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

利用沉积档案研究过去250KYR期间地球S磁场(EMF)的时间和空间演化，其保留高分辨率、准连续的EMF的能力已被普遍证明。将对不同岩相的记录进行比较，以说明古地磁变化的次生变化。这项研究将集中在氧同位素阶段(OIS)7和5期间的地磁场行为，当EMF以地磁事件簇和相对古强度低为特征时。OIS 7和OIS 5被记录在陆相沉积档案中，具有较高的累积速率和良好的记录能力，如导线，可以保留高质量的古电动势记录。我们的主要目标是识别和分析通过磁场矢量与预期的平均地心轴偶极子配置的大偏差而突出的短暂地磁事件的记录。特别是，我们将检验这样的假设，即在北大西洋高纬度存在一块反向磁通量，它可能是OIS 5.3期间电动势闪烁的原因，也可能是更早的地磁事件的原因。地质年代学框架将以发光和TIMS U系列测年为基础。首先，将研究中欧限制区域内具有良好时间控制的剖面，以记录电动势S的时间演化，并识别特征的古地磁模式。其次，将包括更远的路段，以绘制突出特征、它们的时空演变和扩展。只要有可能，还将建立相对古强度的记录。

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.