PALEOMAGNETISM OF SOME SEDIMENTARY ROCKS OF THE LATE PALEOZOIC TUBARÃO AND PASSA DOIS GROUPS, FROM THE PARANÁ BASIN, BRAZIL

The after thermic cleaning magnetic remanence directions of twelve hand samples collected at different stratigraphic positions from the Itararé Subgroup (Tubarão Group) exposures at the Mococa area give a paleomagnetic pole at 57º South, 357° East, α 95 = 15°. The position of this pole is close to other South American paleomagnetic poles assigned to the Upper Carboniferous suggesting an equivalent age for the Itararé redbeds from Mococa. The cleaned magnetic remanences of seventeen hand samples collected at different stratigraphic positions of the Corumbatai Formation exposures (Passa Dois Group) in the Artemis-Piracicaba area define three reversals of the geomagnetic field. On the basis of the geological data and the present knowledge about the Late Paleozoic Interval of Reversed Geomagnetic Polarity, those changes of polarity are interpreted as evidence of an Upper Tartarian age for the Corumbataí redbeds from the Artemis-Piracicaba area. On the assumption of a geocentric dipole the paleomagnetic pole for the Corumbataí redbeds is calculated at 86° South, 294° East, α 95 = 14°. This pole would define a "time group" with the other Middle and Upper Permian paleomagnetic poles for South America.