Insights into fault propagation and fold development through mechanical numerical modeling
Year: 2025
Type: dissertation
Abstract: This study utilizes the Boundary Element Method (BEM) code Growth by Optimization of Work (GROW) to model thrust fault propagation and branching, offering new insights into crustal deformation. GROW, an open-source tool, predicts fault propagation by applying a global work criterion. GROW has recently been enhanced with a new capability to simulate fault branching when shear stress near faults exceeds the inherent shear strength of the material. The goal of my research is to explore fault evolution and the interaction of branched faults with discontinuity contacts through numerical mechanical simulations that simulate the suite of analog experiments of Bonanno et al. (2017). Two-dimensional simulations of 30° and 45° thrust faults—with and without an overlying horizontal weak discontinuity—were used to mimic crustal conditions. These experiments revealed complex, branched fault sequences, where new branches accommodate slip over pre-existing structures. In the first project, I used GROW to simulate reverse fault propagation and interactions with a predefined discontinuity representing a bedding plane during folding. By employing a work optimization approach (McBeck et al., 2016), GROW calculates optimal fault propagation paths and evaluates the evolving mechanical efficiency of the system. Fault systems evolve to maximize efficiency, minimizing the work required to accommodate strain (Fattaruso et al., 2022). Unlike traditional methods, GROW removes the need for step-by-step specification of fault geometry, offering new insights into how variations in mechanical properties influence fault propagation and folding. Numerical results were validated against experimental observations of slip and folding. The second project extended these simulations to crustal-scale models, scaling up the numerical laboratory suite with crustal-scale properties and dimensions. These models maintain the relationships established in the analog experiments while reflecting the upper crust on Earth. My primary goal was to investigate how fault propagation paths differ in crustal-scale configurations compared to laboratory scaled simulations and which parameters impact branching.
DOI: 10.7275/ehaz-xc43
Author: Berenice
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7105752607
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