Continental sedimentary archives of Quaternary warm episodes as high-fidelity recorders of the Earth`s magnetic field - high resolution palaeomagnetism of lake sediments, loess-palaeosol sequences and travertine covering OIS 5 and 7

第四纪温暖时期的大陆沉积档案作为地球磁场的高保真记录器 - 湖泊沉积物、黄土-古土壤层序和覆盖 OIS 5 和 7 的石灰华的高分辨率古地磁学

• 批准号: 5370964
• 负责人: Dr. Ulrich Hambach
• 金额: --
• 依托单位: Lehrstuhl für Geomorphologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5370964?language=en
• 关键词: Continental; sedimentary; archives; Quaternary; warm

The temporal and spatial evolution of the Earth´s magnetic field (EMF) during the past 250 kyr will be studied using sedimentary archives whose ability to retain high-resolution, quasi continuous records of the EMF is generally proven. Records from differing lithofacies´ will be compared to account for secondary alterations of the palaeomagnetic variations. The study will focus on the behaviour of the geomagnetic field during the oxygen isotope stages (OIS) 7 and 5 when the EMF is characterised by clusters of geomagnetic events and relative palaeointensity lows. OIS 7 and 5 are documented in continental sedimentary archives with high accumulation rates and good recording capability such as travertines, which can retain high quality records of the palaeo EMF. It is our main goal to identify and analyse records of short-lived geomagnetic events prominent through large deviations of the magnetic field vector form the expected, average geocentric axial dipole configuration. Particularly, we will test the hypothesis that a patch of reverse flux exists in high northern Atlantic latitudes which could be responsible for a flicker of the EMF during OIS 5.3 and possibly older geomagnetic events. The geochronological framework will be based on luminescence and TIMS U-series dating. Firstly, sections with good time control from a restricted area in Central Europe will be studied to document the EMF´s temporal evolution and to identify characteristic palaeomagnetic patterns. Secondly, more distant sections will be included to map outstanding features, their temporal and spatial evolution and extension. Wherever possible records of the relative palaeointensity will be constructed, too.

将利用沉积档案研究过去250 kyr期间地球磁场（EMF）的时空演变，这些档案保存高分辨率、准连续的EMF记录的能力已得到普遍证实。将比较不同岩相的记录，以解释古地磁变化的次生变化。研究将集中在氧同位素阶段（OIS） 7和5期间地磁场的行为，当EMF以地磁事件集群和相对古强度低为特征时。OIS 7和OIS 5记录在大陆沉积档案中，它们具有较高的堆积速率和较好的记录能力，如石灰华，可以保留高质量的古EMF记录。我们的主要目标是识别和分析短期地磁事件的记录，这些记录主要是由于磁场矢量与预期的平均地心轴向偶极子配置的大偏差而引起的。特别是，我们将检验一个假设，即在北大西洋高纬度地区存在一块反向通量，这可能是在OIS 5.3和可能更早的地磁事件期间造成EMF闪烁的原因。地质年代学框架将基于发光和TIMS u系列测年。首先，将研究中欧受限区域具有良好时间控制的剖面，以记录EMF的时间演变并识别特征古地磁模式。其次，将包括更远的部分，以绘制突出特征及其时空演变和扩展。只要有可能，也会建立相对古强度的记录。