...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Paleoceanography >No major deglaciation across the Miocene-Pliocene boundary: Integrated stratigraphy and astronomical tuning of the Loulja sections (Bou Regreg area, NW Morocco)
【24h】

No major deglaciation across the Miocene-Pliocene boundary: Integrated stratigraphy and astronomical tuning of the Loulja sections (Bou Regreg area, NW Morocco)

机译：中新世-上新世边界没有大的冰消作用：Loulja剖面的综合地层学和天文调谐（摩洛哥西北部，Bou Regreg地区）

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

An integrated high-resolution stratigraphy and orbital tuning is presented for the Loulja sections located in the Bou Regreg area on the Atlantic side of Morocco. The sections constitute the upward continuation of the upper Messinian Ain el Beida section and contain a well-exposed, continuous record of the interval straddling the Miocene-Pliocene (M-P) boundary. The older Loulja-A section, which covers the interval from similar to 5.59 to 5.12 Ma, reveals a dominantly precession-controlled color cyclicity that allows for a straightforward orbital tuning of the boundary interval and for detailed cyclostratigraphic correlations to the Mediterranean; the high-resolution and high-quality benthic isotope record allows us to trace the dominantly obliquity-controlled glacial history. Our results reveal that the M-P boundary coincides with a minor, partly precession-related shift to lighter "interglacial'' values in d18O. This shift and hence the M-P boundary may not correlate with isotope stage TG5, as previously thought, but with an extra (weak) obliquity-controlled cycle between TG7 and TG5. Consequently, the M-P boundary and basal Pliocene flooding of the Mediterranean following the Messinian salinity crisis are not associated with a major deglaciation and glacio-eustatic sea level rise, indicating that other factors, such as tectonics, must have played a fundamental role. On the other hand, the onset of the Upper Evaporites in the Mediterranean marked by hyposaline conditions coincides with the major deglaciation step between marine isotope stage TG12 and TG11, suggesting that the associated sea level rise is at least partly responsible for the apparent onset of intermittently restricted marine conditions following the main desiccation phase. Finally, the Loulja-A section would represent an excellent auxiliary boundary stratotype for the M-P boundary as formally defined at the base of the Trubi marls in the Eraclea Minoa section on Sicily.
机译：针对位于摩洛哥大西洋沿岸的布·雷格里格地区的卢拉贾剖面，提出了一种综合的高分辨率地层学和轨道调谐技术。这些断层构成了墨西尼上层Ain el Beida断层的向上延续，并包含了一个暴露良好的连续记录，该记录跨越了中新世-上新世（M-P）边界。较老的Loulja-A剖面覆盖了从5.59到5.12 Ma的区间，揭示了一个主要由旋进控制的颜色周期性，可以对边界区间进行直接的轨道调整，并获得与地中海的详细地层学相关性。高分辨率和高质量的底栖同位素记录使我们能够追踪到主要由倾斜控制的冰川历史。我们的研究结果表明，MP边界与d18O中较小的，与旋进相关的向较小的“冰间”值转变相吻合，这种转变和MP边界可能与TG5同位素阶段不相关，如先前所认为的，但与额外的TG7和TG5之间的（弱）倾角控制周期，因此，在墨西尼盐度危机之后，地中海的MP边界和基底上新世洪水与主要的冰消冰川作用和冰川消融的海平面上升无关，这表明其他因素，例如另一方面，以次盐水条件为标志的地中海上蒸发岩的爆发与海洋同位素阶段TG12和TG11之间的主要冰消作用步骤相吻合，表明相关的海平面上升是在主要的干燥阶段之后，至少部分原因是间歇性受限制的海洋条件的明显发作。 a-A剖面将代表M-P边界的极佳辅助边界层型，正如在西西里岛的Eraclea Minoa剖面的Trubi沼泽底部所正式定义的那样。

著录项

相似文献

  • 外文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号