Estudio paleomagnético en las sierras de Pajarillo-Copacabana y Masa (Provincia de Córdoba): nuevo polo paleomagnético cretácico temprano para Sudamérica

GEUNA, SILVANA

REVISTA DE LA ASOCIACIÓN GEOLÓGICA ARGENTINA

Asociación Geológica Argentina

Lugar: Buenos Aires; Año: 1996 vol. 51 p. 224 - 234

0004-4822

Palaeomagnetic study is presented for the Early Cretaceous red beds cropping out in the north-western reaches of the Sierra Chica in Córdoba province. Thermal demagnetization effectively isolated a high temperature characteristic magnetization in 12 of the 23 sites sampled at three different localities. Although samples from remaining sites could not be completely demagnetized, they were useful in magnetostratigraphic analysis. The characteristic magnetization yielded a pole position at 84.1oE, 85.3oS (A95 7.5o), overlapping the coeval Serra Geral reference pole. Previous paleomagnetic poles obtained from Early Cretaceous volcanic rocks in Córdoba are not consistent with that reference pole. The results indicate that this documented inconsistency may not be due to peculiarities of the geomagnetic field or to genuine apparent polar wander, but to local block rotation or inadequate sampling of geomagnetic secular variation.