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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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| Van Vliet-lanoe, Brigitte; Goslin, Jerome; Henaff, Alain; Hallegouet, Bernard; Delacourt, Christophe; Le Cornec, Erwan; Meurisse-fort, Murielle. |
| Holocene coastal dune formation under a continuously rising sea level (SL) is an abnormal response to increasing storm frequency. The aim of this work is to understand the coastal sedimentary budget and the present-day sand starvation, controlled by climate and man. Dating in Brittany shows that Aeolian deposition initiated from ca. 4000 cal BP, with the slowing down of the SL rise. Pre-historical dunes appeared here from ca. 3000 cal BP, without SL regression. After, further building phases recycled the same stock of sands. Historical dunes I developed from ca. 350 AD. Major storms between 900 and 1200 AD resulted in the construction of washover coastal ridges, the Historical dunes II. A part of the sand was evacuated offshore. From ca. 1350 AD, the... |
| Tipo: Text |
Palavras-chave: Dunes; Holocene; Climate; Sand starvation; Anthropic perturbation. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00591/70262/68321.pdf |
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| Van Vliet-lanoe, Brigitte; Schneider, Jean-luc; Gudmundsson, Agust; Guillou, Herve; Nomade, Sebastien; Chazot, Gilles; Liorzou, Celine; Guegan, Solene. |
| Central southern Iceland is one of the main outlets of the Icelandic Ice Sheet where a MIS 5e sedimentary complex, the Ranga Formation, is extensively observed below the last deglaciation terminal moraines. Sedimentary facies demonstrate that the Ranga Formation is mostly tidal, up to 215 m (transgression I) and 168 m (transgression II) in altitude. The first highstand reworks a thick tephra from the Grimsvotn volcano, known in marine cores as 5e low/Bas-IV and positioned at ca. 127 Ka BP, the Eemian thermal optimum. This formation is related to a rapid deglaciation followed by two marine transgressions marked by the development of extended mud flats, which were separated by a complex regression phase, associated with loess deposition, ca. 9 Ka in... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00638/75001/75938.pdf |
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| Gupta, Sanjeev; Collier, Jenny S.; Garcia-moreno, David; Oggioni, Francesca; Trentesaux, Alain; Vanneste, Kris; De Batist, Marc; Camelbeeck, Thierry; Potter, Graeme; Van Vliet-lanoe, Brigitte; Arthur, John C. R.. |
| Late Quaternary separation of Britain from mainland Europe is considered to be a consequence of spillover of a large proglacial lake in the Southern North Sea basin. Lake spillover is inferred to have caused breaching of a rock ridge at the Dover Strait, although this hypothesis remains untested. Here we show that opening of the Strait involved at least two major episodes of erosion. Sub-bottom records reveal a remarkable set of sediment-infilled depressions that are deeply incised into bedrock that we interpret as giant plunge pools. These support a model of initial erosion of the Dover Strait by lake overspill, plunge pool erosion by waterfalls and subsequent dam breaching. Cross-cutting of these landforms by a prominent bedrock-eroded valley that is... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00455/56635/58373.pdf |
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| Toucanne, Samuel; Zaragosi, Sebastien; Bourillet, Jean-francois; Marieu, Vincent; Cremer, Michel; Kageyama, Masa; Van Vliet-lanoe, Brigitte; Eynaud, Frederique; Turon, Jean-louis; Gibbard, Philip L.. |
| The Fleuve Manche (English Channel) palaeoriver represents the largest river system that drained the European continent during Pleistocene lowstands, particularly during the Elsterian (Marine Isotope Stage 12) and Saalian Drenthe (MIS 6) glaciations when extensive ice advances into the North Sea area forced the central European rivers to flow southwards to the Bay of Biscay (NE Atlantic). Numerous long piston cores and high-resolution acoustic data from the northern Bay of Biscay have been correlated using a well-constrained chronostratigraphical framework, and for the first time allow the estimation of the discharge of the Fleuve Manche palaeoriver at the end of the last glacial period (i.e. Weichselian). Our results, discussed in the light of... |
| Tipo: Text |
Palavras-chave: Fleuve Manche palaeoriver; English Channel; Sediment and meltwater discharge; European ice sheet; Deglaciation; Termination 1; North Sea area; European drainage network. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00002/11310/7858.pdf |
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