South American reference pole for the mid-Cretaceous: Further constraints in the interpretation of Andean paleomagnetic data

Abstract

A paleomagnetic study of the Aptian Cerro Barcino Formation in central Patagonia showed the presence of a stable magnetization with a positive tilt test. The obtained pole position (lat 85°S, long 181°E, α 95 = 5.6°, N = 11) differs from reliable Early and Late Cretaceous South American cratonic poles. The Cerro Barcino pole overlaps coeval poles from the Chilean Andean fore arc previously interpreted to record crustal block rotations. This new result indicates that previously published Andean tectonic models must be reviewed.