Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

Despite considerable research over the last two decades on the origin of diagenetic fluids involving dolomitization, the debate about the process/ mechanism of dolomite formation is still is ongoing, especially regarding timing of fluid flow and chemistry of these fluids and the extent to which massive dolostones formed in near surface environments as opposed to formation at variable burial depths by hydrothermal and burial processes. The present proposal is part of an ongoing research program, both conceptually and experimentally, on the chemistry, source(s) of diagenetic fluids and timing of fluid flow events in sedimentary basins. It is aimed to put special emphasis on fault and fracture diagenesis, because faults and fractures are often the primary conduits for diagenetic fluids, whether passively or actively. These fluids do not only result in fracture mineralization but may also induce important diagenetic modifications to the host carbonate rocks, such as dissolution, recrystallization and dolomitization. Quantification of the fluid flow using integrated field, structural, petrographic and geochemical tools can be also used to develop conceptual models for the spatial and temporal distribution and connectivity of reservoir porosity and permeability on a regional basinal scale. The proposed research program for the next 5 years will have the following objectives: (1) a better quantification of the main diagenetic events and their responsible originating fluids in sedimentary basins; (2) determination of the relationship between the fractures and deformational or tectonic events (i.e. fracture diagenesis); (3) geochemical simulation of fluid/rock interaction (e.g. using reactive transport modeling); (4) determination of patterns of paleo-fluid flow (e.g. numerical and geochemical modeling); (5) investigate the application of Mg-isotopes and clumped isotopes on source(s) for dolomitizing fluids and temperature-fluid composition relationship; and, (6) unravel the impact of diagenetic events porosity evolution. These objectives can be achieved through careful examination of textural parameters, mapping of regional and local distribution of diagenetic and structural components, geochemistry (stable and radiogenic isotope measurements, fluid inclusions), burial and thermal history curves and quantitative basin modeling techniques. Sampling from carbonate reservoirs and their outcrop analogs from different geologic settings (stable intracratonic areas vs. tectonically more active areas within the basin) will allow a better understanding and quantification of the origin, timing and spatial distribution of dolomites and other diagenetic phases within each setting. Comparative studies on paleo-fluid flow and diagenesis will also be carried out between the Western Canada Sedimentary Basin (WCSB), Michigan Basin and Middle East basins.