The University of Arizona Campus Repository > Organizations > Geosciences > Geosciences Theses and Dissertations > Geosciences Theses >
The Nucleation and Evolution of Riedel Shear Zones as Deformation Bands in Porous Sandstone
- Persistent Link:
- The Nucleation and Evolution of Riedel Shear Zones as Deformation Bands in Porous Sandstone
- Issue Date:
- Copyright © is held by the author. Digital access to this material is made possible by the Antevs Library, Department of Geosciences, and the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author or the department.
- Collection Information:
- This item is part of the Geosciences Theses collection. It was digitized from a physical copy provided by the Antevs Library, Department of Geosciences, University of Arizona. For more information about items in this collection, please email the Antevs Library, email@example.com.
- Riedel shear zones are geometric fault patterns commonly associated with strike-slip fault systems. The progressive evolution of natural Riedel shear zones within the Navajo Sandstone of southern Utah is interpreted from the spatial evolution of small-scale, incipient Proto-Riedel Zones (PRZs) to better-developed Riedel shear zones using field mapping and three-dimensional digital modeling. PRZs nucleate as a tabular zone of localized shearing marked by en èchelon deformation bands, each of which is no more than a few mm wide and tens of cm long, and oriented at 55° - 85° to the trend of the zone. With increasing strain, deformation bands and sedimentary markers are sheared ductily through granular flow and assume a sigmoidal form. The temporal and spatial evolution of bands comprising a Riedel shear zone suggests that PRZs nucleate as transitional-compactional deformation bands under localized, supra-lithostatic fluid pressure. Subsequent bands develop under modified regional stresses as conjugate shear fractures within the strain- hardened axis of the PRZ. These antithetic driven systems are not compatible with traditional synthetic driven models of Riedel shear zones. Unlike most synthetic driven examples, these antithetic driven systems are not controlled by preexisting "basement" structures, thus their geometries reflect a primary propagation or secondary passive deformation mechanism.
- text; Thesis-Reproduction (electronic)
- Degree Name:
- Degree Level:
- Degree Program:
- Degree Grantor:
- University of Arizona
- Committee Chair:
- Davis, George H.
Full metadata record
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.