Tectonophysics2022，Vol.83320.DOI:10.1016/j.tecto.2022.229353

3D imaging of the subsurface electrical resistivity structure in West Bohemia/Upper Palatinate covering mofettes and Quaternary volcanic structures by using Magnetotellurics

Platz, Anna Weckmann, Ute Pek, Josef Kovacikova, Svetlana Klanica, Radek Mair, Johannes Aleid, Basel
Tectonophysics2022，Vol.83320.DOI:10.1016/j.tecto.2022.229353
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  • NSTL
  • Elsevier

3D imaging of the subsurface electrical resistivity structure in West Bohemia/Upper Palatinate covering mofettes and Quaternary volcanic structures by using Magnetotellurics

Platz, Anna 1Weckmann, Ute 1Pek, Josef 2Kovacikova, Svetlana 2Klanica, Radek 2Mair, Johannes 1Aleid, Basel1
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作者信息

  • 1. GFZ German Res Ctr Geosci
  • 2. Czech Acad Sci
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Abstract

The region of West Bohemia and Upper Palatinate belongs to the West Bohemian Massif. The study area is situated at the junction of three different Variscan tectonic units and hosts the ENE-WSW trending Ohre Rift as well as many different fault systems. The entire region is characterized by ongoing magmatic processes in the intra-continental lithospheric mantle expressed by a series of phenomena, including e.g. the occurrence of repeated earthquake swarms and massive degassing of mantle derived CO2 in form of mineral springs and mofettes. Ongoing active tectonics is mainly manifested by Cenozoic volcanism represented by different Quaternary volcanic structures. All these phenomena make the Ohre Rift a unique target area for European intra-continental geo-scientific research. With magnetotelluric (MT) measurements we image the subsurface distribution of the electrical resistivity and map possible fluid pathways. Two-dimensional (2D) inversion results by Munoz et al. (2018) reveal a conductive channel in the vicinity of the earthquake swarm region that extends from the lower crust to the surface forming a pathway for fluids into the region of the mofettes. A second conductive channel is present in the south of their model; however, their 2D inversions allow ambiguous interpretations of this feature. Therefore, we conducted a large 3D MT field experiment extending the study area towards the south. The 3D inversion result matches well with the known geology imaging different fluid/magma reservoirs at crust-mantle depth and mapping possible fluid pathways from the reservoirs to the surface feeding known mofettes and spas. A comparison of 3D and 2D inversion results suggests that the 2D inversion results are considerably characterized by 3D and off-profile structures. In this context, the new results advocate for the swarm earthquakes being located in the resistive host rock surrounding the conductive channels; a finding in line with observations e.g. at the San Andreas Fault, California.

Key words

Magnetotellurics/Ohre Rift/Conductive channel/Fluid/magma reservoir/Earthquake swarm/EGER RIFT/EARTHQUAKE SWARMS/NOISE SEPARATION/FLUID PATHWAYS/CENTRAL-EUROPE/TOMOGRAPHY/MASSIF/BENEATH/BASIN/LITHOSPHERE

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出版年

2022
Tectonophysics

Tectonophysics

EISCI
ISSN：0040-1951
被引量1
参考文献量87
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