The Neualbenreuth dry maar aligns along a tectonic fault zone, together with two scoria cones, Železná hůrka and Komorní hůrka, already known for some hundred years, and another dry maar close to Mýtina, just discovered in 2007. First evidence for a possible maar eruption were provided by geological/tectonic investigations by Dr. Horst Kämpf, German Georesearch Centre (GFZ) Potsdam, Section „Organic Geochemistry“, and Dr. Johann Rohrmüller, Bavarian Environment Agency. By a comprehensive field-geophysical survey, using gravimetric and geomagnetic probing as well as seismic and geoelectric profiling, performed by the Bavarian Environment Agency under supervision of Dr. Erwin Geiss, in cooperation with Dr. Jan Mrlina, Geophysical Institute of the Czech Academy of Science, a hidden maar structure could be discovered close to the german village Neualbenreuth in Upper Palatinate. Finally, a scientific drill core recovered by the Bavarian Environment Agency revealed a sequence of 100 m of lake sediments.

The geophysical, sedimentological, and geochemical analyses of this drill core were performed at the German Georesearch Centre (GFZ) Potsdam, Section “Climate dynamics and Landscape Evolution” under supervision by Dr. Norbert Nowaczyk, Dr. Jens Mingram, and Dr. Birgit Plessen. Palynological investigations by Dr. Martina Stebich, Senckenberg Research Station for Quaternary Palaeontology Weimar supplied additional informations on the vegetational history.

The joint analyses of first results could show that the eruption that formed the Neualbenreuth dry maar must have occurred about 280.000 to 300.000 years ago. The subsequently formed lake compiled sediments with time and got finally silted up about 85.000 years ago. Thus, this recently discovered climate archive provides detailed information about the environmental history of the penultimate glaciation, the so-called Saalian glacial and the subsequent interglacial, the Eemian warm period. Due to advancing glaciers during the last glacial in middle Europe this time interval was documented only fragmentarily up to now.

Based on the results obtained from the Neualbenreuth drill core, for the first time, geoscientists now could prove the existence of three pronounced warm phases within the Saalian glacial, characterized by a mixed deciduous forest, alternating with a glacial steppe vegetation, using continental archives. These new findings were obtained within a larger research project, mainly funded by the International Continental Scientific Drilling Project (ICDP), focussing on the active geodynamics (swarm earthquakes, rising magma, volcanism), the deep-biosphere, and the climate dynamics in the German-Czech borderland.

Partners:
Bavarian Environment Agency, Germany
Institute of Geophysics CAS, Czech Republic
Senckenberg Research Station of Quaternary Palaeontology, Germany

Links:
ICDP project website

Funding:
Bavarian Environment Agency, Germany
GFZ