Biogeochemical processes at the sediment water interface and quantification of metabolically driven calcite dissolution in deep sea sediments.

The main goal of my thesis was to resolve the impact of biogeochemical processes occurring at the sediment water interface in marine sediments. The importance of the oxygen dynamics in deep sea sediments was investigated as weIl as the effect of metabolically mediated CO2 on the calcite dissolution in marine sediments. A third topic was the impact on interface gradients in an extreme environment of a shallow hydrothermal vent site as a result of unique physical processes.