Consulta: creatorFacets:"Loncke, L."
Registros recuperados: 7
Data/hora: 09/06/2024 05:48:29

Menes caldera, a highly active site of brine seepage in the Eastern Mediterranean sea: "In situ" observations from the NAUTINIL expedition (2003)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Huguen, Caroline; Foucher, Jean-paul; Mascle, J.; Ondreas, Helene; Thouement, M.; Gontharet, S.; Stadnitskaia, A.; Pierre, C.; Bayon, Germain; Loncke, L.; Boetius, A.; Bouloubassi, I.; De Lange, G.; Caprais, Jean-claude; Fouquet, Yves; Woodside, J.; Dupre, Stephanie.
This paper reports the first "in situ" seafloor observations of fluid escape structures in a fault-controlled caldera-type depression of about 8 km diameter, named the Menes caldera, in the Eastern Mediterranean sea off Egypt (western province of the Nile Deep Sea Fan). A detailed analysis of seven Nautile dives, performed during the Nautinil cruise in 2003, focused on determining the nature, origin, importance, mechanisms and environmental impacts of the fluid escape processes from the geological observations. Seafloor maps, constructed from direct visual observations and video records made from the submersible, and sampling results, for three mud volcanoes of the caldera, Cheops, Chephren and Mykerinos show differences in activity but many common...
Tipo: Text
Palavras-chave: Mediterranean Sea; Nile Deep Sea Fan; Mud volcano; Brine seep.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11089/10627.pdf

Multi-disciplinary investigation of fluid seepage on an unstable margin: The case of the Central Nile deep sea fan
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bayon, Germain; Loncke, L.; Dupre, Stephanie; Caprais, Jean-claude; Ducassou, E.; Duperron, Sebastien; Etoubleau, Joel; Foucher, Jean-paul; Fouquet, Yves; Gontharet, S.; Henderson, G. M.; Huguen, Caroline; Klaucke, I.; Mascle, J.; Migeon, S.; Olu-le-roy, Karine; Ondreas, Helene; Pierre, C.; Sibuet, Myriam; Stadnitskaia, A.; Woodside, J.
We report on a multidisciplinary study of cold seeps explored in the Central Nile deep-sea fan of the Egyptian margin. Our approach combines in situ seafloor observation, geophysics, sedimentological data, measurement of bottom-water methane anomalies, pore-water and sediment geochemistry, and Th-230/U dating of authigenic carbonates. Two areas were investigated, which correspond to different sedimentary provinces. The lower slope, at similar to 2100 m water depth, indicates deformation of sediments by gravitational processes, exhibiting slope-parallel elongated ridges and seafloor depressions. In contrast, the middle slope, at similar to 1650 m water depth, exhibits a series of debris-flow deposits not remobilized by post-depositional gravity processes....
Tipo: Text
Palavras-chave: Authigenic carbonate; U Th; Cold seep; Continental margin; Nile.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6586.pdf

Structure of the Demerara passive-transform margin and associated sedimentary processes. Initial results from the IGUANES cruise
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Loncke, L.; Maillard, A.; Basile, C.; Roest, Walter; Bayon, Germain; Gaullier, V.; Pattier, France; Mercier De Lépinay, Marion; Grall, Celine; Droz, L.; Marsset, Tania; Giresse, P.; Caprais, Jean-claude; Cathalot, Cecile; Graindorge, D.; Heuret, A.; Lebrun, J. F.; Bermell, Sylvain; Marcaillou, B.; Sotin, C.; Hebert, B.; Patriat, Martin; Bassetti, M. A.; Tallobre, Cedric; Buscail, R.; Durrieu De Madron, X.; Bourrin, F.
he IGUANES cruise took place in May 2013 on the R/V L'Atalante along the Demerara passive transform margin off French Guiana and Surinam. Seismic, multibeam and chirp acquisitions were made. Piston cores were collected for pore geochemistry and sedimentology. A mooring was deployed on the sea-bottom for 10 months (temperature, salinity, turbidity and current measurements). This new dataset highlights the lateral variability of the 350 km-long Guiana–Surinam transform margin due to the presence of a releasing bend between two transform segments. The adjacent Demerara Plateau is affected by a 350 km-long giant slide complex. This complex initiated in Cretaceous times and was regularly reactivated until recent times. Since the Miocene, contourite processes...
Tipo: Text
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00428/53942/55285.pdf

Slope instabilities from echo-character mapping along the French Guiana transform margin and Demerara abyssal plain
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Loncke, L.; Droz, Laurence; Gaullier, V.; Basile, C.; Patriat, Martin; Roest, Walter.
The French Guiana transform margin and Demerara abyssal plain have been recently surveyed in the framework of the EXTRAPLAC French Program of extension of the continental shelf (Guyaplac survey, Ifremer-IFP-SHOM-IPEV). Based on the interpretation of some of the data collected during the Guyaplac survey (Simrad-EM12 multibeam bathymetric data, backscatter imagery, and 3.5 kHz profiles), the area can be divided into three morphostructural domains. (1) The western Guiana margin, including a part of the Demerara plateau, an important bathymetric relief prolonging the continental platform off Guiana and Surinam. This domain is bounded by (1a) the NWSE trending northern border of the Demerara plateau which appears quite steep and corresponds to a transform...
Tipo: Text
Palavras-chave: Structural heritage; Fluids; Creeping; Transform margin; Slope instabilities.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6856.pdf

Origin of an enigmatic regional Mio-Pliocene unconformity on the Demerara plateau
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Pattier, France; Loncke, L.; Imbert, Patrice; Gaullier, V.; Basile, C.; Maillard, Alexandre; Roest, Walter; Patriat, Martin; Vendeville, B. C.; Marsset, Tania; Bayon, Germain; Cathalot, Cecile; Caprais, Jean-claude; Bermell, Sylvain; Sotin, Christine; Hebert, Bertil; Mercier De Lepinay, Marion; Lebrun, J. F.; Marcaillou, B.; Heuret, A.; Droz, Laurence; Graindorge, David; Poetisi, E.; Berrenstein, H.
The Demerara plateau, located offshore French Guiana and Suriname, is part of a passive transform continental margin particularly prone to develop slope instabilities, probably in relation to the presence of a free distal border along its steep continental slope. Slope failure occurred at different periods (Cretaceous to Neogene) and shows an overall retrogressive evolution through time. Upslope these failure headscarp, an enigmatic regional MioPliocene unconformity has been discovered through the interpretation of new academic and industrial datasets. The aim of this work is to describe and understand the origin of this surface. Our analysis shows that this unconformity is made of a series of valleys that cross-cut sedimentary strata. Each one of these...
Tipo: Text
Palavras-chave: Unconformity; Hydrate pockmark; Slide; Contourite; Valley; Canyon; Demerara plateau.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00271/38193/36735.pdf

Mass-transport deposits and fluid venting in a transform margin setting, the eastern Demerara Plateau (French Guiana)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Pattier, France; Loncke, L.; Gaullier, V.; Basile, C.; Maillard, Alexandre; Imbert, Patrice; Roest, Walter; Vendeville, B. C.; Patriat, Martin; Loubrieu, Benoit.
The eastern Demerara Plateau offshore French Guiana was surveyed in 2003 during the GUYAPLAC cruise (multibeam bathymetry and acoustic imagery, 6-channel seismic reflection and 3.5 kHz echo-sounding). The data show the "post-transform" Cenozoic that the series located on the outer part of the plateau (below c. 2000 m) contain at least twelve stacked mass transport deposits (MTDs) that have recorded a history of large-scale slope failure, as well as two main normal fault sets that provide possible pathways for upward fluid migration through the series, reaching at high as the uppermost MTDs. Seabed data show that the area above the failures is characterized by circular-to-elongate (slope-parallel) depressions interpreted as fluid seeps (pockmarks), some of...
Tipo: Text
Palavras-chave: Fluid ascent; Pockmarks; MTDs; Transform margin; Demerara Plateau.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00157/26850/25316.pdf

Transform Marginal Plateaus
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Loncke, L.; Roest, Walter; Klingelhoefer, Frauke; Basile, C.; Graindorge, David; Heuret, A.; Marcaillou, B.; Museur, Thomas; Fanget, Anne-sophie; Mercier De Lépinay, M.
Numerous submarine plateaus form highstanding bathymetric highs at continent to ocean transitions. Due to their proximity to continents, they have been frequently labelled “marginal plateaus”, although this term has not been clearly defined or associated with a specific geology or geodynamic process. Until now, these elevations have been interpreted as submerged thinned continental fragments detached from continents, basaltic buildups formed by hotspots, volcanic margins or oceanic plateaus. Many of these plateaus formed at transform margins connecting oceanic basins of contrasted ages. We propose for the first time to define and review a class of marginal plateaus related to a specific tectonic setting: “Transform Marginal Plateaus” (TMPs). Based on a...
Tipo: Text
Palavras-chave: Transform marginal plateau; Transform margin; Volcanic margin; Large Igneous Province; Continental breakup; Paleoceanography; Land bridge; Gateway.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00512/62407/66663.pdf