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1. Fault-tip damage zone development during normal fault propagation within the Sevier Fault Zone, southern Utah

   https://doi.org/10.18277/AKRSG.2025.37.06  

   Ryter, Lila (July 2025, Keck Geology Consortium)
2. Hematite fault rock thermochronometry and textures inform fault zone processes

   https://doi.org/10.1016/j.jsg.2020.104002  

   Ault, Alexis K. (April 2020, Journal of Structural Geology)
3. Normal fault-tip damage zone structures and geometries from the Sevier fault, Utah

   https://doi.org/10.18277/AKRSG.2023.35.04  

   Nishimoto, Michelle; Surpless, Benjamin (July 2023, Keck Geology Consortium)

   Davidson, Cam; Wirth, Karl (Ed.)

   Fault-tip damage zones develop in response to fault propagation and displacement and are caused by the local amplification of stresses at the fault tip. Understanding the geometry and intensity of damage zones is crucial for evaluating earthquake hazards and assessing the potentials of oil and gas production, geothermal energy, and groundwater resources. Fractures initiate as a result of stresses exceeding rock strength and propagate based on the stress field at the fault tip. We investigate the damage zone of a fault segment within the Sevier normal fault zone near Orderville, Utah, focusing on fractures that developed within the Jurassic Navajo Sandstone, the Temple Cap Formation, and the oldest beds of the Carmel Formation. Because normal faults grow laterally as slip and displacement increase, we focus on the tip zone of a fault segment where fracturing is well-exposed. We executed a series of unmanned aerial vehicle (UAV) flights to capture high-resolution imagery of inaccessible rock exposures. We use these images to construct structure-from-motion (SfM) virtual outcrop models (VOMs) that we georeference and analyze using Agisoft Metashape. We collected and analyzed fracture orientation and intensity data in the field and with VOMs. Both types of data reveal a distribution of fracture intensity that is consistent with inner and outer damage zones similar to previous studies of other fault systems. Adjacent to the tip, the inner damage zone has a higher fracture intensity on the hanging wall compared to the footwall. This high fracture intensity on the hanging wall ends 30 meters over from the fault core where the intensity of the outer damage zone of the hanging wall becomes similar to that within the inner damage zone of the footwall. Laterally, along strike of the fault tip, intense fracturing ends 60 meters to the south and all fracturing ends 350 meters from the fault tip. Our results have implications for the spatial distribution of fracturing and related permeability in similar normal fault systems. 

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4. THE ROLE OF FAULT DAMAGE ZONE DEVELOPMENT IN STRUCTURALLY CONTROLLED LANDSCAPE EVOLUTION, SEVIER FAULT ZONE, SOUTHERN UTAH

   https://doi.org/10.1130/abs/2023AM-390759  

   Hayton, Pierce; Surpless, Benjamin; Grambling, Tyler (January 2023, Geological Society of America Abstracts with Programs)
5. Slip History, Tectonic Evolution, and Fault Zone Structure Along the Southern Alpine Fault, New Zealand

   https://doi.org/10.1029/2024GC011839  

   Mere, A M; Barth, N C; Schwartz, J J; Kylander‐Clark, A (November 2024, Geochemistry, Geophysics, Geosystems)

   The study of active fault zones is fundamental to understanding both long‐term tectonics and short‐term earthquake behavior. Here, we integrate lidar‐enabled geomorphic‐geologic mapping and petrochronological analysis to reveal the slip‐history, tectonic evolution, and structure of the southern Alpine Fault in New Zealand. New petrographic, zircon U‐Pb and zircon trace‐element data from fault‐displaced basement units provides constraint on ∼70–90 km of right‐lateral displacement on the presently active strand of the southern Alpine Fault, which we infer is of Plio‐Quaternary age. This incremental displacement has accumulated while the offshore part of the fault has evolved within a distributed zone of plate boundary deformation. We hypothesize that pre‐existing faults in the continental crust of the Pacific Plate have been exploited as components of this distributed plate boundary system. Along the onshore southern Alpine Fault, detailed mapping of active fault traces reveals complexity in geomorphic fault expression. Our analysis suggests that the major geomorphic features of the southern Alpine Fault correspond to penetrative fault zone structures. We emphasize the region immediately south of the central‐southern section boundary, where a major extensional stepover and restraining bend are located along‐strike of each other. We infer that this geometry may reflect segmentation of the Alpine Fault between two distinct fault segments. The ends of these proposed segments meet near where several Holocene earthquake ruptures have terminated. Our new constraints on the evolution and structure of the southern Alpine Fault help contribute to improved characterization of the greatest onshore source of earthquake hazard in New Zealand. 

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