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Holocene geological layers, located along the Black Sea Romanian coast support the idea that the north-western part of the mentioned marine basin could have been affected by local tsunami events during the last centuries. The presence around the Black Sea basin of important seismic activities, the existence of documented gas-hydrates deposits and submarine landslides represent certain tsunami - triggering mechanisms. Recent outcrop geological investigations, based on visual descriptions, laboratory analyses and instrumental measurements, showed irregular sandy and/or shelly layers, rich in pebbles elements, poor sorted, with a microfauna mixture originated from marine, brackish and lacustrine species.
The presence of the various layers, including the possibly tsunami generated ones, was well underlined by the obvious resistivity contrasts detected by the use of continuous current geoelectrical methods. Vertical electrical sounding (VES) was performed in two geoelectrical profiles in the Vama Veche area, close to the Romanian - Bulgarian border, by using a Schlumberger array with following parameters: AB/2 max = 20m, MN = 0,5m , step AB/2 of 0,5-1m. A numerical procedure was applied for inversion of obtained data.
Five geological strata were identified on the geoelectrical sections on the basis of net resistivity contrasts. The surface horizon is formed by a 2 m thick soil, with resistivity of 7 - 35 Ohmm. The following one, which is interpreted as a possible tsunami - generated layer, has a thickness of about 30-50 cm (associated resistivity being of 25 Ohmm). The following layer consists of 1 m thick clay (resistivity of de 10 Ohmm), while the bottom one being represented by compact limestone about 5 m thick (150 Ohmm) on top of limestone saturated with saline water with resistivities of 30 - 40 Ohmm.
The geophysical data, cumulated with field geological observations pointed out the presence of a sedimentary layer (generated by a possible exceptional marine event) which extends along the cliff and on more than 90 m inland.
The use of geoelectrical methods, as presented in the present paper proved their usefulness to geological studies, specifically in determination of flag layer continuity.
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