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 109 for “"Orogen"”.
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Understanding Himalayan denudation at the catchment and orogen scale
… the dynamic processes that shape active orogens. This includes decoding the roles of tectonic and climate-driven processes in the long-term evolution of high- mountain landscapes in regions with pronounced tectonic activity and steep climatic and surface-process gradients. …
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Contractional tectonics : the Himalayan orogen and Perdido fold-thrust belt
… of contractional tectonics: collisional orogenic belts and toe structures of passive margins, which are characterized by fold-thrust belts that are hundreds of kilometer-scale and tens of kilometer-scale, respectively. The Himalayan orogen is an excellent example of collisional orogenic …
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Evolution of early Proterozoic passive-margin carbonate platform, Rocknest Formation, Wopmay Orogen, N.W.T., Canada
The superbly exposed Rocknest Formation, Wopmay Oroqen, N.W.T., Canada, is an early Proterozoic (l.B9 Ga) passivemargin carbonate platform. It is an eastward-thinning prism, 0 to 1,100 m thick, extending for over 220 km parallel to strike, and over 200 k.m perpendicular to strike. It contains from …
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The thermal structure of collisional orogens – insights from the Grenville orogen in Canada and Scotland
Exhumed collisional orogens provide important time-integrated records of metamorphic, magmatic and deformation processes occurring over timescales of up to hundreds of millions of years. When combined with observations and principles from present-day deformed continental regions, research of …
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The geology, petrography, geochemistry and uranium ore mineralogy of the Namibplaas sheeted leucogranites, Damaran orogen, Namibia
… and thorium (Sppm to 17.5ppm) The late- to post- orogenic conformable and transgressive sheeted leucogranitic bodies range in composition from tonalite to syenogranite. The Namibplaas leucogranites are peraluminous to metaluminous indicating a highly evolved crustal source most probably the …
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Crustal melting in the Himalayan orogen : field, geochemical and geochronological studies in the Everest region, Nepal
… in the Everest region of the Himalayan orogen. Geochemical investigations focused on samples from three outcrops at different structural levels in the Himalayan metamorphic core where in situ crustal melting and multiple generations of leucogranite intrusions were observed. Accessory …
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A Thermochronological Investigation of Orogenic Architecture, Kinematics, and Tectonic-Climatic Interactions within the St. Elias Orogen, Alaska
The kinematics and architecture of orogenic systems may be heavily influenced by climate, but little research has focused on the long-term effects of glacial erosion on orogenesis. Low-temperature thermochronometry and subsidiary structural, earthquake relocation, and offshore seismic reflection …
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Thermochronology and geobarometry of the Granite Mountains, southeast California: Exhumation of a plutonic complex during collapse of the Sevier orogen
Thermochronologic data and geobarometry from the Granite Mountains indicate exhumation of mid-crustal plutons during Late Cretaceous extensional tectonics. U/Pb zircon and 40Ar/39Ar ornblende ages indicate intrusion, crystallization, and geologically instantaneous cooling through 500°C at ∼75 …
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Multi-stage orogenic gold mineralization of the Pine Lake greenstone belt: evidence from the Seabee Gold Operation, Trans-Hudson orogen, northern Saskatchewan
… of the larger Paleoproterozoic Trans-Hudson orogen. At the Seabee Gold Operation, auriferous quartz veins are hosted within shear zones, such as the Santoy shear system, that are focussed along basalt-intrusion contacts, extending south onto the Fisher property. The systematics of gold …
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Aspects of Deformation and Strain in the Appalachian Fold -Thrust Belt (New York) and the Shear Zones of the Sveconorwegian Orogen (Norway)
… to burial) and tectonic (due to the Alleghanian orogeny). In contrast, analysis of the anisotropy of magnetic susceptibility (AMS) yields magnetic lineations that closely parallel structural trends, even at localities where Fry fabrics do not, suggesting that AMS is a more sensitive indicator of …
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Tectonic evolution of the Waldau Ridge structure and the Okahandja Lineament in part of the Central Damara Orogen, west of Okahandja, South West Africa
… forces originating in, and possibly related to, orogenic events in the main trunk of the Pan-African orogenic belt further west. It is proposed that the major tectonic relationships in the area can be related to subduction and continental collision in the southern part of the Khomas Trough in …
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Tectonic significance of the Atnarko complex, Coast Mountains, British Columbia
… Atnarko complex to equivalent portions of the orogen along strike, indicates a post mid-Cretaceous change in structural style. To the northwest the orogen records continued southwest-directed compression which dominates the deformation style; while to the southeast large dextral strike-slip …
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The thermal and metamorphic evolution of mountain belts as a response to erosion, accretion, and radiogenic heating
Simple thermal models of collisional orogenesis generally predict metamorphic temperatures that are much cooler than those revealed by thermo barometric studies of real metamorphic terrains. This thesis focuses on a more realistic model that accounts for the redistribution of crust enriched in …
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A study of epigenetic mineralisation in the Central Zone of the Damara Orogen, Namibia with special reference to gold, tungsten, tin and rare earth elements
… Proterozoic/Early Palaeozoic, Pan-African Damara Orogen is hosted by meta-arkoses, marbles and metaturbidites in the magmatic arc (Central Zone; CZ) of the orogen, a tectonostratigraphic entity that is characterised by multiple deformation, greenschist/amphibolite-facies, …
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The role of extension during the evolution of the NW Indian Himalaya
The evolution of most orogens typically records cogenetic shortening and extension. Pervasive normal faulting in an orogen, however, has been related to late syn- and post-collisional stages of mountain building with shortening focused along the peripheral sectors of the orogen. While extensional …
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EMPLACEMENT OF THE DADEVILLE COMPLEX OF THE SOUTHERNMOST INNER PIEDMONT WITHIN THE 7.5 MIN. CUSSETA QUADRANGLE, CHAMBERS COUNTY, ALABAMA: CHANNEL FLOW, KLIPPE KINEMATICS, OR OROGEN PARALLEL TRANSLATION
… have a complex geologic history spanning three orogenic periods, the Taconic, the Acadian/Neoacadian, and Alleghanian orogenies. The Inner Piedmont of the Appalachian Mountains within Alabama contains two distinct lithologic complexes, the Dadeville Complex, and the Opelika Complex separated by …
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Extensional evolution of the central East Greenland Caledonides
… addresses the complexity of both syn- and post-orogenic extension in the overriding plate during Caledonian continental collision through field and laboratory investigations in the central East Greenland Caledonides. During the course of this work, attempts were made to answer some of the …
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Cenozoic foreland-basin evolution in the northern Andes : insights from thermochronology and basin analysis in the Eastern Cordillera, Colombia
… straddling the eastern margin of the Andean orogen is the prime example of a retro-arc foreland basin system adjacent to a subduction orogen. While widely studied in the central and southern Andes, the spatial and temporal evolution of the Cenozoic foreland basin system in the northern Andes …
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