Organic matter and clays: sedimentary origin, associated resources and reservoirs

Organic matter (OM) accounts for only a small proportion of sedimentation. Unlike other deposited particles, it can evolve rapidly during burial by interacting with the grains of the host rock and producing fluids (gases and liquids) that are highly mobile. Due to its degradation by bacteria, its preservation depends on many parameters, but above all on the fine grain size of the grains deposited at the same time. Thus, clays represent the most favorable environment for the preservation of OM, but their complex mineralogy makes them a special material that will also transform during burial. The products of their interactions have naturally been of interest to the mining and oil industries, since these processes are responsible for the formation of large coal deposits and the production of hydrocarbons. Recently, however, studies have increasingly focused on these two elements as tracers of the origin of sediments and as markers of burial, which is of major interest in understanding the filling of basins and their post-depositional evolution.

The sessions are organized in the following sequence:
- Introduction
- Organic matter in sediments (origin and nature)
- Coals (formation and classification)
- Clays (origin and evolution with burial)
- Maturation of organic matter (transformations and interactions with clays)
- Unconventional resources (use of OM-rich clays)

All of these concepts will then be used to introduce basin modeling (deposition, geodynamic and post-depositional tectonic history, burial curves, and thermal history), which will be covered in S4 in the Resource Evaluation module, "fluids" option.

Students must have a good knowledge of basin geology and sedimentology (Master's S1 and S2).

Knowledge of organic geochemistry can be an advantage in acquiring the complex concepts covered in this module.

Graded exercises punctuate the tutorial/practical sessions, and a final exam will be based on a case study.