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| Registros recuperados: 52 | |
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| Courgeon, Simon; Bachelery, Patrick; Jouet, Gwenael; Jorry, Stephan; Bou, Esther; Boudagher-fadel, Marcelle K.; Revillon, Sidonie; Camoin, Gilbert; Poli, Emmanuelle. |
| The offshore branch of the East African Rift System (EARS) has developed during late Cenozoic time along the eastern Africa continental margin. While Neogene–Pleistocene extensional tectonic deformation has been evidenced along the northern segment of the Davie Ridge, the spatial extent of deformation further south remains poorly documented. Based on recent and various oceanographic data sets (bathymetric surveys, dredge samples and seismic profiles), our study highlights active normal faulting, modern east–west extensional tectonic deformation and Late Cenozoic alkaline volcanism at the Sakalaves Seamounts (18°S, Davie Ridge) that seem tightly linked to the offshore EARS development. In parallel, rift‐related tectonic subsidence appears responsible for... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00452/56344/57934.pdf |
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| Leroux, Estelle; Counts, J.; Jorry, Stephan; Jouet, Gwenael; Révillon, Sidonie; Boudagher-fadel, M.k.; Courgeon, S.; Berthod, C.; Ruffet, G.; Bachèlery, P.; Grenard-grand, E.. |
| Little is known about the geological history of the Glorieuses seamount including basic information about its age and origin related to the regional evolution of the southern tip of the Somali Basin. This study focused on describing and reconstructing the long-term stratigraphic evolution of the Glorieuses seamount (SW Indian Ocean) to identify the mechanisms that have occurred through time to finally shape the emerged modern islands. Distinct terrace levels, currently submerged along the flanks of the seamount and surrounding seamounts, have already been interpreted as resulting from successive carbonate development and back-stepping episodes over the last 62 Myr. New isotopic and biostratigraphic dating on the flanks of the seamount, coupled with... |
| Tipo: Text |
Palavras-chave: Glorieuses seamount; Somali Basin; Seismic stratigraphy; Tectonics; Vertical movement (uplift and subsidence); Volcanism; Shallow-water carbonate platform; Ar-40/Ar-39. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00628/73965/73324.pdf |
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| Schmitt, A.; Elliot, M.; Thirumalai, K.; La, C.; Bassinot, F.; Petersen, J.; Movellan, A.; Jorry, Stephan; Borgomano, J.. |
| The ratio of magnesium to calcium (Mg/Ca) in foraminiferal shells is commonly used as a proxy for past ocean temperature. Recent advances in elemental analyses now enable single-specimen measurements of planktic foraminifera and thus, can provide information on past seasonal and interannual variability, owing to the near-monthly lifespan of foraminifera. In this study, we explore the temperature variance recorded by Mg/Ca in tests of foraminifera Globigerinoides ruber, a planktic species that occurs throughout the year in tropical waters. Using LA-ICP-MS, we characterize Mg/Ca variability in single specimens of two morphotypes of G. ruber picked from a sediment core retrieved offshore New Caledonia. We provide an estimate of the range of calcification... |
| Tipo: Text |
Palavras-chave: Globigerinoides ruber; Mg/Ca ratio; Sea surface temperature; LA-ICPMS; Seasonality; Quaternary. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58336/60890.pdf |
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| Courgeon, Simon; Jorry, Stephan; Jouet, Gwenael; Camoin, G.; Boudagher-fadel, M. K.; Bachelery, P.; Caline, B.; Boichard, R.; Revillon, Sidonie; Thomas, Yannick; Thereau, Estelle; Guerin, Charline. |
| Understanding the impact of tectonic activity and volcanism on long-term (i.e. millions years) evolution of shallow-water carbonate platforms represents a major issue for both industrial and academic perspectives. The southern central Mozambique Channel is characterized by a 100 km-long volcanic ridge hosting two guyots (the Hall and Jaguar banks) and a modern atoll (Bassas da India) fringed by a large terrace. Dredge sampling, geophysical acquisitions and submarines videos carried out during recent oceanographic cruises revealed that submarine flat-top seamounts correspond to karstified and drowned shallow-water carbonate platforms largely covered by volcanic material and structured by a dense network of normal faults. Microfacies and well-constrained... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Drowning; Volcanism; Tectonic; Mozambique Channel. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00384/49554/50048.pdf |
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| Jorry, Stephan; Bievre, Gregory. |
| Ground-penetrating radar has not been applied widely to the recognition of ancient carbonate platform geometries. This article reports the results of an integrated study performed on an Upper Jurassic outcrop from the south-east Paris basin, where coral bioherms laterally change into prograding depositional sequences. Ground-penetrating radar profiles illustrate the different bedding planes and major erosional unconformities visible at outcrop. A ground-penetrating radar profile conducted at the base of the cliff displays a palaeotopographic surface on which the outcropping bioherms settled. The excellent penetration depths of the ground-penetrating radar (20 m with a monostatic 200 MHz antenna) images the carbonate platform geometries, ranging between... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Coral bioherms; Ground-penetrating radar; Late Jurassic; Paris Basin. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00047/15864/13440.pdf |
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| Lombo Tombo, Swesslath; Dennielou, Bernard; Berne, Serge; Bassetti, Maria-angela; Toucanne, Samuel; Jorry, Stephan; Jouet, Gwenael; Fontanier, Christophe. |
| The timing, routing and processes of sediment transfer from the continents to the oceans at millennial time-scale are still largely unknown. The potential of turbidite systems (dominantly deposited during sea-level lowstands) to record global or regional environmental fluctuations is usually under-exploited because of the difficulty to obtain robust chronostratigraphic constraints in turbiditic deposits, and therefore to tie changes in sedimentary processes to environmental fluctuations. We were able to obtain a millennial-scale chronostratigraphy based on oxygen isotopes of the scarce foraminifera preserved in turbiditic deposits of the Rhone Turbidite System within the Western Mediterranean. Our results show that 1) objective criteria can be defined for... |
| Tipo: Text |
Palavras-chave: Rhone Turbidite System; Turbidites; Hyperpycnite; Sea level; Last Glacial Maximum; Western Mediterranean. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00266/37712/35730.pdf |
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| Charles, Claire; Pelleter, Ewan; Révillon, Sidonie; Nonnotte, Philippe; Jorry, Stephan; Kluska, Jean-michel. |
| The Mozambique Channel plays a key role in the exchange of water masses between the Indian and Atlantic Oceans, which include the North Atlantic Deep Water (NADW) inflow from the south and the North Indian Deep Water (NIDW), an aged form of the NADW spreading poleward from the northern and equatorial Indian Ocean basin. Several authors assume that the Davie Ridge acts as a topographic barrier to the northward advection of NADW, which would therefore be absent in the Comoros Basin. Other studies suggest that the NADW flows from the south of the Mozambique Channel to the Comoros Basin, indicating that the Davie Ridge may not currently constitute a blocking topographic barrier to deep water mass circulation. To address this question, we studied ferromanganese... |
| Tipo: Text |
Palavras-chave: Ferromanganese crusts; Nd isotopes; Paleoceanography; Mozambique Channel; North Atlantic Deep Water. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00653/76488/77569.pdf |
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| Bayon, Germain; Toucanne, Samuel; Skonieczny, Charlotte; Andre, L.; Bermell, Sylvain; Cheron, Sandrine; Dennielou, Bernard; Etoubleau, Joel; Freslon, Nicolas; Gauchery, T.; Germain, Yoan; Jorry, Stephan; Menot, G.; Monin, L.; Ponzevera, Emmanuel; Rouget, M. -l.; Tachikawa, K.; Barrat, Jean-alix. |
| Over the past decades, rare earth elements (REE) and their radioactive isotopes have received tremendous attention in sedimentary geochemistry, as tracers for the geological history of the continental crust and provenance studies. In this study, we report on elemental concentrations and neodymium (Nd) isotopic compositions for a large number of sediments collected near the mouth of rivers worldwide, including some of the world’s major rivers. Sediments were leached for removal of non-detrital components, and both clay and silt fractions were retained for separate geochemical analyses. Our aim was to re-examine, at the scale of a large systematic survey, whether or not REE and Nd isotopes could be fractionated during Earth surface processes. Our results... |
| Tipo: Text |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00276/38733/37249.pdf |
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| Miramontes, Elda; Jorry, Stephan; Jouet, Gwenael; Counts, John; Courgeon, Simon; Roy, Philippe; Guerin, Charline; Hernández-molina, F. Javier. |
| Subaqueous sand dunes are common bedforms on continental shelves dominated by tidal and geostrophic currents. However, much less is known about sand dunes in deep‐marine settings that are affected by strong bottom currents. In this study, dune fields were identified on drowned isolated carbonate platforms in the Mozambique Channel (south‐west Indian Ocean). The acquired data include multibeam bathymetry, multi‐channel high‐resolution seismic reflection data, sea floor imagery, a sediment sample and current measurements from a moored current meter and hull‐mounted acoustic Doppler current profiler. The dunes are located at water depths ranging from 200 to 600 m on the slope terraces of a modern atoll (Bassas da India Atoll) and within small depressions... |
| Tipo: Text |
Palavras-chave: Bedform; Bottom currents; Contourite; Deep-marine environment; Eddy; Geostrophic current; Oceanic circulation. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58418/60989.pdf |
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| Mazuel, Aude; Sisavath, Emmanuelle; Babonneau, Nathalie; Jorry, Stephan; Bachelery, Patrick; Delacourt, Christophe. |
| Recent marine geophysical surveys reveal the existence of well-developed volcaniclastic deep-sea fans around La Réunion Island, Indian Ocean. The Mafate turbidite complex, located in the northwestern part of the island, is a large sedimentary system formed by two coalescent-like volcaniclastic deep-sea fans: the Mafate fan and the Saint-Denis fan. They are both connected to terrestrial rivers supplying sediment produced by erosion on the island, particularly during austral summer cyclonic floods. Through the integration of marine geophysical data (including bathymetry, backscatter multibeam sounder images, TOBI side-scan sonar images and seismic reflection profiles) and piston cores, a submarine morpho-sedimentary map of the surface architecture of the... |
| Tipo: Text |
Palavras-chave: Deep-sea fan; Turbidite; Volcaniclastic; Land-to-sea transfer; La Reunion Island; Late Quaternary. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00312/42273/41597.pdf |
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| Miramontes Garcia, Elda; Jouet, Gwenael; Cattaneo, Antonio; Thereau, Estelle; Guerin, Charline; Jorry, Stephan; Droz, Laurence. |
| The upper slopes of continental margins are very energetic areas where nepheloid layers are often observed. Multibeam bathymetry, sub-bottom profiler and multi-channel highresolution seismic reflection data acquired during the PAMELA-MOZ04 survey in the Mozambique Channel revealed the presence of sand dunes on the upper slope at 120-250 m water depth. The dunes migrate upslope and their crests are oblique to the contours. They are medium to large dunes, with wavelengths between 20 and 150 m and heights between 0.15 and 1.50 m, and their size decreases upslope. Seismic reflection data of the water column show internal solitary waves travelling offshore in the depth range of the dune field. The formation of the dune field could be related to the interaction... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00499/61049/64460.pdf |
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| Bachelery, Patrick; Babonneau, Nathalie; Jorry, Stephan; Mazuel, Aude. |
| The discovery in 2006, during the oceanographic survey FOREVER, of large volcaniclastic sedimentary systems off La Réunion Island (western Indian ocean) revealed a new image of the evolution of oceanic shield volcanoes and their dismantling. Marine data obtained from 2006 to 2011 during the oceanographic surveys ERODER 1 to ERODER 4 included bathymetry, acoustic imagery, echosounding profiles, dredging and coring. Six major turbidite systems were mapped and described on the submarine flanks of La Reunion volcanic edifice and the surrounding oceanic plate. The interpretation of sediment cores enable us to characterise the processes of gravity-driven sediment transfer from land to deep sea and also to revisit the history of the volcanoes of La Réunion... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00200/31118/29529.pdf |
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| Jorry, Stephan; Droxler, Andre W.; Francis, Jason M.. |
| The late Quaternary has experienced large glacial/interglacial climatic variations and related 10's to 100 meters high-amplitude sea level fluctuations at Milankovich frequencies from 10's to 100 kyr during which carbonate platform tops have been exposed and re-flooded in many occasions. This study focuses on the accumulation of calci-turbidites, the aragonite onset/sharp increase in fine sediments and their timing in deep basins adjacent to carbonate platforms. A particular emphasis is developed on the occurrence of the first gravity flow event and aragonite onset/sharp increase and their linkage to the initial re-flooding of the platform tops during deglaciations. Three basins adjacent to isolated platforms in the Bahamas, the Northern Nicaragua Rise,... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00012/12298/9095.pdf |
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| Courgeon, Simon; Bourget, Julien; Jorry, Stephan. |
| During the Plio-Quaternary, the Bonaparte Basin is characterized by a very wide (> 600 km, > 370 mi) carbonate platform and 200 km-wide (125 mi-wide) intra-shelf basin (the Malita ISB). Using 3D and 2D seismic data combined with exploration well data, this study characterizes the stratigraphic evolution of the Malita ISB during the last 3.5 million years. Two third-order transgressive sequences can be distinguished. A late Pliocene transgression occurred over an irregular topography resulting from the flexural reactivation of the Malita graben. In the centre of the intra-shelf basin, carbonate aggradation resulted in the formation of isolated carbonate platforms separated by deeper water seaways and inter-platform areas. Wider and more numerous... |
| Tipo: Text |
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| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00319/42985/46567.pdf |
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| Marsac, Francis; Galletti, Florence; Ternon, Jean-francois; Romanov, Evgeny V.; Demarcq, Herve; Corbari, Laure; Bouchet, Philippe; Roest, Walter; Jorry, Stephan; Olu, Karine; Loncke, Lies; Roberts, Michael J.; Ménard, Frédéric. |
| There is a growing interest in the management of seamounts of the South Western Indian Ocean (SWIO) both in waters under national jurisdictions and in the Areas Beyond National Jurisdiction (ABNJ). On the one hand, new scientific knowledge has been gathered through various oceanographic cruises during the past decade and, on the other hand, new agreements are under consideration globally to promote conservation and sustainable use of the biodiversity in the ABNJ, where the deep sea ecosystems associated to seamounts are a growing matter of concern. SWIO seamounts have attracted interests from fishing operators since the 1960s, while mining exploration contracts have been recently granted. Seamounts are known to shelter rich, fragile and poorly resilient... |
| Tipo: Text |
Palavras-chave: International Law of the Sea; Vulnerable Marine Ecosystems; Deep-sea fisheries; Deep-sea mining; Benthic biodiversity; Saya de Malha Bank; South Indian Ocean Fisheries Agreement; Areas Beyond National Jurisdiction; Amended Nairobi Convention; Marine protected areas. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00598/71049/69362.pdf |
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| Bonneau, Lucile; Toucanne, Samuel; Bayon, Germain; Jorry, Stephan; Emmanuel, Laurent; Silva Jacinto, Ricardo. |
| In this study we used major element composition, neodymium isotopes ratios (εNdεNd) and concentration of REE to track and quantify the sediment routing in the Var sedimentary system from source (Southern French Alps) to sink (Ligurian Sea) over the last 50 ka. Our data reveal that changes in sediment sources over that period, associated with concomitant changes in the hyperpycnal (i.e. flood-generated turbidity currents) activity in the Var submarine canyon, were mainly driven by paleoenvironmental conditions in the upper basin and in particular by the presence of glaciers during the last glacial period. Based on this evidence, we determined when and how glacier-derived sediments were produced, then excavated and transferred to the ocean, allowing us to... |
| Tipo: Text |
Palavras-chave: Var; Routing system; Glacial erosion; Source-to-sink. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00358/46957/47130.pdf |
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| Babonneau, Nathalie; Delacourt, Christophe; Cancouet, R.; Sisavath, Emmanuelle; Bachelery, Patrick; Mazuel, Aude; Jorry, Stephan; Deschamps, Anne; Ammann, Jerome; Villeneuve, N.. |
| Submarine canyon heads are key areas for understanding the triggering factors of gravity currents responsible for the transfer of detrital sediment to the deep basins. This contribution offers a detailed picture of canyon heads off La Réunion Island, with high-resolution multibeam bathymetry in the water depth range of 4–220 m. The present feeding of the Cilaos turbidite system, one of the largest modern volcaniclastic systems in the world, is deduced from morphological and sedimentological interpretations of newly acquired data. The study highlights small-scale sedimentary features indicating hydrodynamic and sedimentary processes. A direct connexion between the Saint-Etienne river mouth and submarine canyons is evidenced by the complete incision of the... |
| Tipo: Text |
Palavras-chave: Submarine canyon; Canyon head; Turbidity current; Hyperpycnal flow; Coastal instability. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00156/26697/24790.pdf |
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| Jorry, Stephan; Davaud, E; Caline, B. |
| Eocene nummulite deposits along the southern Tethys margin locally constitute important hydrocarbon reservoir rocks. In order to understand the heterogeneity of these complex reservoirs, we have carried out a detailed field study of the nummulite limestones which crop out at the Kesra Plateau in Central Tunisia. The main contributions of this paper can be summarised as follows: 1. Various species of Nummulites and planktonic foraminifera were identified in late Ypresian carbonates in the Kesra area and provided accurate biostratigraphic ages. Nummulitic limestones occur in the Chouabine and El Garia Formations representing deposition over a period of about 2Ma. 2. Six depositional facies have been identified in the El Garia Formation, ranging from... |
| Tipo: Text |
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| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00085/19596/17231.pdf |
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| Registros recuperados: 52 | |
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