Paleogene-Lower Miocene local clockwise vertical axis tectonic rotations in the Northern Argentine Puna: New data.

PREZZI, CLAUDIA BEATRIZ; CAFFE, PABLO; IGLESIA LLANOS, MARÍA P.

Tandil

Congreso; Second Biennial Meeting of Latinmag; 2011

Along the Central Andes a pattern of vertical axis tectonic rotations has been paleomagnetically identified.Such rotations are counterclockwise north of Arica Deflection (~19° S) and clockwise to the south. Different hypothesis and models have been proposed to explain the Central Andean Rotation Pattern (CARP). However, the CARP is a subject of ongoing debate. Recently, different authors have proposed the possible existence of different rotational domains with distinct characteristics. Particularly, paleogene rocks cropping out in northern Chile and in the Eastern Cordillera would have registered large rotations. A close correlation would exist between the style and the temporal and spatial pattern of deformation and the amount of recorded vertical axis rotations in the Southern Central Andes. In order to further investigate such relationship, new paleomagnetic studies were carried out in Paleogene – Lower Miocene rocks of the northern Argentine Puna. Our results indicate that while one of the sampled localities did not undergo significant vertical axis tectonic rotations, the other two registered clockwise vertical axis tectonic rotations larger than 30°. These results suggest that rotations are of local character, and would indicate that while rocks older than 17 Ma underwent large magnitude vertical axis rotations, the overlying rocks were not affected by rotational deformation.