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.
Results
Showing 1 to 20 of 41 for “"orogenesis"”.
-
Continental Deformation: Collisional Orogenesis to Passive Margin Processes
My research investigates continental deformation at opposing ends of the Wilson cycle, intracontinental collision and passive margin development. I present a map of NW Nepal river channel steepness (ksn), a proxy for rock uplift rate over 103-105 years, coupled with a seismotectonic model, and then …
-
Stratigraphic signatures of convergent orogenesis from the plate interior : studies from Tibet and the southern Rocky Mountains
… Through these studies of the basin records of orogenesis in the Qaidam basin of northern Tibet and the southern Rocky Mountain basins of North America, we provide new constraints on the timing of deformation, the development of proximal basins, and the evolution of continental-scale drainage …
-
Eo-Variscan Orogenesis in the Guilleries Massif, Catalan Coastal Ranges, Northeastern Spain Recorded by U-Th-Pb ages of Monazite Inclusions in Metamorphic Garnet
<p>A chronicle of the Variscan Orogeny is recorded in high grade pelitic schists of the Guilleries Massif of the Catalan Coastal Ranges of northeastern Spain which preserve multiple rounds of deformation and metamorphism. The massif records a classic Variscan low-pressure and high-temperature …
-
Paleoenvironmental Variability across the Cretaceous-Tertiary Boundary in the Alberta Foreland Basin, as Interpreted from Fluvial Deposits and Paleosols, Red Deer River Valley, Alberta, Canada.
… of paleosol morphology in response to foreland orogenesis. The depositional history records an evolution from amalgamated, multi-story, braided sand bodies to accretionary, single-story, overbank-prone meandering deposits. The distribution of paleosols throughout the section is also cyclic. …
-
The timing of prograde metamorphism in the Garhwal Himalaya, India
… the most significant example of present-day orogenesis and consequently have been extensively studied to gain an understanding of the principle controls on the response of the crust to continental collision. However, our understanding of the prograde metamorphic evolution of the orogen …
-
A stable isotope investigation into fluid-rock interaction during regional metamorphism in western dronning maud land, East Antarctica
… for Pan African overprinting of Grenvillian orogenesis in western Dronning Maud Land.
-
Supercontinents and glaciation: a perspective from western Gondwana.
… Block. The alleged ‘Brasiliano’ age (~620 Ma) of orogenesis was recently questioned by palaeomagnetic and radioisotopic ages that indicate the closing stages of orogenesis occurred well into the Cambrian that are believed to mark the suture zone of the Clymene Ocean—interpreted amongst the …
-
The thermal and metamorphic evolution of the Northern Highlands Terrane, Scotland
… preserve a record of Scandian (435-410 Ma) orogenesis. High grade metamorphism in the hinterland Naver nappe likely resulted from the widespread infiltration of granitic magmas at c. 425 Ma, which coincided with peak metamorphism. The timing of metamorphism in the hinterland Scandian thrust …
-
Thermo-tectonic record of hyperextension, structural inversion, and foreland basin evolution of the eastern and central Pyrenees
… the role of pre-existing crustal architecture on orogenesis and foreland basin development. This work constrains the Early Cretaceous hyperextension history along the Iberia-European margin and how rift inheritance affected the structural and foreland basin evolution of the Late …
-
Testing models of ultra-fast India-Asia convergence : new paleomagnetic results from Ladakh, Western Himalaya
… the tectonic history and dynamics of Himalayan orogenesis. We present new paleomagnetic data from the Khardung volcanic rocks of the Shyok-Nubra valley region of Ladakh, western Himalaya. Samples from all four sites (KP1-KP4) display high-temperature components indicating a roughly equatorial …
-
A metamorphic and geochemical study of mafic rocks across the Pencksökket-Jutulstraumen Discontinuity, western Dronning Maud Land, East Antarctica
… a major thrust that developed during Pan-African orogenesis (possibly as the continuation of the East African Mozambique Belt into East Antarctica) prior to extension and its development as a normal listric fault or succession of fault slices during the Mesozoic break-up of Gondwana.
-
Geological and thermochronological evolution of the lower crust of southern Africa
… was generated during 1.1 to 1.0 Ga Namaqua-Natal orogenesis, in response to collisional crustal thickening. Ultra-high temperature granulites in the central cratonic lower crust were generated during dramatic advective perturbation of the lithosphere during 2.7 Ga Ventersdorp rifting and …
-
Mesoproterozoic tectonic evolution of southwestern North America : protracted intracratonic deformation, sedimentation, and differential exhumation in Grand Canyon and the Rocky Mountain Region
… that far-field stresses related to Grenville orogenesis (NW shortening and orthogonal NE-SW extension) dominated the sedimentary and tectonic regime of southwestern Laurentia from 1.25 to 1.1 Ga. The dominant structural grains of the Ancestral Rockies and Laramide Rockies (N-S and NW-trending) …
-
Fluid flow and deformation history of the Denver basin, CO region: fluid inclusions, U-Pb geochronology and isotope geochemistry of calcite-filled fracture cements in the Niobrara Formation
… in the Late Cretaceous to middle Cenozoic by orogenesis, basin formation, and burial. The fracture network (e.g., joints, faults, open stylolites) acted as conduits for fluid flow. However, little to no constraints on the origin, temperature, composition, and timing of these fluid flow events …
-
The sedimentology and stratigraphy of Salt Creek Field, Kent County, Texas
… is contemporaneous with peak Marathon-Ouachita orogenesis. A critical question for understanding the Horseshoe Atoll geologic framework is whether LPIA-associated glacioeustacy or Ouachita tectonics was the main driver for the development of the observed stratigraphic architecture and the …
-
The Foyers Granitic Complex and its aureole
… psammites, after the cessation of Caledonian orogenesis, and developed an extensive thermal aureole, with minor anatexis occuring in the inner aureole. Granitoid fabrics, enclaves, xenoliths and internal contacts imply emplacement whilst in a magmatic state. The adamellite was emplaced into a …
-
The Post Triassic uplift and erosion history of the Southwestern UK
… by compressional deformation related to Alpine orogenesis and/or Atlantic ridge-push. These observations imply that events at plate margins have exerted the primary control upon intra-plate exhumation in the Southwest UK onshore and offshore basin system with local faults providing an important …
-
Long-term exhumation of landscapes along the Pacific-North American plate boundary as inferred from apatite (U-Th)/He and ArcGIS analyses
… terrane accretion, but relating plate boundary orogenesis to variations in plate geometry and behavior requires detailed case studies. The northern San Gabriel Mountains along the San Andreas fault and the Chugach-Kenai Mountains above the Aleutian subduction zone are located along highly …
-
High Resolution Stratigraphy of Ordovician Carbonates, Kentucky: Evidence for a Greenhouse to Glacial Transition
… of the subducting margin at the onset of Taconic orogenesis. Middle Ordovician carbonates were deposited on a ramp peripheral to a foredeep in Tennessee. The Middle Ordovician High Bridge Group consists of a 2nd-order supersequence with three 3rd-order sequences (each 30 to 100 m thick), which …
-
Sedimentary basin evolution and structural compartmentalization in the northernmost Andes : Eastern Cordillera and Magdalena Valley, Colombia
… Cenozoic basin inversion during early Andean orogenesis. This study helps assess the kinematic sequence of deformation to identify linkages between uplift and sediment dispersal across the Middle Magdalena Valley, and the flanking Eastern Cordillera and Central Cordillera during Andean …
Page 1 of 3