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| Registros recuperados: 105 | |
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| Masetto,Ebráilon; Lorscheitter,Maria Luisa. |
| This paper presents the results of a qualitative palynological analysis of a 140 cm-thick section of Holocene sediments from a paleolagoon, representing the last 2600 years, taken from an outcrop at Hermenegildo Beach (33º42'S; 53º18'W), located in the municipality of Santa Vitória do Palmar, in the state of Rio Grande do Sul, Brazil. Samples were treated with hydrochloric acid, hydrofluoric acid and potassium hydroxide, after which they were subjected to acetolysis and mounted on glycerin-coated slides for light microscopy analysis. Among the 48 palynomorphs identified were 25 fungi, eight algae, three bryophytes, and 12 pteridophytes. Brief descriptions and illustrations of each palynomorph are presented, together with ecological data from the organism... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Palynomorph descriptions; Paleolagoon; Holocene; Southern coastal plain; Rio Grande do Sul. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062014000200003 |
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| Rodrigues,Sabrina Coelho; Simões,Marcello Guimarães. |
| This study analyzes taphonomic alteration of brachiopod shells, i.e., Bouchardia rosea (Mawe) from Ubatuba Bay, northern coast of São Paulo State, Brazil. The average age of the studied shell deposits is 674 years BP. The underlying hypothesis is that taphonomic signatures are not uniformly distributed along a bathymetric gradient. Assemblages were sampled using a Van Veen grab sampler (31 x 40cm) along transect of fourteen stations from zero (beach) to 35 m water depth. Four sedimentary environments were recognized: (a) beach, (b) protected bay with clay bottom, (c) protected bay with sandy bottom, and (d) inner shelf with sandy bottom. All brachiopod shells (i.e., total fraction including fragments) from each of the five stations with appreciable... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bouchardia rosea; Brachiopods; Taphonomic signatures; Shell texture; Ubatuba Bay; Holocene. |
| Ano: 2010 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0002-70142010000300008 |
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| Martínez,Sergio; Rojas,Alejandra; Ubilla,Martín; Verde,Mariano; Perea,Daniel; Piñeiro,Graciela. |
| Dates of marine Holocene molluscs from Uruguay (Villa Soriano Formation) range from 6849 to 1858 cal. years BP. There are no significative gaps among the different ages obtained, with the exception of the interval 2276-2830 calculated years BP. Two kinds of concentrations are distinguished: autochthonous, for which a low energy depositional environment is inferred, and parautochthonous, deposited in foreshore and nearshore high-energy environments. Results of different types of multivariate analyses on presence-absence and abundance data show that only three localities are clearly differentiated from the others. The discrimination of two of them (Arazatí, Las Cañas) is explained by the presence of only one or two species, but the third (Punta Rasa) is the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Uruguay; Holocene; Paleoecology; Shell-beds; Mollusca; Bivalvia; Gastropoda. |
| Ano: 2006 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0002-70142006000200009 |
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| 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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| Pessenda,Luiz C.R.; Gouveia,Susy E.M.; Ledru,Marie-Pierre; Aravena,Ramon; Ricardi-Branco,Fresia S.; Bendassolli,José A.; Ribeiro,Adauto de S.; Saia,Soraya E.M.G.; Sifeddine,Abdelfettah; Menor,Eldemar de A.; Oliveira,Sônia M.B. de; Cordeiro,Renato C.; Freitas,Ângela M. de M.; Boulet,René; Filizola,Heloisa F.. |
| The aim of this research was to reconstruct vegetation changes (with climate inferences) that occurred during the Holocene in the Fernando de Noronha Island, Pernambuco State, northeastern Brazil. The research approach included the use of geochemical (mineralogy, elemental), carbon isotopes (δ13C, 14C) and pollen analyses in soil organic matter (SOM) and sediments collected in Lagoa da Viração and Manguezal do Sueste. The carbon isotopes data of SOM indicated that there was no significant vegetation changes during the last 7400 BP, suggesting that the climate was not the determinant factor for the vegetation dynamics. The pollen analysis of the sediment of a core collected in the Lagoa da Viração showed the absence of Quaternary material in the period... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pollen; Carbon isotopes; Paleovegetation; Fernando de Noronha; Holocene. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000400009 |
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| 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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| OLIVEIRA,PAULO V.; RIBEIRO,ANA MARIA; OLIVEIRA,ÉDISON V.; VIANA,MARIA SOMÁLIA S.. |
| This paper deals with xenarthrans osteoderms assigned toDasypus aff. D. novemcinctus,Euphractus sexcinctus and Cabassous sp. The material was collected in subsurface, from 0.10 to 0.60 m in the Urso Fóssil Cave, Parque Nacional de Ubajara, State of Ceará, northeastern Brazil. The ages of sediment samples from levels 4 and 5 (depths of 0.40 and 0.50 m) were determined by thermoluminescence technique, and indicated ages of 8,000 and 8,200 years BP for each layer respectively. The presence in these layers of early Holocene xenarthrans taxa can contribute to the understanding of the biotic evolution of the northwest region of Ceará during the last 10,000 years. Two of the three identified taxa still occur in the region: Dasypus novemcinctus andEuphractus... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mammals; Dasypodidae; Holocene; Cave; Parque Nacional de Ubajara; Northeastern Brazil. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000100147 |
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| OLIVEIRA,EMILIANO C.; ROSSETTI,DILCE F.; UTIDA,GISELLE. |
| ABSTRACT This paper presents a sedimentological and stratigraphical study of Quaternary (Middle to Late Pleistocene/Holocene) continental carbonates outcrops inside Pantanal Basin and its surroundings, especially in Serra da Bodoquena, Pantanal do Miranda and Corumbá/Ladário plateau, in the state of Mato Grosso do Sul, as well as in Serra das Araras, in the state of Mato Grosso. The aim is to understand the depositional paleoenvironments and analyse climate and tectonic influences in their genesis and evolution. The results show that the deposition of these continental carbonates started in the Middle to Late Pleistocene and have continued, with some interruptions, until the present days. Sedimentary successions were identified in the different areas,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Central Brazil; Continental carbonates; Holocene; Paleoenvironments; Pantanal Basin; Pleistocene. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000200407 |
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| 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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| KUHN,LIDIA A.; SOUZA,PAULO A.; CANCELLI,RODRIGO R.; SILVA,WAGNER G.; MACEDO,RENATO B.. |
| ABSTRACT This paper presents a paleoenvironmental reconstruction from palynological analyses of a sedimentary core of Holocene age, drilled at municipality of Garopaba (Santa Catarina), Southern Brazil. A total of 46 samples was collected for palynological analyses in the 450 cm-long core PCSC-3, as also three samples for radiocarbon dating and granulometric analyses. The palynological content includes 84 taxa related to pollen grains of angiosperms (38) and gimnosperm (3), spores of pteridophyta (16) and bryophyta (2), spores of fungi (8), algae (3), acritarchs (3), dinoflagellate cysts (2) and microforaminiferal linings (1). Three specimens of acritarchs are described and illustrated in detail. Three palynological phases were defined based on changes in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coastal plain; Environmental evolution; Holocene; Palynology; Santa Catarina. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000602581 |
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| 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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| 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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| 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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| 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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| 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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| Registros recuperados: 105 | |
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