Abstract

KOSTADINOFF, José; FERRACUTTI, Gabriela  and  BJERG, Ernesto. Interpretation of a gravimagnetometric section over Pampa de las Invernadas, Sierra Grande de San Luis. Rev. Asoc. Geol. Argent. [online]. 2010, vol.67, n.3, pp.349-353. ISSN 0004-4822.

A geophysical profile in the NW part of the Sierra Grande de San Luis has shown the existence of gravity field anomalies in an area with outcrops of mafic-ultramafic rocks hosted by Ordovician granitic bodies. Bouguer gravity anomalies where compared with those of the earth magnetic field. Geophysical models were constructed based on the measured density of the units outcropping in this area (granitoids, gneisses, mafic and ultramafic rocks) and the theoretical value of the upper crust. As a result, it is suggested that mafic-ultramafic inclusions in the granitic bodies constitute up to 40 % of the total volume of the last ones. These results suggest that Pampa de las Invernadas area could be of economic significance, since its geophysical signature is similar to that of the Río de Las Águilas mafic-ultramafic complex, in the southern portion of this region. In this complex a significant mineralization of base metals and platinum group minerals has been established.

Keywords : Geophysics; Gravimetric; Magnetometric; Mafic-ultramafic; Pampa de las Invernadas.

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