GREEN CONTINENTS AND BLACK OCEANS DURING THE EARLY CRETACEOUS

Sediments of Early Cretaceous age provide us with information on our Earth, which functioned in an intensified greenhouse mode. The principal motor assumed behind this high-energy mode is a quite exceptional phase of enhanced volcanic activity and the formation of large igneous provinces. Its direct and indirect consequences are detectable in every compartment of the Earth: continents were generally ice-free and lushy vegetation regimes lead to the build-up of important coal deposits. Biogeochemical weathering rates were generally elevated and nutrient transfer rates into the ocean high. Shallow-water carbonate-producing ecosystems coped with eutrophic phases, and anoxic conditions developed in deeper waters. In particular the Valanginian and the Early Aptian are periods of pronounced change in the Cretaceous Earth system, and the reconstruction of carbon and phosphorus fluxes during these periods provides us with a sense of the complex functioning and regulative capacities of the Early Cretaceous Earth in coping with the volcanic perturbations.