Valanginian climate cooling and environmental change driven by Paraná-Etendeka basalt erosion

The Valanginian Weissert Event (ca. 134.5 Ma) has long been linked to emplacement of the Paraná-Etendeka large igneous province (LIP). Although several Mesozoic crises were triggered by volcanic CO2 emissions and global warming, causing oceanic oxygen depletion, featured climate cooling limited marine anoxia. Here, impact silicate weathering on environmental change during is investigated presenting first osmium isotope (187Os/188Os) data sets for late Berriasian–Valanginian interval. These records document a possible rise in nutrient runoff latest Berriasian, followed switch basalt erosion Valanginian. high weatherability LIP basalts enhanced despite coeval warming. This documented cooling, with consequent micronutrient potentially aiding ocean fertilization, highlighting mechanism linking formation that was uniquely different than other crises.