Abstract

SAGRIPANTI, GuillermoLuis  and  VILLALBA, Diego. Paleoseismicity and estimation of therecurrence interval during strong earthquakes associated with intraplate faultsat the 33ºS latitude, Las Lagunas fault, Sampacho, Córdoba. Rev. Asoc. Geol. Argent. [online]. 2009, vol.65, n.3, pp.417-428. ISSN 0004-4822.

Morphologies and deformations of Quaternary sediments, added to theoccurrence of shallow seismicity in a sector of the Argentine intraplate atlatitude 33ºS, in the southern region of Córdoba province, evidence that theMiocene-Pleistocene tectonic activity continued into the Holocene. Thisactivity has been certainly associated with strong earthquake occurrences,whose number, magnitude and recurrence interval remained unknown. The objectiveof the present work is to reconstruct the prehistoric seismicity and toestimate the recurrence interval of strong earthquakes for the region throughpaleoseismic investigations based on the study of coseismic deformations intrenches. Data obtained from the description and interpretation of lithologicprofiles and mesoscopic structures from two trenches allowed us to propose amodel of faulting retrodeformation for Las Lagunas fault; the occurrence ofmany paleoearthquakes in the last 3,700 years was recognized, with a recurrenceinterval between 900 and 1,200 years for this sector of intraplatesetting.

Keywords : Fault; Intraplate; Trench; Paleoearthquake; Recurrence intervals.

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