La prolongación austral de las Sierras de San Luis

KOSTADINOFF, J; GREGORI, D; BJERG, E A; RANIOLO, A; ALVAREZ, G; BJERG, E A

Revista de La Asociacion Geologica Argentina

Asociación Geológica Argentina

Año: 2002 vol. 57 p. 359 - 364

0004-4822

The sierras de Varela, Pozo Peje and Los Cerrillos are the southernmost geomorphological expression of the Sierras de San Luis, a N-S trending mountain range. In the Sierras de Varela, the basement consists of several kinds of schist and migmatites. South of Sierra de Varela, the main outcrops are those of a Triassic rhyolitic volcanic complex. Gravity and magnetic measurements reveal strong anomalies, which are attributed to the presence of mafic and ultramafic rocks in the subsurface. The same type of rocks are responsible for similar geophysical anomalies observedin the area of Las Aguilas and Virorco, in the northern part of the Sierras de San Luis. Geophysical studies suggest that basic rocks are also present in the western part of the Alvear basin.