Interpretation of Las Salinas sedimentary basin - Argentina, based on integration of geological and geophysical data

Abstract

Las Salinas sedimentary basin is located at 31º S and 67º W approximately, in the central-western part of Argentina. Its dimensions are 100 km long, about 50 km wide, plus an average altitude of 500 m above sea level. The basin is situated among the mountain ranges of De la Huerta, Guayaguas and Las Quijadas to the west, and the ranges of Chepes, Ulapes and San Luis to the east, with a NW-SE orientation. Its surface is approximately 5,700 km2 with an average depth of 5 km increasing in a northerly direction. The southern part of the basin is separated from the Beazley basin by the buried San Pedro ridge. New gravimetric information and archive file data, density data (from wells) and seismic reinterpretation allowed us to obtain an integrated model, which involved: a) seismic basement situated at a depth of 3.5 km obtained from seismic reinterpretation; b) crystalline basement with an average depth of 5 km obtained from inverted gravimetric data; c) perimeter and internal faults system reaching 11 km in depth suggesting a listric type disposition in depth, thick-skinned type, obtained from 2-D seismic reinterpretation, spectral analysis technique and alignments obtained from Euler’s technique; d) succession of density data extracted from wells allowing us to perform a gravimetric inversion from Bouguer’s anomalies operating with variable density; e) a system of three asymmetric breached anticlines crossed by three systems of inverse faults and f) regional structure serving as evidence, permitting us to dimension the compressive framework to which the region has been subjected. Our purpose is that this well-defined integrated model will contribute to the search for further geological structures of economic interest.