Experimental constraints on carbon transformation and reactivity of abiotic/ biotic compounds during serpentinization within the lithosphere

Circulation of seawater through the oceanic lithosphere represents the largest fluid-rock interaction system on Earth. As a volatile part of biological and geological cycles, carbon is profoundly affected by fluid-rock interactions.

As gaseous CO2 and CH4, carbon is a greenhouse gas, and in the form of simple carboxylic acids, it is an energy source for subsurface life.

However, our knowledge of carbon fluxes and the fate of especially organic carbon in hydrothermal systems remains limited.

Detailed datasets of rock-dominated open system experiments and in situ identification of organic compounds are needed to determine the mechanism that controls CO2 fluxes and reactivity in the subsurface and to extend our knowledge of the deep biosphere. Conventional experiments often use closed system reactors, and microbiology studies often depend on bulk rock analyses.

These methods only provide a first idea of the reactions occurring in the lithosphere.

The project presented here aims to conduct novel open-system experiments to increase our understanding of environmental conditions and processes that control the in situ transformation and reactivity of carbon compounds within hydrothermal systems.

Parameters influencing the reactivity will be disentangled by combining state-of-the-art element and microstructural analyses with new powerful 3D visualization methods. First, a better understanding of organic matter flow within the lithosphere is established.

Afterward, a conceptual model for C-transformation will be developed by applying experiments in a monitored environment.

Finally, the results will highlight the effect of coupled processes occurring at the pore scale on the carbonation rate and efficiency relevant to industrial implementation.

ECoCT will allow me to improve my interdisciplinary skills and thinking, increase my professional network and gain experience in outreach and management, thus greatly enhancing my future career opportunities.