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| Registros recuperados: 17 | |
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| Jorry, Stephan; Jouet, Gwenael; Le Roy, Pascal; Prat, Sophie; Camoin, Gilbert; Vella, Claude; Caline, Bruno. |
| Suite à l’initiation du programme REEFCORES (REEFs and CORals form the EparseS), deux missions menées en 2011 et en 2013 dans l’Archipel des Glorieuses (Nord Madagascar) ont permis de documenter les empreintes des épisodes de déglaciation dans la morphologie des terrasses récifales émergées et submergées. L’objectif principal de cette étude est d’abord de documenter les stagnations du niveau marin qui ont été engendrées au cours de la dernière remontée du niveau marin et sur les terrasses du dernier interglaciaire (MIS 5e). Cette zone située autour des Seychelles, du fait de sa stabilité (isostasie très faible), est idéalement placée pour reconstituer avec précision les variations globales du niveau marin (Milne and Mitrovica, 2008). Des données de... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00202/31279/29686.pdf |
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| Le Roy, Pascal; Gracia-garay, Claire; Guennoc, Pol; Bourillet, Jean-francois; Reynaud, Jean-yves; Thinon, Isabelle; Kervevan, Patrick; Paquet, Fabien; Menier, David; Bulois, Cedric. |
| The geology of the Channel Western Approaches is a key to understand the post-rift evolution of the NW European continental margin in relation with the Europe/Africa collision. Despite considerable evidence of Tertiary tectonic inversion throughout the Channel basin, the structures and amplitudes of the tectonic movements remain poorly documented across the French sector of the Western Approaches. The effect of the tectonic inversion for the evolution of the "Channel River", the major system that flowed into the English Channel during the Plio-Quaternary eustatic lowstands, also needs to be clarified. Its drainage basin was larger than the present-day English Channel and constituted the source of terrigenous fluxes of the Armorican and Celtic deep sea... |
| Tipo: Text |
Palavras-chave: English Channel; Western Approaches basins; Cenozoic; Palaeovalley; Seismic stratigraphy; Tectonic inversion. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16706/15776.pdf |
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| Gregoire, Gwendoline; Le Roy, Pascal; Ehrhold, Axel; Jouet, Gwenael; Garlan, Thierry. |
| This study details the sedimentary infilling of an original tidal-dominated estuary system during the final stage of the last marine transgression. The Bay of Brest is confined and connects the rivers Elorn and Aulne, to the sea of Iroise by a narrow strait encasing a well preserved paleo-channel. The compilation of high- and very-high-resolution bathymetric and seismic data, constrained by sediments datations, allows us to classify the paleo-morphology of the bay into three stepped domains: the paleo-valley floor surrounded by fluvial terraces, the central plateau, and the shallow embayments. Taking into account the main factors controlling the infilling, including sea-level rise, substratum morphology, and hydrodynamics, the stratigraphic scheme of the... |
| Tipo: Text |
Palavras-chave: Tide-dominated estuary; Incised-valley; Holocene infill; Seismic stratigraphy; Estuarine processes; Bay of Brest. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00358/46968/46883.pdf |
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| Jorry, Stephan; Jouet, Gwenael; Edinger, Evan N.; Toucanne, Samuel; Counts, John W.; Miramontes, Elda; Courgeon, Simon; Riveiros, Natalia Vázquez; Le Roy, Pascal; Camoin, Gilbert F.. |
| Over the past ten years, a huge amount of source-to-sink studies have aimed to unravel the tectonic, climatic and other processes that shape the landscape from mountains to the deep ocean. Interestingly, these studies have been mainly dedicated to siliciclastic or mixed systems, for which the connection between drainage basins, continental shelves, slope and basin environments are often well constrained. Here we present a study focusing on a source-to-sink study dedicated to a pure carbonate system, located in the SW Indian Ocean (Glorieuses archipelago). Extensive field sampling and geophysical acquisition across the carbonate platform have allowed us to estimate the composition, the lateral variability, and volumes of neritic sands deposited on the... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Coral reef; Calciturbidite; Aragonite; Carbonate budget; Indian Ocean. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00607/71879/70574.pdf |
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| Prat, Sophie; Jorry, Stephan; Jouet, Gwenael; Le Roy, Pascal; Camoin, Gilbert; Vella, Claude; Caline, Bruno. |
| Améliorer nos connaissances sur la distribution des sédiments carbonatés dans les systèmes récifaux actuels sert à définir des analogues afin de mieux comprendre les réservoirs à hydrocarbures exploités dans les formations récifales fossiles. Bien que le rôle des changements du niveau marin, de la tectonique et de la sédimentation sur la dynamique et l'évolution des plates-formes carbonatés tropicales ait été largement étudié, la variabilité sédimentaire et les facteurs qui contrôlent cette hétérogénéité sont moins bien connus. Quelques études illustrent bien cette répartition des sédiments au sein des plates-formes carbonatées actuelles (Purdy et Gischler, 2003; Thudhope et al., 1985; Maxwell, 1973), mais il existe peu de cas étudiés dans l'océan Indien.... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00202/31281/29688.pdf |
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| Prat, Sophie; Jorry, Stephan; Jouet, Gwenael; Camoin, Gilbert; Vella, Claude; Le Roy, Pascal; Caline, Bruno; Boichard, Robert; Pastol, Yves. |
| The study of modern carbonate systems is commonly helps in improving facies interpretation in fossil reefs and in providing analogues of sediment distribution depending on the specific platform configuration (i.e. rimmed shelves and isolated carbonate platforms). This paper deals with a geomorphological and sedimentological study of the Glorieuses Archipelago, an isolated carbonate platform located between the northern tip of Madagascar and Mayotte. The dataset consists of Digital Terrain Model, satellite imagery, and box-sediment samples. Analyses of grain-size and composition of carbonate grains are used to characterize the distribution and heterogeneity of sediment accumulated on the isolated platform. Main results show that the Glorieuses Archipelago... |
| Tipo: Text |
Palavras-chave: Carbonate platform; Modern coral reefs; Pleistocene fossil reefs; Sandwaves. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00326/43761/43318.pdf |
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| Kaub, C; Geoffroy, Laurent; Bollinger, L; Perrot, Julie; Le Roy, Pascal; Authemayou, C. |
| The ∼M6 1799 Bouin earthquake is considered as one of the largest earthquakes to have struck Western France. However, the seismogenic source potentially responsible for this event remain marginally documented. We present results from a focused offshore-onshore multidisciplinary survey in its meizoseismal area in order to identify the fault segments that potentially ruptured during this earthquake. Based on macroseismic data and the geology, we focused our study on the so-called Machecoul Fault as a potential source of the 1799 Bouin event. Our survey includes extensive high-resolution seismic reflection, high resolution bathymetry and a one-year seismological survey. These data were combined with existing topography, onshore gravity data and drill data to... |
| Tipo: Text |
Palavras-chave: Intra-plate processes; Seismicity and tectonics; Marine geophysics; Geomorphology; Europe. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79394/81927.pdf |
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| Van Vliet-lanoe, Brigitte; Authemayou, Christine; Molliex, Stephane; Field, Michael Hugh; Frechen, Manfred; Le Roy, Pascal; Perrot, Julie; Andrieu-ponel, Valerie; Gregoire, Gwendoline; Hallegouet, Bernard. |
| The Brittany region of France is located in a low seismicity intraplate zone. Most of the instrumented earthquakes are limited to a shallow crustal depth without surface rupture. A paleoseismological analysis was performed on deposits on the Crozon Peninsula and in the Elorn estuary. We highlight hydroplastic deformations induced by liquefaction leading to clay diapirism, which were likely triggered by past earthquakes. This diapirism seems to be frequent in continental nonconsolidated sediments and to develop on the inherited tectonic structures, when a shallow water table and confining layers exist. Timing of deformation is dated using paleoenvironmental data, and electron spin resonance and infrared-stimulated luminescence dating methods. Two seismic... |
| Tipo: Text |
Palavras-chave: Clay diapirism; Liquefaction; Earthquake; Saprolite; Brittany; Variscan structures; Paleoseismology; Intraplate; Middle Pleistocene. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74955/76029.pdf |
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| Gregoire, Gwendoline; Ehrhold, Axel; Le Roy, Pascal; Jouet, Gwenael; Garlan, Thierry. |
| Long-studied with respect to its sedimentological features (1897), the Bay of Brest (Western Britanny, France) is a textbook example of a tide-dominated estuary. Characterised by macrotidal conditions, this estuary system is sheltered from the open sea (Iroise Sea) by a narrow strait that partitions the wave tide influences and continental/marine inputs. Sediments are supplied to the bay both by rivers (the Aulne and Elorn rivers) and by marine tidal currents. This study presents new analyses of detailed facies and morphological patterns, based on the integration of multisource data compiling seabed sampling, swath and LIDAR bathymetry, and backscatter imagery. The Main Map, at a scale of 1:90,000, contains (1) a sedimentological distribution using the... |
| Tipo: Text |
Palavras-chave: Morpho-sedimentological cartography; Tide-dominated; Estuary system; Estuarine sedimentation; Backscatter imagery; Bay of Brest. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00334/44492/44224.pdf |
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| Jorry, Stephan; Camoin, Gilbert F.; Jouet, Gwenael; Le Roy, Pascal; Vella, Claude; Courgeon, Simon; Prat, Sophie; Fontanier, Christophe; Paumard, Victorien; Boulle, Julien; Caline, Bruno; Borgomano, Jean. |
| Isolated carbonate platforms occur throughout the geologic record, from Archean to present. Although the respective roles of tectonics, sediment supply and sea-level changes in the stratigraphical architecture of these systems are relatively well constrained, the details of the nature and controls on the variability of sedimentological patterns between and within individual geomorphologic units on platforms have been barely investigated. This study aims at describing and comparing geomorphological and sedimentological features of surficial sediments and fossil reefs from three isolated carbonate platforms located in the SW Indian Ocean (Glorieuses, Juan de Nova and Europa). These carbonate platforms are relatively small and lack continuous reef margins,... |
| Tipo: Text |
Palavras-chave: Mozambique channel; Carbonate sediments; Fossil reefs; Isolated carbonate platforms. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00292/40329/39074.pdf |
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| Lambert, Clément; Vidal, Muriel; Penaud, Aurélie; Le Roy, Pascal; Goubert, Evelyne; Pailler, Yvan; Stephan, Pierre; Ehrhold, Axel. |
| Sedimentological, palynological, and micropalaeontological studies carried out throughout the first half of the Holocene, during the Mesolithic/Neolithic transition in the Bay of Brest (i.e. 9200–9000 and 6600–5300 cal. BP) and in the Bay of Douarnenez (i.e. 9200–8400 cal. BP), allowed characterizing coastal environmental changes under the increasing influence of the relative sea-level rise. The gradual flooding of the two studied sites implied a transition from river valleys to oceanic bays as revealed by the gradual retreat of salt marsh environments, as detected through palynological analysis. In addition, these high-resolution studies highlight the regional imprint of the North Atlantic millennial climate variability in north-western coastal... |
| Tipo: Text |
Palavras-chave: Benthic foraminifera; Climate variability; Dinoflagellate cysts; Human impacts; Palaeoenvironments reconstructions; Pollen grains. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00472/58341/60920.pdf |
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| Domzig, Anne; Yelles, Karim; Le Roy, Charlotte; Deverchere, Jacques; Bouillin, Jean-pierre; Bracene, Rabah; De Lepinay, Bernard Mercier; Le Roy, Pascal; Calais, Eric; Kherroubi, Abdelaziz; Gaullier, Virginie; Savoye, Bruno; Pauc, Henri. |
| We present new results from the MARADJA'03 cruise depicting the geological structures offshore central and western Algeria. Using swath bathymetry and seismic reflection data, we map and discuss the offshore limits of the Internal Zones corresponding to relics of the AIKaPeCa domain that drifted and collided the African plate during the Miocene. We identify large reverse faults and folds that reactivate part of these limits and are still active today. The morphology of the westernmost NE-SW margin suggests a former strike-slip activity accommodating a westward block translation responsible for the shift of the Internal Zones towards the Moroccan Rif. |
| Tipo: Text |
Palavras-chave: Sismique réflexion; Bathymétrie multifaisceau; Évolution tectonique du Bassin méditerranéen; Néotectonique; Zones Internes; Marge Algérienne; Seismic reflection; Swath bathymetry; Tectonic evolution of the Mediterranean; Internal zones neotectonics; Algerian margin. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1211.pdf |
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| Traoré, Kalil; Menier, David; Gensac, Erwan; Le Roy, Pascal; Lambert, Clément; Bessin, Paul; Pédoja, Kevin; Duperret, Anne; Le Gall, Romain. |
| The morphology and internal structure of the Horaine Bank (Bay of Saint-Brieuc, NW France) are described based on multibeam echosounder and high-resolution seismic datasets coupled with vibro-core data. The Horaine Bank shows large-scale bedforms in the lee of a submerged rocky shoal, which allowed defining it as a Banner Bank. The internal structure of the sandbank reveals four seismic units (U1–U4) on a Cambrian basement (U0). The basal unit U1 is interpreted as reworked lowstand fluvial sediments those infilled micro incised valleys during a rise in sea level. This unit is overlain by paleo-coastal barrier sand-spit (U2) whose development was controlled by swell in the context of a rapid rise in sea level. The successive prograding unit (U3) is... |
| Tipo: Text |
Palavras-chave: Sand banks; Banner bank; Holocene climate; Geomorphology; Sea level rise; Tidal gyre.. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00685/79660/82424.pdf |
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| Miramontes, Elda; Jouet, Gwenael; Thereau, Estelle; Bruno, Miguel; Penven, Pierrick; Guerin, Charline; Le Roy, Pascal; Droz, Laurence; Jorry, Stephan; Hernández‐molina, F. Javier; Thiéblemont, Antoine; Silva Jacinto, Ricardo; Cattaneo, Antonio. |
| Evidences of sedimentation affected by oceanic circulation, such as nepheloid layers and contourites are often observed along continental slopes. However, the oceanographic processes controlling sedimentation along continental margins remain poorly understood. Multibeam bathymetry and high‐resolution seismic reflection data revealed a contourite depositional system in the Mozambican upper continental slope composed of a contourite terrace (a surface with a gentle seaward slope dominated by erosion) and a plastered drift (a convex‐shape sedimentary deposit). A continuous alongslope channel and a field of sand dunes (mainly migrating upslope), formed during Holocene, were identified in the contourite terrace at the present seafloor. Seismic reflection data... |
| Tipo: Text |
Palavras-chave: Contourite; Sediment drift; Bedform; Sedimentary processes; Tide; Internal solitary waves; Bottom currents. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00605/71730/70205.pdf |
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| Registros recuperados: 17 | |
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