Year: 2026
Type: article
Abstract: Cyclic fluid pressurization can promote repeated fault reactivation and transient permeability changes, a behavior often discussed within the fault‐valve concept in which faults alternate between acting as hydraulic barriers and conduits. To investigate the micromechanical processes involved during fluid induced reactivations, we simulate cyclic fluid injection into a pre‐sheared granular gouge using a discrete element model. The simulations reproduce key behaviors observed in laboratory and in situ studies and reveal pronounced cycle‐to‐cycle variability in the onset of reactivation and slip magnitude. Some cycles generate large slip episodes, whereas others produce comparatively small slip under similar loading conditions. Micromechanical analysis of force‐chain evolution reveals a strong inverse correlation between slip magnitude and the population of load‐bearing chains, with sparser force‐chain backbones generating larger slip events. Our results highlight the role of micromechanical processes in controlling macroscopic cyclic fault behavior, offering a physically grounded perspective on fault‐valve behavior.
Source: Geophysical Research Letters
DOI: 10.1029/2026gl124845
Authors: Oussama Larkem, Luc Scholtès, Fabrice Golfier
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
Funder: Agence Nationale de la Recherche
OpenAlex ID: W7221897788