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| Pasquier, V.; Revillon, Sidonie; Leroux, Estelle; Molliex, Stephane; Mocochain, L.; Rabineau, Marina. |
| The terrigenous sedimentary budget of passive margins, records variations in past sedimentary fluxes, and thus can be used to infer past variations of Earth surface deformation processes or climate change. Accurate estimates of sediment fluxes over various times and spatial scales are therefore crucial. Traditionally, offshore sediment volume determination only considers siliciclastic accumulation, the carbonate fraction (i.e., CaCO3) being considered only as in situ production. Here we propose a new geochemical methodology to decipher and quantify the number of detrital carbonates in comparison to in situ produced biogenic carbonates. This isotopic approach enables considering the export of detrital carbonates and investigating its effect on sediment... |
| Tipo: Text |
Palavras-chave: Sr-87/Sr-86(carbonate); Detrital carbonate export; Source-to-sink; Glacial - interglacial; Strontium isotope stratigraphy. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00505/61638/65563.pdf |
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| Leroux, Estelle; Rabineau, Marina; Aslanian, Daniel; Gorini, Christian; Molliex, Stephane; Bache, Francois; Robin, Cecile; Droz, Laurence; Moulin, Maryline; Poort, Jeffrey; Rubino, Jean-loup; Suc, Jean-pierre. |
| Basin-wide correlation of Messinian units and Plio-Quaternary chronostratigraphic markers (5.3 Ma, 2.6 Ma, 0.9 Ma and 0.45 Ma), the mapping of total sediment thickness and the determination of overall sedimentary volumes enabled us to provide a high-resolution quantitative history of sediment volumes for the last 6 Ma along the Gulf of Lions margin. The results point to (i) a dramatic increase in terrigenous sediment input during the Messinian Salinity Crisis. This increased sedimentation reflects enhanced regional fluvial erosion related to the dramatic fall of Mediterranean base-level. Stronger weathering due to a regional wetter climate probably also increased erosional fluxes. (ii) A sediment input three times higher during the Plio-Quaternary compared... |
| Tipo: Text |
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| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00310/42087/41520.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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| Molliex, Stephane; Siame, Lionel L.; Bourles, Didier L.; Bellier, Olivier; Braucher, Regis; Clauzon, Georges. |
| Located in the foreland of the Western Alps, the Crau Plain was the outlet of the Durance River in the Pleistocene. In order to constrain its geodynamic evolution in terms of chronology and denudation rates, the two main Quaternary deposits of this plain have been studied based on cosmogenic nuclide Be-10 concentration measurements along depth profiles. The abandonment of the Miramas and Luquier alluvial surfaces occurred at the beginning of glacial periods, Wurm (isotopic stage 4) and Riss (isotopic stage 6), respectively. Discrepancy in denudation rates under similar geomorphological and lithological conditions suggests different denudation processes during glacial and interglacial periods. The denudation rate has been estimated at about 25 mm ka(-1) for... |
| Tipo: Text |
Palavras-chave: Quaternary; Denudation rate; Cosmic ray exposure (CRE) dating; Be-10 depth profile; Provence; Periglacial setting. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00149/26040/24740.pdf |
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| Mariotti, Apolline; Blard, Pierre-henri; Charreau, Julien; Petit, Carole; Molliex, Stephane; Aumaitre, Georges; Bourles, Didier L.; Keddadouche, Karim. |
| Marine sedimentary archives are well dated and often span several glacial cycles; cosmogenic Be-10 concentrations in their detrital quartz grains could thus offer the opportunity to reconstruct a wealth of past denudation rates. However, these archives often comprise sediments much finer (< 250 mu m) than typically analyzed in Be-10 studies, and few studies have measured Be-10 concentrations in quartz grains smaller than 100 mu m or assessed the impacts of mixing, grain size, and interannual variability on the Be-10 concentrations of such fine-grained sediments. Here, we analyzed the in situ cosmogenic Be-10 concentrations of quartz grains in the 50-100 and 100-250 mu m size fractions of sediments from the Var basin (southern French Alps) to test the... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74894/76066.pdf |
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| Rabineau, Marina; Leroux, Estelle; Aslanian, Daniel; Bache, F.; Gorini, Christian; Moulin, Maryline; Molliex, Stephane; Droz, Laurence; Dos Reis, Antonio; Rubino, J. L.; Guillocheau, Francois; Olivet, Jean-louis. |
| Passive margins are characterised by an important tectonic and thermal subsidence, which favours a good preservation of sedimentary sequences. This sedimentation in turn enhances the subsidence because of loading effects. We present here a direct method based on sedimentary markers seen on seismic data, to evaluate total subsidence rates from the coast to the outer shelf and to the deep basin in the Gulf of Lion, from the beginning of massive salt deposition up to present day (the last circa 6 Ma) with minimal theoretical assumptions. On the shelf, the Pliocene-Quaternary subsidence shows a seaward tilt reaching a rate of 240 m/Ma (±15 m/Ma) at the shelf break (70 km from the present day coastline) (i.e. a total angle of rotation of 0.88° (0.16°/Ma)). We... |
| Tipo: Text |
Palavras-chave: Subsidence; Pliocene-quaternary; Messinian salinity crisis; Isostasy; Mediterranean Sea; Gulf of Lion. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00171/28176/32147.pdf |
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