11 resultados para Foraminíferos fósiles

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Pós-graduação em Geociências e Meio Ambiente - IGCE

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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Foraminifera scientific studies became, historically, of your apply in relative dating of rocks, stratigraphic correlations and paleoenvironmental reconstruction. In the last decades, they have been applied on the studies of modern ecosystems, with or without antrhopic influence. Both aspects are interest of petroleum industry. Among other approaches, foraminífera are used as good indicators of the fluctuation of relative sea level. This study aimed to survey and taxonomic study of the community structure of foraminifera in surface samples of a core, 60 cm, collected in mangrove located in Itapanhaú river in Bertioga (SP).It also aims to contribute to the discussion about typical patterns of community structure of mangrove margins and provide elements for discussion on the relative sea level behavior in this area in almost modern times. It was been collected 6 samples along the core of 60 cm of length, each one 10 cm depth. They were made in laboratory and in each sample sought to find at least 100 foraminifera per ml. The species identification was made with reference specified material and collection available on IGCE-UNESPetro, Rio Claro. The community structure was studied in terms of richness, diversity and species composition and was made the results comparison from similar areas to interpret the depositional environment. Were found 21 species within them 13 calcareous and 8 binders, being the most abundant and frequent species Ammonia tepida, Ammonia parkinsoniana e Elphidium spp. Essentially there wasn’t change in the community structure within the period covered by the core which reflects an environment of outer margin of mangrove without noticeable change in relative sea level at the respective time of deposition of muddy sediments. The community structure here recognized its similar to estuarine environment well maintained which indicates a low human impact in the area over the time interval. The agreement of the results...

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O estudo do conteúdo de foraminíferos de 8 amostras de sedimentos superficiais coletados em manguezal do norte da Ilha do Cardoso, sul do Estado de São Paulo, no verão (período chuvoso) de 2001, ao longo de um transecto no sentido da Baía de Trapandé para o interior, revelou dois segmentos distintos: a) uma planície inferior lamosa, com menor tempo de exposição sub-aérea e maior diversidade específica, dominada por Ammotiumcassis, A.salsum, Arenoparrella mexicana e Trochamminainflata, com abundância expressiva de Caroniaexilis na parte mais baixa e de Miliammina fusca na parte mais alta; b) uma planície superior arenosa, com maior tempo de exposição sub-aérea e menor diversidade, dominada por M. fusca e com abundância expressiva de T. inflatana parte mais baixa. Os sedimentos investigados são colonizados por foraminíferos exclusivamente aglutinantes, representados por 21 espécies de 16 gêneros. Dados de abundância relativa, riqueza, diversidade e equitatividade das espécies ao longo do transecto são apresentados, bem como os valores de salinidade, pH, oxigênio dissolvido e temperatura, medidos a partir da água intersticial dos sedimentos no momento da coleta das amostras. São feitas comparações com um estudo anterior, similar, que focalizou amostras coletadas, nos mesmos pontos, no inverno (período seco) de 2002. Os resultados obtidos interessam às análises de sistemas estuarinos modernos e antigos, bem como a projetos envolvidos com o diagnóstico do estado de conservação de áreas litorâneas, sendo úteis ao Setor de Petróleo e Gás

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Nowadays, there is a search for knowledgment that could be applied in the solution of the problems caused by petrolific activities involving the environment, like the biodiversity preservation and the ecosystems monitoring and management. Foraminifera (Protista) are used as an important tool to the environment characterizarion, because they answer quickly to the fisic-quimic variations and indicate local alterations. The goal of this job is to create models of foraminiferal communities composition through the screening of subsuperficial samples obtained from a core collect from Bertioga Channel, Baixada Santista (SP), trying to understand the influence of the environmental variations along the time upon the indicator species presence, as well as making paleoenvironmentals reconstructions of the area. A 80 cm-core was removed in the outer edge of marsh adjacent to Bertioga Channel, not far from the confluence with the Itapanhaú River. There are presented in abundance, equitability, diversity and species richness obtained in nine samples along the sediment. The lower part of the core is compound by calcareous species (rotalideos and miliolideos) with domain Ammonia (Biofacies 1) and the intermediate and upper parts contain mainly agglutinated species (Biofacies 2 and 3, which is dominated by species of Ammotium). The qualitative and quantitative study of the microfauna of foraminifera present in the core reveals that in recent decades the sampling area passed from a condition of infra-marginal strip under significant coastal marine influence for the condition of inter-coastal swamp covered with mangrove vegetation. This change indicates that the site has undergone a process of sediment progradation, a phenomenon that may have been timely, localized, or a reflection of a relative fall in sea level at the regional level

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O sistema estuarino do Rio Curimataú, uma planície lamosa amplamente coberta por vegetação de mangue e relativamente pouco impactada, foi estudado quanto à distribuição espacial da microfauna de foraminíferos e suas condicionantes. Vinte e cinco gêneros e quarenta espécies foram identificadas a partir dos sedimentos superficiais, considerando-se os indivíduos vivos e mortos presentes em 10 pontos ao longo do estuário, dos quais se extraíram ao menos 100 espécimes por amostra. O sistema pôde ser compartimentado em quatro sub-ambientes halínicos (hiperhalino, mesohalino, polihalino e euhalino), correspondentes, respectivamente, a quatro ecofácies de foraminíferos designadas de Ammotium spp., Miliammina fusca, Arenoparrella mexicana e Ammonia spp. Cada um destes segmentos ambientais foi caracterizado segundo os padrões de riqueza, diversidade e equitatividade das espécies. Os resultados deste estudo poderão servir para comparações a serem feitas com outros estuários tropicais modernos (impactados antropicamente ou não) e antigos. Tem aplicação, portanto, no setor de petróleo e gás, sendo de interesse às atividades de gestão ambiental de áreas litorâneas e de investigação da história geológica das bacias sedimentares

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The occurrence of brachiopods in Cenozoic rocks of the Pelotas Basin is known since 1862. In spite of that, detailed systematic and taphonomic studies are still missing. Investigations made a half century ago, have suggested that these brachiopods could belong to Bouchardia cf. zitteli, a species found in the San Julian Formation, Late Oligocene, Argentina. Our data suggest that those brachiopods may resemble Bouchardia transplatina. In the Uruguayan portion of the Pelotas Basin B. transplatina is known in rocks of the Camacho Formation, Miocene. In addition, small recrystallized shells of brachiopods were also recovered from three Petrobras boreholes (2PJ-1-RS, 2PN-1-RS, and 2GA-1-RS) from the Pelotas Basin. Brachiopods come from the interval of 130 to 150 meters within the Miocene Henryhowella evax Zone. Despite the degree of taphonomic modiication of those brachiopod shells they indubitably belong to Bouchardia sp. This is noteworthy for various reasons: 1- Bouchardia is a brachiopod with warm water afinities. Presently, extant members of this genus are unknown in latitudes up to 34[degree]S, with the main records at 23[degree]S. 2- Although occurring in depths down to 200 meters, the living member (Bouchardia rosea) of this genus is most abundant in shallow platformal, nutrient-rich waters. 3- The occurrence of Bouchardia in the Miocene of the Pelotas Basin indicates that, at least to the interval of Henryhowella evax Zone, warm waters of the Brazilian currents prevail. This interpretation is in strong accordance with other paleoeoceanographic and paleoclimatic data offered by various groups of co-occurring microfossils, such as ostracodes and foraminifers.

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This work aims to identify and photograph grains that compose important Cretaceous carbonate units of the Potiguar Basin, represented by the Ponta do Mel and Jandaíra formations (Albian-Campanian). Petrographic investigation of thin sections was essential. The samples studied come from wells and surface samples from the collection UNESPetro – UNESP, Rio Claro. In the Ponta do Mel Formation, the grains consist of ooids, oncoids, peloids and bioclasts. Regarding to the identified bioclasts, the solenoporacean red algae, mollusks (bivalves and gastropods), echinoids, foraminifera, ostracods and worms were the dominant elements. In the Jandaíra Formation, the grains are composed by ooids, peloids and bioclasts, which are represented by green algae, mollusks (bivalves and gastropods), benthic foraminifera miliolids, worms, echinoderms and ostracods. The grains found in the Ponta do Mel Formation are somewhat similar to those found in the Jandaíra Formation, with the exception of calcareous algae. The subsurface material from the Ponta do Mel Formation is derived from the upper part of the unit, representing marine high-energy carbonates, which also contains ooids and Trocholina. The samples of Jandaíra Formation, collected in outcrops, often contain green algae, mollusks and miliolids, and come from inner shelf and lagoon facies previously described

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This article discusses the policy implications of agricultural modernization implemented by the military - after 1964. This policy, which became known as the Green Revolution, on the one hand contributed to the development of big business, but another caused serious social and environmental impacts. Currently, not only in Brazil but all over the world, have been in a great debate about the need to find alternatives to contain the problems caused to the environment resulting from the use of high technology in the field. One alternative proposed by several researchers is to replace fossil fuels by biofuels. As we believe that the error is in the current model of agricultural production based on mass production, which serves the major markets, the attention in this article, the need to develop an agricultural model designed for small property, with the use of family work and agroecology.