Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 67 for “"fault zones"”.
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Physics-based modeling of earthquake cycles and tsunamis in strike-slip fault zones
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-04-12 without embargo terms
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The hydrogeological structure of fault zones in poorly lithified sediment, Gulf of Corinth rift
Often, the structure of fault zones cutting poorly lithified sediment examined in outcrop indicate such fault zones should behave as hydraulic barriers, but hydrological observations indicate they behave as conduit-barriers. This thesis investigates the hydrogeological structure of fault zones …
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UNDERSTANDING BLOCK ROTATION ALONG STRIKE-SLIP FAULT ZONES IN YUNNAN (CHINA): PALEOMAGNETIC AND STRUCTURAL APPROACH
I dati raccolti durante i tre anni di attività di Dottorato di Ricerca riguardano il paleomagnetismo di rocce sedimentarie e vulcaniche affioranti lungo due importanti zone di taglio che caratterizzano la provincia dello Yunnan (Cina): la faglia Gaoligong e la faglia del Red River. Durante il …
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Petrology and structural geology of the Sanarate-El Progreso area, Guatemala
… and structure associated with the Motagua Valley fault zones. The entire Sanarate quadrangle was mapped as part of the geological program of the Instituto Geografico Nacional, which provides field support for detailed quadrangle mapping. Work was continued into the El Progreso quadrangle to extend …
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Modification of magnetic properties in granite during hydrothermal alteration (EPS-1 borehole, Upper Rhine Graben)
… which led to the formation of first permeable fault zones at temperatures ~300 °C, obtained from chlorite-geothermometry. The formation of permeable zones allowed the circulation of O2-rich fluids, which caused the oxidation of magnetite into martite (hematite) within discrete zones. Granites, …
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Deciphering the signature of fluid/rock reactions in the lower oceanic crust: The Oman ophiolite analogue
… in the lower crust, particularly associated with faulting, is scarce due to limited sampling. The Oman Drilling Project has sampled three 400 metre boreholes in the lower oceanic crust of the Semail ophiolite. Hole GT1A located in Wadi Gideah targeted a hydrothermal fault zone, recovering multiple …
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The Box Ankle and Ocmulgee shear zones of central Georgia: a study of geochemical response to Southern Appalachian deformation events
… Is bounded on the east by the Box Ankle thrust fault which juxtaposes basement lithologies from hanging wall paragneiss, schist, and metavolcanic rocks of the Piedmont terrane. The Ocmulgee strike-slip fault separates Piedmont Terrane rocks from Avalon Terrane lithologies to the south and east …
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Geologic Mapping in the Black Mountain Area, Northern Eastern California Shear Zone: Testing a Kinematic and Geometric Fault Slip Transfer Model
… shear zone, are used to test a kinematic fault slip transfer model for the Owens Valley fault-Mina deflection transition. In the Black Mountain area, range bounding ~NNW- to ~NS-striking and lesser NW- to NE-striking normal faults cut Mesozoic, Miocene (22.42 ± 0.05 Ma), Pliocene (3.53 ± …
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Tectonics, cru[s]tal and upper mantle structures of Taiwan
… delineated a number of major active fault zones in central and eastern parts of Taiwan. Judging from both the seismicity and focal mechanism solutions, these fault zones are essentially thrusts of crustal origin. They are likely to be the intraplate structures.</p> <p>A compilation of …
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Controls on the diversity of the fault slip styles at the brittle-ductile transition: examples from the Cape Fold Belt, Nuy Valley, South Africa
… brittle and viscous deformation. Complex fault zones exhumed to the surface may preserve evidence that can explain the mechanics and the complex slip behaviour of faults. Fault rocks response to applied shear stress is affected by environmental conditions during deformation (such as …
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In Situ Compressional Wave Velocity Across An Exposed Brittle Fault Zone
… mineralization on the geophysical properties of fault zones are not very well understood. In situ seismic data collected over the exhumed San Gregorio Fault at Moss Beach, CA were used to relate in situ compressional wave velocity to internal fault zone properties. This active strike-slip fault …
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The geological record of oceanic crustal accretion and tectonism at slow-spreading ridges
… this Thesis provides detailed documentation of faults and volcanoes (seamounts) at the Mid-Atlantic Ridge from 25°25'N to 27°10'N and extending from zero-age crust at the ridge axis to -29 Ma crust on the ridge flank. This information was used to analyze the evolution of ocean crust from initial …
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P- and S- wave tomography of the crust and uppermost mantle in China and surrounding areas
… such as lithological variations and large fault zones across the major geological terranes.
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Localization and instability in sheared granular materials: role of friction and vibration
… and strength evolution in gouge filled fault zones.
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Principal Slip Zones in Nature and Experiments and Their Role in the Earthquake Cycle
… within extremely narrow (≤10 cm) principal slip zones found along fault zones. These slip zones are relatively weaker than the surrounding wall rocks suggesting they play an important through the earthquake cycle. This thesis explores the microphysical processes occurring along principal slip …
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Tectonics of the East Pacific rise : studies of faulting characteristics and magnetic and gravity anomalies
… four main topics: (1) characterization of normal faulting from Sea Beam bathymetric data, (2) application of mechanical models to explore the hypothesis that buoyancy arising from crustal magma chambers and gravitational spreading of the upper crust are the principal processes leading to the …
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Reevaluation of the southwestern end of the Salem synclinorium
… veins, fractures, slickensides, oblique-slip faults and thrusts in a riverbed exposure within the southwestern portion of the Salem synclinorium, offers a structural model for the Salem synclinorium. Thrusting induced extensional fractures and veins. Oblique-slip faults which cut the thrusts …
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Geometric and hydrodynamic modelling of fluid-structural relationships in the southeastern Athabasca Basin, Saskatchewan, Canada, with implications for uranium ore genesis
… spatial relationships with reactivated basement faults. However, the nature of this relationship has not been well understood. This thesis aims to address this problem through two interrelated components of research. The first phase of the research involved 3-dimensional (3D) geometric modelling …
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Local Earthquake Tomography at Mt. Pinatubo, Philippines
… These bands of earthquakes appear to represent fault-related structures. Three low-velocity (relative to the horizontal average) anomalies exist within the well-resolved portion of the velocity model. These anomalies are spatially associated with pre- and post-eruption earthquakes oriented along …
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The Saltville thrust: investigation of a regional thrust fault in a foreland fold and thrust belt
… at the thrust terminus is the transition from faulting to folding. Mesoscopic fabrics show variations in deformation intensity across the anticline, with high strains on the northwest limb, and low strains on the upright southeast limb. Strain accommodation on the overturned limb was by …
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