Multiple geophysical methods examining neotectonic structures in the western foothills of the sierra del Maitén (Argentina), North Patagonian Andes.

LINCE KLINGER, F; ORTS, D; GIMENEZ, M.; ANDRES FOLGUERA

NEAR SURFACE GEOPHYSICS

EUROPEAN ASSOC GEOSCIENTISTS & ENGINEERS

Lugar: Houten (Holanda); Año: 2015

1569-4445

A high-resolution geophysical study was carried out in a region of the retroarc of the PatagonianAndes located on the western slope of the Sierra de El Maitén. This structure is characterized by animbricated west-vergent fault system developed in the orogenic front area of the North PatagonianAndes that has uplifted. Oligocene volcanic rocks (Ventana Formation) affect Miocene toQuaternary sediments. Even though neotectonic fault scarps are affecting Quaternary deposits in thefoothills of this range, no direct observation of slip in Quaternary strata was determined. The mainobjective of this study is to determine geometry of recognized neotectonic structures, characterizingthem by variations in magnetic susceptibility, density, and p-wave velocities. The combined applicationof different geophysical methods has allowed the characterization of the bedrock geometry andthe determination of neotectonic displacements along faults. The potential field model and its integrationwith a seismic profile show the accurate geometry of this tectonic zone, which is crucial forseismogenic hazard analysis, in the area of northern Patagonia, a highly significant economic zonedue to tourism with several towns (El Maitén, Esquel, and San Carlos de Bariloche) dispersedthroughout the area of young tectonic activity.