NEOPROTEROZOIC TO EARLY PALEOZOIC CRUSTAL DISCONTINUITIES IN CENTRAL ARGENTINA IMAGED BY 3-D MAGNETOTELLURICS

MARTINEZ DOPICO, C.I.; GUEVARA LILIANA; FAVETTO, A.; LÓPEZ DE LUCHI, M. G.

Rio de Janeiro

Congreso; 49º Congresso Brasileiro de Geologia; 2018

Sociedad Brasileña de Geologia

Magnetotelluric (MT) method is an indirect way to unravel complex crustal structures. The interpretation of 2-D MT data could be enhanced applying a three-dimensional (3-D) processing. This procedure generates more realistic images of the crust beneath than MT analysis assuming a 2-D structure. We have reprocessed MT data using 3-D inversion methods incorporating profiles that cut across the central region of Argentina from 60.00ºW and 67.00ºW along an E-W transects at 31.7ºS and 29.5ºS latitude and NW-SE, NE-SW around the north of San Luis province (>44 stations). We analized vertical E-W slices (600 km length, 100 km depth) from the city of Santa Fé to Ulapes town (south of La Rioja Province). These slices start at 31.7ºS latitude and are separated from each other by 50 km until Ceres town, 200 km towards north. 3-D modelling of MT data shows a significant lateral and vertical heterogeneities in the lithospheric structure of central Argentina. From east to west we recognize a high resistive anomaly (R1; Rio de la Plata Craton) that is covered by a supracrustal conductor (C1;