Abstract

SAGRIPANTI, Guillermo L et al. Strong intraplate paleoearthquakes and their recurrence related to Las Lagunas fault, Sierras Pampeanas of Cordoba. Rev. Asoc. Geol. Argent. [online]. 2011, vol.68, n.1, pp.53-71. ISSN 0004-4822.

Evidences like landforms and deformations in loose quaternary sediments, in the argentinian intraplate, at latitude 33° S, southern part of the Cordoba province, suggest that the Neogene tectonic activity continues into the Holocene and certainly had been associated to strong paleoearthquakes. The objectives of this work are to make a reconstruction of the prehistoric seis-micity record of the region by paleoseismological investigations, and to estimate the seismogenic potential of a source with proven Quaternary activity, with the aim of setting the basis to estimate the seismic risk of the region. Six trenches were dug across the trace of the Las Lagunas fault, cutting eolian, fluvial, and lagoon sediments. In the sites, several coseismic deformation and liquefaction structures were observed at a mesoscopic scale. The results allowed the proposal of a retrodeformation model for the fault, calculating the period of recurrence of strong earthquakes, around of 1,2 - 2,0 Kyr. The magnitude of some paleoevents Ms > 6,6 and maximum earthquake were also estimated.

Keywords : Fault; Intraplate; Trench; Paleoearthquake; Seismites.

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