Precambrian metamorphic rocks in the Beaver Dam Mountains display asymmetric, isoclinal folds with consistent fold axes plunging to the NW. These folds are parasitic and have a recursive nature that occurs on wavelengths from centimeters to perhaps kilometers as part of a NW-SE striking shear zone. The vergence of the folds indicates oblique shearing with a transport direction plunging 29° to the south. This shear zone may be associated with the collision of Yavapai Province island arcs with Laurentia. Structurally overlying, and adjacent to the metamorphic rocks are allochthonous and attenuated Mississippian limestone blocks and other strata debated to be either the result of mega-landsliding or fragments of the hanging wall rocks above a low-angle normal fault. We document previously unreported cataclastic damage zones tens of meters thick, an anastomosing zone of greenschist facies alteration hundreds of meters thick, and polished low-angle fault surfaces beneath these blocks. Other observations previously used to support a mega-landslide hypothesis are blocks of Redwall Limestone structurally overlying what was interpreted as Tertiary conglomerate. However, this contact is depositional, and the conglomerate is likely a sedimentary breccia facies of the Mississippian Redwall Limestone which is documented in several locations within the region. Additionally, some of the deformation and attenuation that was wrongly attributed to mega-landsliding or low-angle normal faulting is due to previously undocumented soft-sediment deformation. This deformation was gravity driven and accommodated by ductile granular flow, resulting in recumbent folds within the Mississippian Redwall Limestone and a prominent non-brittle detachment surface between the Redwall Limestone and the Cambrian Bonanza King Formation at Castle Cliff. This detachment was previously interpreted as the Castle Cliff Detachment, a low-angle normal fault, or as the slip surface of a landslide.

A multi-scale high-resolution geophysical and geological study was conducted in the Sevier Desert, central Utah, found within the Colorado Plateau-Basin and Range Transition Zone. The region is marked by with Quaternary volcanics and faulting as young as 660 yr B.P., with many fault scarps thought to have the potential for 7+ magnitude earthquakes. Three locations within the Sevier Desert which represent three different tectonic expressions of possible faulting at the surface were selected. These include a location found within surface sedimentation, a location with surface sedimentation and sub-surface basalts and a location with basalts, at the surface with very limited sedimentation. A suite of geophysical data were obtained including the use of P-wave, SH-wave, ground-penetrating radar (GPR). Auger holes, microprobe glass analysis, and mapping information were also completed in order to constrain and gain a more complete understanding of the sub-surface structure. These data were used to determine if there are sub-surface expressions of the possible surface scarps and if all the faults within the fault zone have the same structural style. The possible surface fault expressions were found to be connected to sub-surface fault expressions but with differing results within both sediments and basalts. Our data show that a multi-scale approach is needed to obtain a complete view of tectonic activity. The area faulting in the Sevier Desert penetrates at depth involving multiple complex styles that include some faulting that cuts recent lava flows and some that do not. The evidence also indicates that in at least some area faulting was episodic and others may be single events having implications on level of activity and hazard.

As the world pushes for ‘greener’ technologies and carbon neutrality, efforts have focused on creating novel ways to mitigate humankind’s carbon footprint. Carbon capture and storage (CCS) has become a prevalent technique that has proven to be an effective long-term method to safely relocate excess carbon dioxide (CO2) into subsurface formations. However, CCS is a newer technique which requires constant monitoring due to potential leakage pathways present in CO2 storage sites; therefore, a preventive approach to seal leakage pathways is recommended. This dissertation explores the potential of CO2-sensitive polyacrylamide (CO2-SPAM) as a novel sealing agent for enhanced oil recovery (EOR) and CCS applications. This manuscript explores the strength and weaknesses of various CO2-triggered chemicals and selects the appropriate fit for subsurface in-situ sealing. Relevant literature shows that CO2-SPAM can significantly reduce permeability in porous media. Additionally, organically cross-linked polyacrylamide-based gels, of which CO2-SPAM is one, are thermally stable, resistant to low pH levels, highly injectable, and widely used in various industrial processes. These characteristics make CO2-SPAM a suitable candidate for in-situ sealing. Further studies were performed to comprehend the chemical mechanism, rheological behavior, and injection effects of CO2-SPAM into subsurface formations. Firstly, past literature knowledge and organic chemistry principals were used to develop the complete chemical breakdown of CO2-SPAM gel’s synthesis. Secondly, the effect of salt and polyacrylamide (PAM) concentrations on gelation time, gel strength and viscosity were tested through qualitative (Sydansk gel strength coding system) and quantitative methods (rheometer measurement). The results showed that high salinities increase gelation time and decrease gel strength and viscosity, while high PAM concentrations do the opposite. Lastly, the effects on geomechanical stresses caused by CO2-SPAM injection into the subsurface are also addressed by using the image well method for pore pressure estimation, and frictional faulting theory. The final results determined that the injection of aqueous CO2-SPAM would induce seismicity in normal faulting zones dipping at a large array of angles in the plane of failure. These findings are significant as they determine the potential of induced seismicity in the area of CCS, which in this case was the Raton basin.

Thesis (Ph.D, Civil Engineering) -- Queen's University, 2011-01-31 20:52:11.162 / One of the most severe hazards for buried pipelines, which are sometimes referred to as lifelines due to their essential role in delivering vital resources, is the hazard due to Permanent Ground Deformation (PGD). Earthquake induced PGD can be caused by surface faulting, landslides and seismic settlement. In this thesis, the behaviour of buried pipelines subject to normal faulting has been experimentally investigated through a series of centrifuge tests performed on both continuous and jointed pipelines. Both pipe and soil displacements were measured using image analysis. Signal processing techniques were then developed to filter this data so as to enable the calculation of curvature and other aspects of the response from the observed pipe deformations. First, a series of centrifuge tests was conducted on continuous pipelines of varying materials, representing a wide range of pipe stiffness relative to the soil and investigating the effect of pipe stiffness relative to the soil on soil-pipe interaction. The experimentally derived p-y curves at different locations along the pipe were compared to the recommended soil-pipe interaction models in the relevant guidelines. These p-y curves showed that the central shearing region was not captured well with independent soil springs. The response of the pipelines predicted by the ALA (2001) guideline, however, was shown to match the experimental data within 50%. Two new simplified design approaches were then developed. The first features calculations based on simplified pressure distributions. The second featured peak curvature normalized using a characteristic length, ipipe, the distance from peak to zero moment. A series of centrifuge tests using brittle pipes was also performed. The pipes were buried at three different depths, and the post-failure fracture angle of the pipe was measured to be used as an input for design of liners. Based on the experimental data, a computationally efficient approach was developed to estimate the initial fracture angle which occurs immediately after the pipe breaks. The last series of centrifuge tests was conducted on jointed pipelines with five different joint stiffnesses to investigate the flexural behaviour of jointed pipelines under normal faulting. Based on the observed pipe response, a simplified kinematic model was proposed to estimate the maximum joint rotation for a given geometry, pipe segment length, and the magnitude of the imposed ground displacement. / Ph.D

<p> The BAR CLAIM GROUP is located on the western margin of the Selwyn Basin geologic province in south central Yukon. The rock sequence is eugeosynclinal in nature, belonging to the Englishman's Group of the Mississippian. Chronologically, these rocks include massive limestone, white to red chert breccia, dark grey chert breccia, chert pebble conglomerate, lithic wacke, massive barite, grey green chert, and hornblende microdiorite. The elastic units in particular appear to be correlative with the units on the eastern margin of the Selwyn Basin. </p> <p> The barite is light grey, bedded, massive, and contains rare relic rosette structures. Associated minerals include pyrite, galena and minor sphalerite. Extensive recrystallisation and mobilization has occurred, probably as a result of regional compression and faulting. The barite may have had an exhalative origin along fault or extensional zones; however, sedimentogenic sources, such as the redistribution of pre-existing barite, cannot be precluded. </p> / Thesis / Bachelor of Science (BSc)

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