OIP gathers three projects - Dynamo, Organo-Min and Ramom- which are all focussed on the study of the natural organic matter (OM) and in its reactivity, with a large array of observation means, from the total scale to the molecular level.
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As straightforwardly illustrated by the humus of forest soils (photo) the so-called Organic Matter (OM) of natural environments (soils, waters and sediments) primarily originates from the living biota. The biological remains first serve as substrates for a whole range of decomposers (animals, fungi and bacteria). The high reactivity of the OM also confers it the ability to interact with inorganic elements, minerals or extraneous organic compounds (e.g. pesticides). Once buried in sediments the OM undergoes deep transformations which first permits long rang carbon storage and lately too, the production fossil fuels: gas, petroleum and coal. The various projects gathered in the OIP program deals with most of these various topics. |
Dynamo focuses on the intrinsic reactivity of the OM, i.e. on the whole of the organic components and the various processes which affect them, transform them and finally lead either to their mineralisation or their preservation in the sediments. All these processes are dependent on medium conditions and on the activity of the (primarily biological) agents responsible for OM evolution, under the constraint of climatic and/or anthropic forcing.
Resp. F. Laggoun-Défarge
Organo-Min is primarily interested in the badly known part that organic components can play in crystallogenesis. For example, carbonatogenesis is approached through two models, on the one hand the shell of certain molluscs and on the other hand the biofilms that develop in hypersalin lakes. To these models also adds the fossilization of micro-organisms realized in vitro in support to the identification of terrestrial and extraterrestrial microbiological signatures (e.g. March).
Resp. P. Gautret
Ramom deals with the study of OM-clay-metal relationships under through three complementary approaches. The first one relates to the processes of OM-clay association and their role in the preservation of organic components against degradation. The second approach deals with the transformations that clay minerals can undergo when they are in contact with organic molecules or metal species. A third approach deals with the “speciation” of metal elements in the natural environments where clays and OM are their two most common vectors.
Resp. F. Muller
