Geomicrobiology of the Kraubath magnesite deposit

Archaea form one of the three domains of life – next to bacteria and organisms containing cell nuclei. They are also the only known organisms that can produce methane. Methanogenic archaea have been discovered along mid-ocean ridges, where they utilize Hydrogen as a source of energy.

This molecular hydrogen is released during serpentinization, a geological process in which olivine rich rocks of the oceanic crust are converted into serpentinite rock or serpentine minerals through contact with water (e.g., lizardite, antigorite, chrysotile). However, serpentinization can also take place on land wherever groundwater circulates in continental ocean floor rocks whose composition leads to the formation of Carbonate minerals such as magnesite. This is the case in Kraubath an der Mur, a small town in Styria.

The formation of magnesite (MgCO3) at temperatures below 80°C is a key research question with implications beyond geobiology. Namely because of the possibility to capture and store carbon dioxide from the atmosphere.

At temperatures below 80°C, magnesite is only formed in certain mineral deposits, such as lakes with high salt content (soda lakes or sabkhas) or some alkaline springs. The Styrian Kraubath massif, the largest ultramafic complex of the Eastern Alps, represents one of the typical localities for its formation. The mechanisms of how the cryptocrystalline gel magnesite is formed, is still poorly understood and a microbiological formation process cannot currently be excluded.

The aim of this project is to research whether methanogenic Archaea encourage the formation of magnesite at low temperatures, and are thus key organisms in the formation of magnesite deposits.

Duration: 01.10.2020-30.09.2023

Funding agency: Austrian Science Fund (FWF): T 1189 Firnberg-Programm

Project leader: Jennifer Zwicker, Department of Mineralogy and Crystallography, University of Vienna

National collaborators: Dr. Simon K.-M. R. Rittmann 

Participants: Hayk Palabikyan