...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Asian earth sciences >Paleomagnetic record for the past 80 ka from the Mahanadi basin, Bay of Bengal
【24h】

Paleomagnetic record for the past 80 ka from the Mahanadi basin, Bay of Bengal

机译：孟加拉湾Mahanadi盆地过去80 ka的古磁记录

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

High resolution paleomagnetic investigations were performed on a 50.08 m long sediment core (MD161/20) from Mahanadi basin, Bay of Bengal. Core yielded reliable paleomagnetic results for top 20 m below seafloor (mbsf) which spans about 80 ka. Based on the analysis of rock magnetic data, the core is subdivided into five distinct Zones: Zone 1 and Zone 2 cover top 20 mbsf and do not show any abrupt change in magnetic mineralogy, concentration and grain size. Zones 3 and 5 show significant reduction in chi(LF), chi(ARM) and SIRM due to dissolution of magnetic minerals. Zone 4 shows moderate values of chi(LF) and SIRM. The low value of Mum suggests that magnetic signal is mostly carried by magnetic grains in PSD/MD state. The paleomagnetic data for the top 20 mbsf show four prominent geomagnetic excursions at similar to 9 mbsf, similar to 13.5 to 15 mbsf, similar to 16.3 mbsf and similar to 18 to 18.2 mbsf. The age-depth relationship is established using stratigraphic correlation between well-dated sedimentary core NGHP-01-19B and the core MD161/20. The ages of the observed excursions correspond to similar to 18 to 20 ka, similar to 42 to 49 ka, similar to 54 to 57 ka and similar to 69 to 70 ka. The excursions at similar to 42 to 49 ka, similar to 54 to 57 ka, and similar to 67 to 70 ka is similar to the known excursions the Laschamp and the split Norwegian-Greenland Sea events (NGS-I and NGSII). The excursion at 18-20 ka is not observed globally and may be related to lithological/sedimentological changes occurring during last glacial maxima (LGM). The virtual geomagnetic path (VGP) of Laschamp excursion traces clockwise loop. All excursions identified in present study fall in the periods of relatively low paleointensity.
机译：对来自孟加拉湾Mahanadi盆地的50.08 m长的沉积岩心（MD161 / 20）进行了高分辨率的古磁研究。在海底（mbsf）下方20 m（跨度约80 ka）的顶部，铁芯产生了可靠的古磁结果。根据对岩石磁数据的分析，将岩心分为五个不同的区域：区域1和区域2覆盖了最高20 mbsf，并且在磁性矿物学，浓度和晶粒尺寸方面均未出现任何突然变化。 3区和5区显示由于磁性矿物的溶解，chi（LF），chi（ARM）和SIRM显着减少。区域4显示chi（LF）和SIRM的中等值。 Mum的值较低，表明磁信号主要由处于PSD / MD状态的磁粒携带。前20 mbsf的古磁数据显示四个显着的地磁偏移，分别为9 mbsf，约13.5到15 mbsf，约16.3 mbsf和约18到18.2 mbsf。利用年代久远的沉积岩心NGHP-01-19B和岩心MD161 / 20之间的地层相关性建立了年龄-深度关系。所观察到的偏移的年龄对应于类似于18至20 ka，相似于42至49 ka，相似于54至57 ka和相似于69至70 ka。相似于42至49 ka，相似于54至57 ka，相似于67至70 ka的偏移与已知的偏移Laschamp和分开的挪威-格陵兰海事件（NGS-1和NGSII）相似。在全球范围内未观察到18-20 ka的偏移，这可能与上一次冰期最大值（LGM）期间发生的岩性/沉积学变化有关。 Laschamp偏移的虚拟地磁路径（VGP）沿顺时针方向跟踪。在本研究中确定的所有偏移都属于相对较低的古强度时期。

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