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

The Valanginian Weissert Event (ca. 134 Ma) has long been linked to emplacement of the Parana-Etendeka large igneous province (LIP). Although several Mesozoic crises were triggered by volcanic CO2 emissions and global warming, causing oceanic oxygen depletion, the Weissert Event featured climate cooling and limited marine anoxia. Here, the impact of silicate weathering on environmental change during the Weissert Event is investigated by presenting the first osmium isotope (Os-187/Os-188) data sets for the late Berriasian-Valanginian interval. These records document a possible rise in weathering and nutrient runoff during the latest Berriasian, followed by a switch to Parana-Etendeka basalt erosion during the Valanginian. The high weatherability of LIP basalts enhanced global silicate weathering despite limited coeval climate warming. This weathering triggered the documented cooling, with consequent micronutrient runoff potentially aiding ocean fertilization, highlighting a mechanism linking LIP formation with environmental change that was uniquely different than that of other Mesozoic crises.

Automated summary

This study investigates the impact of silicate weathering on environmental change during the Valanginian Weissert Event, and provides the first osmium isotope (Os-187/Os-188) data sets for the late Berriasian-Valanginian interval. The results suggest a possible increase in weathering and nutrient runoff during the late Berriasian, followed by erosion of Parana-Etendeka basalts during the Valanginian. The enhanced global silicate weathering triggered cooling and potential ocean fertilization, highlighting a unique mechanism linking LIP formation with environmental change.