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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Redéfinition de la formation crétacée de Blanche au Liban par une étude taxinomique micropaléontologique / Re-definition of the cretaceous Blanche Formation in Lebanon via a micropalaeontological taxonomic study

Maksoud, Sibelle 15 July 2015 (has links)
Les calcaires du Crétacé inférieur de la "Falaise de BLANCHE" affleurent sur une grande partie du territoire libanais. Ils apparaissent dans le paysage sous forme d'escarpements linéaires saillants constituant autant de points d'ancrage remarquables pour tout recalage stratigraphique. Toutefois, jusqu'à très récemment, cette unité était piètrement caractérisée : il lui manquait notamment une définition rigoureuse. Nous introduisons ici l'Étage régional Jezzinien, dont la localité-type est sise à Jezzine. Il s'agit également d'une unité stratigraphique particulière, une « unconformity-bounded unit", une unité qui, par définition, est encadrée par deux discontinuités. Le nouvel étage régional couvre deux séquences. Le canevas lithostratigraphique étant clairement redéfini, nous avons pu étudier les associations micropaléontologiques, constituées essentiellement de foraminifères benthiques et d'algues calcaires, associations dorénavant relativement bien contraintes du point de vue de leur âge. Typiquement sud-téthysiennes, elles facilitent les corrélations holostratigraphiques à haute résolution avec la région du Golfe persique, sur le côté oriental de la Plaque arabique. L'intervalle Jezzinien correspond ainsi à la partie supérieure de l'Étage Régional Kharaïbien (aussi connu comme unité réservoir "Thamama II" dans l'industrie pétrolière). À son tour, le Jezzinien est indirectement corrélé avec les unités stratigraphiques urgoniennes nord-téthysiennes où il correspond à un intervalle relativement court comprenant la limite des étages standards (internationaux) Barrémien et Bédoulien. Les associations macropaléontologiques reconnues dans le Jezzinien (échinides) et au-dessus de cette unité (ammonites) viennent à l'appui de notre datation micropaléontologique ou tout au moins ne la contredisent pas. / The "Falaise de Blanche" is a prominent cliff consisting mostly of Lower Cretaceous limestones that extends as linear outcrops over most of the Lebanese territory and provides geologists a remarkable reference for stratigraphic studies. However, until now, this unit was lacking a clear definition. We introduce herein the Jezzinian Regional Stage, the type-locality of which is at Jezzine. It is an unconformity-bounded unit and, per definition, it is framed by two discontinuities. The new regional stage implicitly spans two sequences. The lithostratigraphic framework having been properly redefined, we were able to investigate time-constrained micropaleontological assemblages consisting mostly of benthic foraminifers and calcareous algae. Typically Southern Tethysian, these assemblages contribute to high-resolution, holostratigraphic correlations with the Persian Gulf area on the eastern part of the Arabian Plate. The Jezzinian interval correlates with the upper part of the Kharaibian Regional Stage (also known as the "Thamama II" reservoir unit in the oil industry). The Jezzinian is also indirectly correlated with the Northern Tethysian Urgonian stratigraphic units where it corresponds to a rather short interval encompassing the standard Barremian - Bedoulian stage boundary.Locally the upper discontinuity is associated with a significant intra-Bedoulian hiatus. The macrofossil assemblages found in the Jezzinian (echinids) and above it (ammonites) support, or at least do not contradict, our micropaleontological dating.
12

Caracterização da plataforma continental da Bacia de Campos (Brasil, SE) fundamentada em foraminíferos bentônicos recentes

Disaró, Sibelle Trevisan January 2014 (has links)
Foraminíferos bentônicos vivos foram estudados visando a caracterização da plataforma continental da Bacia de Campos (sudeste do Brasil; 20.5°S - 24°S). Espécimes coletados no período seco/inverno/ressurgências menos frequentes de 2008 e no período chuvoso/verão/ressurgências mais frequentes de 2009 foram analisados para investigar padrões de distribuição espacial e temporal. As estações foram distribuídas em cinco isóbatas (25, 50, 75, 100 e 150 m), de nove transectos perpendiculares à linha de costa, totalizando 45 estações. Em cada estação, com busca-fundo e com delimitador 10 cm2 coletou-se três amostras de sedimento superficial (estrato 0-2 cm). Em laboratório, 20 cm³ de sedimento úmido por amostra foi lavado em peneira (63 μm), depois seco e triado na lupa. Material excedente foi estocado para contraprovas. Análises de Agrupamento e nMDS foram utilizadas para reconhecer grupos de estações e a Análise Canônica de Correspondência foi utilizada para investigar relações dos foraminíferos com dados ambientais. As variáveis-resposta quantitativas básicas foram biomassa e abundância; biomassa foi estimada por biovolume. A estrutura ecológica das associações (densidade, diversidade, dominância, equitatividade) foi estimada. Os dados foram avaliados visando caracterização da área e gestão ambiental da bacia. Registrou-se 519 táxons de foraminíferos. A análise integrada dos períodos identificou três áreas principais: (i) Plataforma interna (entre 25 e 50 m) - tem sedimentos predominantemente siliciclásticos, predominam espécies epifaunais, positivamente correlacionadas com areia, temperatura mais alta e concentração mais alta de clorofila-a; nela ocorrem Tiphotrocha concava, Bolivina paula, Nonionella sp.C, Discorbis williamsoni, Ammonia parkinsoniana, Ammonia tepida, Bolivina striatula, Textularia agglutinans, Angulogerina cf. A. jamaicensis Buliminella elegantissima, Paracassidulina nipponensis, Rectocibicides miocenicus, Placopsilina bradyi e muitas espécies dos seguintes gêneros Quinqueloculina, Textularia, Asterotrochammina, Eoeponidella, Porosononion, Polymorphina, Rotaliammina e Discorbis. (ii) Plataforma média/externa – (entre 75 e 100 m) - tem características predominantemente oligotróficas; areia, cascalho e lama, todos com alto teor de carbonato; as associações são compostas por Uvigerina auberiana, Technitella harrisii, Paratrochammina brasiliensis s.l., Planulina foveolata, Seabrookia earlandi, Svratkina spp., Pullenia spp., Discorbinella floridensis, Cibicidoides corpulentus, Stomatorbina torrei, Labrospira jeffreysii, Tetrataxiella ayalai, Mychostomina revertens, Amphicoryna scalaris, Globocassidulina rossensis, Ehrenbergina spinea, Spirotextularia floridana, Siphonina reticulata, Spirillina vivipara, Patellina corrugata e algumas espécies de Astrononion, Fissurina e Lenticulina entre outras. (iii) Área de ressurgências – predomínio de espécies infaunais positivamente correlacionadas com lama, feofitina-a e carbono orgânico total; a associação é composta por muitos rotalídeos pequenos como Bulimina marginata, Pappina compressa, Angulogerina angulosa, s.l., Alabaminella weddellensis, Bolivina fragilis, Bolivina ordinaria, Nonionella stella, Hopkinsina pacifica, Bolivinellina translucens, Stainforthia complanata, Bulimina patagonica, Hanzawaia concentrica, Gyroidina umbonata, Nonionella opima, Epistominella exigua, Cassidulina carinata, Fursenkoina pontoni e Nonionella atlantica; e alguns aglutinantes como Adercotryma glomeratum, Lagenammina atlantica, Ammoscalaria pseudospiralis, Reophax scorpiurus, Sepetibaella sepetibaensis, Labrospira crassimargo, Reophax pauciloculatus, Leptohalysis scottii, Textularia ? torquata e Reophax arayaensis e milliolídeos como Quinqueloculina sabulosa, Quinqueloculina atlantica s.l. e Pyrgo nasuta. A distribuição espacial dos foraminíferos é determinada pela profundidade, sedimento (tamanho de grão e conteúdo de carbonato) e disponibilidade de alimento. Foraminíferos fitodetritívoros indicaram áreas de ressurgência em Cabo Frio, Cabo de São Tomé e também ao norte da área estudada. A biomassa na plataforma interna é similar à de outras áreas investigadas, mas os valores da plataforma média e externa são mais altos que o esperado para uma região oligotrófica, sazonalmente mesotrófica. As curvas ABC indicaram a isóbata de 25 m como a mais perturbada da plataforma, especialmente durante o período chuvoso quando recebe maior aporte da drenagem fluvial e pluvial, talvez amplificada por contaminantes antropogênicos. Área com ressurgência mostraram perturbação moderada pelo método das curvas ABC; provavelmente trata-se apenas de perturbação natural, causada pelo incremento de produção primária. O estudo aporta dados para a gestão ambiental e a reconstrução paleoambiental. / Spatial and seasonal differences over the continental shelf and along the shelf break edges of Campos Basin, southeastern Brazil (20.5°S - 24°S) were investigated during 2008 (downwelling setting/dry/winter) and 2009 (upwelling setting/rainy/summer), based on living benthic foraminiferal assemblages, as part of the “HABITATS Project - Evaluation of the Environmental Heterogeneity of the Campos Basin, Brazil”. The assemblages and their relationship with environmental variables were studied to support the research and development activities of PETROBRAS, the Brazilian state-owned oil Company. The sampling design consisted of nine transects (45 stations) perpendicular to the coastline. Three replicates were taken from each station using a modified grab that performs as a box corer. The surface (0-2 cm) bottom sediment was collected (10 cm x 10 cm), fixed with 4 % formaldehyde buffered solution, stained with Bengal Rose, washed and sieved through a 63 μm mesh. Of the 200 cm3 of each replicate, 20 cm³ were analyzed and the remainder stored for retesting. Foraminiferal assemblages were recognized using cluster analysis, indicator species analysis and nonmetric multidimensional scaling. Spatial and temporal patterns of the foraminiferal assemblages were identified and the ecological structure (density, diversity, dominance, equitability) of these assemblages investigated. Foraminiferal biomass was estimated by measuring biovolume. The correlations of biotic and abiotic parameters were evaluated using canonical correspondence analysis. A total of 519 foraminiferal taxa were recorded. Spatial distribution responds to depth, sediment (grain size and carbonate content) and food availability. Cluster analysis with integrated periods allowed the recognition of three distinct areas: (i) an Inner shelf (25 – 50 m) area positively correlated with sand, higher temperature and higher chlorophyll-a content; it was occupied by Tiphotrocha concava, Bolivina paula, Nonionella sp. C, Discorbis williamsoni, Ammonia parkinsoniana, Ammonia tepida, Bolivina striatula, Textularia agglutinans, Angulogerina cf. A. jamaicensis, Buliminella elegantissima, Paracassidulina nipponensis, Rectocibicides miocenicus, Placopsilina bradyi and species of Quinqueloculina, Textularia, Asterotrochammina, Eoeponidella, Porosononion, Polymorphina, Rotaliammina and Discorbis. (ii) a Medium/outer shelf (75 – 150 m) area is composed by two subgroups correlated with depth and elevated carbonate levels; its species association includes Uvigerina auberiana, Technitella harrisii, Paratrochammina brasiliensis s.l., Planulina foveolata, Seabrookia earlandi, Svratkina spp., Pullenia spp., Eponides antillarum, Discorbinella floridensis, Cibicidoides corpulentus, Stomatorbina torrei, Labrospira jeffreysii, Tetrataxiella ayalai, Mychostomina revertens, Amphicoryna scalaris, Globocassidulina rossensis, Ehrenbergina spinea, Spirotextularia floridana, Siphonina reticulata, Spirillina vivipara, Patellina corrugata and some species from Astrononion, Fissurina and Lenticulina. (iii) an Upwelling area is positively correlated with phaeopigment (phytodetritus), mud and total organic carbon; this group includes abundant small rotalids such as Bulimina marginata, Pappina compressa, Angulogerina angulosa, s.l., Alabaminella weddellensis, Bolivina fragilis, Bolivina ordinaria, Nonionella stella, Hopkinsina pacifica, Bolivinellina translucens, Stainforthia complanata, Bulimina patagonica, Hanzawaia concentrica, Gyroidina umbonata, Nonionella opima, Epistominella exigua, Cassidulina carinata, Fursenkoina pontoni and Nonionella atlantica, and such agglutinated foraminifers as Adercotryma glomeratum, Lagenammina atlantica, Ammoscalaria pseudospiralis, Reophax scorpiurus, Sepetibaella sepetibaensis, Labrospira crassimargo, Reophax pauciloculatus, Leptohalysis scottii, Textularia ? torquata, Pseudobolivina fusiformis and Reophax arayaensis, and some miliolids (Quinqueloculina sabulosa, Quinqueloculina atlantica s.l. and Pyrgo nasuta). During the upwelling period the South Atlantic Coastal Waters enlarged its influence to include not only the Cape Frio area, but also an area at about 75 meters depth off Cape Sao Tome. Biomass values at the inner shelf agreed with available published data, but on the middle and outer shelf the values are higher than expected for an oligotrophic, seasonally mesotrophic basin. The ABC curves indicate the 25 m isobath as the most disturbed one and recognize a moderated disturbance in the upwelling area. During rainy season the 25 m isobath is disturbed by natural eutrophication phenomena that may be significantly amplified by anthropogenic activities. This study provides data for the monitoring plan for the area and for paleoenvironmental reconstructions.
13

Caracterização da plataforma continental da Bacia de Campos (Brasil, SE) fundamentada em foraminíferos bentônicos recentes

Disaró, Sibelle Trevisan January 2014 (has links)
Foraminíferos bentônicos vivos foram estudados visando a caracterização da plataforma continental da Bacia de Campos (sudeste do Brasil; 20.5°S - 24°S). Espécimes coletados no período seco/inverno/ressurgências menos frequentes de 2008 e no período chuvoso/verão/ressurgências mais frequentes de 2009 foram analisados para investigar padrões de distribuição espacial e temporal. As estações foram distribuídas em cinco isóbatas (25, 50, 75, 100 e 150 m), de nove transectos perpendiculares à linha de costa, totalizando 45 estações. Em cada estação, com busca-fundo e com delimitador 10 cm2 coletou-se três amostras de sedimento superficial (estrato 0-2 cm). Em laboratório, 20 cm³ de sedimento úmido por amostra foi lavado em peneira (63 μm), depois seco e triado na lupa. Material excedente foi estocado para contraprovas. Análises de Agrupamento e nMDS foram utilizadas para reconhecer grupos de estações e a Análise Canônica de Correspondência foi utilizada para investigar relações dos foraminíferos com dados ambientais. As variáveis-resposta quantitativas básicas foram biomassa e abundância; biomassa foi estimada por biovolume. A estrutura ecológica das associações (densidade, diversidade, dominância, equitatividade) foi estimada. Os dados foram avaliados visando caracterização da área e gestão ambiental da bacia. Registrou-se 519 táxons de foraminíferos. A análise integrada dos períodos identificou três áreas principais: (i) Plataforma interna (entre 25 e 50 m) - tem sedimentos predominantemente siliciclásticos, predominam espécies epifaunais, positivamente correlacionadas com areia, temperatura mais alta e concentração mais alta de clorofila-a; nela ocorrem Tiphotrocha concava, Bolivina paula, Nonionella sp.C, Discorbis williamsoni, Ammonia parkinsoniana, Ammonia tepida, Bolivina striatula, Textularia agglutinans, Angulogerina cf. A. jamaicensis Buliminella elegantissima, Paracassidulina nipponensis, Rectocibicides miocenicus, Placopsilina bradyi e muitas espécies dos seguintes gêneros Quinqueloculina, Textularia, Asterotrochammina, Eoeponidella, Porosononion, Polymorphina, Rotaliammina e Discorbis. (ii) Plataforma média/externa – (entre 75 e 100 m) - tem características predominantemente oligotróficas; areia, cascalho e lama, todos com alto teor de carbonato; as associações são compostas por Uvigerina auberiana, Technitella harrisii, Paratrochammina brasiliensis s.l., Planulina foveolata, Seabrookia earlandi, Svratkina spp., Pullenia spp., Discorbinella floridensis, Cibicidoides corpulentus, Stomatorbina torrei, Labrospira jeffreysii, Tetrataxiella ayalai, Mychostomina revertens, Amphicoryna scalaris, Globocassidulina rossensis, Ehrenbergina spinea, Spirotextularia floridana, Siphonina reticulata, Spirillina vivipara, Patellina corrugata e algumas espécies de Astrononion, Fissurina e Lenticulina entre outras. (iii) Área de ressurgências – predomínio de espécies infaunais positivamente correlacionadas com lama, feofitina-a e carbono orgânico total; a associação é composta por muitos rotalídeos pequenos como Bulimina marginata, Pappina compressa, Angulogerina angulosa, s.l., Alabaminella weddellensis, Bolivina fragilis, Bolivina ordinaria, Nonionella stella, Hopkinsina pacifica, Bolivinellina translucens, Stainforthia complanata, Bulimina patagonica, Hanzawaia concentrica, Gyroidina umbonata, Nonionella opima, Epistominella exigua, Cassidulina carinata, Fursenkoina pontoni e Nonionella atlantica; e alguns aglutinantes como Adercotryma glomeratum, Lagenammina atlantica, Ammoscalaria pseudospiralis, Reophax scorpiurus, Sepetibaella sepetibaensis, Labrospira crassimargo, Reophax pauciloculatus, Leptohalysis scottii, Textularia ? torquata e Reophax arayaensis e milliolídeos como Quinqueloculina sabulosa, Quinqueloculina atlantica s.l. e Pyrgo nasuta. A distribuição espacial dos foraminíferos é determinada pela profundidade, sedimento (tamanho de grão e conteúdo de carbonato) e disponibilidade de alimento. Foraminíferos fitodetritívoros indicaram áreas de ressurgência em Cabo Frio, Cabo de São Tomé e também ao norte da área estudada. A biomassa na plataforma interna é similar à de outras áreas investigadas, mas os valores da plataforma média e externa são mais altos que o esperado para uma região oligotrófica, sazonalmente mesotrófica. As curvas ABC indicaram a isóbata de 25 m como a mais perturbada da plataforma, especialmente durante o período chuvoso quando recebe maior aporte da drenagem fluvial e pluvial, talvez amplificada por contaminantes antropogênicos. Área com ressurgência mostraram perturbação moderada pelo método das curvas ABC; provavelmente trata-se apenas de perturbação natural, causada pelo incremento de produção primária. O estudo aporta dados para a gestão ambiental e a reconstrução paleoambiental. / Spatial and seasonal differences over the continental shelf and along the shelf break edges of Campos Basin, southeastern Brazil (20.5°S - 24°S) were investigated during 2008 (downwelling setting/dry/winter) and 2009 (upwelling setting/rainy/summer), based on living benthic foraminiferal assemblages, as part of the “HABITATS Project - Evaluation of the Environmental Heterogeneity of the Campos Basin, Brazil”. The assemblages and their relationship with environmental variables were studied to support the research and development activities of PETROBRAS, the Brazilian state-owned oil Company. The sampling design consisted of nine transects (45 stations) perpendicular to the coastline. Three replicates were taken from each station using a modified grab that performs as a box corer. The surface (0-2 cm) bottom sediment was collected (10 cm x 10 cm), fixed with 4 % formaldehyde buffered solution, stained with Bengal Rose, washed and sieved through a 63 μm mesh. Of the 200 cm3 of each replicate, 20 cm³ were analyzed and the remainder stored for retesting. Foraminiferal assemblages were recognized using cluster analysis, indicator species analysis and nonmetric multidimensional scaling. Spatial and temporal patterns of the foraminiferal assemblages were identified and the ecological structure (density, diversity, dominance, equitability) of these assemblages investigated. Foraminiferal biomass was estimated by measuring biovolume. The correlations of biotic and abiotic parameters were evaluated using canonical correspondence analysis. A total of 519 foraminiferal taxa were recorded. Spatial distribution responds to depth, sediment (grain size and carbonate content) and food availability. Cluster analysis with integrated periods allowed the recognition of three distinct areas: (i) an Inner shelf (25 – 50 m) area positively correlated with sand, higher temperature and higher chlorophyll-a content; it was occupied by Tiphotrocha concava, Bolivina paula, Nonionella sp. C, Discorbis williamsoni, Ammonia parkinsoniana, Ammonia tepida, Bolivina striatula, Textularia agglutinans, Angulogerina cf. A. jamaicensis, Buliminella elegantissima, Paracassidulina nipponensis, Rectocibicides miocenicus, Placopsilina bradyi and species of Quinqueloculina, Textularia, Asterotrochammina, Eoeponidella, Porosononion, Polymorphina, Rotaliammina and Discorbis. (ii) a Medium/outer shelf (75 – 150 m) area is composed by two subgroups correlated with depth and elevated carbonate levels; its species association includes Uvigerina auberiana, Technitella harrisii, Paratrochammina brasiliensis s.l., Planulina foveolata, Seabrookia earlandi, Svratkina spp., Pullenia spp., Eponides antillarum, Discorbinella floridensis, Cibicidoides corpulentus, Stomatorbina torrei, Labrospira jeffreysii, Tetrataxiella ayalai, Mychostomina revertens, Amphicoryna scalaris, Globocassidulina rossensis, Ehrenbergina spinea, Spirotextularia floridana, Siphonina reticulata, Spirillina vivipara, Patellina corrugata and some species from Astrononion, Fissurina and Lenticulina. (iii) an Upwelling area is positively correlated with phaeopigment (phytodetritus), mud and total organic carbon; this group includes abundant small rotalids such as Bulimina marginata, Pappina compressa, Angulogerina angulosa, s.l., Alabaminella weddellensis, Bolivina fragilis, Bolivina ordinaria, Nonionella stella, Hopkinsina pacifica, Bolivinellina translucens, Stainforthia complanata, Bulimina patagonica, Hanzawaia concentrica, Gyroidina umbonata, Nonionella opima, Epistominella exigua, Cassidulina carinata, Fursenkoina pontoni and Nonionella atlantica, and such agglutinated foraminifers as Adercotryma glomeratum, Lagenammina atlantica, Ammoscalaria pseudospiralis, Reophax scorpiurus, Sepetibaella sepetibaensis, Labrospira crassimargo, Reophax pauciloculatus, Leptohalysis scottii, Textularia ? torquata, Pseudobolivina fusiformis and Reophax arayaensis, and some miliolids (Quinqueloculina sabulosa, Quinqueloculina atlantica s.l. and Pyrgo nasuta). During the upwelling period the South Atlantic Coastal Waters enlarged its influence to include not only the Cape Frio area, but also an area at about 75 meters depth off Cape Sao Tome. Biomass values at the inner shelf agreed with available published data, but on the middle and outer shelf the values are higher than expected for an oligotrophic, seasonally mesotrophic basin. The ABC curves indicate the 25 m isobath as the most disturbed one and recognize a moderated disturbance in the upwelling area. During rainy season the 25 m isobath is disturbed by natural eutrophication phenomena that may be significantly amplified by anthropogenic activities. This study provides data for the monitoring plan for the area and for paleoenvironmental reconstructions.
14

Heat and salinity transport across the Indonesian Archipelago over the last 270,000 years : new insights into the orbital and millennial dynamics of the Indonesian Throughflow and the Intertropical Convergence Zone / Transport de chaleur et de salinité à travers l'archipel indonésien au cours des 270 000 dernières années : nouveaux enregistrements de la dynamique orbitale et millénaire du flux indonésien et de la zone de convergence intertropicale

Pang, Xiaolei 14 October 2019 (has links)
Ce travail avait pour but de reconstituer l'évolution de la température et du δ¹⁸O des eaux de surface et des eaux de la thermocline dans la Warmpool indo-pacifique (IPWP) en combinant la thermométrie Mg / Ca et la mesure des isotopes stables de l'oxygène sur des foraminifères planctoniques de surface et de sub-surface prélevés dans des carottes de sédiments situées dans l'océan Indien tropical oriental. Ce travail a permis de ré-évaluer les effets des différentes méthodes de nettoyage et de la dissolution in situ sur la thermométrie Mg/Ca des foraminifères planctoniques, mettant en évidence la nécessité de corrections différentes suivant les espèces. L’évolution de l’IPWP au cours des 270 000 dernières années a été reconstituée. Les résultats indiquent que le δ¹⁸O des eaux de surface reflètent principalement l'advection latérale plutôt que l'historique des précipitations régionales, et suggèrent que l'hydrologie de surface IPWP est contrôlée par la migration latitudinale de la zone de convergence intertropicale aux échelles de temps orbitales mais aussi en réponse aux événements climatiques abrupts de l'hémisphère nord (eg. événements de Heinrich). Les variations de salinité de surface sont étroitement corrélées aux changements d’export vers l’Atlantique au niveau du Courant des Aiguilles (Sud de l’Afrique). Puis, les changements dans le transport des eaux de la thermocline issues de l’ITF vers l'océan Indien ont été étudiés. Les résultats montrent que le transport était plus faible pendant les glaciations (ie. MIS 6 et 4-2) que pendant les périodes interglaciaires (ie. MIS 7, MIS 5 et Holocène) et exerçaient une influence significative sur les changements de la température de la thermocline dans l'Océan Indien. / This work aimed at reconstructing the late Quaternary evolution of surface and thermocline temperature and ocean surface water δ¹⁸O in the Indo-Pacific Warm Pool by combining Mg/Ca-thermometry and stable oxygen isotope analyses on surface and thermocline-dwelling planktonic foraminifers retrieved from sediment cores in the eastern tropical Indian Ocean. This study allowed to re-evaluate the effects of different cleaning methods and in-situ dissolution on the Mg-thermometry of planktonic foraminifers, evidencing the need for species-dependent corrections. Then, the IPWP evolution over the last 270,000 years has been explored. Results indicate that surface water δ¹⁸O chiefly reflects lateral advection rather than local precipitation history, and suggest that surface IPWP hydrology is controlled by the latitudinal migration of the Intertropical Convergence Zone at orbital timescale as well as during abrupt northern hemisphere climatic events (i.e. Heinrich events). Ocean surface salinity in the IPWP and Agulhas leakage region varied synchronously, implying their teleconnection through oceanic and atmospheric circulation. Moreover, changes in the transport of thermocline water to the Indian Ocean by the Indonesian Throughflow (ITF) have been reconstructed. Results show that thermocline water transport was weaker during glacials (i.e. MIS 6 and 4-2) than during interglacials (MIS 7, MIS 5 and Holocene), and exerted significant influence on Indian Ocean TWT change.

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