The Valanginian isotope event: A complex suite of palaeoenvironmental perturbations

► Synchronous but inverse response of carbonate systems to increase in nutrient input. ► Increased weathering controls nutrient influx and nannoplankton production. ► More humid climates are most probably the cause for weathering intensification. ► Pelagic production matches Valanginian carbon isotopic fluctuations. ► Combination of cooling and nutrient increase led of carbonate platform demise.