The project aims at improving global geomagnetic field reconstructions spanning the past millennia by investigating the quality of Holocene paleomagnetic sediment records. Global field models are used both to study geodynamo processes in the Earth's core and to take into account the shielding effect of the geomagnetic field in the interaction of galactic cosmic rays with our planet's environment. The resolution and reliability of Holocene field models at present are limited for two reasons:

• The sparse southern hemisphere archeomagnetic data coverage,
• and secondly, large data and dating uncertainties particularly in sediment data.

A re-evaluation of all compiled sediment records based on lithology and comparison to global models will improve the growing understanding of sediment data quality, possibly leading to correction methods and improved age models.

We are compiling a database containing relevant meta-data for all available sediment records (e.g. lithology, dating method) and then use this information to investigate the quality of the magnetic signal and age control in individual records.

The objective is an improvement of Holocene field reconstructions as a prerequisite to investigate the long-term evolution of our planet's magnetic shield and its interaction with the planetary environment.

This project is part of the DFG priority programme SPP 1488, "Planetary Magnetism".