Dissertations / Theses on the topic 'Geology, Structural Victoria, Southeastern'
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1
Kuang, Jian. "Intraplate stress and seismicity in the southeastern United States." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/25809.
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Davisson, Cole M. "Stratigraphic and structural evolution of the early Diligencia Basin, Orocopia Mountains, Southeastern California." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-04072010-020140/.
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Klepacki, David Walter. "Stratigraphy and structural geology of the Goat Range Area, Southeastern British Columbia." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/14785.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. MIT's copy accompanied by maps in separate folder.
Bibliography: leaves 256-268.
by David Walter Klepacki.
Ph.D.
4
Valentino, David W. "Tectonics of the lower Susquehhanna River region, southeastern Pennsylvania and northern Maryland: late proterozoic rifting to late paleozoic dextral transpression." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/30108.
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Neri, Gezatt Julia. "Thermal evolution of the southeastern Brazilian continental margin." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=239961.
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The southeastern Brazilian continental margin has a debated evolution regarding postrift events and formation of topography. Apatite fission track (AFT) and apatite U-Th/He (AHe) analysis ages for the N-S transect between Rio de Janeiro and Três Rios range between 98.5±11.9 and 54.1±4.2 Ma. Ages are younger towards the coast and increase progressively inland. Highest samples (around 1500 m above sea level) have older AFT ages. A wide range of ages was not found in the area, contrasting with the large AFT age span found by other studies in adjacent portions of the Brazilian continental margin, where age ranges of up to ~200 Ma from the coast to the innermost sample in the continent have been reported. The cooling ages and the thermal history models produced with software QTQt corroborate a uniform and continuous cooling process for the rifted margin, with total depths of denudation between 2.5 and 4.4 km, attesting to the absence of post-Cretaceous rift reburial in the area. Towards the continental interior, at the back of the Serra do Mar escarpment, thermal history models point to a change in cooling rate in the Upper Cretaceous, compatible with reported reactivation of the regional Neoproterozoic structures which led to the formation of the Cenozoic Rift System of Southeastern Brazil. Collision episodes in the western margin of W Gondwana have important role on platewide stress distribution, inducing regional structure reactivation and creation throughout the South American Platform. The plate-wide deformation arising from the western plate margin collisions is possibly responsible for the formation of the many Paleozoic grabens, which were the precursors of the cratonic basins of the South American continent. Among those, evidence from zircon U-Pb detrital provenance indicates that the Ordovician Piranhas Graben in central Brazil is in fact an early manifestation of the Paraná Basin, since its progressive increase in catchment area matches the sediment sources of the Silurian Vila Maria and Devonian Ponta Grossa formations of the Paraná Basin. The present-day landscape is mainly a result of isostatic rebound due to erosional unloading, although combined with post-rift magmatism and regional structure reactivation. The post-rift continuous uplift of the southeastern Brazilian margin supplied vast volumes of clastic sediments to the Santos and Campos basins during the late Cretaceous and Cenozoic, generating high quality reservoirs for hydrocarbons.
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Miller, Lance Davison. "Tectonic evolution and structural control of auriferous veins in the Juneau gold belt, southeastern Alaska." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186623.
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A portion of northern southeastern Alaska known as the Juneau gold belt is composed of a disparate assemblage of lithotectonic terranes which range in age from Paleozoic and perhaps older to Cretaceous. Five progressive deformational events associated with contractional tectonism began in the mid-Cretaceous time and continued well into the Tertiary. Widespread plutonism occurred in the region from Cretaceous through Tertiary time. Gold-bearing quartz vein systems in the Juneau gold belt formed within a 160-km-long by 5- to 8-km-wide zone along the western margin of the Coast Mountains, Alaska. The vein systems are localized in second and third order shear zones spatially associated with terrane-bounding, mid-Cretaceous thrust faults. Mesoscopic structures integrated with ⁴⁰Ar/ ³⁹Ar ages from vein sericite are interpreted to indicate that a fluid cycling event along the entire belt occurred between 56.5 and >52.8 Ma. Structural analysis of the vein orientations and geometries are interpreted to indicate that mineralization developed under a near-field stress regime of subhorizontal contraction along a west-southwest to east-northeast trending axis. The axis of extension plunged steeply to the southeast. Slight variations in the interpreted stress axes may have been the result of variations in fluid pressure. Post-mineralization deformation was associated with a dextral transpressive regime along the Denali-Chatham Strait fault system. Gold vein mineralization occurred during the latter stages of orogenesis. Fluid flow and subsequent vein development was temporally associated with changes in plate motion during Eocene time. Veining was also synchronous with exhumation and voluminous plutonism immediately inboard of the gold belt. These interacting tectonic events likely facilitated fault-valve action and vein development along now exhumed shear zones.
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Dowe, David S. "Deformational History of the Granjeno Schist Near Ciudad Victoria, Mexico." Ohio University / OhioLINK, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1089910191.
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Blankenau, James J. "Cenozoic Structural and Stratigraphic Evolution of the Southeastern Salmon Basin, East-Central Idaho." DigitalCommons@USU, 1999. https://digitalcommons.usu.edu/etd/6711.
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The southeastern Salmon basin (SB) of east-central Idaho is a complex east-dipping half graben containing four unconformity-bounded sequences of Tertiary volcanic, alluvial fan, lacustrine, and fluvial deposits. From oldest to youngest these are the Challis volcanic group, sedimentary rocks of Tendoy (new name), sedimentary rocks of Sacajaweja (new name), and Quaternary-Tertiary deposits . The thick sequence of volcanic rocks was deposited in a southeast-trending paleovalley . New mapping, cross-cutting relationships, 40Ar/39Ar age determinations, and angular unconformities show that the SB has experienced at least four episodes of extension, and that it lies in the core of an Eocene to Oligocene rift zone. T
he largest episodes of extension in the SB were the second and third episodes of extension. These were responsible for the deposition of the sedimentary rocks of Tendoy and sedimentary rocks of Sacajaweja, respectively. Episode 2 occurred along the west southwest-dipping Agency Yearian fault, and can be attributed to gravitational collapse of the Sevier fold and thrust belt between the late middle Eocene and Oligocene (?). Several southwest-dipping low-angle normal faults were active during the third episode and may have been active into early Miocene time. The third episode of extension reflects continued gravitational collapse. Also active during episode 3 was the Salmon basin detachment fault, which is interpreted as a regional detachment based on its lateral extent and low dip angle (11°).
Extensional folds are common in the southeastern Salmon basin and represent at least two generations of folds. Interference between northnortheast and southeast-trending folds locally produced dome and basin features. The folds are typically open to gentle, and have a maximum fold height of 2.2 km. Most of the folds are fault-bend folds, and some are associated with growth strata. The development of the Tendoy anticline and Pattee Creek syncline in the hanging wall of the Agency-Yearian fault produced two depositional basins during the deposition of the sedimentary rocks of Tendoy. Facies patterns and megabreccia deposits in the subbasins indicate that there was considerable topography along the margins of the subbasins .
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Hare, Alison (Alison Grace) 1976. "The stratigraphy and evolution of the late Cenozoic, intra-plate Werribee Plains basaltic lava flow-field, Newer Volcanic Province, Victoria, Australia." Monash University, School of Geosciences, 2002. http://arrow.monash.edu.au/hdl/1959.1/7586.
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McClelland, William Cabell. "The accretionary history of the Alexander terrane and structural evolution of the Coast Mountains batholith: Evidence from geologic, geochronologic, and thermobarometric studies in the Petersburg region, central southeastern Alaska." Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185033.
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Rocks west of the Coast Mountains batholith in central southeastern Alaska include the Alexander terrane, Gravina belt, Taku terrane, and newly defined Ruth assemblage. Geologic, geochronologic and thermobarometric studies of these rocks in the Petersburg region provide new constraints on the accretionary history of the Alexander terrane and structural evolution of the Coast Mountains batholith. Paleozoic and Upper Triassic strata of the Alexander terrane were deformed within the Duncan Canal shear zone. Dextral shear in this zone during Early or Middle Jurassic time is inferred to reflect deformation along the eastern margin of the Alexander terrane and record the juxtaposition of the Alexander terrane with the North American margin. Deposition of the Upper Jurassic-Lower Cretaceous Gravina belt occurred within a transtensional back-arc to intra-arc basin that evolved during the northward translation of the Alexander terrane. The Ruth assemblage and Taku terrane were structurally emplaced over the Gravina belt and Alexander terrane along the Sumdum-Fanshaw fault system during mid-Cretaceous time. West-vergent thrusting of the Ruth assemblage was accompanied by metamorphic P,T conditions of 6.8 kb, < 450°C in the Gravina belt and 6.9 to > 7.4 kb, > 550°C in the Ruth assemblage. The age of deformation is constrained by syntectonic and post tectonic intrusive bodies that yield U-Pb lower intercept apparent ages of 92.3 ± 3 Ma and 91.3 ± 6.3 Ma, respectively. Late Devonian-Mississippian orthogneiss and felsic metavolcanic rocks in the Ruth assemblage suggest correlation of the assemblage with continental margin rocks of the Yukon-Tanana and Nisling terranes east of the Coast Mountains batholith. Thus the mid-Cretaceous Sumdum-Fanshow fault system marks the fundamental boundary between the Alexander terrane and inboard fragments. This deformation records the final structural accretion of the Alexander, Wrangellia, and Peninsular terranes to the western margin of North America. The mid-Cretaceous thrust system is truncated to the east by the LeConte Bay shear zone: a complex zone of Late Cretaceous-early Tertiary fabrics that occur within and west of the Coast Mountains batholith. This zone has apparently accommodated both west-side-up and east-side-up displacement during the collapse of the overthickened crust developed during mid-Cretaceous time.
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Biesiada, Veronica Catherine. "A Characterization of Structures Across the Hurricane Ridge Fault in the Southeastern Olympic Peninsula, WA, Hamma Hamma River Transect." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4883.
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The Olympic Mountains in northwestern Washington, USA are defined by the arcuate shape of the basaltic Crescent Formation (Fm.) that wraps a faulted and folded meta-sedimentary core. This area was developed through accretion and exhumation by subduction-related processes, but how this relates to the deformational history of the area is not fully understood. The region has been mapped geologically, however little focus has been placed on interpreting meso-scale structures. This study investigates structures along a transect where the Hamma Hamma River crosses the Hurricane Ridge Fault, which juxtaposes the meta-sedimentary core (west) and the basaltic Crescent Fm. (east). In the study area, the meta-sedimentary unit is characterized by outcrop scale folding with a calculated fold axis of 69-->342 and a penetrative foliation with a representative orientation of (178, 75). The folds and foliation are crosscut by two fracture populations with representative orientations of (115, 61) and (303, 76). The pillow basalts of the Crescent Fm. are near vertical, N-S striking beds that are cut by four fault groups. Fault Groups A and B have representative orientations of (304, 37) and (207, 59), respectively, and are associated with similarly oriented fracture populations. Fault Group C crosscuts Groups A and B and has a representative orientation of (031, 61). Fault Group D runs subparallel to the outcrop, cuts all other faults, and has a representative orientation of (087, 50). From an interpretation of this data, a deformation model is presented that proposes three distinct periods of deformation under three different states of stress. The first period was dominated by E-W or ENE-WSW oriented compression, followed by a period of N-S or NNW-SSE oriented compression, followed by vertical compression.
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Williams, Anthony P. "Structural Analysis of CO2 Leakage Through the Salt Wash and Little Grand Wash Faults from Natural Reservoirs in the Colorado Plateau, Southeastern Utah." DigitalCommons@USU, 2004. https://digitalcommons.usu.edu/etd/6733.
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The Little Grand Wash fault and the Salt Wash Graben in the Colorado Plateau of southeastern Utah emit CO2 gas from abandoned drillholes, springs, and a hydrocarbon seep. Similar CO2-charged water has also been emitted in the past, as shown by large localized travertine deposits and veins along and near the fault traces. The faults cut natural CO2 reservoirs and provide an excellent analog for geologic CO2 sequestration. The faults cut a north-plunging anticline of rocks consisting of siltstones, shales, and sandstones from the Permian Cutler Formation through the Cretaceous Mancos Shale. The Little Grand Wash fault has 260 m of throw and the stratigraphic separation across the Salt Wash Graben is 50 m. The fault rocks in the damage zone show hundreds of fractures, which decrease in density farther away from the faults. In specific areas, fractures with the presence of calcite mineralization indicate fluid migration and bleach zones from a few millimeters to 30 cm. This is evidence of past fluid migration directly associated with the fault zone. Calcite mineralization fills these fractures and is also deposited in a variety of other bed forms. Foliated fault gouge, 5 to 20 cm thick, forms clay smear structures with a scaly shear fabric in a zone l0 to 15 cm thick is seen in the fault core. The leakage is constrained to the footwalls of the northernmost faults throughout the area. Clay-rich gouge structures should be effective barriers to cross-fault flow . Well log, surface geologic, and geochemical data indicate that the CO2 reservoirs have been cut by the faults at depth, providing a conduit for the vertical migration of CO2 to the surface, but not for horizontal flow across the fault plane. Even though lateral cross-fault migration may be impeded, this study clearly indicates that there are possible migration pathways for the escape of CO2 from faulted subsurface aquifers, including aquifers faulted by "low-permeability" faults with clay gouge. Three-dimensional flow models show how the fault's maximum permeability in the damage zone is parallel to the faults, and the leakage though the damage zone is localized near the fold axis of the regional anticline. Direct dating of the clay in the fault gouge was done by ExxonMobil with 40Ar/39Ar methods, indicating that fault movement occurred between the middle Eocene and the end of the Miocene. During this time, the Colorado Plateau is interpreted to have been experiencing rapid uplift. The middle Jurassic, upper Jurassic, and Cretaceous rocks at the surface have been uplifted approximately 1.8 km since the end of the Eocene. This uplift may have influenced fault movement in the Colorado Plateau and along the Little Grand Wash fault, and Salt Wash and Ten Mile Graben. In evaluating these deep aquifers for CO2 sequestration, careful design and monitoring of the geological structure and stress regimes must be considered to avoid leakage.
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Gomes, Leonardo Corrêa. "Análise da tectônica de colocação de diques cretácicos na região de São Sebastião, SP." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3691.
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O trabalho foi desenvolvido no litoral norte do estado de São Paulo, onde ocorrem boas exposições de rochas intrusivas da porção meridional do Enxame de Diques da Serra do Mar, de idade eocretácica. O objetivo principal da dissertação é caracterizar os regimes tectônicos associados à colocação e à deformação de diques máficos na área de São Sebastião (SP) e sua distribuição espacial, a partir de interpretações de imagens de sensores remotos, análise de dados estruturais de campo e descrição petrográfica das rochas ígneas. A área apresenta grande complexidade no tocante ao magmatismo, uma vez que ocorrem diques de diabásios toleítico e alcalino, lamprófiro e rochas alcalinas félsicas como fonolitos, traquitos e sienitos, estes sob a forma diques, sills e plugs. Os diabásios toleíticos tem idades em torno 134 Ma, correlatas com o início do rifteamento sul-atlântico, enquanto que as rochas alcalinas datam de 86 Ma e estão relacionadas com um magmatismo intraplaca posterior. Os lineamentos estruturais orientam-se majoritariamente na direção ENE-WSW, paralela às foliações metamórficas e zonas de cisalhamento observadas no campo e descritas na literatura, referentes ao Domínio Costeiro da Faixa Ribeira. Os diques se orientam na direção NE-SW, com azimute semelhante porém ângulos de mergulho discordantes da foliação em grande parte da área, onde as foliações são de baixo ângulo. Um segundo conjunto de lineamentos orientado NW-SE ocorre como um importante conjunto de fraturas que cortam tanto as rochas do embasamento proterozóico quanto as rochas alcalinas neocretácicas. Diques com esta orientação são escassos. Um terceiro conjunto NNE-SSW ocorre na porção oeste da área, associado à presença de diques de diabásio que por vezes mostram indicadores de movimentação sinistral. A análise cinemática dos diques mostra um predomínio de distensão pura durante sua colocação, com um tensor de compressão mínima de orientação NW-SE, ortogonal ao principal trend dos diques. Componentes direcionais, por vezes ambíguas, são comumente observadas, com um discreto predomínio de componente sinistral. O mesmo padrão cinemático é observado para os diques toleíticos e para os alcalinos, sugerindo que o campo de tensões local pouco variou durante o Cretáceo. Embora o embasamento não tenha sido diretamente reativado durante a colocação dos diques, sua anisotropia pode ter controlado de certa forma a orientação do campo de tensões local durante o Cretáceo. Os mapas geofísicos da bacia de Santos existentes na literatura sugerem certo paralelismo entre as estruturas observadas na área de estudo e aquelas interpretadas na bacia. As estruturas NNE-SSW são paralelas ao trend das sub-bacias e ao gráben de Merluza, enquanto que as estruturas NW-SE são paralelas a zonas de transferência descritas na literatura.The study was developed at the northern coast of São Paulo state, southeastern Brazil, where there are good exposures of intrusive rocks of the southern portion of the Early Cretaceous Serra do Mar Dyke Swarm. The main purpose is to define the tectonic regimes related to the emplacement and deformation of mafic dykes in the area of São Sebastião (SP) and their spatial and relative temporal distribution, based on interpretations of remote sensing images, field analysis of structural data, and petrographic description of igneous rocks. The area is quite complex in terms of Cretaceous magmatim, since there are dolerite dykes (tholeiitic and alkaline), lamprophyric dykes and felsic alkaline rocks (mainly phonolites, trachytes and syenites) which occur as dykes, sills and plugs. The tholeiitic dolerites yield ages around 134 Ma, related to the early South Atlantic rifting, while the alkaline rocks are dated as 86 Ma and are related to a subsequent intraplate magmatism. The structural lineaments are oriented mostly ENE-WSW, parallel to the metamorphic foliation and shear zones observed in the field and described in the literature, as part of the Costeiro Complex of the Ribeira Belt. The dykes are oriented NE-SW, with similar azimuth but different dip angles compared to the foliations, which are gently dipping in many areas. A second set of lineaments oriented NW-SE occurs as a major set of brittle fractures which cut both the Proterozoic rocks and the Late Cretaceous alkaline rocks. Dykes with this orientation are scarce. A third set oriented NNE-SSW occurs in the western area associated with some dolerite dykes which sometimes show evidence of sinistral component during emplacement. The kinematic analysis of the dykes shows a predominance of pure extension during emplacement, with an extension direction oriented NW-SE, orthogonal to the main dyke trend. Directional components, sometimes ambiguous, are commonly observed, with a slight predominance of sinistral components. The same kinematic pattern is observed for both tholeiitic and alkaline dykes, so that the local stress field orientation remained unaltered during the Cretaceous. Although the basement has not been directly reactivated during dyke emplacement, their anisotropies can account for some control on the orientation of the local stress field during the Cretaceous. The available geophysical maps of the Santos Basin suggest certain parallelism among the structures observed in the study area and those interpreted in the basin. The NNE-SSW trending structures are parallel to the trend of sub-basins and to the Merluza graben, while the NW-SE structures are parallel to transfer zones described in the literature.
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Guo, Dijiang. "Caractéristiques structurales de la zone de cisaillement de Wulong et de la minéralisation relative d'or dans le camp d'or de Wulong, Province du Sud-Est de Liaoning, Chine = [Structural characteristics of the Wulong shear zone and related gold mineralization in the Wulong Gold Camp, southeastern Liaoning Province, China] /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2001. http://theses.uqac.ca.
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Spitz, Herbert M. "Subsurface geology of the southeastern Cuyama Valley, southern Coast Ranges, California /." 1985. http://hdl.handle.net/1957/11940.
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Thesis (M.S.)--Oregon State University, 1986.Typescript (photocopy). Eight maps and twelve ill. folded in pocket. Includes bibliographical references (leaves 79-83). Also available on the World Wide Web.
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Galeazzi, Jose Sebastian. "Stratigraphic and structural evolution of the western Malvinas and southeastern Magallanes basins, Argentina." Thesis, 1994. http://hdl.handle.net/1911/13833.
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The area evolved from a Jurassic rifting stage to a Cretaceous sag and a Tertiary foredeep stage.
The sedimentary record is subdivided into four tectonostratigraphic units: Jurassic rift deposits, late-Jurassic-Cretaceous sag deposits, latest Cretaceous-Eocene foredeep-transition deposits, and late Eocene-Pliocene foredeep deposits. The rifts are filled with continental volcanics and pyroclastics. The sag deposits form a backstepping marine wedge, which contains the Springhill Formation (main reservoir) and is covered by a muddy and marly aggradational interval deposited in neritic waters of an epeiric sea (main petroleum source and seal). The latest Cretaceous to Eocene is a forestepping-backstepping wedge of glauconitic sandstones and claystones and carbonate buildups of shallow marine origin. The foredeep deepens during the late-Eocene to Oligocene. It is infilled during the Oligocene-late Miocene by a forestepping wedge that prograded from the west and southwest.
The age of the foredeep suggests that the southern Andean Orocline formed during the Paleocene-late Eocene interval.
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Gómez-Cabrera, Pedro Tomás. "Stratigraphic and structural analysis of the Neogene sediments of the offshore portion of the Salina del Istmo Basin, southeastern Mexico." Thesis, 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3119621.
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Vankeuren, Marc Anthony. "A Structural and 40Ar/39Ar Geochronological Re-Evaluation of Low-Angle Normal Faults in Southeastern Idaho." Thesis, 2015. https://doi.org/10.7916/D8NP2441.
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The development of gently inclined faults with large stratigraphic separation has long been enigmatic in the corridor of southeastern Idaho. Recent interpretations have culled examples from across the Basin and Range to suggest that these faults originated at a low dip and represent a regional scale low-angle normal fault system. In contrast, others cite extensive studies from fault mechanics and seismological data that cast doubt on whether these extensional structures could have formed at low inclination in the upper crust. This dissertation reviews the evidence and timing of the proposed Bannock detachment system in the Bannock Range of southeastern Idaho and puts forth a re-evaluation of the styles of extension in the region and a regional framework in which to place them.
Chapter 1 re-evaluates gently dipping normal faults in the southern Bannock Range of southeastern Idaho that have previously been interpreted as evidence for a regional detachment system originating and slipping at a low inclination. Previous work was based on geometrical relations between faults and bedding in lacustrine sediments of the upper Miocene to lower Pliocene Salt Lake Formation. The detachment argument was underpinned by three locations on the Oxford Mountain at which Salt Lake Formation was inferred to have been cut by low-angle normal faults. These locations have been re-evaluated. Two of the locations were found to preserve bedding-to-fault geometries that are well explained by offset from a fault of moderately dipping inclination. The third example is re-interpreted as an unconformable contact, not a fault, an observation that by itself precludes the existence of a detachment at that location.
Chapter 2 presents a test of tephronchronology by the 40Ar/39Ar isotopic method. This study compares ages obtained by the geochronologic method of tephrochronology to ages obtained by 40Ar/39Ar single grain laser fusion of feldspars. The results of this study suggest certain considerations must be made when employing the method of tephrochronology for chronological work.
Chapter 3 presents a regional synthesis for the tectonics of southeastern Idaho expanding on the new data presented in chapters 1 and 2. 40Ar/39Ar ages obtained from the Salt Lake Formation show evidence that extension in this region was underway > 15 Ma. Bedding-to-fault cutoff angles for the low-angle faults with the largest stratigraphic separations in the region suggest that the now gently inclined normal faults developed with moderate to steep dips, then tilted to lower inclination during continued extension. A splay of the Paris thrust is interpreted to account for both geometric relations between Paleozoic age rocks and the Neoproterozoic Pocatello Formation, as well as an unconformable contact between Pocatello Formation and late Miocene to Pliocene lake deposits of the Salt Lake Formation.
This dissertation focuses on one example of a detachment system. However, it has implications for low-angle faults in general – particularly in regions like the Basin and Range that have had a protracted deformation history. The examples we have studied are important because they involve strata as young as Pliocene and they provide strong support for the role of tilting in accounting for the present-day attitude of large-offset normal faults, eliminating the need for the well-known mechanical paradox of low-angle normal fault formation.
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Riley, Brook Colleen Daun Cloos Mark. "Laramide exhumation and heating in southeastern Arizona low-temperature thermal history and implications for zircon fission-track systematics /." 2004. http://repositories.lib.utexas.edu/bitstream/handle/2152/2172/rileybcd042.pdf.
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Sadeqi, AbdulWahab Mohammed. "Structural geometry of the late Paleozoic thrusting in the Hartshorne, Higgins, Adamson and Gowen quadrangles, southeastern Oklahoma." 2007. http://digital.library.okstate.edu/etd/umi-okstate-2241.pdf.
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Raine, Matthew David. "Polyphase deformation and the structural controls on economic gold occurrences within the Bendigo Goldfield, Central Victoria, Australia." 2005. http://eprints.jcu.edu.au/1172.
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Riley, Brook Colleen Daun. "Laramide exhumation and heating in southeastern Arizona: low-temperature thermal history and implications for zircon fission-track systematics." Thesis, 2004. http://hdl.handle.net/2152/2172.
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Ramírez-Ramírez, Calixto 1949. "Pre-Mesozoic geology of Huizachal-Peregrina Anticlinorium, Ciudad Victoria, Tamaulipas, and adjacent parts of eastern Mexico." 1992. http://hdl.handle.net/2152/12989.
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The Huizachal-Peregrina Anticlinorium is a large NNW-trending structure in the front ranges of the Sierra Madre Oriental of Mexico (23° 45ʹ N; 99° 10ʹ W). The breached core of the anticlinorium exposes three major geologic terranes: (1) . A late Precambrian granulite terrane (Novillo Gneiss) remarkably similar in composition, appearance, grade and age of metamorphism to rocks of the Grenville Province, especially the Adirondacks; (2). A mid-Paleozoic low-grade metamorphic complex (Granjeno Schist) of volcano-sedimentary origin with ophiolite rock assemblages, that resemble rocks of the Ouachita-Appalachian inner zones; and (3). A strongly folded and faulted section of Paleozoic fossilifireous sedimentary strata, more than 1500 m thick, similar to the rocks of the Ouachita frontal zone exposed in the Marathon region of Texas. Except for an extensive subcrop terrain of Permo-Triassic granitic intrusives, the terranes in the area studied represent "unique samples" of the Pre-Mesozoic basement framework of eastern Mexico. These terranes belong to two ancient superposed orogenic systems: the Late Precambrian Oaxacan (Grenville) and the Paleozoic Huastecan (Ouachita-Appalachian) structural belts. Based on the geologic study of these pre-Mesozoic terranes at Huizachal-Peregrina, and compared with the widely spaced and limited outcrops (and sub-crops) of equivalent rock units of eastern Mexico, a tectonic model is proposed which interprets the granulite terrane as representative of continental crust, and the low-grade metamorphic terrane as rocks that accumulated on top of the ocean crust of a marginal basin. This latter sequence experienced a complex history of deformation and metamorphism as it was subducted towards the east, culminating 330 m.y. ago. The onset of Carboniferous-Permian orogenic flysch sedimentation is interpreted to have occurred when the marginal basin became closed by an arc-continent collision. The Permo-Triassic granitic rock terrane of the subsurface of the Gulf Coastal Plain represents the magmatic roots of that volcanic arc. The pervasive NW to NNW-trending structural grain, of the Oaxacan and Huastecan structural belts south of Huizachal-Peregrina through Oaxaca, when compared to the NE-trending distribution of Precambrian and Paleozoic terranes in the United States are compatible with the existence of a proposed zone of large left-lateral displacement across northern Mexico.text
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Marzen, Rachel. "The Role of Tectonic Inheritance: Mountain-Building, Rifting, Magmatism, and Earthquakes in the Southeastern United States." Thesis, 2021. https://doi.org/10.7916/d8-c7ag-gg94.
Full textAbstract:
The Southeastern US is an ideal location to explore the interactions between mountain-building, rifting, magmatism and intraplate deformation. It experienced the formation of the Southern Appalachians over multiple episodes of orogenesis, continental rifting that formed the South Georgia Rift Basin, and widespread magmatism associated with the Central Atlantic Magmatic Province (CAMP). CAMP was followed by the breakup of Pangea, but the suture between Laurentia and Gondwana from the Appalachian orogeny is preserved in the crust of the Southeastern US. Intraplate seismicity indicates ongoing deformation in the Southeastern US today, but the mechanisms controlling this seismicity are poorly understood. This thesis uses seismic constraints to examine the tectonic history of the Southeastern United States (US). We use new wide-angle refraction seismic data to model crustal and upper mantle velocities in order to investigate the structures formed by mountain-building, rifting, and magmatism. Broadband seismic data are then used to detect and characterize earthquakes in the central Georgia-South Carolina region. Wide-angle seismic data were collected on three profiles crossing major geological features in Georgia to investigate the tectonic history of the Southeastern United States as a part of the SUwanee Suture and GA Rift basin experiment (SUGAR) project. We model VP and VS of the crust and upper mantle on SUGAR Line 2, which extends from the Inner Piedmont to the Georgia coast. We identify a north to south decrease in upper crustal VP/VS at the Higgins-Zietz magnetic boundary, which other recent studies have identified as the location of the suture between Laurentia and Gondwana. This boundary also lies near the northwestern edge of the South Georgia Rift Basin, the southeastern termination of the low velocity zone interpreted as the Appalachian detachment, and localized crustal thinning. Together, these results provide new evidence in support of the Alleghanian suture being located at the Higgins-Zietz magnetic boundary, and suggest that this orogenic boundary influenced the location of subsequent rifting.
We compare the VP structures of two SUGAR wide-angle transects that cross western and eastern segments of the South Georgia Rift, respectively. Elevated (>7.0 km/s) lower crustal velocities are observed where the rift basin sedimentary fill is thickest and the crust is most thinned. The quantities of mafic magmatic intrusions are consistent with decompression melting at modestly elevated mantle potential temperatures, such as those estimated for CAMP intrusions. These results suggest that, in contrast with the widespread CAMP-aged magmatism at the Earth’s surface, lower crustal magmatic intrusions in the Southeastern US are limited and localized in areas that experienced extension.
These new constraints on the velocity structure and tectonic history of the Southeastern United States are then applied to understand earthquakes in the region today. Using broadband seismic data, we find that earthquakes southeast of the Eastern Tennessee Seismic Zone are concentrated within the Carolina Terrane, a particularly heterogeneous accreted terrane of the Southern Appalachians. Within this terrane, seismicity concentrates near rivers and reservoirs, including a sequence of earthquakes in 2013 associated with an increase in water levels at Thurmond Lake on the Georgia-South Carolina border. Focal mechanisms suggest that the earthquakes are occurring on structures that are oblique to the trend of the Appalachians that are more optimally oriented in the modern stress regime.
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Nelson, Emma Jane. "Present-day stress in Central and Southeast Australian sedimentary basins." 2007. http://hdl.handle.net/2440/45071.
Full textAbstract:
This thesis consists of six published papers. The present-day stress tensor has been determined using petroleum well data in the Gippsland and Otway Basins in Southeast Australia (Papers 1 and 4) and the Cooper Basin in Central Australia (Paper 5). In the Gippsland Basin, the present-day stress regime is transitional between one of reverse and strike-slip faulting and the maximum horizontal stress (SHmax) is oriented ~139°N. The present-day stress regime in the Victorian sector of the Otway Basin is also transitional between one of reverse and strike-slip faulting and SHmax is oriented ~135°N. Horizontal stresses are lower in the South Australian sector of the Otway Basin where the stress regime is one of strike-slip faulting and SHmax is oriented ~124°N. The orientations of SHmax in Southeast Australia are consistent with focal mechanism solutions, neotectonic structures and modelling of plate-boundary forces (Paper 4). Closure pressures from mini-frac injection tests are commonly used to determine the minimum horizontal stress (Shmin) magnitude. However, in high stress basins such as the Cooper and Gippsland Basins, these pressures may not reliably yield Shmin (Papers 2 and 5). In the Cooper Basin, high closure pressures (>18 MPa/km) were observed in tests where pressure-declines indicated complex hydraulic fracture growth. Closure pressures in these injections are unlikely to be representative of Shmin. They are believed to reflect the normal stress incident on pre-existing planes of weakness that are exploited by hydraulic fluid during the mini-frac injection (Paper 5). Sub-horizontal fabrics that are open at the wellbore wall were observed on image logs in the Cooper and Gippsland Basins (Papers 2 and 5). This fabric is believed to be at least partially responsible for the complex growth of hydraulic fractures observed in the Cooper Basin. The occurrence of these sub-horizontal fabrics and knowledge of rock strength have been used to constrain the magnitudes of SHmax and Shmin independently of mini-frac injections in the Cooper and Gippsland Basins (Papers 2 and 5). The present-day stress tensor is often quoted as a single gradient at a sedimentary basinor petroleum field-scale. Image logs and mini-frac data from Central and Southeast Australia indicate significant stress differences between stratigraphic units (Papers 3 and 5). Finite element modelling of the stress distribution between interbedded sands and shales in the Gippsland Basin indicates that stress is ‘partitioned’ to ‘hard’ lithological units in high stress areas. This accounts for the observation that borehole breakout only occurs in hard, cemented sandstones in the Gippsland Basin (Paper 3). A generic ‘mechanical stratigraphy’ derived from knowledge of wellbore failure (from image logs), rock strength and rock properties in individual rock units in the Cooper Basin allows an approximation of the present-day stress-state to be made directly from image-logs for individual rock units prior to mini-frac injection (Paper 6). This is important for predicting and understanding hydraulic fracture growth and containment. When considered together, the papers comprising this thesis provide significant new data on the orientation and magnitude of present-day stresses in Central and Southeast Australia. They also provide insight into the tectonic origin of those stresses and their distribution within sedimentary basins. In particular the papers develop and use new methods for constraining the present-day stress in regions of high tectonic stress. They also discuss implications for problems in petroleum development including wellbore stability and hydraulic fracturing.http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283781
Thesis(Ph.D.) -- Australian School of Petroleum, 2007
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Nelson, Emma Jane. "Present-day stress in Central and Southeast Australian sedimentary basins." Thesis, 2007. http://hdl.handle.net/2440/45071.
Full textAbstract:
This thesis consists of six published papers. The present-day stress tensor has been determined using petroleum well data in the Gippsland and Otway Basins in Southeast Australia (Papers 1 and 4) and the Cooper Basin in Central Australia (Paper 5). In the Gippsland Basin, the present-day stress regime is transitional between one of reverse and strike-slip faulting and the maximum horizontal stress (SHmax) is oriented ~139°N. The
present-day stress regime in the Victorian sector of the Otway Basin is also transitional between one of reverse and strike-slip faulting and SHmax is oriented ~135°N. Horizontal stresses are lower in the South Australian sector of the Otway Basin where the stress regime is one of strike-slip faulting and SHmax is oriented ~124°N. The orientations of SHmax in Southeast Australia are consistent with focal mechanism solutions, neotectonic structures and modelling of plate-boundary forces (Paper 4).
Closure pressures from mini-frac injection tests are commonly used to determine the minimum horizontal stress (Shmin) magnitude. However, in high stress basins such as the Cooper and Gippsland Basins, these pressures may not reliably yield Shmin (Papers 2 and 5). In the Cooper Basin, high closure pressures (>18 MPa/km) were observed in tests where pressure-declines indicated complex hydraulic fracture growth. Closure pressures in these injections are unlikely to be representative of Shmin. They are believed to reflect the normal stress incident on pre-existing planes of weakness that are exploited by hydraulic fluid during the mini-frac injection (Paper 5). Sub-horizontal fabrics that are open at the wellbore wall were observed on image logs in the Cooper and Gippsland Basins (Papers 2 and 5). This fabric is believed to be at least partially responsible for the complex growth of hydraulic fractures observed in the Cooper Basin. The occurrence of these sub-horizontal fabrics and knowledge of rock strength have been used to constrain the magnitudes of SHmax and Shmin independently of mini-frac injections in the Cooper and Gippsland Basins (Papers 2 and 5).
The present-day stress tensor is often quoted as a single gradient at a sedimentary basinor petroleum field-scale. Image logs and mini-frac data from Central and Southeast Australia indicate significant stress differences between stratigraphic units (Papers 3 and 5). Finite element modelling of the stress distribution between interbedded sands and shales in the Gippsland Basin indicates that stress is ‘partitioned’ to ‘hard’ lithological units in high stress areas. This accounts for the observation that borehole breakout only occurs in hard, cemented sandstones in the Gippsland Basin (Paper 3). A generic ‘mechanical stratigraphy’ derived from knowledge of wellbore failure (from image logs), rock strength and rock properties in individual rock units in the Cooper Basin allows an approximation of the present-day stress-state to be made directly from image-logs for individual rock units prior to mini-frac injection (Paper 6). This is important for predicting and understanding hydraulic fracture growth and containment.
When considered together, the papers comprising this thesis provide significant new data on the orientation and magnitude of present-day stresses in Central and Southeast Australia. They also provide insight into the tectonic origin of those stresses and their distribution within sedimentary basins. In particular the papers develop and use new methods for constraining the present-day stress in regions of high tectonic stress. They also discuss implications for problems in petroleum development including wellbore stability and hydraulic fracturing.Thesis(Ph.D.) -- Australian School of Petroleum, 2007
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Parker, William Floyd Jr. "Structural interpretation of Paleozoic strata as part of the transition zone in the Wilburton gas field using 3D seismic, Hartshorne, Higgins, Adamson and Gowen quadrangles, southeastern Oklahoma, Arkoma Basin /." 2007. http://digital.library.okstate.edu/etd/umi-okstate-2244.pdf.
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Meaney, Kieran James. "Proterozoic crustal growth in the southeastern Gawler Craton: the development of the Barossa Complex, and an assessment of the detrital zircon method." Thesis, 2017. http://hdl.handle.net/2440/114255.
Full textAbstract:
The Barossa Complex, southeast Gawler Craton, South Australia, forms the southeastern-most exposure of pre-Neoproterozoic crust in Australia. Understanding the geodynamic evolution of this area can improve paleogeographic reconstructions of the economically significant Gawler Craton, as well as global reconstructions in the Proterozoic. The first part of this thesis addresses the geological development of the Barossa Complex during the Palaeo-Mesoproterozoic.
The Barossa Complex is composed of metasedimentary and metaigneous gneisses. These include calcsilicate, quartzofeldspathic, psammopelitic, and pelitic gneisses. In the northern inliers, the protoliths to these gneisses are indicative of a progressively deepening basin. Syndepositional felsic orthogneisses and mafic amphibolites indicate a tectonically active basin.
Deposition of the metasedimentary protoliths to the Barossa Complex occurred between 1730-1655 Ma, synchronous to the onset of the Kimban Orogeny in the Gawler Craton and the deposition of the Willyama Supergroup in the Curnamona Province. U-Pb and Hf isotopic analyses from detrital zircon indicates sediment was largely derived from the Gawler Craton. Syndepositional granite intrusions occurred in the northern extent of the Barossa Complex at 1717 ±7 Ma.
Metamorphism initiated in the Barossa Complex at c. 1630 Ma with the development of a low angle metamorphic fabric. Peak granulite conditions of approximately 8-9 kbar and 800-850 °C occurred at c. 1590 Ma in the southern Barossa Complex. The northern Barossa Complex preserves lower grade metamorphic features and c. 1600 Ma zircon with hydrothermal Rare Earth Element (REE) signatures, which are potentially linked to the Hiltaba event in the Gawler Craton. Post peak metamorphism continued until c. 1550 Ma and is associated with retrograde shear zones in the southern Barossa Complex, and late pegmatites in the northern inliers.
The Barossa Complex shares a depositional and metamorphic history with the Willyama Supergroup in the Curnamona Province and Mt. Isa Inlier basin sequences, and was part of a transcontinental plate margin system during the Late Palaeo- Early Mesoproterozoic. East dipping subduction was the likely driver for extensive rift basin development across the eastern margin of Proterozoic Australia before the Isan-Olarian Orogeny inverted these basins. The Barossa Complex is the southern-most exposure of this system.
The second part of this thesis addresses the use of detrital zircon in modern sediment as a means of characterising the bedrock of a catchment area, which has been used previously in the Gawler Craton and Curnamona Province.
In the Broken Hill area of the Curnamona Province, stream sediments were sampled from drainage pathways with catchments that have stratigraphically and chronologically well characterised bedrock lithologies. Zircon ages from the modern sediment found up to 30% of the zircons were significantly younger than what expected from the bedrock sources (>1.6 Ga). Aeolian dune sands from the Strzelecki Desert to the north of the study area are found to contain zircon with U-Pb and Lu-Hf isotopic compositions matching the ‘exotic’ zircon populations in Broken Hill. Aeolian detritus is considered to have contributed zircon to the stream sediments in Broken Hill, and should be considered in any study utilising modern detritus in arid environments. Detrital zircon provenance studies of the geological record should be interpreted cautiously if aeolian input may have occurred.Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Physical Sciences, 2018