...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Facies >Planktonic versus benthic foraminifera response to Milankovitch forcing (Late Jurassic, Betic Cordillera): testing methods for cyclostratigraphic analysis
【24h】

Planktonic versus benthic foraminifera response to Milankovitch forcing (Late Jurassic, Betic Cordillera): testing methods for cyclostratigraphic analysis

机译：浮游有孔虫与底栖有孔虫对米兰科维奇强迫的响应（侏罗纪晚期，Betic Cordillera）：旋回地层分析的测试方法

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

Foraminiferal assemblages from the Bifurcatus Zone (Oxfordian, Upper Jurassic) are studied in the Navalperal section (Betic Cordillera, southern Spain). A total of 24 sampling stations and around 5,700 specimens of foraminifera were recognized on thin-section analysis and classified into two major categories: planktonic and benthic. The abundance of foraminifera (number of specimens/cm2) was calculated for both categories and the cyclic pattern was studied by spectral analysis, considering the autochthonous and para-autochthonous character of the studied assemblages. The Lomb-Scargle periodogram together with a permutation test were tested for performing the high-resolution spectral analysis, being particularly well suited for working with short time series and uneven sampling. Spectral analysis reveals the influence of orbital-scale Milankovitch cyclicity at the eccentricity, obliquity, and precession bands. Moreover, this incidence is significantly different depending on the analyzed group (benthic versus planktonic). Whereas the long-range eccentricity band is not distinguishable from a trend and the short-range eccentricity band is not statistically significant (at 90% confidence level), the obliquity band is better represented in the planktonic component and the precession band is better developed in the benthic group. Variations in temperature affecting upper waters, determined by obliquity-scale fluctuations, could be responsible for changes in the planktonic foraminiferal assemblage, while changes in nutrient availability and substrate oxygenation, as a consequence of input variations from source areas at the precession-scale cycles, could affect the benthic foraminiferal assemblage.
机译：在海军部（西班牙南部的比迪科迪勒拉）研究了Bifurcatus区（牛津，上侏罗纪）的有孔虫组合。在薄层分析中总共识别出24个采样站和大约5700个有孔虫标本，并将其分为浮游和底栖两大类。分别计算了两个类别的有孔虫的数量（标本数量/ cm 2 ），并通过光谱分析研究了循环模式，并考虑了所研究组合的自生和副自生特性。测试了Lomb-Scargle周期图和置换测试以执行高分辨率光谱分析，特别适合用于短时间序列和不均匀采样的情况。光谱分析揭示了轨道尺度的米兰科维奇周期对偏心率，倾角和进动带的影响。此外，根据所分析的人群（水底浮游动物与浮游生物），这种发生率显着不同。远距离偏心率带和趋势无法区分开，短距离偏心率带在统计上不显着（在90％置信水平下），但在浮游成分中较好地代表了倾斜带，而在岁月中，旋进带则更好地发展了。底栖群。由倾斜规模的波动确定的影响上层水域的温度变化可能是浮游有孔虫组合的变化，而养分利用率和底物氧合的变化是由于进动规模周期中源区输入变化的结果，可能会影响底栖有孔虫的组装。

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