New paleomagnetic data from the Paraná Magmatic Province: Brief emplacement time and tectonism. (March 2021) - Ernesto, Marcia
Abstract: The Paraná Magmatic Province (PMP) in southern Brazil is divided into three sub-provinces historically characterized by their Ti content (low-Ti in the southern sub-province, high-Ti in the northern, and mixed in the central sub-province). Ar/Ar and U-Pb ages for the PMP usually places the whole volcanism in a brief interval of ∼135-133 Ma with younger ages to the north. The existing paleomagnetic data tend to show differences among the three areas, so far related to the age migration. The new data from 39 flows and sills from the Northern Paraná Magmatic Province incorporated into the pre-existing database allowed the calculation of a new paleomagnetic pole after filtering the over-represented sites. However, the recalculated pole for the central PMP using all available data is distinct from the other poles. The mean magnetic inclination for the rocks of central PMP is ∼5° lower than the inclination for the other areas, which may be caused by an N-S dipping of the central area. Highlights: New high-quality paleomagnetic pole for the north Paraná Magmatic Province (PMP). The pole for the central PMP suggests a ∼5° N-S tilting of the area. The new data reinforces the short duration (∼1 Ma) for the emplacement of the whole PMP.