Dr Cédric M. John
Broadly speaking, I am interested in neritic and pelagic carbonates, what they tell us about the history of climate and paleo-fluid flow, and what controls the architecture of carbonate platforms. I am notably keen on applying novel isotopic techniques to carbonate material in order to extract relevant proxy data. My research group is currently working on clumped isotope paleothermometry. This new paleotemperature proxy is very promising, tricky to master, and (let’s admit it) fun to work with. Now is an exciting time to work on clumped isotope because a number of labs are finally able to run the technique (making inter-laboratory calibration possible) and new studies suggest additional interesting kinetic controls on the clumping of heavy isotopes in carbonates.
Finally, a completely different aspect of my research interests is to explore the interaction through time between carbonate rocks and the surrounding fluids: this interaction promotes dissolution of the original phases, and/or precipitation of new cement, i.e. carbonate diagenesis. An interesting approach is to link the depositional environment of carbonate platform (climate, eustasy, paleoceanography, biological constraints, etc…) with the diagenetic potential of carbonate rocks, the potential for fracturation, and the resulting fracture network with diagenetic fluid circulation and further modifications of the carbonate rocks. This approach is multidisciplinary, and because diagenesis impacts on the porosity and permeability of carbonate rocks, our research has tremendous implications for oil and gas reservoirs, and for safe carbon capture and storage (CCS) in carbonate rocks.