SOUTH-AMERICAN REFERENCE POLE FOR THE MIDCRETACEOUS - FURTHER CONSTRAINTS IN THE INTERPRETATION OF ANDEAN PALEOMAGNETIC DATA

A paleomagnetic study of the Aptian Cerro Barcino Formation in central Patagonia showed the presence of a stable magnetization with a positi ve tilt test. The obtained pole position (lat 85-degrees-S, long 181-d egrees-E, alpha95 = 5.6-degrees, N = 11) differs from reliable Early a nd Late Cretaceous South American cratonic poles. The Cerro Barcino po le overlaps coeval poles from the Chilean Andean fore arc previously i nterpreted to record crustal block rotations. This new result indicate s that previously published Andean tectonic models must be reviewed.