于重要航道的开放（塔斯马尼亚航道和德雷克海峡）以及随后的新生代南极极地洋流的形成，就海洋环流和二氧化碳之间的交换而言，南洋成为气候系统的重要特征。地表海洋和大气层。因此，至关重要的是，我们必须通过物理过程（例如海洋环流和海冰范围的变化）或通过生物碳泵（尤其是出口生产）的变化，了解南大洋在强迫或放大新生代气候变化中的作用。 。;这项研究的目的是使用主要和次要元素的大量沉积物地球化学指标，评估始新世-渐新世边界附近的南大洋的出口生产和陆源出处的变化，以及冰川/间冰期的尺度。这项研究的主要发现表明：（1）较低的核心P / Ti比值与反应性P浓度的记录相匹配，这表明在南大洋，两种基于P的代理具有可比性； （2）AIM比和Ba浓度表明Drake通道是开放的或在32.8 Ma时开放； （3）始新世-渐新世边界上的P和Ba元素比表明存在一定的出口产量增加区间，这支持了以前基于微化石组合的观察结果，即该时期的初级生产力较高； （4）在某些冰川终止期间，整个东南大西洋的出口产量最高，这与其他发现相反，这表明在冰川间隔期间生产力在南极极地锋（APF）以北增加，而在冰川间隔期间生产力在APF以南增加; （5）对出口生产记录与冰芯大气CO2记录时间之间的比较，表明南大洋生产力与冰川CO2的下降无关。

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