Possible Holocene excursion of the Earth's magnetic field in southern South America: New records from archaeological sites in Argentina

Abstract

Palaeomagnetic studies were carried out in several archaeological and palaeontological sites across Argentina and Chile. Remanence directions far removed from the present magnetic field, probably corresponding to a field excursion were recorded in several stratigraphic sections spaning ~11 to 2 ky bp. Detailed palaeomagnetic data from 235 cores obtained in six sections from archaeological sites in Argentina are reported. Stability of the NRM was analyzed by progressive thermal and alternating field demagnetization and ChRM directions determined in most cases. Computed VGPs from those directions tend to be concentrated over North America, Europe, Eastern Asia and Africa. Using 275 VGPs a palaeomagnetic pole that is ~20°apart from the Earth's rotation's axis was obtained.