oai-hal-tel-00690779v1
type: Dataset
contact point: Organization
  fn: CCSD
keyword: modeles-geodynamique
keyword: sdustugcsciences-of-the-universe-physicsearth-sciencesgeochemistry
keyword: sdemcgenvironmental-sciencesglobal-changes
keyword: arcs-insulaires
keyword: black-dyke
keyword: accretion-continentale
keyword: terrane-chilliwack
keyword: marge-active
keyword: theses
keyword: sdustutesciences-of-the-universe-physicsearth-sciencestectonics
keyword: cordilleres-nord-americaines
keyword: infoeu-reposemanticsdoctoralthesis
keyword: volcanisme-triasique
landing page: https://theses.hal.science/tel-00690779
description: The North American Cordillera is composed of several lithospheric fragments that accreted to North America since the late Devonian. These lithospheric fragments are characterized by oceanic basin or volcanic arc sequences. The Late Paleozoic and Triassic arc sequences were interpreted to belong to a single arc system. In the past ten years, major advances have been made in understanding Permlan arc rocks. The late Paleozoic to Triassic arc sequences of Eastern Klamath and Sierra Nevada (California) are built on oceanic and continental basement, respectively. In western Nevada, upper Paleozoic arc sequences are exposed in two distinct areas: Black Rock Desert and Excelsior Mountains. In the .Black Rock Desert, the Bilk Creek Paleozoic-Triassic arc sequences show strikig slmllarities with the Eastern Klamath and Blue Mountains arc terranes. Magmatism is continuous from mid-Permian until Late Triassic time, and rests conformably on Early Permian carbonates with Tethyan affinities, and derives from a N-MORB type mantle source. In the Excelsior Mountains, the Black Dyke Formation is composed of lavas and pyroclastic breccias overlain conformably by volcaniclastic turbldities. This volcanic actlvity occurs during Early Permian around 276 Ma. This arc magmatism shares similarities with the upper Paleozoic Sierra Nevada arc. In both areas, volcanic arc sequences are characterized by: (i) Early Permian age; (ii) calc-alkaline volcanic rocks; and (iii) low eNd (T) values ranging between -11 to +5.5. In Sierra Nevada, upper Paleozoic arc was built on a lower Paleozoic metamorphose sedimentary sequence the Shoo Fly Complex. This arc was separated from North American margin by an oceanic basin, Golconda Basin. Low eNd(T) values of magmatic rocks of Sierra Nevada and Excelsior Mountains suggest that magmas derive from a mantle source contaminated by an old continental crustal component, probably Proterozoic. During magma ascent and stocking in the arc crust, assimilation of crust…
issued: 2026-05-20T22:33:19.482498
language: fr
modified: 2026-05-20T22:33:19.482503
title: Les séquences magmatiques d'arc du Paléozoïque supérieur et du Trias du Nevada (Etats-Unis d'Amérique) et de Colombie britannique (Canada) : structure, pétrologie et géochimie : implications dans l'évolution géodynamique des Cordillères nord-américaines et les processus d'accrétion continentale .

test_moissonnage_selune
type: Agent

https://rec.harvest-normandie.data4citizen.com/dataset/oai-hal-tel-00690779v1/resource/7b8d31b3-4696-4f7e-bf53-8b2604d3441b
type: Distribution
access URL: https://theses.hal.science/tel-00690779
format: HTML
issued: 2026-05-20T22:33:19.605409
modified: 2026-05-20T22:33:19.452294
title: Les séquences magmatiques d'arc du Paléozoïque supérieur et du Trias du Nevada (Etats-Unis d'Amérique) et de Colombie britannique (Canada) : structure, pétrologie et géochimie : implications dans l'évolution géodynamique des Cordillères nord-américaines et les processus d'accrétion continentale .