Beschreibung
The Early Jurassic (~201 to 174 Ma) was marked by multiple periods of major global climatic and environmental change, biotic turnover and perturbed global geochemical cycles, which have been linked to volcanic outgassing and the release of biogenic or thermogenic methane into the ocean-atmosphere system. Major events in this interval include not only the mass extinction at the Triassic-Jurassic boundary, and the Toarcian Oceanic Anoxic Event (T-OAE) but also major global environmental changes at the Sinemurian-Pliensbachian boundary at ~190 Ma and during the Late Pliensbachian at ~181 Ma where climate extremes may have ranged from glacial to ice free. The time interval of the Pliensbachian will be investigated using sample material from a previously drilled core ‘Mochras A’ and supplemented by the newly drilled ‘Mochras B’ core on the coast of West Wales, England. The time interval of the Pliensbachian provides the unique opportunity to study the coupling of the global carbon and calcium cycles as well as the influence of orbital Milankovitch forcing on the global calcium cycle.