<p> Geophysical studies of the northwest trending Sudbury olivine diabase dikes, to the south of Coniston, Ontario establish a deformation zone, within the Southern province up to 10 km from the Grenville Front. Paleomagnetics reveal two directional groups within the dikes; those with a NRM direction of 300°/32° representing the primary magnetization of the dikes and those dikes with a Grenville overprint direction of 116°/56°. The deviation in direction of the two groups, in relation to previous studies (Palmer et al., 1977) is interpreted to be due to fault block movement. Aeromagnetics reveal extensive ductile and brittle deformation in the dikes as they approach the front. The general orientation of deformation is to the northeast. </p> / Thesis / Bachelor of Science (BSc)

<p> The last major episode of deformation occurred in the area studied during the Grenville orogeny (~1000 Ma ago). Deformation of this zone is characterized by a northeast trending penetrative foliation and southeast plunging mineral lineation which increase in intensity and decrease in inclination from northwest to southeast. The deformation was imposed during reverse fault movement in which the southeastern block (the Grenville province) was vertically displaced on the order of 20 kilometers above the adjacent block (the Southern province). The Killarney belt of granites, which separate the Grenville province from the Southern province in this area, are intrusive into the Huronian metasediments and predate the Grenville orogeny. These granites also show evidence of Grenvillian deformation. </p> <p> Paleopiezometry has shown that the differential stress during deformation increases from less than 1 Kbar to more than 6 Kbar from southeast to northwest. The microstructural strain features in quartz and felspar and the mineralogy indicate that a temperature change o£ 400 C is associated with this change in differential stress. Kinematic analysis of mylonites supports the reverse fault model o£ the Grenville Front. </p> / Thesis / Master of Science (MSc)

<p> The Thelon Tectonic Zone is a major structural, metamorphic and lithological feature of the Precambrian Shield in the Northwest Territories. Situated within this Zone is a 30 square kilometre plutonic body. Rubidium- Strontium whole rock geochronology yields an age range of 1650 - 2200 Ma for the emplacement of this pluton. Field and petrographic evidence indicates that the pluton has suffered post-emplacement deformation, representative of a late Proterozoic metamorphic event. Major and trace element geochemistry suggests that this high Ca, ferrogranodiorite-tonalite intrusive body is associated with a subduction-related, continental margin tectonic environment. </p> / Thesis / Bachelor of Science (BSc)

Master of Science / Department of Geology / Abdelmoneam Raef / Matthew W. Totten / This study examines an ovoid drainage feature southwest of Topeka, Kansas, whose discovery sparked a flurry of activity. Geomicrobial and surface gamma ray surveys indicated possible vertical migration of hydrocarbons, and a ground magnetic survey produced anomalies that resemble the profile of a crater. The area was dubbed the Echo Cliff structure and considered analogous to the Ames structure in Oklahoma, an Ordovician impact structure remarkable for significant hydrocarbon recovery. However, four wells drilled in the area were dry and abandoned. The Echo Cliff structure did yield further indications of its origins by the discovery of possible shocked quartz in drill cuttings from the Ordovician Simpson Group. Our study integrated well log analysis, geophysical modeling, and petrographic analysis to verify or refute the proposed identity of the Echo Cliff structure. Well logs from the area were used to create a structural and stratigraphic cross-section in Petrel® 2016. A gravity survey was conducted in the study area and combined with an aeromagnetic survey, donated by Applied Geophyics, Inc., to use as the basis for geophysical modeling within GM-SYS®. Finally, drill cuttings from the Simpson Group of two wells in the study area were mounted for thin sectioning. These thin sections were examined for planar deformation features, which are indicative of an impact event. The structural and stratigraphic cross sections indicated minimal variation in the subsurface, which is uncharacteristic of an impact event. The GM-SYS® geophysical models seem to indicate that variations in the topography of the Precambrian basement and faulting from the Bolivar-Mansfield Tectonic Zone are responsible for the geophysical anomalies and possibly the current drainage pattern of the study area. Finally, no planar deformation features were observed in any of the examined thin sections. Therefore, there is currently no evidence in support of the claim that the Echo Cliff structure is an impact structure.