Radiocarbon Dating
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. Vegetation and climate changes in the forest of Campinas, São Paulo State, Brazil, during the last 25,000 cal yr BP
Abstract A paleoenvironmental reconstruction was performed in a Riparian Forest near Campinas to improve knowledge of paleoclimate and paleoenvironment in the State of São Paulo, Brazil. A sediment core of 182 cm depth was collected in a swamp located within a Cerrado/Seasonal Semi-deciduous ecotone forest. The chronological frame is given by eight radiocar
Braz. J. Geol.. Publicado em: 10/10/2019
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2. Comments to Angulo et al. 2016 on “Sea-level fluctuations and coastal evolution in the state of Rio de Janeiro, southeastern - Brazil” by Castro et al. 2014
ABSTRACT Interpretation of sea-level indicators is essential when studying paleo sea-level fluctuations during the Holocene. Sea-level indicators may have different origins, such as geological (beachrocks) and biological (vermetids and barnacles). In order to reconstruct paleo sea-level, it is necessary to attribute an indicative meaning to each sea-level in
An. Acad. Bras. Ciênc.. Publicado em: 2018-04
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3. Paleoenvironmental evolution of the coastal plain of Southern Brazil: palynological data from a Holocene core in Santa Catarina State
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
An. Acad. Bras. Ciênc.. Publicado em: 23/10/2017
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4. Environmental changes in the western Amazônia: morphological framework, geochemistry, palynology and radiocarbon dating data
Os sedimentos do lago Coari, de ambiente de terra firme eesculpido nos depósitos do Plio-Pleistocenos, e o Acará, típico lago de várzea e ambos formados nos sedimentos quaternários da planície de inundação do médio Solimões, no oeste da Amazônia, Brasil, foram estudados para investigar as condições ambientais durante sua formação. Este estudo
Anais da Academia Brasileira de Ciências. Publicado em: 05/08/2011
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5. Reconstrução da vegetação e do clima em alta resolução no Holoceno na Ilha do Marajó, com o uso de indicadores biológicos e isotópicos / Reconstruction of vegetation and climate in high resolution at Holocene on Marajo Island, with biologic and isotopic indicators uses
Um estudo interdisciplinar, envolvendo análises de fácies, elementares e isotópicas de carbono e nitrogênio, palinologia e diatomáceas, teve como objetivo reconstruir a dinâmica da vegetação, na Ilha do Marajó, com inferências climáticas. Testemunhos sedimentares foram coletados em dois pontos diferentes na porção leste da Ilha, um no manguezal
Publicado em: 2011
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6. Estudo interdisciplinar em sedimentos lacustres da região sul do estado de São Paulo. Reconstrução da vegetação e do clima no Quaternário tardio / Interdisciplinary study of lacustrine sediments from Southeastern São Paulo state (Brazil). Late Quaternary vegetation and climate changes
One sediment core collected at the margins of a lake surrounded by Atlantic rainforest vegetation at Parque Estadual do Alto Ribeira (PETAR), southern São Paulo state (Brazil), was analyzed, in order to reconstruct the history of the local vegetation over the last 2500 years. Elemental (Total Organic Carbon TOC and Total Organic Nitrogen), isotopic (C and N
Publicado em: 2009
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7. Relação solo-relevo-substrato geológico na planíce costeira de Bertioga (SP) / Soil-relief-geologic substract relationship on the coastal plain of Bertioga (SP)
Knowledge of the chronology, relief, geology and soils in sedimentary coastal environments is relevant for their interpretation, reconstitution and conservation. In Bertioga, São Paulo State Brazil, several sections of the Pleistocene and Holocene morphostratigraphic costal plain units are preserved in the landscape. This thesis seeks the perception of the
Publicado em: 2009
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8. Reevaluation of dating results for some 14C - AMS applications on the basis of the new calibration curves available
In this paper we describe briefly some characteristics of the Accelerator Mass Spectrometry (AMS) technique and the need of corrections in the radiocarbon ages by specific calibration curves. Then we discuss previous results of some Brazilian projects where radiocarbon AMS had been applied in order to reevaluate the dates obtained on the basis of the new cal
Brazilian Journal of Physics. Publicado em: 2008-03
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9. Significado morfotectônico dos planaltos isolados da Bocaina / Morphotectonics of the isolated plateaus of Bocaina
The Bocaina Plateau is situated on the eastern flank of the Continental Rift of Southeastern Brasil (CRSB), in the highest portions of the Serra do Mar, reaching more than 2000 meters in altitude. This and the Campos do Jordão Plateau comprise the high blocks of crystalline massifs of Southeastern Brasil. The Bocaina presents a succession of NW-SE topograph
Publicado em: 2007
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10. Soil mineralogy and sedimentary environment in mangroves of São Paulo State / Mineralogia de solos e ambientes de sedimentação em manguezais do Estado de São Paulo
Mangroves are formed by groups of trees and shrubs that develop in the intertidal zone of tropical regions. This ecosystem to establish in the interface of both marine and continental environment, present its formation related to the sea-level fluctuations during the quaternary period, where the terrigenous and marine sediments are deposited in rivers valley
Publicado em: 2006
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11. Concordance of Collagen-Based Radiocarbon and Aspartic-Acid Racemization Ages
By determining the extent of racemization of aspartic acid in a well-dated bone, it is possible to calculate the in situ first-order rate constant for the interconversion of the L and D enantiomers of aspartic acid. Collagen-based radiocarbon-dated bones are shown to be suitable samples for use in “calibrating” the racemization reaction. Once the asparti
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12. Racemization Reaction of Aspartic Acid and Its Use in Dating Fossil Bones
In the time interval datable by radiocarbon, and at the temperatures of most archeological sites, a substantial amount of racemization of aspartic acid takes place. By determination of the amount of racemization of aspartic acid in bones from a particular location which have been dated by the radiocarbon technique, it is possible to calculate the in situ fir