Record details

Title
    Imaging the Marianske Lazne Fault (Czech Republic) by 3-D ground-penetrating radar and electric resistivity tomography
Author
    Fischer, Tomáš
    Flechsig, Christina
    Gaballah, Mahmoud
    Karousová, Magda
    Stepancikova, Petra
    Tábořík, Petr
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Studia Geophysica et Geodaetica
Vol./nr.
    Roč. 56, č. 4
Pages
    18
Year
    2012
Thesaurus term
    fault tectonics
    ground penetrating radar
    resistivity tomography
Keyword
    3-D
    Czech
    Electric
    Fault
    Ground-penetrating
    Imaging
    Lazne
    Marianske
    Radar
    Republic
    Resistivity
    Tomography
Abstract (in english)
   Geodynamic activity in the area of West Bohemia is typified by the occurrence of earthquake swarms, Quaternary volcanism and high flux of mantle-derived CO2. The highest swarm activity occurs beneath the eastern edge of the Cheb basin, which is delineated by the NW-SE trending morphologically pronounced Marianske Lazne. Fault (WE) controlling the formation of the basin. The previous trenching survey across the MLF zone has identified several fault strands with possible Quaternary activity. In this paper we present the results of the geophysical survey focused to trace the faults signatures in geophysical sections and to build an image of near surface tectonics. The method of electric resistivity tomography (ERT) along two profiles parallel to the trench identified a strong resistivity contrast between the bodies of sandy gravels in the middle and conductive clayey sands to the west and weathered crystalline basement to the east. The 2-D ground penetration radar (GPR) sections show dire
   ct correlation of reflections with lithological boundaries identified in the trench. As expected the GPR signal amplitudes increase with the resistivities found in the ERT sections. Two of the four faults identified in the trench are indicated in the resistivity and GPR sections. A 3-D GPR measurement has identified a spot of high amplitudes elongated parallel to the MLF trend, which coincides with the high resistivity body. To improve the signal-to-noise ratio of the time slices' we stacked the GPR time slices within vertically homogeneous blocks. This provided a contrast image of the sand-gravel body including its boundaries in three dimensions. The detailed analysis of the 3-D GPR cube revealed additional fault that limits the highly reflective sands and appears to be offset by another younger fault. Our results suggest a complex fault pattern in the studied area, which deserves deserves study.
Contributor
    UK Praha, Přírodovědecká fakulta
Contributor code
    UK, PřF
Source format
    R
Import date
    27. 4. 2014