...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Paleoceanography >Maastrichtian North Atlantic warming, increasing stratification, and foraminiferal paleobiology at three timescales
【24h】

Maastrichtian North Atlantic warming, increasing stratification, and foraminiferal paleobiology at three timescales

机译：在三个时间尺度上马斯特里赫特北大西洋的变暖，分层增加和有孔虫古生物学

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

Analysis of 944 single specimens of three species of late Maastrichtian planktonic foraminifera (Racemiguembelina fructicosa, Contusotruncana contusa, and Rugoglobigerina rugosa) from 38 samples spanning the last 3 Myr of the Cretaceous shows consistent isotopic trends through time, consistent isotopic differences among taxa, and high within-sample isotopic variability throughout. Within-sample variability does not change systematically through time for any taxon, but average delta O-18 values decrease by similar to 1.5 parts per thousand, and average delta C-13 values diverge up section. Comparing taxa, average delta O-18 values are similar within most samples, but average delta C-13 values generally decrease from R. fructicosa to R. rugosa to C. contusa. In addition, the within-sample variability of individual delta C-13 measurements is larger for R. fructicosa than for either C. contusa or R. rugosa, an observation which is consistent with a photosymbiotic habitat for R. fructicosa. In terms of Maastrichtian paleoceanography the negative delta O-18 trend of similar to 1.5 parts per thousand corresponds to a temperature increase of similar to 6 degrees C, and the divergence of delta C-13 values up section suggests an increasingly stratified water column in the western Atlantic through the late Maastrichtian. We suggest that these trends are best explained by increasing import of South Atlantic waters into the North Atlantic and an intensification of the Northern Hemisphere polar front.
机译：从横跨白垩纪最后3个Myr的38个样品中分析了三种晚期马斯特里赫特浮游有孔虫（Racemiguembelina fructicosa，Contusotruncana contusa和Rugoglobigerina rugosa）的944个单一标本，显示随时间的同位素变化趋势一致，分类单元之间的同位素差异一致，并且高物种整个样本内的同位素变异性。对于任何分类单元，样本内的变异性都不会随着时间的推移而系统地改变，但O-18的平均平均值下降了约千分之1.5，而C-13的平均值却出现了变化。比较分类单元，大多数样品中的平均δO-18值相似，但是平均δC-13值通常从果蝇（R. fructicosa）到皱褶果（R. rugosa）再到圆锥角锥菌（C. contusa）降低。此外，对于褐毛红景天，单个δC-13测量值的样本内变异性大于褐毛红景天或皱纹红景天，这一观察结果与褐毛红景天的光共生生境相一致。就马斯特里赫特古海洋学而言，O-18的负三角洲O-18趋势接近千分之几，对应于温度升高约6摄氏度，而C-13区域上段的三角洲C-13值的发散表明，该地区的水柱逐渐分层西大西洋经过马斯特里赫特晚期。我们认为，最好的解释是通过增加南大西洋水域对北大西洋的进口以及北半球极地锋的加剧来解释。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
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