Relevamiento geofísico del Lago Yehuin. Andes Fueguinos. Argentina

LOZANO, J. G.; BRAN, D. M.; ISOLA, J.I.; CERREDO, M. E.; A.A. TASSONE

Tucuman

Congreso; XX Congreso Geológico Argentino; 2017

Asociación Geológica Argentina

Lago Yehuin occupies a compartmented structural depression originated along a segment of the left-lateral strike-slip Lago Deseado fault system. This work deals with the first geophysical survey performed within the lake. New acquired high-resolution single-channel seismic data, integrated with geological information in the surroundings of the Lago Yehuin, allowed to present a bathymetric map, reconstruct the basement surface of the lake, and the geometry, distribution, and thickness of the sedimentary infill. Two sub-basins were recognized within Lago Yehuin, both limited by a set of normal faults of medium to high angle, which overprint NE-vergent thrusts. Three seismostratigraphic units have been interpreted in the seismic records. The Lago Yehuin is considered a Neogene strike slip basin that was later affected by glacial and glacio-lacustrine deposistional events. Interpreted submerged ridge moraines within Lago Yehuin correlated with onland moraine arcs allowed to complete recesssional paths of Fuego and Ewan ice lobes. Strong structural conterol is proposed not oncly for Lago Yehuin formation but also for the general routes of the northern diffluents of Fagnano paleoglacier.