Crystalline basement characterization using magnetotellurics in the Chacoparanaense basin (31.5ºS), Argentina.

FAVETTO, A., POMPOSIELLO, AND BOOKER

Rio de Janeiro

Congreso; 10 Congreso de la Sociedad Geofísica Brasilera; 2007

New magnetotelluric data were collected in the Llanura Chacopampeana through the western part of Córdoba  province up to the Rio Uruguay. These data allowed us to complete the characterization of the eastern end of the Chacoparanense sedimentary basin. The crystalline basement depth and electrical features of sediments permitted to describe the boundaries between the different formations. Dimensionality analysis showed that electrical structure is one dimensional (1D) for periods less than 30 s while for longer periods they are mainly two-dimensional (2D). In the last case a strike direction oriented parallel to the surface geological strike (around NS) was found. From previous results at profiles measured to the west, the resistivity model permitted to delimitate the western part of the basin.  The model obtained in this paper shows the description of the basin where the bottom of the sedimentary basin extends to a depth of about 5 - 6 km in the central part and being in agreement with data from deep wells existing in the area