Morphotectonic characteristics of Lefkas Island during the Quaternary (Ionian Sea, Greece)

Pages: 
pp. 23-33
Department of Geography & Climatology, Faculty of Geology & Geoenvironment, National & Kapodistrian University of Athens, University Campus (Panepistimiopolis), Zografou, ZC 15784, Athens, Greece
Department of Dynamic-Tectonic-Applied Geology, Faculty of Geology & Geoenvironment, National & Kapodistrian University of Athens, University Campus (Panepistimiopolis), Zografou, ZC 15784, Athens, Greece
Department of Geography & Climatology, Faculty of Geology & Geoenvironment, National & Kapodistrian University of Athens, University Campus (Panepistimiopolis), Zografou, ZC 15784, Athens, Greece
Abstract: 

This paper focuses on the study of the Quaternary morphotectonic evolution of the Lefkas Island using morphological and tectonic data. Based on our mainly morphological studies, two principal tectonic structures have been distinguished: (i) the Nydri-Vasiliki Fault Zone (NVF) and (ii) the Ionian Zone overthrust onto the Paxos Zone, which both divide the island into three morphotectonic units of Karya (KMTU), Maradochori (MMTU) and Athani (AMTU).
   Paleogeographically, it has been suggested that the broader Lefkas area was dominated by a NE–SW to ENE–WSW compressional regime since the early Pliocene that continuous in our days, resulting in the uplift of the southwestern part of the island and the submergence of the northeastern part of the island. This deformation is characterized by principal fault structures of a N110°–130° strike. These structures, combined with a fault system of N40°–60° strike representing an older Miocene fault zone, control the main morphological characteristics such as watersheds and streams and are responsible for the KMTU formation producing a northeastward plunging monoclinal en-echelon structure.
   During the Early Pleistocene, a shift of the compressional regime towards the east was responsible for the formation of a N70°–90° strike fault system. These faults had a morphotectonic effect throughout the island, controlling the watersheds and stream evolution. The continuous compressional regime recorded in our days results in the formation of fault structures, striking N20°–40° and N170°–190° that bound almost exclusively the coastal area of the island.

Keywords: 

surface analysis, drainage network, hydrological basins, morphotectonic units, Lefkas Island, Greece

VOLUME 38 (1-3)/December 2009

Geological Institute, Bulgarian Academy of Science, 1113 Sofia; Institute of Isotope Geochemistry and Mineral Resources, ETH-Zurich, 8092 Zurich
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Institute of Isotope Geochemistry and Mineral Resources, ETH-Zurich, 8092 Zurich
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Central Laboratory of Mineralogy and Crystallography, Bulgarian Academy of Science, 1113 Sofia
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Central Laboratory of Mineralogy and Crystallography, Bulgarian Academy of Science, 1113 Sofia
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Central Laboratory of Mineralogy and Crystallography, Bulgarian Academy of Science, 1113 Sofia;
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Institute of Geology, Ural Division, Russian Academy of Sciences, 167982 Syktyvkar, Russia

Department of Geography & Climatology, Faculty of Geology & Geoenvironment, National & Kapodistrian University of Athens, University Campus (Panepistimiopolis), Zografou, ZC 15784, Athens, Greece
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Department of Dynamic-Tectonic-Applied Geology, Faculty of Geology & Geoenvironment, National & Kapodistrian University of Athens, University Campus (Panepistimiopolis), Zografou, ZC 15784, Athens, Greece
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Department of Geography & Climatology, Faculty of Geology & Geoenvironment, National & Kapodistrian University of Athens, University Campus (Panepistimiopolis), Zografou, ZC 15784, Athens, Greece

Institute of Botany, Bulgarian Academy of Sciences, Sofia 1113, Acad. G. Bonchev Str., Bl. 23
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Institute of Botany, Bulgarian Academy of Sciences, Sofia 1113, Acad. G. Bonchev Str., Bl. 23

Department of Hydrogeology, Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Department of Hydrogeology, Geological Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Hydrogeology Laboratory, Institute of Water Problems, Russian Academy of Sciences, 119991 Moscow, Russia

Sofia University, Dept. of Geology, Paleontology and Fossil Fuels, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria
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Sofia University, Dept. of Geology, Paleontology and Fossil Fuels, 15 Tsar Osvoboditel Blvd., 1504 Sofia, Bulgaria