Bajada del Diablo Circular Structures (Chubut, Argentina): ground gravity, magnetic and electromagnetic surveys.

PREZZI, CLAUDIA BEATRIZ; MARÍA JULIA ORGEIRA; ACEVEDO, ROGELIO; PONCE, FEDERICO; MARTÍNEZ, OSCAR; SARNATARO, ALDO; RABASSA, JORGE

Montevideo

Congreso; Latinmag Tercera Reunión Bienal de la Asociación Latinoamericana de Paleomagnetismo y Geomagnetismo; 2013

Bajada del Diablo is located in the Northern Patagonian Massif, Chubut, Argentina. Circular structures have been identified on two rock types: basalts of the Quiñelaf Eruptive Complex and comglomerates of Pampa Sastre Formation. An impact origin has been proposed for these circular structures. It is widely accepted that a key tool in the initial recognition and characterization of terrestrial impact craters is geophysics. A set of general criteria has been established, which corresponds to the geophysical signature of impact craters. These criteria can be used to evaluate the hypothesis of impact origin of circular structures. With the aim of further investigate the proposed impact origin of the circular structures identified in Bajada del Diablo, we carried out detailed topographic, gravimetric, magnetic and electromagnetic ground surveys in two craters (8 and G) found in Pampa Sastre conglomerates and in basalts of the Quiñelaf Eruptive Complex, respectively. We conclude that the morphological, geological and geophysical features of the studied circular structures could be satisfactorily explained assuming an extra-terrestrial projectile impact.