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Titre : | 3D representation of the fracture network in the Upper Rhine Graben : 3D representation of the fracture network in the Upper Rhine Graben |
Auteurs : | Armand POMART ; Enzo LORNE ; Enzo LORNE |
Type de document : | Projet d'initiation à la recherche apprenti |
Concepts : |
EVOLUTION
RIFT COMPRESSION EXTENSION |
Résumé : | The goal of the project is to represent and analyse the geological structure of the Upper Rhine Graben (URG) and to correlate it with the temperature data. That is why the final aim is to model the fracture network and temperatures in three dimensions. Each period through time modelled the URG. It is a rift system that appears in Cenozoic period thanks to the collision between African and European blocs. The currently structures are the result of inherited structures from Variscan orogeny. The major direction is so NE/SW to ENE/WSW. During Cenozoic times, there were four brittle tectonic episodes: N/S compression during Eocene, E/W extension during Oligocene, NE/SW compression during Miocene and finally a NW/SE compression. In the upper crust, the URG rift has a symmetric rift structure but in the deepest crust (lower crust), it seems to be dissymmetric with major fault for one side only. These fractures are permeable elements that permit to contain and allow the fluid to circulate. The fluids are an up-flow movement. Moreover, this brine is hot because of the radiogenic activity of the basement or purely due to the natural geothermal earth gradient. The circulation of these fluids allows the dissolution of crystalline rocks and sedimentary layers that increase the permeability. Nonetheless, according to conditions, some mineral can precipitate. Thermal anomalies are also due to the thickness of sediments and their conductivity. The maps from GeORG project have permitted the creation of vectors of both faults and temperatures. Then a 3D model has been created with different software. Finally, the extrusion of faults was possible thanks to Move software. The three dimensions model, which shows the link between fracture network and thermal anomalies, confirm a part of the information cited above. |
Spécialité : | Géologie |
Numéro de promo : | 81 |
numéro MIR : | 20 |