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

• Applicant: Dr. Ulrich Hambach
• Subject Area: Geophysics
• Term: from 2002 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5370964

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.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1097: Geomagnetic Variations: Spatio-Temporal Structure, Processes, and Effects on System Earth
• Participating Person: Professor Dr. Ludwig Zöller