Testing the Mesozoic Dipole Low in the Early Cretaceous with multispecimen paleointensities from the Paraná Flood Basalts, Southern Brazil

Abstract

The Mesozoic Dipole Low (MDL), when the mean geomagnetic field intensity did not exceed one-third of the mean value in the Late Cenozoic, was suggested from the end of the Early Jurassic to the Late Cretaceous (180–120 Ma) in the 1990s. Subsequent studies evidenced that the MDL could have lasted from 260 to 50 Ma. We report new high-quality absolute paleointensity data based on a multispecimen approach from basaltic lava flows associated with the 132–135 Ma Paraná Magmatic Province. Our results suggest that the geomagnetic field in the middle Cretaceous was higher compared to the present-day value, and the MDL extent was likely shorter than usually considered.