Thesis (D.Sc.)--University of Adelaide, Dept. of Geology and Geophysics, 2000. / Includes bibliographical references.

Thesis (B.Sc.(Hons))--University of Adelaide, Department of Geology and Mineralogy, 1973.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Map in back pocket. Vita. Abstract. Includes bibliographical references (leaves 79-84). Also available via the Internet.

Thesis (M.S.)--University of Wisconsin, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 70-72).

Thesis (M.S.)--Humboldt State University, 1992. / Includes bibliographical references (leaves 59-63).

Thesis (M.S.)--Humboldt State University, 2007. / Includes bibliographical references (leaves 58-65). Also available via Humboldt Digital Scholar.

M.Sc. (Geology) / Rocks of the Witwatersrand Super group in the northern portion of the East Rand Goldfield have been examined on surface and in underground exposures in an attempt to establish the chronology, movement vectors, amount of strain and displacement associated with bedding parallel faults. It was found that more than one age of movement occurred along most of the non-bedding parallel fault planes with normal, reverse and strike-slip senses of motion. The ductile bedding plane faults are manifested in all lithologies, but the shale units have, in particular, acted as a locus for shearing and it is suggested that they should be regarded as phyllonites. Bedding parallel faults are generally characterised by the presence of quartz veins and the development of phyllosilicates. They are categorised as mylonitic quartz schists. Syntectonic fault restricted quartz veins generally parallel the foliation, developed in the plane of flattening, and aided the movement of overlying strata during fault formation. Kinematic indicators imply a broad northerly up dip movement on the bedding parallel faults; implying they are thrust faults. Directionally specific kinematic indicators display at least two directions of thrust movement in the Central Rand Group, one to the NE and a second to the N to NW. The second group may represent two overlapping directions of movement. Only NE thrust movement are indicated in the West Rand Group. The NE thrust event occurred after emplacement of Ventersdorp dykes and before deposition of the rocks of the Black Reef Quartzite Formation. The N thrust fault event occurred after deposition of the Black Reef Quartzite Formation and before deposition of Karoo age rocks. A possible third event of Bushveld Igneous Intrusion age may be manifested as thrust faults towards the NW. The contact between the Central and West Rand Groups has acted as a major decollement during the N thrust event. The folds in this region may initially have been the result of thrust faulting towards the NE. Tilting of the fold axes during the postulated NW event is possible.

Four maps in pocket. / Digitized by Kansas State University Libraries

This research is an investigation into two different aspects of the faulting process. The first part of the study focuses on the initial stages of fault formation, while the second analyzes the deformation produced by an existing fault. The section on fault formation is an attempt to determine whether slip on an existing fault has a significant effect on the formation of subsequent faults. A two-dimensional elastic finite element technique is used to examine the system of stresses produced by slip on an initial fault, assuming that deformation occurs either elastically or by brittle failure. A Mohr-Coulomb failure criterion is used to determine the most likely region of secondary fault initiation. A strain energy criterion is then used to find the preferred direction of fault propagation. The study on fault formation is subdivided into two sections representing two idealized tectonic environments: purely extensional and purely compressional. The section on extensional fault formation explains the prevalence of grabens in extensional tectonic regimes as a consequence of the stress perturbations due to slip on an initial normal fault. Slip on the initial fault produces a region of high proximity to failure at the surface of the downthrown block. A secondary fault would be expected to initiate in this region. The direction of propagation of this fault that most effectively relieves the shear stress (and therefore minimizes the total strain energy) is toward the initial fault, resulting in an antithetic orientation, or graben. The width of the graben is found to be controlled by the depth of the initial normal fault, rather than the depth to a change in material properties. The study of compressional fault formation indicates that, except for steeply-dipping faults, the presence of an initial thrust fault tends to suppress the formation of other faults in its vicinity. However, if a secondary fault initiates near an initial thrust fault, the direction in which it propagates will be influenced by the presence of the initial fault. The way in which it is influenced is dependent on the fault dip. The final part of this study examines the deformation produced by repeated earthquake cycles on the San Andreas fault in southern California. A three-dimensional, time-dependent kinematic finite element model is used to investigate the influence of slip distribution and rheological parameters on the predicted horizontal and vertical deformation. The models include depth-varying rheological properties and power-law viscoelastic behavior. The predicted deformation patterns are fairly sensitive to the parameters used in this study. Of particular importance is the calculation of vertical uplift rate since, in many cases, models that cannot be distinguished from each other on the basis of horizontal deformation may produce distinctive vertical uplift patterns.

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