New proposal for the track of the Apparent Polar Wander Path for South America during the Permian-Triassic age.

TOMEZZOLI, R.N.

Santiago de Chile

Simposio; GEOSUR; 2007

New proposal for the track of the Apparent Polar Wander Path for South America during the Permian-Triassic age Renata Nela Tomezzoli (1)* renata@gl.fcen.uba.ar (1) INGEODAV, Depto. Cs. Geológicas, FCEN, Universidad de Buenos Aires, Argentina             Based on the best fitting of the apparent polar wander paths (APWPs) of the continents, there are different proposals of Pangea´s configuration. The differences have been explained as consequences of local rotation, incorrect age assignment of the rocks, and also the theory of the axial dipole configuration of the terrestrial magnetic field have been discuss. More recently, with the publication of new reliable paleomagnetic data, there is a general acceptation of the track of the APWP of South America between the Upper Carboniferous and Lower upper Permian. This arrangement of the paleomagnetic poles gives, when are compared with the curves of the others continents, in a Pangea type B. However, the absence of reliable paleomagnetic poles make unclear which is track of the curve during the lapse of the Upper Permian – Lower Triassic and results in a high controversy about the movements of the continents. Most the available paleomagnetic poles for that period are considered unreliable according to the new parameters. The differences between those paleomagnetic poles with this part of the curve usually have been explained as consequences of tectonic rotation.  However, a careful revision with the original contributions of the all publish paleomagnetic poles gives the conclusion that the age of the paleomagnetic poles explained as tectonic rotation have been assigned based on regional correlations and therefore could be different. The other important observation was that in most of the cases started to appear the normal direction of the magnetic field, instead of the typical Kiaman reverse direction. Based on that observation a new hypothetical track of the APWP for South America during Permo – Triassic times is proposed.