High-precision geochronology of the Equatorial Atlantic Magmatic Province (EQUAMP): Temporal correlations with the Paraná-Etendeka Magmatic Province and the Weissert Event

The Equatorial Atlantic Magmatic Province (EQUAMP) is an intrusive large igneous province (LIP) related to the dismembering of the West Gondwana supercontinent and early opening stage of the South Atlantic Ocean. Here, we present the first set of high-precision (at the 100 ka-level) U-Pb zircon geochronology for the EQUAMP by the chemical abrasion isotope dilution thermal ionization mass spectrometry method. Based on our results, the EQUAMP was emplaced in a short time interval, between 133.805 ± 0.021 Ma and 133.071 ± 0.031 Ma and appears to be coeval with the Paraná Etendeka Magmatic Province (∼134.5–132.0 Ma). Both LIPs are currently exposed at the margins of the South Atlantic Ocean and could have jointly contributed greenhouse gasses and fresh mafic exposures susceptible to chemical weathering that ultimately fertilized the oceans, cooled the Earth, affected calcareous nannoplankton and produced a paleoclimate disturbance — the Valanginian Weissert Event.