Paleoenvironmental Changes at ODP Site 702 (South Atlantic): Anatomy of the Middle Eocene Climatic Optimum
Paleoenvironmental Changes at ODP Site 702 (South Atlantic): Anatomy of the Middle Eocene Climatic Optimum
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ODP 702 站点（南大西洋）的古环境变化：中始新世气候最佳状态的剖析
DOI：
10.1029/2019pa003806
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发表时间：
2019
影响因子：
3.5
通讯作者：
L. Alegret
中科院分区：
文献类型：
--
作者：
Lucía Rivero;T. Westerhold;C. Agnini;E. Dallanave;R. Wilkens;L. Alegret
始新世中期气候适宜期（MECO）是一个不寻常的全球变暖事件，中断了始新世的长期冷却趋势。40马。在这里，我们提出了新的高分辨率散装和底栖同位素记录从南大西洋ODP网站702在高纬度设置的MECO的特点。MECO事件，包括早期和峰值变暖以及恢复到背景水平，估计持续时间约为300 Kyr（约40.51至40.21 Ma）。交叉图（δ 18 O vs. δ 13 C）表明，在事件发生前，驱动整个MECO中O和C同位素值耦合变化的机制较弱或不存在。通过对钙质超微化石和底栖有孔虫组合的定量分析，评价了古生态响应。我们记录了暖温带钙质nannoplankton类群，由于在MECO温度升高向高纬度迁移的地理分布的转变。相反，有机物质流向海底的变化似乎控制了702号站点的底栖有孔虫动态。底栖植物碎屑开采类群的丰度增加与δ 13 C的正偏移相一致，在δ 18 O负偏移开始之前约150 Kyr，这标志着MECO变暖的开始。我们的数据表明，深海古生态扰动早于MECO δ 18 O漂移，它是由到达海底的有机物质的类型和/或数量的变化而不是由温度升高驱动的。
The Middle Eocene Climatic Optimum (MECO) was an unusual global warming event that interrupted the long‐term Eocene cooling trend ca. 40 Ma. Here we present new high‐resolution bulk and benthic isotope records from South Atlantic ODP Site 702 to characterize the MECO at a high latitude setting. The MECO event, including early and peak warming as well as recovery to background levels, had an estimated ~300 Kyr duration (~40.51 to ~40.21 Ma). Cross‐plots (δ18O vs. δ13C) suggest that the mechanisms driving coupled changes in O and C isotope values across the MECO were weaker or absent before the event. The paleoecological response has been evaluated by quantitative analysis of calcareous nannofossils and benthic foraminifera assemblages. We document a shift in the biogeographical distribution of warm and temperate calcareous nannoplankton taxa, which migrated toward higher latitudes due to increased temperatures during the MECO. Conversely, changes in the organic matter flux to the seafloor appear to have controlled benthic foraminifera dynamics at Site 702. Benthic phytodetritus exploiting taxa increased in abundance coinciding with a positive δ13C excursion, ~150 Kyr before the start of the δ18O negative excursion that marks the start of MECO warming. Our data suggest that paleoecological disturbance in the deep sea predates MECO δ18O excursion and that it was driven by changes in the type and/or amount of organic matter reaching the seafloor rather than by increased temperature.
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影响因子：
4.3
作者：
T. Westerhold;U. Röhl;H. Pälike;R. Wilkens;P. Wilson;G. Acton
通讯作者：
T. Westerhold;U. Röhl;H. Pälike;R. Wilkens;P. Wilson;G. Acton
影响因子：
--
作者：
L. Tauxe;C. Stickley;S. Sugisaki;P. Bijl;S. Bohaty;H. Brinkhuis;C. Escutia;J. Flores;A. Houben;M. Iwai;F. Jiménez-Espejo;R. McKay;S. Passchier;J. Pross;C. Riesselman;U. Röhl;F. Sangiorgi;K. Welsh;A. Klaus;Annick Fehr;J. Bendle;R. Dunbar;J. Gonzàlez;T. Hayden;K. Katsuki;M. Olney;S. Pekar;P. Shrivastava;T. Flierdt;T. Williams;M. Yamane
通讯作者：
L. Tauxe;C. Stickley;S. Sugisaki;P. Bijl;S. Bohaty;H. Brinkhuis;C. Escutia;J. Flores;A. Houben;M. Iwai;F. Jiménez-Espejo;R. McKay;S. Passchier;J. Pross;C. Riesselman;U. Röhl;F. Sangiorgi;K. Welsh;A. Klaus;Annick Fehr;J. Bendle;R. Dunbar;J. Gonzàlez;T. Hayden;K. Katsuki;M. Olney;S. Pekar;P. Shrivastava;T. Flierdt;T. Williams;M. Yamane
影响因子：
--
作者：
I. Moebius;O. Friedrich;K. Edgar;P. Sexton
通讯作者：
I. Moebius;O. Friedrich;K. Edgar;P. Sexton
大西洋沃尔维斯海脊古新世和始新世海洋变暖事件期间海底的差异响应（ODP 站点 1262）
影响因子：
2.4
作者：
Deprez;Bornemann;Speijer
通讯作者：
Speijer