Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology
The main scientific aim of this work is the understanding of driving forces and erosion rates, at the scale of several dozens of millions of years, of an oceanic volcanic island. A low and mid temperature thermochronological approach on intrusive rocks is used, in order to reconstruct exhumation pat...
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Online Access: | https://theses.hal.science/tel-02614387 https://theses.hal.science/tel-02614387/document https://theses.hal.science/tel-02614387/file/73308_AHADI_2019_archivage.pdf |
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ftccsdartic:oai:HAL:tel-02614387v1 2023-05-15T17:02:09+02:00 Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology Taux et moteurs d’exhumation de complexes plutoniques en contexte intraplaque océanique (archipel de Kerguelen) : apports de la thermochronologie basse et moyenne température Ahadi, Floriane Géosciences Paris Sud (GEOPS) Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) Université Paris Saclay (COmUE) Cécile Gautheron Sébastien Nomade 2019-11-29 https://theses.hal.science/tel-02614387 https://theses.hal.science/tel-02614387/document https://theses.hal.science/tel-02614387/file/73308_AHADI_2019_archivage.pdf fr fre HAL CCSD NNT: 2019SACLS425 tel-02614387 https://theses.hal.science/tel-02614387 https://theses.hal.science/tel-02614387/document https://theses.hal.science/tel-02614387/file/73308_AHADI_2019_archivage.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-02614387 Géochimie. Université Paris Saclay (COmUE), 2019. Français. ⟨NNT : 2019SACLS425⟩ Thermochronology (U-Th)/He Oceanic island Kerguelen Exhumation Erosion Île océanique Thermochronologie Érosion [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology info:eu-repo/semantics/doctoralThesis Theses 2019 ftccsdartic 2023-03-26T14:23:34Z The main scientific aim of this work is the understanding of driving forces and erosion rates, at the scale of several dozens of millions of years, of an oceanic volcanic island. A low and mid temperature thermochronological approach on intrusive rocks is used, in order to reconstruct exhumation paths in the oceanic crust of the Kerguelen archipelago (southern Indian Ocean). This archipelago was created 30 Ma years ago and is the emerged part of the eponymous oceanic plateau, formed following the activity of the Kerguelen hot spot, which began 120 Ma ago. The singularity of the Kerguelen archipelago, compared to other oceanic islands, is the occurrence of acid plutonic rocks, on which we can perform thermochronology on. Such methods allow reconstructing the thermal cooling paths, and thus, exhumation paths of the plutons since their deep formation to their surface exhumation. In this work, three thermochronometers were used: the ⁴⁰Ar/³⁹Ar on biotite method, and the (U-Th)/He on apatite and zircon methods. The data obtained on Kerguelen Islands indicate a differential erosion over the archipelago, with local erosion pulses within a plutonic complex, contrasting with regional low erosion rates since 25 Ma. This observation points to the predominant role of magmatic activity, and the associated local tectonic activity, on the exhumation of plutonic bodies and surface denudation. La question scientifique principale de ce travail de thèse est la compréhension des moteurs et des taux d’érosion, à l’échelle de plusieurs dizaines de millions d’années, d’un archipel océanique volcanique. Une approche thermochronologique basse et moyenne température sur des roches intrusives est utilisée, afin de contraindre les trajets d’exhumation de roches plutoniques dans la croûte océanique de l’archipel de Kerguelen (sud de l’Océan Indien). Cet archipel, dont la formation a débuté il y a 30 Ma, est la partie émergée du plateau océanique du même nom, formé suite à l’activité du point chaud de Kerguelen, qui commence il y a 120 Ma. ... Doctoral or Postdoctoral Thesis Kerguelen Islands Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Indian Kerguelen Kerguelen Islands |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
French |
topic |
Thermochronology (U-Th)/He Oceanic island Kerguelen Exhumation Erosion Île océanique Thermochronologie Érosion [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology |
spellingShingle |
Thermochronology (U-Th)/He Oceanic island Kerguelen Exhumation Erosion Île océanique Thermochronologie Érosion [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology Ahadi, Floriane Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology |
topic_facet |
Thermochronology (U-Th)/He Oceanic island Kerguelen Exhumation Erosion Île océanique Thermochronologie Érosion [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology |
description |
The main scientific aim of this work is the understanding of driving forces and erosion rates, at the scale of several dozens of millions of years, of an oceanic volcanic island. A low and mid temperature thermochronological approach on intrusive rocks is used, in order to reconstruct exhumation paths in the oceanic crust of the Kerguelen archipelago (southern Indian Ocean). This archipelago was created 30 Ma years ago and is the emerged part of the eponymous oceanic plateau, formed following the activity of the Kerguelen hot spot, which began 120 Ma ago. The singularity of the Kerguelen archipelago, compared to other oceanic islands, is the occurrence of acid plutonic rocks, on which we can perform thermochronology on. Such methods allow reconstructing the thermal cooling paths, and thus, exhumation paths of the plutons since their deep formation to their surface exhumation. In this work, three thermochronometers were used: the ⁴⁰Ar/³⁹Ar on biotite method, and the (U-Th)/He on apatite and zircon methods. The data obtained on Kerguelen Islands indicate a differential erosion over the archipelago, with local erosion pulses within a plutonic complex, contrasting with regional low erosion rates since 25 Ma. This observation points to the predominant role of magmatic activity, and the associated local tectonic activity, on the exhumation of plutonic bodies and surface denudation. La question scientifique principale de ce travail de thèse est la compréhension des moteurs et des taux d’érosion, à l’échelle de plusieurs dizaines de millions d’années, d’un archipel océanique volcanique. Une approche thermochronologique basse et moyenne température sur des roches intrusives est utilisée, afin de contraindre les trajets d’exhumation de roches plutoniques dans la croûte océanique de l’archipel de Kerguelen (sud de l’Océan Indien). Cet archipel, dont la formation a débuté il y a 30 Ma, est la partie émergée du plateau océanique du même nom, formé suite à l’activité du point chaud de Kerguelen, qui commence il y a 120 Ma. ... |
author2 |
Géosciences Paris Sud (GEOPS) Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) Université Paris Saclay (COmUE) Cécile Gautheron Sébastien Nomade |
format |
Doctoral or Postdoctoral Thesis |
author |
Ahadi, Floriane |
author_facet |
Ahadi, Floriane |
author_sort |
Ahadi, Floriane |
title |
Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology |
title_short |
Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology |
title_full |
Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology |
title_fullStr |
Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology |
title_full_unstemmed |
Rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (Kerguelen archipelago) : contributions of low and mid temperature thermochronology |
title_sort |
rates and driving forces of the exhumation of plutonic complexes in oceanic intraplate settings (kerguelen archipelago) : contributions of low and mid temperature thermochronology |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://theses.hal.science/tel-02614387 https://theses.hal.science/tel-02614387/document https://theses.hal.science/tel-02614387/file/73308_AHADI_2019_archivage.pdf |
geographic |
Indian Kerguelen Kerguelen Islands |
geographic_facet |
Indian Kerguelen Kerguelen Islands |
genre |
Kerguelen Islands |
genre_facet |
Kerguelen Islands |
op_source |
https://theses.hal.science/tel-02614387 Géochimie. Université Paris Saclay (COmUE), 2019. Français. ⟨NNT : 2019SACLS425⟩ |
op_relation |
NNT: 2019SACLS425 tel-02614387 https://theses.hal.science/tel-02614387 https://theses.hal.science/tel-02614387/document https://theses.hal.science/tel-02614387/file/73308_AHADI_2019_archivage.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1766055413234532352 |