Crystallization age of alpine cleft monazite-(Ce) and correlation with tectonically driven hydrothermal dissolution/precipitation events

Diplôme Thèse Crystallization age of alpine cleft monazite-(Ce) and correlation with tectonically driven hydrothermal dissolution/precipitation events eng 2017-10-23 author Bergemann Christian 802879 director Gnos Edwin 704533 director Schaltegger Urs 0000-0003-4404-8607 134356 10.13097/archive-ouverte/unige:102553 urn:nbn:ch:unige-1025533 Sc. 5135 Hydrothermal monazite-(Ce) from open clefts/fissure veins in the Alps was utilized as a complimentary tool for dating brittle-ductile/brittle deformation. It may preserve evidence of several crystallization events, commonly over 4-7 Ma, up to ~20 Ma. Monazite-(Ce) crystallizes within ~350-200 °C during tectonic and/or fluid flux events disequilibrating the fluid-crystal/rock chemistry within a cleft. It resists alteration/diffusion under prevailing p-T conditions, but may experience new/re-crystallization or dissolution-reprecipitation. Ages from the northeastern Alps, Austria, of 90-70 Ma cover near peak metamorphism during Eo-Alpine collision over orogenic collapse to extension. In the eastern Tauern Window, ages date metamorphic dome exhumation during Alpine collision at ~19-15 Ma. In the Lepontine dome area ages of ~19-5 Ma date early exhumation, doming and a later change after 12 Ma from thrusting to strike-slip movements, linked to a progressive concentration of deformation towards the extended Rhone-Simplon/Penninic Front fault system in the Mont-Blanc/Aiguilles-Rouges, Aar and western Lepontine areas. Dewey 550 Swiss National Science Foundation Age and crystallization duration of alpine cleft monazite and correlation with tectonically driven hydrothermal dissolution/precipitation events 143972 CH Project funding Swiss National Science Foundation Age and crystallization duration of Alpine cleft monazite and correlation with tectonically driven hydrothermal dissolution/precipitation events 165513 CH Project funding 42 Département des sciences de la Terre 154 false 663 Isotope Geochemistry, Geochronology and Thermochronology 6f30a021-ec46-4718-b8d7-b3cd962f49a1 Thesis Public PhD_thesis_Bergemann_2017.pdf 35231947 application/pdf Restricted 2019-02-13 a837034170c41295bbd9e5f56791ef96cfe09c6ae15103ffe22576e72ff5df81 openAccess Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département des sciences de la Terre

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Crystallization age of alpine cleft monazite-(Ce) and correlation with tectonically driven hydrothermal dissolution/precipitation events				2017	799	85

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Bergemann, Christian