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  • 1 Geodetic and Geophysical Research Institute of the Hung. Acad. Sci. H-9401 Sopron, POB 5, Hungary
  • | 2 Geodetic and Geophysical Institute of the Hungarian Academy of Sciences H-9400 Sopron, POB 5, Hungary
  • | 3 Geodetic and Geophysical Research Institute of the Hung. Acad. Sci. H-9401 Sopron, POB 5, Hungary
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Firstly the authors give an overview on the geological, geophysical and tectonical features of the Diósjenő  dislocation belt (or zone, according to some authors) around the river Ipoly near the Hungarian-Slovak border among great structural units: Vepor, Gemericum and formations of the Mid Hungarian Mts. The longest magnetic anomaly of the Pannonian Basin lies in this belt. It is assumed that it is due to ultrabasic magmatite of greenschist facies. The near-surface geoelectric soundings did not find any conductivity increase near Diósjenő  (western part of the zone), but there are graphitic micaschists in the boreholes around Szécsény. There is some earthquake activitiy in the region with hypothetical depth of 7-8 km. Two deep magnetotelluric (MT) profiles cross the dislocation zone. The resistivity distribution from the surface to the conductive asthenosphere along these profiles was obtained by using instruments, operating in two different period ranges. After processing the measured data by 1D/2D inversion, it became obvious that the dislocation zone includes electrically conducting roots at a depth of 7-11 km. This result hints at the presence of fluid in the broken rocks having increased porosity in the dislocation zone. Another component that can increase the conductivity could be the graphite (carbon) originating from the Paleozoic crystalline rocks of the Gemericum (or Vepor). The ductile phase (fluid/graphite) observed by high conductivity in the centre of the dislocation zone can play an important role in the generation of the earthquakes according to the most recent statements of the international literature.

  • Balla Z 1989: Reinterpretation of the Diósjenő dislocation zone (in Hungarian). National Report of the Eótvós Loránd Geophysical Institute of Hungary for 1987, 45--57.

  • Ádám A, Wesztergom V 2001: Acta Geol. Hung., 44, 167--192.

    () 44 Acta Geol. Hung. : 167 -192.

  • Ádám A, Szarka L 1989: MT phase anomalies due to deep conducting dikes. 34th International Geophysical Symposium, Budapest, 33--43.

    , , .

  • Ivancsics J, Kisházi P 1982: Petrographic investigation of the borehole samples from the basement of the Veporides and Zemplén Mts (in Hungarian). Manuscrip, MÁFI data storage, Budapest

    Petrographic investigation of the borehole samples from the basement of the Veporides and Zemplén Mts (in Hungarian). Manuscrip , ().

    • Search Google Scholar
  • Kárnik V 1953: Geofisikálni Sbornik, 2, 17--40.

    () 2 Geofisikálni Sbornik : 17 -40.

  • Koroknai B, Horváth P, Balogh K, Dunkl I 2001: Int. J. Earth Sciences (Geol. Rundsch.), 90, 740--741.

    () 90 Int. J. Earth Sciences (Geol. Rundsch.) : 740 -741.

  • Posgay K 1963: Acta Technica, 43, 271--287.

    () 43 Acta Technica : 271 -287.

  • Schónviszky L, Zalai Z 1985: Diósjenő dislocation belt (in Hungarian). Report of the Eövös Loránd Geophysical Institute of Hungary for 1984, 45--47.

  • Vass D, Konečný, V, Šefara J, Pristaš J, Škvarka L 1979: Geologická stavba Ipelskej kotliny a Krupinskej planiny (in Slovak with English summary: Geology of Ipelská kotlina (depression) and Krupinská planina Mts). Geol. Úst. D. Štúra Bratislava, 277.

    'Geologická stavba Ipelskej kotliny a Krupinskej planiny (in Slovak with English summary: Geology of Ipelská kotlina (depression) and Krupinská planina Mts) ' () Geol. Úst. D. Štúra Bratislava : 277.

    • Search Google Scholar
  • Zsíros T 1999: Acta Geod. Geoph. Hung., 34, 137--147.

    () 34 Acta Geod. Geoph. Hung. : 137 -147.

  • Zsíros T 2002: Earthquakes around the river Ipoly (in Hungarian). Manuscript, 1--6.

  • Zbořil L, Konečný V, Filo M 1971: Geol. Práce, Spr., 57, 239--264.

    () 57 Geol. Práce, Spr. : 239 -264.

  • Ádám A 1987: Gerlands Beitr. Geophysik, 96, 17--31.

    () 96 Gerlands Beitr. Geophysik : 17 -31.

  • Haáz I, Komáromy I 1967--1968: Geomagnetic map of Hungary. A series of 200000, M-34-XXXII. Salgótarján, L-34-I. Tatabánya, L-34-II. Budapest, ELGI, Budapest

    Geomagnetic map of Hungary , ().

  • Dapeng Zhao, Mishra O P, Sanda R 2002: Phys. Earth Planet Inter., 132, 249--267.

    () 132 Phys. Earth Planet Inter. : 249 -267.