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Lake Bourget regional erosion patterns reconstruction reveals Holocene NW European Alps soil evolution and paleohydrology ArchiMer
Arnaud, Fabien; Revillon, Sidonie; Debret, Maxime; Revel, Marie; Chapron, Emmanuel; Jacob, Jeremy; Giguet-covex, Charline; Poulenard, Jerome; Magny, Michel.
Two well-dated ca Holocene-long sedimentary sequences from deepest parts of Lake Bourget provide new insights onto the evolution of erosion patterns at a regional scale in NW European Alps. The combination of high resolution geochemistry - XRF core scanning, calibrated by 150 punctual measurements - and isotope geochemistry (epsilon Nd) of the terrigenous fraction permitted the reconstruction not only of the intensity, but also the type (physical erosion vs. chemical weathering) and the location (Prealpine massifs vs. High Crystalline massifs) of dominant erosion processes. Those data point the persistency of weak erosion fluxes from 9600 to 5500 cal. BP due both to a dry climate and the growing sheltering effect of soils that rapidly progressed between...
Tipo: Text Palavras-chave: Holocene; Alps; Erosion; Soil dynamics; Paleohydrology.
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00106/21723/20064.pdf
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Cartographie du prisme sedimentaire Holocene en baie de Seine orientale, par sismique reflexion a haute definition ArchiMer
Auffret, J; D'Ozouville, L.
After the cartography of a Holocene sedimentary prism, results of 8,000 years of natural evolution and 150 years of coastal equipment, the authors research an active sedimentary system, characteristic of present evolution.
Tipo: Text Palavras-chave: Holocene; Sedimentary structures; Paleoceanography; Estuarine sedimentation; Sediment distribution; Seismic reflection profiling; Cartography.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1273.pdf
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Turbidite chronostratigraphy off Algiers, central Algerian margin: A key for reconstructing Holocene paleo-earthquake cycles ArchiMer
Babonneau, Nathalie; Cattaneo, Antonio; Ratzov, Gueorgui; Deverchere, Jacques; Yelles-chaouche, Abdelkarim; Lateb, Tassadit; Bachir, Roza Si.
Northern Algeria is threatened by moderate to large magnitude earthquakes resulting from the slow convergence between the African and European plates. Main active faults are located offshore along the Algerian coast, as exemplified by the 2003 Mw 6.9 Boumerdès earthquake. This event triggered numerous and widespread turbidity currents over ∼ 150 km along strike in the Algerian basin (reaching 2800 m of water depth) and demonstrates the multi-source and multi-path characteristics of earthquake-triggered turbidity flows along this margin segment. We rely on the sedimentological analysis of five cores located at the toe of the Algiers margin, close to the 2003 cable break sites, to explore the potential for Holocene turbidite paleoseismology. Radiocarbon...
Tipo: Text Palavras-chave: Algerian margin; Marine paleoseismology; Turbidite; Holocene.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00356/46701/46563.pdf
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Past and current sediment dispersion pattern estimates through numerical modeling of wave climate: an example of the Holocene delta of the Doce River, Espírito Santo, Brazil Anais da ABC (AABC)
Bittencourt,Abílio C.S.P.; Dominguez,José M.L.; Martin,Louis; Silva,Iracema R.; de-Medeiros,Karla O.P..
This paper presents a numerical modeling estimation of the sediment dispersion patterns caused by waves inciding through four distinct coastline contours of the delta plain of the Doce River during the Late Holocene. For this, a wave climate model based on the construction of wave refraction diagrams, as a function of current boundary conditions, was defined and was assumed to be valid for the four coastlines. The numerical modeling was carried out on basis of the refraction diagrams, taking into account the angle of approximation and the wave height along the coastline. The results are shown to be comparable with existing data regarding the directions of net longshore drift of sediments estimated from the integration of sediment cores, interpretation of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Past and current sediment dispersion; Wave refraction; Numerical modeling; Holocene; Brazil.
Ano: 2007 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652007000200014
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A diachronic view of the net longshore sediment drift during the Late Holocene at the Jequitinhonha River delta, Brazil, using numerical modeling Anais da ABC (AABC)
Bittencourt,Abilio C.S.P.; Dominguez,José M.L.; Tanajura,Clemente A.S.; Silva,Iracema R.; Martin,Louis.
Using numerical modeling, this work estimates sediment dispersion patterns caused by the incidence of waves in five distinct coastline contours of the Jequitinhonha River delta plain during the Late Holocene. For this study, a wave cliate odel based on the construction of ave refraction diagras relative to the current boundary conditions as defined and assumed to be valid for the five coastlines. Numerical modeling from the refraction diagrams was carried out considering the angle of incidence and wave height along the coastline. This work has allowed us to reproduce past and current patterns of net longshore sediment drift defined by a conceptual model developed from the integration of sediment cores, aerial photograph interpretation, C14 datings and...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Past and current longshore transport; Wave refraction; Numerical modeling; Holocene; Brazil.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000400008
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Late Pleistocene to Recent ostracod assemblages from the western Black Sea ArchiMer
Boomer, Ian; Guichard, Francois; Lericolais, Gilles.
During the last glacial phase the Black Sea basin was isolated from the world's oceans due to the lowering of global sea-levels. As sea-levels rose during the latest glacial and early Holocene period, the Black Sea was once again connected to the eastern Mediterranean via the Dardanelles-Marmara-Bosporus seaway. In recent years, trace element and stable isotope analyses of ostracod assemblages have yielded important details regarding the hydrological evolution of the Black Sea during these events. Despite this focus on the geochemical signatures of the ostracods, little if any attention has been paid to the taxonomic composition of the ostracod assemblages themselves and there are notably few publications on the sub-littoral fauna of this important water...
Tipo: Text Palavras-chave: Ponto-Caspian; Black Sea; Ostracoda; Pleistocene; Holocene.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00025/13646/10887.pdf
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The rise and fall of the Refugial Hypothesis of Amazonian speciation: a paleoecological perspective Biota Neotropica
Bush,Mark B.; Oliveira,Paulo E. de.
The refugial hypothesis is treated as the definitive history of Amazonian forests in many texts. Surprisingly, this important theoretical framework has not been based on paleoecological data. Consequently, a model of Amazonian aridity during the northern hemispheric glaciation has been accepted uncritically. Ironically, the Refuge Hypothesis has not been tested by paleobotanical data. We present a revision of the concept of Neotropical Pleistocene Forest Refuges and test it in the light of paleocological studies derived from pollen analysis of Amazonian lake sediments deposited during the last 20,000 years. Our analysis is based primarily on paleoenvironmental data obtained from sites in Brazil and Ecuador. These data are contrasted with those that favor...
Tipo: Info:eu-repo/semantics/other Palavras-chave: Amazonia; Refugia; Fossil pollen; Glaciations; Pleistocene; Holocene; Miocene; Phylogeny; Speciation diversity.
Ano: 2006 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032006000100002
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Environmental significance of microbialites in reef environments during the last deglaciation ArchiMer
Camoin, G; Cabioch, G; Eisenhauer, A; Braga, J; Hamelin, B; Lericolais, Gilles.
In situ microbialites occurring in reef rocks dredged between 80 and 130 in water depth on the modern fore-reef slopes of Tahiti and the Marquesas islands yield ages ranging from 17,100 2900 to 4410 2250 years BP, suggesting that they played a prominent role during the last deglacial sea level rise. Microbialites developed in both shallow and deep water depositional environments where they characterize various zones of the reef tracts (reef crests, upper reef slopes, deep fore-reef slopes), reflecting contrasting scenarios of microbialite development involving ''reefal microbialites'' in shallow-water settings and ''slope microbialites'' that formed in environments deeper than 1020 in and extending down to more than 100 m. Reefal microbialites...
Tipo: Text Palavras-chave: Sea level changes; Nutrients; French polynesia; Holocene; Last deglaciation; Microbialites; Coral reefs.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-4204.pdf
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Changes in magnetic susceptibility and grain size of Holocene sediments of the Pearl River estuary and climate changes reflected by them. OceanDocs
Cao, Linglong; Wang, Ping; Wang, Jianhua; Wang, Xiaojing; Yang, Jie.
Through the Pearl River Estuary Wan Qing-sha W2 core AMS 14C dating of sediments, combining with paleomagnetic test, pollen analysis, and comprehensive comparison with other relevant records, the regional framework of Holocene age was established. Using the combined feature grain size and magnetic susceptibility proxies for the environment, climate change information in the area since about 6 000 cal yr BP was obtained. The result showed the area since the middle Holocene had experienced three stages climate changes of warm and dry - cool and wet temperature and humidity. South area of China in the late Holocene climate (especially rainfall) had important changes, corresponding to the Northern Hemisphere solar radiation reducing, air temperature...
Tipo: Journal Contribution Palavras-chave: Grain size; Magnetic susceptibility; Holocene; Palaeoclimate.
Ano: 2012 URL: http://hdl.handle.net/1834/5851
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Reconstitution de la variabilité naturelle climatique et océanographique dans l’estuaire et le golfe du Saint-Laurent au cours des 10,000 dernières années ArchiMer
Casse, Marie.
L’estuaire et le golfe du Saint-Laurent (EGSL, Est du Canada) sont des milieux très dynamiques d’un point de vue sédimentaire. Pourtant, les voies de propagation des sédiments fluviaux ainsi que l’origine et le mélange des apports sédimentaires en milieu marin ne sont pas bien documentés dans cette zone. Or, ces connaissances sont fondamentales pour déterminer les sources principales des apports terrigènes et mieux comprendre la dynamique de ce système sédimentaire. Dans ce contexte, les propriétés physiques, la distribution granulométrique, la minéralogie, les éléments majeurs et traces, et les isotopes radiogéniques (néodyme et strontium) d’un ensemble de sédiments de surface et de carottes sédimentaires de l’EGSL ont été étudiées dans cette thèse afin...
Tipo: Text Palavras-chave: Estuary and gulf of St.Lawrence; Holocene; Laurentide Ice Sheet; Relative sea level; Sedimentary dynamic; Mineralogy; Geochemistry; Radiogenic isotopes; Rare earth elements..
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00494/60611/64095.pdf
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Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern Brazil Anais da ABC (AABC)
CASTRO,JOÃO WAGNER A.; SUGUIO,KENITIRO; SEOANE,JOSÉ C.S.; CUNHA,ALINE M. DA; DIAS,FABIO F..
The present paper aims to investigate the relative sea-level and the coastal evolution during the Holocene in the Rio de Janeiro coastline, based on geological and biological indicators. Using topographic survey, excavation and coring, and 14C dating of these coastal deposits and beachrocks outcrops, we have reconstructed a sea-level curve for the Holocene. For the first time on the Brazilian coast it was identified a negative record of relative sea-level during Late Pleistocene and Early Holocene transition. After the transition, a relatively rapid increase of sea-level began. At approximately at 8500 cal yr BP, the sea-level was 0.5 m below the current level, was overtaken for the first time in the Holocene, at approximately 7500 cal yr BP. The maximum...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Sea-level fluctuations; Coastal evolution; Holocene; Brazilian coast.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000200671
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Holocene coastal changes and infilling of the La Perroche marsh (French Atlantic coast) ArchiMer
Clave, B; Masse, L; Carbonel, P; Tastet, Jp.
The La Perroche marsh is a small Holocene marsh on the south-western coast of the Oleron island (Bay of Biscay, France) presently occupied by a freshwater swamp and separated from the ocean by a continuous sand dune ridge. The study of its infill shows first basal conglomeratic deposits with calcareous pebbles on a Cenomanian rough substrate. The Holocene infill since 6000 years BP begins with a very fast sedimentation of sands. Then, the sedimentation becomes finer, with lagoonal to freshwater influences recorded by ostracods. The distribution of these deposits inside the marsh is asymmetric, with a thick sandy-gravely layer in the eastern part and a succession of sands, clays and organic layers in the western part. Communication with the sea is episodic,...
Tipo: Text Palavras-chave: Changements côtiers; Marais maritime; Holocène; Ostracodes; Sédiments; Coastal changes; Coastal salt marsh; Holocene; Ostracods; Sediments.
Ano: 2001 URL: http://archimer.ifremer.fr/doc/00322/43349/42877.pdf
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Pollen analysis of Holocene sediments from the Poço das Antas National Biological Reserve, Silva Jardim, Rio de Janeiro, Brazil Anais da ABC (AABC)
Coelho,Luciane G.; Barth,Ortrud M.; Araujo,Dorothy S.D. de.
The Poço das Antas National Biological Reserve is located in Rio de Janeiro State, southeast Brazil. This paper presents information on past environmental characteristics of the area through pollen analysis. Two sedimentary columns were collected and five samples were selected for radiocarbon dating. The following ages of the columns from bottom to top were detected: column 1 - 1.20-1.16 m: 6080 ±40 years BP, 0.775-0.735 m: 4090 ±40 years BP, 0.385-0.345 m: 1880 ±80 years BP; column 2 - 1.22-1.18 m: 3520 ±40 years BP, 0.23-0.19 m: 1810 ±40 years BP. Three samples from column 1 and two samples from column 2 were selected for pollen analysis: 1.20 m, 0.77 m and 0.37 m of column1 and 1.22 m and 0.21 m of column 2. Chemical treatment followed standard...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Palynology; Paleo-environment; Holocene; Brazil.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000300013
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Element enrichment and provenance of the detrital component in Holocene sediments from the western Black Sea ArchiMer
Dekov, Vesselin M.; Darakchieva, Valentina Y.; Billström, Kjell; Garbe-schönberg, C-dieter; Kamenov, George D.; Gallinari, Morgane; Dimitrov, Lyubo; Ragueneau, Olivier; Kooijman, Ellen.
Concentrations of a large set of major and trace elements, and Sr, Nd and Pb isotope ratios were measured in Holocene sediments cored in the western deep Black Sea in order to unravel: (1) the controls of element enrichment, and (2) sources of the detrital component. The transition of the basin from oxic to euxinic resulted in enrichment or depletion in a number of elements in the deep-sea sediments. Authigenic Fe enrichment appears to depend on the amount of Fe mobilized from the sediment through the benthic redox shuttle mechanism and free H2S in the water column (degree of “euxinization”). Manganese enrichment is controlled by diagenetic reactions within the sediment: the dissolution of Mn minerals, Mn2+ diffusion upward and reprecipitation. Barium...
Tipo: Text Palavras-chave: Anoxic; Black Sea; Element enrichment; Sr-Nd-Pb-isotopes; Holocene.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00590/70164/68171.pdf
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Seasonal and subseasonal climate changes recorded in laminated diatom ooze sediments, Adelie Land, East Antarctica ArchiMer
Denis, Delphine; Crosta, X; Zaragosi, S; Romero, O; Martin, B; Mas, Virginie.
A 40 m long sediment core covering the 1000-9600 years BP period was retrieved from the Dumont d'Urville Trough off Adelie Land, East Antarctica, during the MD 130-Images X-CADO cruise. This sedimentary sequence allows the documentation of changes in climate seasonality during the Holocene. Here we show preliminary results of diatom communities, lithic grain distribution and titanium content measured on two 30 cm long sequences of thin sections. The two sequences originate from two different climate regimes, the colder Neoglacial and the warmer Hypsithermal. Proxies were measured at microscale resolution on 25 laminations for the Neoglacial and 14 laminations for the Hypsithermal. The two sequences reveal alternating light-green and dark-green laminae....
Tipo: Text Palavras-chave: East Antarctica; Sea ice; Seasonality; Diatom ooze; Laminated sediments; Holocene; Adelie Land.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-2275.pdf
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Post-glacial persistence of turbiditic activity within the Rhone deep-sea turbidite system (Gulf of Lions, Western Mediterranean): Linking the outer shelf and the basin sedimentary records ArchiMer
Dennielou, Bernard; Jallet, Laurent; Sultan, Nabil; Jouet, Gwenael; Giresse, Pierre; Voisset, Michel; Berne, Serge.
Emplacement of post-glacial turbidites is commonly controlled by rapid changes in sea level or by seismicity. On the continental rise of the Gulf of Lions (Western Mediterranean), an aseismic area, we identified turbiditic beds deposited during the rising stage and highstand of sea level. Swath bathymetry, sediment cores, in situ Cone Penetrating Tests (CPTU), heavy mineral associations and radiocarbon dating determined the source, composition, distribution and age of the turbiditic beds. Turbidites are composed of homogeneous to positively graded silts to medium sand with quartz (up to 90%), shell debris and shelfal benthic faunas. Their distribution on the sea floor is very patchy and controlled by abundant inherited erosional bedforms. Their source is...
Tipo: Text Palavras-chave: Holocene; Late Pleistocene; Sea level; Turbidites; Sand; Outer shelf; Canyons.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6316.pdf
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Holocene evolution of relative sea level and local mean high water spring tides in Belgium: a first assessment OMA
Denys, L.; Baeteman, C..
Holocene age-depth data from the Belgian coastal plain, basal peat data particularly, are assessed in terms of local water and tide levels. Basal peat formation was generally induced by sea-level rise; effects of local seepage were limited and significant river-gradient effects were absent. No relation was found between the timing of basal peat inception and substrate permeability. In general, edaphic (moisture) conditions were unfavourable for organic accumulation prior to sea-level related rise of the groundwater table. Error envelopes for the minimum level of local mean high water spring tides and for upper and extreme lower relative mean sea-level limits during the last 9400 solar years (8400 yrs B.P.) are presented. These indicate that the rate of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Holocene; Marine geology; Peat; Sea level changes; Sedimentation.
Ano: 1995 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2960
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The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf south of Istanbul ArchiMer
Eris, K; Ryan, W; Cagatay, M; Sancar, U; Lericolais, Gilles; Menot, G; Bard, E.
High-resolution reflection seismic profiles with core analyses of sedimentary sequence near the Sea of Marmara (SoM) entrance to the Strait of İstanbul (SoI, Bosphorus) provide detailed record of sealevel changes since the Late Glacial Maximum (LGM). The sequence is deposited over the LGM erosional surface at a maximum depth of -105 m. It includes seven seismic units that can be confidently correlated with 14C-dated sedimentary units in the cores. Unit 6 represents levee deposits of the paleo-SoI channel that was deposited by a Black Sea outflow during 11.2-10.6 kyr BP. The reflection surfaces at base of Unit 5 and 4 correspond to wave-cut terraces at -71and -63 m, respectively, and are estimated to be 10.6 and 9.8 kyr BP. The seismic Unit 2, overlaying a...
Tipo: Text Palavras-chave: Sapropel; Delta; Marmara Sea; Holocene; Sea level; Seismic stratigraphy.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3574.pdf
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Epi-bathyal ostracod assemblage in Holocene Rhone deltaic sediments (Gulf of Lions, NW Mediterranean) and their palaeoecological implications ArchiMer
Fanget, Anne-sophie; Bassetti, Maria Angela; Berne, Serge; Arnaud, Mireille.
Since the Last Glacial Maximum, the Rhone River, which is the most important source of freshwater and sediment to the western Mediterranean Sea, migrated in a north-westward direction during the rapid Deglacial and Early Holocene sea-level rise. During the phase of global high sea-level (Middle and Late Holocene), an overall eastward migration of the Rhone outlet, under natural and/or human influence, is recorded through several sediment accumulations confined along the inner shelf in the form of deltaic lobes. These lobes that make up the whole Rhone subaqueous delta represent very expanded sedimentary archives of the Rhone Holocene history. In this paper, using three long piston cores retrieved from the most recent Bras de Fer (RHS-KS55) and Roustan...
Tipo: Text Palavras-chave: Ostracodes; Delta sous-marin; Paléoécologie; Holocène; Méditerranée occidentale; Ostracoda; Subaqueous delta; Palaeoecology; Holocene; Western Mediterranean..
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00217/32810/31253.pdf
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Impact of relative sea level and rapid climate changes on the architecture and lithofacies of the Holocene Rhone subaqueous delta (Western Mediterranean Sea) ArchiMer
Fanget, Anne-sophie; Berne, Serge; Jouet, Gwenael; Bassetti, Maria-angela; Dennielou, Bernard; Maillet, Gregoire M.; Tondut, Mathieu.
The modern Rhone delta in the Gulf of Lions (NW Mediterranean) is a typical wave-dominated delta that developed after the stabilization of relative sea level following the last deglacial sea-level rise. Similar to most other deltas worldwide, it displays several stacked parasequences and lobes that reflect the complex interaction between accommodation, sediment supply and autogenic processes on the architecture of a wave-dominated delta. The interpretation of a large set of newly acquired very high-resolution seismic and sedimentological data, well constrained by 14C dates, provides a refined three-dimensional image of the detailed architecture (seismic bounding surfaces, sedimentary facies) of the Rhone subaqueous delta, and allows us to propose a...
Tipo: Text Palavras-chave: Delta; Holocene; Maximum Flooding Surface; Sea level; Tempestites; Western Mediterranean.
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00179/29017/27445.pdf
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