The Pannon LitH2Oscope magnetotelluric array in the Pannonian Basin

Abstract

The Pannonian Basin is one of the best natural laboratories in the world to study the lithospheric response to continental extension and subsequent tectonic inversion. Here we address the topic of lithospheric structure by a combined geochemical and magnetotelluric analysis, which has been carried out in the framework of the Pannon LitH2Oscope project. The main objective was to detect the resistivity distribution over the entire lithosphere by magnetotelluric measurements, considering the lithological resistivity properties and relate the results to the structure and evolution of the Pannonian Basin. The Pannon LitH2Oscope MT array was used to estimate the depth of the Lithosphere-Asthenosphere Boundary (LAB), considering the legacy MT data and compared to previous estimates for the region. Using the MT and geomagnetic response functions, major structural zones of the Pannonian basin, such as the Mid-Hungarian Shear Zone or fault systems like the Makó Trough and the Békés Basin, were also imaged. In addition, we used the apparent resistivity soundings to compare 1D resistivity models computed from geochemistry and obtained from field MT measurements. This comparison provided new constrains for the composition, fluid and melt content variations at the local lithosphere-asthenosphere boundary. The Pannon LitH2Oscope MT dataset and the results presented in this paper provide input for more complex 3D inversions and further investigations of the lithospheric structure in the Carpathian-Pannonian region.

Electrical Resistivity Imaging of the Northeast Carpathian Volcanic Arc With 3‐D Magnetotellurics Reveals Shallow Hydrothermal System

“…In the study area (see Figure 2), the Miocene calc-alkaline arc magmatism, possibly related to a slab breakoff (Seghedi et al, 2004), was localized along the inner part of the Carpathian fold belt and affected the northern part of the Pannonian Basin. Using 2-D magnetotelluric profiling Patkó et al (2021) have shown that the volcanic field in the inner part of the Western Carpathians (Hungary) is connected to a deep sublithospheric magmatic source region by an electrically conductive conduit interpreted as a zone of metasomatism and/or partial melting, which is supported by a recent study by Rubóczki et al (2024).…”