Brittle features along two prominent shear zones in the Grenville Province of southeastern Ontario, the Central Metasedimentary Belt boundary thrust zone (CMBbtz) and Robertson Lake mylonite zone (RLmz), are investigated to understand the brittle deformation history of this intraplate region. Evolution of brittle deformation is interpreted from detailed mapping and characterization of joint, fault and vein patterns in Proterozoic basement rocks, Paleozoic cover rocks and Pleistocene sediments. Relationships among joint and fault orientations and maximum-horizontal stress directions associated with major tectonic events suggest a history of repeated stages of deformation along the CMBbtz and RLmz. Neoproterozoic-Cambrian opening of the Iapetus Ocean is interpreted to have produced NNE-striking Proterozoic structural highs in Paleozoic cover above the RLmz. Normal faults striking NW to WNW and ESE-striking dextral strike-slip faults in the RLmz and Paleozoic cover above both shear zones are compatible with Ordovician-Devonian Taconic and Acadian stresses. Prominent NNE- and NW-striking subvertical joint sets along the RLmz, CMBbtz and Paleozoic cover above the CMBbtz are compatible with Late Carboniferous to Permian Alleghanian stresses. Brittle features attributed to Mesozoic opening of the Atlantic Ocean are numerous and include: NNE-, ENE-, NW- and WNW-striking subvertical joint sets, WNW-striking normal faults, and NNE-striking normal faults in Paleozoic cover above the RLmz; NNW-striking dextral strike-slip faults and NW-striking normal faults in the RLmz; N- and NW-striking normal faults in Paleozoic cover above the CMBbtz; and, E- and SSW-striking normal faults in the CMBbtz. Joint sets in Pleistocene sediments above the CMBbtz and RLmz (oriented NNE, NW, NE, NNW and ENE) are compatible with both Pleistocene post-glacial flexural stress and the current in-situ stress. Strike-slip faults oriented SSW and W in the CMBbtz and a NNW-striking reverse fault in the RLmz are compatible with the current regional stress field. Further understanding of this neotectonic deformation is relevant to assess the seismic risk in the intraplate region of southern Ontario. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2007-07-30 15:14:44.542

No description available.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

We investigate the evolution of the regional stress state near the Pit River, northern California, in order to understand the faulting style in a tectonic transition zone and to inform the hazard analysis of Fault 3432 near the Pit 3 Dam. By analyzing faults and folds preserved in and adjacent to a diatomite mine north of the Pit River, we have determined principal stress directions preserved during the past million years. We find that the stress state has evolved from predominantly normal to strike slip and most recently to reverse, which is consistent with regional structures such as the extensional Hat Creek Fault to the south and the compressional folding of Mushroom Rock to the north. South of the Pit River, we still observe normal and strike slip faults, suggesting that changes in stress state are moving from north to south through time.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 28, 2007) Vita. Includes bibliographical references.

Seismic reflection (P- and SH-wave), ground-penetrating radar, correlative drilling, and age dating data provide evidence of neotectonic deformation along the Caborn (CF) and Hovey Lake (HLF) faults, in the Wabash Valley fault system (WVFS). The WVFS is a series of high-angle normal faults located primarily in southern Indiana and Illinois. Since their formation, these faults have likely been transpressionally reactivated in the contemporary E-W-oriented compressive stress state. The WVFS has experienced large prehistoric earthquakes, but only moderate historic and contemporary seismicity; therefore, the seismic potential in this region is poorly defined. The bedrock expressions of the CF and HLF were imaged with seismic reflection data (P- and SH-wave). Higher resolution analyses were performed with seismic (SHwave) and ground-penetrating radar surveys to characterize structure that may extend into the overlying Quaternary sediments. Anomalous features were cored to verify structure, and to collect datable material. The CF and HLF are interpreted to extend into the uppermost five meters of sediment and to displace horizons dated to 19,740 and 31,000 years before present, respectively. Displacement along the HLF is interpreted to extend 2-3 meters above the associated age date. These structures represent the only known primary coseismic deformation of the Late Quaternary within the WVFS.

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--Oregon State University, 1993. / Typescript (photocopy). Includes bibliographical references (leaves 123-129). Also available on the World Wide Web.

No description available.

The Garlock Fault consists of three distinct segments, known as western, central, and eastern, together reaching approximately 260 km from the San Andreas Fault to the southern end of Death Valley. Although published slip rates are available along the western and central Garlock Fault segments, little is currently known of the Garlock Fault earthquake history or slip rate farther east. Using LiDAR and satellite imagery, the central and eastern Garlock Fault segments were analyzed for visibly offset, fault-adjacent, geomorphic surfaces that may potentially be used for estimating slip rate. Qualitative methods of assessing preserved alluvial surface maturity were adapted and used to establish unit age categories. Qualitative comparisons of late Pleistocene-Holocene surfaces reveal that the total offset at sites along the eastern Garlock Fault are less than half that of sites of comparable age along the central Garlock Fault, suggesting a significant reduction in slip rate across the intersection of the Brown Mountain, Owl Lake, and Garlock Faults. Digitally-measured offsets and their age groups were plotted in order to achieve preliminary slip-rate estimates. The resulting plot shows an eastward decrease in late Pleistocene-Holocene slip rate at sites along the central and eastern Garlock Fault segments. The central Garlock Fault slip-rate estimate taken from Slate Range West and Slate Range East sites in Pilot Knob Valley is approximately 4.2 mm/yr, within the error (but on the low side) of previously published rates. The slip-rate estimate from the Quail Mountains site, at the easternmost extent of the central Garlock Fault, is approximately 2.7 mm/yr. The slip-rate estimate from the Avawatz section of the eastern Garlock Fault is approximately 1.0 mm/yr.