Preliminary Paleomagnetic Results From The Cambrian Mesón Group: Implications For The Bolivian Orocline

SPAGNUOLO, CECILIA M.; RAPALINI, AUGUSTO E.; ASTINI, RICARDO A.

Barcelona, España

Simposio; 6th International Symposium on Andean Geodynamics; 2005

A reconnaissance paleomagnetic study was carried out on the Lizoite and Campanario Formations exposed along the Iruya River in the province of Salta, Argentina, near the Matancillas anticline. Paleomagnetic results of Lizoite Formation were negative. The Campanario Formation, on the other hand, carried stable and possibly primary magnetic remanence, which permit the calculation of a paleomagnetic pole (4.0°S; 359.0°E). This pole is not consistent with the Cambrian to Ordovician poles of Gondwana, indicating an anomaly of 38° ± 8° in declination value is observed. This suggests a clockwise rotation of the studied area of around 30°, which may be related to the regional deflections associated to the Bolivian Orocline, or to local crustal block rotations related to a dextral transfer zone along the Andean front.