Mechanisms and time relationships of rapid climate change during the Lower Aptian OAE 1a in the southeastern North Atlantic: gas hydrate deterioration?

A key mechanism which controls rapid climate change during greenhouse periods of Mesozoic climate system is the catastrophic release of methane from gas hydrates to the oceanic and atmospheric carbon reservoirs. Excess CO2 liberated from gas hydrate desiccation is expected to result in the intensification of greenhouse conditions leading to an acceleration of the hydrological cycle, intensified weathering conditions, an elevated supply of nutrients to the ocean and extensive black shale deposition. In this project we investigate the chain of processes induced by the rapid injection of CO2 to the atmosphere-ocean system exemplified by the lower Aptian Oceanic Anoxic Event 1a, in order to elucidate the feedback mechanisms and time relationships of the atmosphere-continent-ocean system. We conduct a multi-proxy, high resolution study of OAE 1a off shore Northern Portugal at the Galicia Margin based on ODP Hole 641C.