I am presently involved in several research programs

1. 1.The geochemical effect of chemical weathering. Chemical weathering is a major process of planet Earth, made possible by the water cycle. During interaction between water and rocks, chemical elements are fractionated between a soluble phase and a solid phase comprising a whole range of grainsizes. Chemical weathering is responsible for a mass transfer at the surface of the Earth between the upper contintental crust, the atmosphere and the ocean. Important questions are
   

- How are element fractionated by chemical weathering reactions ?

1. -What is controlling chemical weathering at the global scale ?
   

2. -Has chemical weathering played an important role in the Earth’s history ?
   

3. -What is is impact of chemical weathering on the global carbon cycle and thus climate evolution, at small and large scale ?
   

4. -The mass balance of chemical weathering and erosion at the surface of the Earth.
   

2. 2.Development of isotopic proxies of chemical weathering. A number of soluble elements have isotopes that are fractionated during chemical weathering, such as boron, lithium, magnesium. By understanding the effect of water-rock interaction on the isotopic partitioning between the solid and water, we learn about chemical weathering processes, rates and develop oceanic proxies of erosion that can be used to reconstruct the history of chemical weathering.
   

3. 3.Development of isotopic proxies of pollution. Human activity has perturbed the natural cycles of elements. Using isotopes of elements like Zinc, copper, boron, lithium, we can trace the pathways and of these elements in the Environment and constrain the processes that affect their behavior.
   

4. 4.The use of boron isotopes as a proxy for paleo-pH of the ocean and maybe of paleo atmospheric CO2 contents. Boron isotopes in limestone reflect both the pH of precipitation and the boron isotopic composition of the ocean at time of precipitation. How the boron isotopic composition of the ocean evolved through time is still poorly known as well as the mechanisms of boron coprecipitation in limestones.
   

5. 5.Development of Critical Zone observatories. The surface of the continents is a critical zone in our understanding of the global geophysiology because this is an interface between the lithosphere, the hydrosphere, the biosphere and the atmosphere. It is also critical because this is were humanity lives and find its resources. In response to global change (land use, atmospheric composition, water cycle), this critical zone is changing and observatories must be designed in order to observe, understand and predict its evolution. I have been involved in the creation of a drainage basin observatory in the Lesser Antilles, and more generally work to design a global network of «critical zone observatories»