Magnetic and gravity anomalies in the Sierra del Padre and Sierra del Tala, San Luis province, Argentina: evidence of buried mafic-ultramafic rocks.

KOSTADINOFF, J; BJERG, E A; GREGORI, D; DELPINO, S; DIMIERI, L; RANIOLO, A; MOGESSIE, A; HOINKES, G; HAUZENBERGER, CH; FELFERNIG, A; BJERG, E A

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

Elsevier

Lugar: Amsterdam; Año: 2001 vol. 14 p. 271 - 276

0895-9811

This paper presents the results of a geophysical study of the southern portion of the Sierra Grande de San Luis, San Luis Province, Argentina. A 26 mGal amplitude anomaly (Charlone anomaly), measuring 40 km long by 7 km wide, between Sierra de los Padres and Zanjitas reflects the presence of high-density rocks located at approximately 2000 m depth. Geophysical models based on more than 300 gravimetric, magnetometric and geological field measurements and observations suggest that the mafic-ultramafic belt of Sierra Grande de San Luis continues south of San Luis. The low magnitude of the terrestrial magnetic field anomalies indicates that these mafic-ultramafic rocks do not carry a base metal sulfides (BSE) mineralization. The Charlone gravimetric anomaly is generated by a belt of mafic-ultramafic rocks whose amplitude is comparable with that responsible for the Virorco-Las Aguilas gravimetric anomaly.