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Showing 1 to 20 of 45 for “"orogenesis"”.
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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 …
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Combining microstructural analysis with EPMA monazite geochronology to constrain progressive stages of orogenesis in the Appalachians
… Between these regions, over 150 million years of orogenesis, within three major events are recorded. The protocol for analysing monazite was (and still is) a continual process of refinement and learning. As such, the data presented here reflects this natural progression, and some of the methods …
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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 …
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Microprobe dating of monazite in relation to porphyroblast growth and thermodynamic modelling P-T paths for rocks affected by prolonged orogenesis
… at 350 Ma. Previous tectonic models for Acadian orogenesis for the region have suggested that deformation and accompanying metamorphism was a two-stage process. Crustal thickening was thought to be the result of nappe style thrusting followed by regional scale doming. The integration of …
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N-S shortening during orogenesis in the Mt Isa Inlier: the preservation of W-E structures and their tectonic and metamorphic significance
Mesoproterozoic Mt Isa inlier of NW Queensland exhibits complex tectonometamorphic history that is generally considered to result from low-pressure/high-temperature (LP/HT) metamorphism with an anticlockwise pressure-temperature-deformation path. Yet studies regarding the nature of the P-T history …
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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 …
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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. …
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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 …
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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.
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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 …
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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 …
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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 …
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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 …
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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.
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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 …
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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) …
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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 …
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Structural and metamorphic evolution of the Robertson River metamorphics with pressure-temperature-deformation-time (P-T-D-t) path
… of metamorphism, revealing a lengthy history of orogenesis in the Robertson River Metamorphics (NE Australia). A complete pressure-temperature-deformation-time (P-T-D-t) path has been deciphered involving an early clockwise P-T loop (not previously recognized in the NE Australian Craton) followed …
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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 …
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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 …
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