Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah

Research Article| January 01, 2005 Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah Nicholas C. Davatzes; Nicholas C. Davatzes 1Department of Geological and Environmental Science, Stanford University, Stanford, California 94305-2115, USA Search for other works by this author on: GSW Google Scholar Peter Eichhubl; Peter Eichhubl 1Department of Geological and Environmental Science, Stanford University, Stanford, California 94305-2115, USA Search for other works by this author on: GSW Google Scholar Atilla Aydin Atilla Aydin 1Department of Geological and Environmental Science, Stanford University, Stanford, California 94305-2115, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Nicholas C. Davatzes 1Department of Geological and Environmental Science, Stanford University, Stanford, California 94305-2115, USA Peter Eichhubl 1Department of Geological and Environmental Science, Stanford University, Stanford, California 94305-2115, USA Atilla Aydin 1Department of Geological and Environmental Science, Stanford University, Stanford, California 94305-2115, USA Publisher: Geological Society of America Received: 26 Aug 2003 Revision Received: 30 Mar 2004 Accepted: 13 May 2004 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2005) 117 (1-2): 135–148. https://doi.org/10.1130/B25473.1 Article history Received: 26 Aug 2003 Revision Received: 30 Mar 2004 Accepted: 13 May 2004 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Nicholas C. Davatzes, Peter Eichhubl, Atilla Aydin; Structural evolution of fault zones in sandstone by multiple deformation mechanisms: Moab fault, southeast Utah. GSA Bulletin 2005;; 117 (1-2): 135–148. doi: https://doi.org/10.1130/B25473.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Faults in sandstone are frequently composed of two classes of structures: (1) deformation bands and (2) joints and sheared joints. Whereas the former structures are associated with cataclastic deformation, the latter ones represent brittle fracturing, fragmentation, and brecciation. We investigated the distribution of these structures, their formation, and the underlying mechanical controls for their occurrence along the Moab normal fault in southeastern Utah through the use of structural mapping and numerical elastic boundary element modeling. We found that deformation bands occur everywhere along the fault, but with increased density in contractional relays. Joints and sheared joints only occur at intersections and extensional relays. In all locations, joints consistently overprint deformation bands. Localization of joints and sheared joints in extensional relays suggests that their distribution is controlled by local variations in stress state that are due to mechanical interaction between the fault segments. This interpretation is consistent with elastic boundary element models that predict a local reduction in mean stress and least compressive principal stress at intersections and extensional relays. The transition from deformation band to joint formation along these sections of the fault system likely resulted from the combined effects of changes in remote tectonic loading, burial depth, fluid pressure, and rock properties. In the case of the Moab fault, we conclude that the structural heterogeneity in the fault zone is systematically related to the geometric evolution of the fault, the local state of stress associated with fault slip, and the remote loading history. Because the type and distribution of structures affect fault permeability and strength, our results predict systematic variations in these parameters with fault evolution. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.