Tecttôniica póss--riifftte na Baciia Pottiiguar

The study of Brazilian sedimentary basins concentrates on their rift phase, whereas the Post-rift phase has been considered a tectonic quiescent period. The post-rift sequence of the Potiguar Basin, in the far northeastern Brazil, was once considered little deformed, however several studies have shown how that it was affected by major fault systems. The purpose of this thesis is to characterize the post-rift tectonic. The specific objectives are: to characterize the Neogene and Quaternary sedimentary units that outcrop of the Potiguar Basin; to show how the NW-SEtrending Afonso Bezerra Faults System deformed outcrop rocks in the Basin; to describe soft-sediment deformation in gravels of the Quaternary Alluvial Deposits from Açu River. Facies analyses, grain-size studies, luminescence dating, remote sensing, structural mapping, shallow geophysics (georadar), paleostress and petrography were carried out. The structural mapping and the georadar sections indicated that the Carnaubais and Afonso Bezerra fault systems formed fractures, silicified and non-silicified faults or deformation bands, affecting mainly the Açu, Jandaíra and Barreiras formations. The petrographic data indicate that the strong silicification resulted in a sealant character of the faults. Paleostress analysis indicates that two stress fields affected the Basin: the first presented N-S-trending compression, occurred from the Neocretaceous to the Miocene; the second stress field presents E-W-trending compression, acts from the Miocene to the present. It was verified once the Afonso Bezerra System Faults was reactivated in periods post-Campanian and affects all post-rift lithostratigraphic units of Potiguar Basin, including Quaternary sedimentary covers. The study about soft-sediment deformation structures indicates that they are similar in morphology and size to modern examples of seismically-induced deformation strutures in coarse sediments. TL and OSL ages indicate that sediment deposition and associated soft-sediment deformation occurred at least six times from ~352 Ka to ~9 Ka. Finally these studies demonstrate how recent is tectonics in the Basin Potiguar

Late Pleistocene and Holocene paleoenvironments in ponds and alluvial sediments of Upper Paraná River, Brazil

Freshwater sponge spicules were analyzed as a paleoenvironmental proxy indicator in five cores of ponds and alluvial fan sediments in the Upper Paraná River's left bank, near Querência do Norte town, northwestern of State of Paraná, southern Brazil. Two optically stimulated luminescence (OSL) dates were obtained from sediments of ponds and one radiocarbon (14C) date was obtained from the alluvial fan. Microscopic analysis of spicules preserved in the sediments allowed a determination of freshwater sponge species. The species assemblage provides evidence for dominantly dry conditions in the Upper Paraná River during the Late Pleistocene. A wetter climate phase was recognized at 14C 7,540 yrs BP, with alluvial fan formation commencing at the transition of the dry Pleistocene climate to the Early Holocene wet climate. This wet interval was characterized by a sponge assemblage marked by the presence of the Neotropical families and typically associated with lotic environments. Sponge spicules analysis from pond sediments reject the possibility that lotic environments contributed to pond genesis and evolution. © 2013 by the Sociedade Brasileira de Paleontologia.

Caracterização dos ambientes deposicionais na bacia do Ribeirão Entupido, complexo alcalino do Passa Quatro, estado de São Paulo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evolução geomorfológica e mudanças ambientais no megaleque do Nabileque, quaternário do Pantanal mato-grossense

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Geomorfologia fluvial, mudanças ambientais e evolução do megaleque do Rio São Lourenço, quaternário do pantanal mato-grossense

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Geomorfologia do megaleque do Rio Paraguai, quaternário do pantanal mato-grossense, centro-oeste do Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização dos sedimentos superficiais e avaliação ambiental da Serra de Monte Alto entre os municípios de Palmas de Monte Alto e Sebastião Laranjeiras, BA

Pós-graduação em Geociências e Meio Ambiente - IGCE

Datação por luminescência opticamente estimulada (Loe) e por 14C de materiais de uma topossequência de solos na Serra do Espinhaço Meridional - MG: abordagem paleoambiental

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Contribuição da dinâmica morfoestrutural e morfoescultural na estruturação da bacia do Ribeirão Entupido, complexo alcalino do Passa Quatro - SP

Pós-graduação em Geografia - IGCE

Depósitos pleistocenos da formação Itaubal: paleoambiente e implicações na evolução da planície costeira do Amapá

A costa norte da América do Sul durante o Pleistoceno tardio esteve sujeita a oscilações do nível do mar, relacionadas a variações climáticas e influência da dinâmica de sedimentos carreados pelo Rio Amazonas, que moldaram a paisagem desta região. Terraços Pleistocenos da Formação Itaubal, anteriormente considerados como pertencentes à Formação Barreiras (Mioceno), constituem parte da Planície Costeira do Amapá e recobrem rochas do Escudo das Guianas. A integração das análises de fácies, estratigráfica e datações por Luminescência Opticamente Estimulada / regeneração de alíquota única e múltipla (LOE / SAR-MAR) entre 120.600 (± 12.000) e 23.150 (±6.800) anos AP permitiu o posicionamento da Formação Itaubal no Pleistoceno Superior. Estes depósitos siliciclásticos, de espessura máxima de 10 m, cor amarronzada a avermelhada com camadas de geometria tabular foram divididos em duas unidades separadas por inconformidade. A Unidade Inferior compreende as associações de fácies, de planície de inframaré (AF1) e de canal fluvial meandrante influenciado por maré (AF2), enquanto que a Unidade Superior, com maior concentração de argila que a Unidade Inferior, consiste em depósitos de planície de maré (AF3) e de canal fluvial entrelaçado (AF4). As duas unidades têm caracteristicas progradacionais dentro de trato de sistema de mar alto e regressivo, e foram depositadas diretamente sobre rochas do embasamento intensamente intemperizadas durante o Mioceno-Pleistoceno. Os depósitos da Formação Itaubal foram expostos durante o Último Máximo Glacial (22.000 - 18.000 anos AP) e posteriormente sobrepostos por depósitos finos do Rio Amazonas, que configuram a atual linha de costa da Costa norte da América do Sul. Pela primeira vez a Formação Itaubal define os eventos sedimentares do Pleistoceno na evolução da Planície Costeira do Amapá. A correlação de seus depósitos com os de Suriname e nordeste do Pará amplia a discussão sobre a configuração da linha de costa do norte da América do Sul desde o Pleistoceno.

Aproveitamento de resíduos de laminação da madeira para a produção de painel estrutural

Products derived from wood or engineered products are becoming interesting alternatives to the replacement of solid wood in various applications, from structural components to the furniture industry and packaging. Among these products, there are panels built by strands, particles and fibers, each one having their particular characteristics and potential of use. Since the different types of panels are produced, waste generation is part of the process, and that more technological it is, it still generates losses of raw materials. Based on the need for rational use of raw materials and using almost full of industrially processed wood, It arises the proposal of this work, which seeks to use waste from the lamination, like pieces of strands, broken strands, strands rough, cracked strands to produce panels with structural characteristics of the OSL panel (Oriented Strand Lumber), LSL (Laminated Strand Lumber) and OSB (Oriented Strand Lumber). Besides the use of waste, this paper seeks an alternative to the use of the adhesive, because the industry uses formaldehyde-based adhesives, which over the press, they emit large amounts of formaldehyde, which is very aggressive to humans and environment. The panels made with polyurethane resin based on castor oil and hot-pressed were characterized by physical and mechanical tests according to specifications of European Standard (EN). High values of tensile strength, elastic modulus and density were found in the results of tests. Adding to stable values of swelling and moisture content, the panel studied adds attractive features to the panel market, especially in the civil construction

Geomorfologia e paleo-hidrologia dos megaleques dos rios Cuiabá e São Lourenço, quaternário da Bacia do Pantanal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Geocronologia de formas deposicionais e evolução da planície interleques do Rio Negro, quartenário da Bacia do Pantanal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evolução geomorfológica e palaeoambiental dos terraços da margem esquerda do alto rio Paraná

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

How Old Is Luzia? Luminescence Dating and Stratigraphic Integrity at Lapa Vermelha, Lagoa Santa, Brazil

During an excavation in the 1970s, a disarticulated female human skeleton, later nicknamed Luzia, was discovered at 12m depth at Lapa Vermelha rockshelter in central Brazil. Radiocarbon dating of associated charcoal suggested an age of 11.4-16.4 ka for the skeleton. The scattering of the skeletal parts, some uncertainty about the exact provenience of the skeleton, and evidence of pervasive insect turbation in the archaeological layers have raised doubts about the accuracy of the age. Luminescence dates for the depositional ages of the sediments at Lapa Vermelha are reported here. Single-grain optically stimulated luminescence (OSL) of quartz along with grain-size, chemical and micro-morphological analyses of the sediments were employed to assess stratigraphic integrity, particularly the degree of sediment mixing. These various lines of evidence point to high stratigraphic integrity with little mixing at Lapa Vermelha. Sediments closest to where Luzia was recovered give OSL ages ranging from 12.7 to 16.0 ka, thus not refuting the original dates. (C) 2010 Wiley Periodicals, Inc.