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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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A new midshelf record in the northern Bay of Biscay (NE Atlantic, CBT-CS11 core): sedimentological, geochemical and palynological data over the last 7 kyrs ArchiMer
Penaud, Aurélie; Ganne, Axelle; Coste, Pierre-olivier; Herlédan, Maïwenn; Durand, Matthieu; Mojtahid, Meryem; Nizou, Jean; Toucanne, Samuel.
The high-time resolution (∼70 years in average) multi-proxy analysis conducted on the midshelf core CBT-CS11 (47°46.429’N; 4°25.308’W; 73m depth; 3.96 m long; NW France, S Brittany) revealed the complexity of the palaeohydrological and palaeoclimatic signals recorded over the last 7 kyrs in the recently published paper: “Oceanic versus continental influences over the last 7 kyrs from a midshelf record in the northern Bay of Biscay (NE Atlantic)” [1]. This study presents the whole CBT-CS11 dataset discussed in [1] including sedimentological (XRF and grain-size (total from [1] and CaCO3-free from [2]) analyses), geochemical (oxygen and carbon stable isotopes on two different benthic foraminiferal species: Ammonia falsobeccarii from [1] and Cibicides...
Tipo: Text Palavras-chave: Holocene; NE Atlantic Ocean; Pollen assemblages; Dinoflagellate cyst assemblages; Stable isotopes; Grain-size analysis; XRF.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00610/72209/71003.pdf
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A reevaluation of the late quaternary sedimentation in todos os Santos Bay (BA), Brazil Anais da ABC (AABC)
LESSA,GUILHERME C.; BITTENCOURT,ABÍLIO C.S.P.; BRICHTA,ARNO; DOMINGUEZ,JOSÉ M. L..
Todos os Santos Bay is a large (<img ALIGN="BOTTOM" BORDER="0" SRC="http:/img/fbpe/aabc/v72n4/0052img1.gif" ALT="$ \approx$"> 1000 km²), structurally controlled tidal bay in northeast Brazil. Three main drainage basins debouch into the bay, providing a mean freshwater discharge of 200 m³/s (prior to 1985), or less than 1% of the spring tidal discharge through the bay mouth. Based on the result of several sedimentological studies performed in the 1970's, five surface sedimentary facies were identified inside the bay, namely i) transgressive siliciclastic marine sand facies; ii) transgressive bay sand-mud facies; iii) a transgressive carbonate marine sand facies; iv) regressive bay-mud facies, and v) regressive fluvial sand facies. The spatial...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Estuary; Sediment; Stratigraphy; Holocene.
Ano: 2000 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652000000400008
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A role for icebergs in the 8.2 ka climate event ArchiMer
Wiersma, Ane P.; Jongma, Jochem I..
We investigate the potential role of icebergs in the 8.2 ka climate event, using a coupled climate model equipped with an iceberg component. First, we evaluate the effect of a large iceberg discharge originating from the decaying Laurentide ice sheet on ocean circulation, compared to a release of an identical volume of freshwater alone. Our results show that, on top of the freshwater effect, a large iceberg discharge facilitates sea-ice growth as a result of lower sea-surface temperatures induced by latent heat of melting. This causes an 8% increased sea-ice cover, 5% stronger reduction in North Atlantic Deep Water production and 1A degrees C lower temperature in Greenland. Second, we use the model to investigate the effect of a hypothetical two-stage lake...
Tipo: Text Palavras-chave: 8.2 ka event; Climate modeling; Icebergs; Laurentide ice sheet; Hudson Strait; Holocene; Heinrich events.
Ano: 2010 URL: https://archimer.ifremer.fr/doc/00496/60749/65152.pdf
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Abrupt climate variability during the last glacial and the late Holocene from the western tropical Pacific perspective ArchiMer
Saikku, Reetta Maaria.
In Project I, Western tropical Pacific sea surface temperatures and Pacific Deep Water temperatures during Marine Isotope Stage 3 have been reconstructed from the δ18O and Mg/Ca of planktonic and benthic foraminifera from Marion Dufresne core MD98-2181. This 36m marine core was collected at 6.3°N from a water depth of 2114m. With sediment accumulation rates of up to 80cm/ky, it provides a decadally-resolved history of ocean variability during the last glacial period. Surface temperatures and salinities at this site varied in close association with millennial-scale atmospheric temperature swings at high northern latitudes as reflected in the GISP2 ice core. At times of colder atmospheric temperatures over Greenland, the western Pacific was more saline and...
Tipo: Text Palavras-chave: Climate; Pacific; Tropical; Glacial; Holocene.
Ano: 2009 URL: https://archimer.ifremer.fr/doc/00495/60653/64150.pdf
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Analysis of the Holocene climate variability using a data assimilation method in the model LOVECLIM ArchiMer
Mairesse, Aurélien.
The study of past climates and of mechanisms that have influenced their evolution is the key to anticipate the future climate changes. This doctoral thesis focusses on the Holocene climate, the ongoing interglacial, that starts about 11,700 years ago. The current paleoclimate knowledge is based on the one hand, on the climate models results and, on the other hand, on the reconstruction of physical variables derived from climate archives as the ice cores, the marine cores or the pollens for instance. These two types of information are complementary. Here we have combined them to obtain reconstructions of past climates using data assimilation. This technique is standard in many disciplines but not yet in paleoclimatology. The data assimilation method applied...
Tipo: Text Palavras-chave: Climate; Data assimilation; Paleoclimate; Holocene; LOVECLIM model; Proxy record.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00506/61719/65687.pdf
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Beach ridges, foredunes or transgressive dunefields? Definitions and an examination of the Torres to Tramandaí barrier system, Southern Brazil Anais da ABC (AABC)
Hesp,Patrick A.; Dillenburg,Sergio R.; Barboza,Eduardo G.; Tomazelli,Luiz J.; Ayup-Zouain,Ricardo N.; Esteves,Luciana S.; Gruber,Nelson L.S.; Toldo-Jr.,Elirio E.; Tabajara,Luiz L.C. de A.; Clerot,Luiz C.P..
Many prograded barriers and some dunefields in theworld have been termed 'beach ridge' plains, but the actual genesis of the 'ridges' is often unknown. Use of the terms, berms, beach ridges and foredunes is also confusing in the literature because their definitions are highly variable and are commonly used interchangeably. Thus, the formation and definition of sand berms, beach ridges and foredunes is briefly reviewed. Beach ridges are re-defined as entirely wave formed deposits which are most commonly formed during high wave conditions and/or elevated water levels (e.g. storm surges). Foredunes are formed by aeolian sand deposition in vegetation on the backshore. Some dunefields in Brazil have been called beach ridge plains when they are, in fact,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Beach ridges; Coastal barriers; Transgressive dunefields; Holocene; Southern Brazil.
Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000300010
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Carbonate cements in contemporaneous beachrocks, Jaguaribe beach, Itamaracá island, northeastern Brazil: petrographic, geochemical and isotopic aspects Anais da ABC (AABC)
Guerra,Núbia C.; Kiang,Chang H.; Sial,Alcides N..
Holocene beachrocks of the Jaguaribe beach, State of Pernambuco, northeastern Brazil, consist of horizontal, cemented layers approximately 40 cm thick. The cement shows three textural varieties: (a) calciferous, surrounding siliciclastic grains, (b) micritic, with an acicular fringe; and (c) cryptocrystalline calcite in pores. Early cementation took place at the water table below beach ridges, where geochemical, hydrodynamic and, perhaps, also microbiological conditions favored rapid precipitation of aragonite and/or high-Mg calcite. delta13C values range from -1.8 to +1.5‰ for dissolved carbonate in interstitial water and from +0.2 to +2.1‰ for bioclastic components. delta18O values range from -2.8 to +0.5‰ for seawater, freshwater and interstitial water....
Tipo: Info:eu-repo/semantics/article Palavras-chave: Beachrocks; Early diagenesis; O and C isotopes; Holocene.
Ano: 2005 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652005000200011
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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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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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Climatic characteristics of the late Pleistocene and Holocene continental deposits from southwestern Syria based on palynological data Darwiniana
Hussein,Kamal M..
The goal of this research was to reconstruct the vegetational and climatic changes that took place during the late Pleisocene and Holocene in southwestern Syria. This reconstruction was based on palynological data obtained from the analysis of 27 sediments and surface samples (with a total thickness of 4.55 m) collected from Al-Hijaneh Lake basin (late Pleistocene) and from Al-Aouaj River valley (Holocene). Three pollen zones were established. The oldest one (zone A) corresponds to the late Pleistocene lacustrine deposits of Lake Al-Hijaneh. Zones B and C were defined in the Holocene fluvial- lacustrine deposits of the Al-Aouaj River valley. These three pollen assemblage zones are correlated to synchronic and similar C14 dated pollen zones from Syria,...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Flora; Holocene; Late Pleistocene; Paleoclimates; Palynology; Syria.
Ano: 2006 URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0011-67932006000200003
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Coral Reef and High Sea Level at Luhuitou, Hainan Island during the Holocene. OceanDocs
Huang, Deyin; Shi, Qi; Zhang, Yechun.
According to the field survey and 14C dating at Luhuitou, southern Hainan Island, a subsiding area, the authors conclude the high sea level history recorded by coral reef in the Holocene. At least 4 sea level high-stands can be identified from the distribution of coral reef ages: 7300 - 6000 cal.aBP, 4800 - 4700 cal.aBP, 4300 - 4200 cal.aBP and 3100 - 2900 cal.aBP. The highest sea level occurred around 7300 - 6700 cal.aBP, and biological-morphological zones took their shape during the stage. The later coral reefs developed in ponds, depressions, and developed outwards on both sides of Luhuitou peninsula. The modern coral reefs are developing in out reef flat and reef-front slope. Moreover, the time of high sea levels in the northern South China Sea...
Tipo: Journal Contribution Palavras-chave: Coral reefs; Sea level; Holocene.
Ano: 2007 URL: http://hdl.handle.net/1834/5863
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East Asian monsoon history and paleoceanography of the Japan Sea over the last 460,000 years ArchiMer
Gallagher, Stephen J; Sagawa, Takuya; Henderson, Andrew C. G.; Saavedra-pellitero, Mariem; De Vleeschouwe, David; Black, Heather; Itaki, Takuya; Toucanne, Samuel; Bassetti, Maria-angela; Clemens, Steve; Anderson, William; Alvarez-zarikian, Carlos; Tada, Ryuji.
The Japan Sea is directly influenced by the Asian monsoon, a system that transports moisture and heat across southeast Asia during the boreal summer, and is a major driver of the Earth's ocean‐atmospheric circulation. Foraminiferal and facies analyses of a 460 kyr record from IODP Expedition 346 Site U1427 in the Japan Sea reveal a record of nutrient flux and oxygenation that varied due to sea level and East Asian monsoon intensity. The East Asian summer monsoon (EASM) was most intense during MIS (Marine Isotope Stage) 5e, 7e, 9e and 11c when the Tsushima Warm Current flowed into an unrestricted well mixed normal salinity Japan Sea. Whereas East Asian winter monsoon (EAWM) conditions dominated MIS 2, 4, 6 and 8 when sea level minima restricted the Japan...
Tipo: Text Palavras-chave: Tsushima Warm Current; Pleistocene; Holocene; Paleoceanography; East Asian summer monsoon; East Asian winter monsoon.
Ano: 2018 URL: http://archimer.ifremer.fr/doc/00444/55591/57215.pdf
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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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Environmental changes in the western Amazônia: morphological framework, geochemistry, palynology and radiocarbon dating data Anais da ABC (AABC)
Horbe,Adriana M.C.; Behling,Hermann; Nogueira,Afonso C.R.; Mapes,Russell.
The sediments from the Coari lake, a “terra firme” lake sculpted into Plio-Pleistocene deposits, and the Acará lake, a flooding-type lake developed on Quaternary sediments in the floodplain of the mid-Solimões river, in the western Amazônia, Brazil, were studied to investigate the environmental condition of their developing. This study includes mineral composition, geochemistry, Pb isotope, palinology, radiocarbon-age and morphological framework of the lakes obtained from SRTM satellite images. The geological and the environmental conditions in the two lakes are highly variable and suggest that their evolution reflect autogenic processes under humid rainforest condition. Although kaolinite, quartz, muscovite, illite, and smectite are the main minerals in...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Pb isotopes; Lacustrine environment; Paleovegetation; Flooding plain; Holocene.
Ano: 2011 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300008
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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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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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Fishing strategies among prehistoric populations at Saquarema Lagoonal Complex, Rio de Janeiro, Brazil Anais da ABC (AABC)
Guimarães,Márica B.
Two distinct fishing technologies were identified among the shellmound builders of the Saquarema Lagoonal Complex, in the Brazilian state of Rio de Janeiro: bone point technology and worked fish spines. These technologies were related to the acquisition of specific fish resources; Worked fish spines were used in the capture of Micropogonias furnieri (Desmarest), and bone points used for fishing specimens of the Ariidae family. Worked spines technology was predominant between 6,726 cal. years BP and 3,699 cal. years BP, while the bone point technology was dominant after 3,699 cal. years BP. It is believed these different strategies for obtaining fishing resources before 3,699 years cal. BP was related to environmental. Notably the gradual regression of...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Subsistence resources; Fishing strategies; Shellmound; Holocene.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652013000100415
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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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Holocene distribution of Octodontid rodents in central Chile RChHN
SAAVEDRA,BÁRBARA; SIMONETTI,JAVIER A.
We describe the Holocene distribution of the Octodontids Aconaemys fuscus, Octodon bridgesi, O. degus, O. lunatus, O. pacificus and Spalacopus cyanus from Central Chile. We compared ancient and present day ranges. The Holocene pattern was inferred from zooarchaeological records. Octodon degus, O. lunatus, O. bridgesi, and Aconaemys fuscus showed a reduction in their geographic range. Although specific mechanisms remain to be tested, human disturbance seems to be the distal factor that explains the reduction of ranges for some taxa.
Tipo: Journal article Palavras-chave: Octodontidae; Holocene; Central Chile; Zooarchaeology.
Ano: 2003 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000300004
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