Late Cretaceous alkaline complexes, southeastern Brazil: Paleomagnetism and geochronology

Late Cretaceous alkaline rocks from Poços de Caldas, Itatiaia, Passa Quatro and Sمo Sebastiمo Island were studied with the main purpose of improving the South American apparent polar wander path (APWP). RbSr age determinations for Passa Quatro and alkaline stocks from Sمo Sebastiمo Island are around 70 and 81 Ma respectively. The magnetic carriers in the rocks studied were maghemite and highly oxidized titanomagnetites. The paleomagnetic poles obtained in this work are 320.1°E, 83.2°S (N = 47, A95 = 2.7°, KSC = 2609.8) for Poços de Caldas, 360.0°E, 79.5°S (N = 18, A95 = 5.7°, KSC = 607.4) for Passa Quatro and Itatiaia, and 331.9°E, 79.4°S (N = 18, A95 = 4.9°, KSC = 862.4) for Sمo Sebastiمo Island (the ISLAND set).