The western North Atlantic record of MIS 13 to 10: Changes in primary productivity, organic carbon accumulation and benthic foraminiferal assemblages in sediments from the Blake Outer Ridge (ODP Site 1058)
The western North Atlantic record of MIS 13 to 10: Changes in primary productivity, organic carbon accumulation and benthic foraminiferal assemblages in sediments from the Blake Outer Ridge (ODP Site 1058)
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MIS 13 至 10 的北大西洋西部记录：布莱克外脊沉积物中初级生产力、有机碳积累和底栖有孔虫组合的变化（ODP 站点 1058）
DOI：
10.1016/j.palaeo.2010.05.018
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
R. Thunell
中科院分区：
文献类型：
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作者：
M. Poli;P. Meyers;R. Thunell
我们使用了多个古海洋学代理研究跨越MIS 13-10时间间隔的布莱克外脊（ODP站点1058，2996米水深）的沉积物。底栖有孔虫δ 13 C、有机δ 13 C和总δ 15 N值在MIS 12和10中低于MS 11，表明影响深层和表层沃茨的温盐环流和海洋地球化学过程的冰川-间冰期变化。三个较高生产力的时间间隔，如较高的有机碳积累速率（1.6-4.5gm− 2 yr −1）所证明的，发生在MIS 13的末期和MIS 11的早期和晚期，与从丰度最小值到丰度最大值的过渡有关。这些间隔期的底栖动物显示，以植物碎屑为食（Epistominella exigua）或适应高但间歇性有机碳通量（Bulimina aculeata和Bulimina marginata）的机会性物种明显增加，这意味着在表面经常发生浮游植物水华，随后将不稳定的有机物质输出到海底。晚间冰期MIS 11.3是一个有机碳通量较低的时期（<0.5gm− 2 yr −1），其特征是表生底栖有孔虫类群（Cibicidoides wuellerstorfi，Gyroidina spp.，拟旋纹藻属和Nuttallides umbonifera），它们是现代贫营养环境的典型。相比之下，在冰川期MIS 12和10较高的有机碳通量（>0.5gm− 2 yr −1）和底栖生物组合占主导地位的底栖动物类群（Uvigerina spp.）。和Bulimina alazanensis）表明持续的有机碳输送和减少的孔隙水氧合。
We used multiple paleoceanographic proxies to examine sediments from the Blake Outer Ridge (ODP Site 1058, 2996m water depth) that span the MIS 13–10 time interval. Benthic foraminiferal δ13C, organic δ13C, and total δ15N values are lower in MIS 12 and 10 than in MS 11, and indicate glacial–interglacial changes in both thermohaline circulation and ocean-wide biogeochemical processes that affect deep and surface waters. Three time intervals of higher productivity, as evidenced by higher organic carbon accumulation rates (1.6–4.5gm−2yr−1), occur at the end of MIS 13 and during the early and late parts of MIS 11, in association with the transition from obliquity minima to obliquity maxima. Benthic faunas in these intervals show a distinct increase in opportunistic species that feed on phytodetritus (Epistominella exigua) or are adapted to elevated but intermittent organic carbon fluxes (Bulimina aculeata and Bulimina marginata) and that imply episodes of recurrent phytoplankton blooms at the surface and consequent export of labile organic matter to the seafloor. Late interglacial MIS 11.3 is a time of low organic carbon fluxes (<0.5gm−2yr−1) and is characterized by higher abundances of epifaunal benthic foraminiferal taxa (Cibicidoides wuellerstorfi, Gyroidina spp., Gyroidinoides spp. and Nuttallides umbonifera) that are typical of modern oligotrophic environments. In contrast, during glacial MIS 12 and 10 higher organic carbon fluxes (>0.5gm−2yr−1) and benthic assemblages dominated by infaunal taxa (Uvigerina spp. and Bulimina alazanensis) indicate sustained organic carbon delivery and diminished pore water oxygenation.