Toward the calibration of 2D thermomechanical simulations of magma poor passive continental margins: method, validation and case example

• Published in: Comptes Rendus. Géoscience
• Main Authors: Perron, Paul, Le Pourhiet, Laetitia, Jourdon, Anthony, Cornu, Tristan, Gout, Claude
• Other Authors: Institut des Sciences de la Terre de Paris (iSTeP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre scientifique et Technique Jean Feger (CSTJF), TOTAL FINA ELF, TOTAL SA funded this post-doctoral work
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: Thermomechanical modelling; Rifted margins; Kinematic reconstruction; Modélisation thermomécanique; Marges riftées; Reconstruction cinématique; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation; Newfoundland
• Online Access: https://hal.science/hal-04587010; https://hal.science/hal-04587010/document; https://hal.science/hal-04587010/file/CRGEOS_2024__356_S2_A21_0.pdf; https://doi.org/10.5802/crgeos.258

International audience In recent decades, geodynamic modelers have aimed to comprehend key factors governing continental rifting, such as the extension rate, lithospheric thickness, Moho mechanical coupling, and mantle convection’s thermal influence. While prior models offered insights into rifting processes, they lacked the calibration to specific Earth regions. Introducing heterogeneities into the model does in some cases help to calibrate the simulation results to a geological data from a specific region. Acknowledging structural inheritance as a form of kinematic forcing in the models, and recognizing the challenge of anticipating and identifying all inherited geological structures present before rifting, a new modeling approach was devised. This method integrates a new kinematic module into the pTatin2D code, allowing for calibrating numerical simulations with regional geological and geophysical dataset over time while solving for mechanical balance using Stokes flow to ensure that crustal deformation remains consistent with mantle dynamics. By calibrating against a 2D cross-section extracted from the final state of a 3D model, we show that the approach predicts thermal history and deformation paths beyond calibration points. In particular, the thermo-mechanical feedback can help mitigate some uncertainties in the deformation path. Applied to Iberia–Newfoundland margins, the method demonstrates effectiveness in real-case scenarios, aligning with previous reconstructions by incorporating faults and lower crustal flow. Au cours des dernières décennies, les modélisateurs géodynamiques ont cherché à comprendre les facteurs clés régissant le rifting continental, tels que le taux d’extension, l’épaisseur lithosphérique, le couplage mécanique au Moho et l’influence thermique de la convection du manteau. Alors que ces modèles offrent un aperçu des processus de rifting, ils n’offrent pas la possibilité pas d’être calibrés à des régions spécifiques de la Terre. L’introduction d’hétérogénéités dans le modèle aide ...