Magnetotellurics

Magnetotelluric station in Mongolia
© Institut fuer Geophysik

The magnetotellurics method uses variations of natural electromagnetic fields to map the electrical conductivity distribution in the lithosphere. The sources of these field variations lie in the Earth's exterior in the ionosphere and the magnetosphere.
For example, the research group has been conducting magnetotelluric measurements in Mongolia since 2016 to investigate the structure of the Earth's crust and upper mantle beneath the Hangai mountains and the Gobi-Altai region, with the aim of gaining a better understanding of the present deformation processes far from tectonic plate boundaries, prevailing intraplate volcanism and intracontinental earthquake zones.

Topographic map of the studied area at the Bayankhongor Metal Belt, Mongolia, and corresponding crustal resistivity model (modified after: Comeau et al., 2021).
© Comeau et al., 2021

Shown here is a crustal resistivity model across the Bayankhongor Metal Belt, Mongolia, derived from three-dimensional magentotelluric inversion. The study suggests that processes leading to the formation of the mineralization zone are deeply rooted and inherited in the present-day lithospheric structure (modified after: Comeau et al., 2021).

More on this topic can be found in the project overview.

 

Comeau, M. J., Becken, M., Kuvshinov, A. V., & Demberel, S. (2021). Crustal architecture of a metallogenic belt and ophiolite belt: implications for mineral genesis and emplacement from 3-D electrical resistivity models (Bayankhongor area, Mongolia). Earth, Planets and Space, 73(1), 1-20.