986 resultados para Rock - Brasil


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The Serra do Caramuru and Tapuio stocks, located in the extreme NE of Rio Piranhas-Seridó Domain (RN), are representative of the Ediacaran-Cambrian magmatism, an important magmatic feature of the Brasilian / Panafrican orogeny of the Borborema Province. These bodies are lithologically similar, intrusive in paleoproterozoic gneiss embasement, being separated by a thin belt of mylonitic orthogneiss. The field relations show a magmatic stratigraphy initiated by dioritic facies that coexists with the porphyritic granitic and equigranular granitic I facies, and less frequently with equigranular granitic II facies. These rocks are crosscut by late granitic dykes and sheets with NE-SW / NNE-SSW orientation. The dioritic facies (diorite, quartz diorite, quartz monzodiorites, tonalite and granodiorite) is leucocratic to melanocratic, rich in biotite and hornblende. The granitic facies are hololeucocratic to leucocratic, and have biotite ± hornblende. Petrographic and geochemical (whole rock) data, especially from Serra do Caramuru pluton, suggest fractionation of zircon, apatite, clinopyroxene (in diorites), opaque minerals, titanite, biotite, hornblende, allanite, plagioclase, microcline and garnet (in dykes). The behavior of trace elements such as Zr, La and Yb indicates that the dioritic magma does not constitute the parental magma for the granitic facies. On the other hand, the granitic facies seems to be cogenetic to each other, displaying differentiation trends and very similar rare earth elements (REE) spectra [12.3≤(La/Yb)N≤190.8; Eu/Eu*=0.30-0.68]. Field relationships and REE patterns [6.96≤(La/Yb)N≤277.8; Eu/Eu*=0.18-0.58] demonstrate that the granitic dykes and sheets are not cogenetically related to the Serra do Caramuru magmatism. The dioritic facies is metaluminous (A/CNK = 0.88-0.74) and shoshonitic, whereas the granitic ones are metaluminous to peraluminous (A/CNK = 1.08-0.93) and high potassium calc-alkaline. Dykes and sheets are strictly peraluminous (A/CNK = 1.01-1.04). Binary diagrams relating compatible and incompatible trace elements and microtextures indicate the fractional crystallization as the dominant mechanism of magmatic evolution of the various facies. The Serra do Caramuru and Tapuio stocks have well preserved magmatic fabric, do not show metamorphic minerals and are structurally isotropic, showing crosscutting contact with the ductile fabric of the basement. These observations lead to interpretate a stage of relative tectonic stability, consistent with the orogenic relaxation period of the Brasiliano / Pan-African orogeny. Chemical plots involving oxides and trace elements indicate late to post-collisional emplacement. In this context, the assumed better mechanism to describe the stocks emplacement within an extensional T Riedel joint, with ENE-WSW extensional vector. The U-Pb zircon age of 553 ± 10 Ma allows correlating the Serra do Caramuru magmatism to the group of post-collisional bodies, equigranular high potassium calc-alkaline granites of the NE of Rio Piranhas-Seridó Domain.

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The Serra do Caramuru and Tapuio stocks, located in the extreme NE of Rio Piranhas-Seridó Domain (RN), are representative of the Ediacaran-Cambrian magmatism, an important magmatic feature of the Brasilian / Panafrican orogeny of the Borborema Province. These bodies are lithologically similar, intrusive in paleoproterozoic gneiss embasement, being separated by a thin belt of mylonitic orthogneiss. The field relations show a magmatic stratigraphy initiated by dioritic facies that coexists with the porphyritic granitic and equigranular granitic I facies, and less frequently with equigranular granitic II facies. These rocks are crosscut by late granitic dykes and sheets with NE-SW / NNE-SSW orientation. The dioritic facies (diorite, quartz diorite, quartz monzodiorites, tonalite and granodiorite) is leucocratic to melanocratic, rich in biotite and hornblende. The granitic facies are hololeucocratic to leucocratic, and have biotite ± hornblende. Petrographic and geochemical (whole rock) data, especially from Serra do Caramuru pluton, suggest fractionation of zircon, apatite, clinopyroxene (in diorites), opaque minerals, titanite, biotite, hornblende, allanite, plagioclase, microcline and garnet (in dykes). The behavior of trace elements such as Zr, La and Yb indicates that the dioritic magma does not constitute the parental magma for the granitic facies. On the other hand, the granitic facies seems to be cogenetic to each other, displaying differentiation trends and very similar rare earth elements (REE) spectra [12.3≤(La/Yb)N≤190.8; Eu/Eu*=0.30-0.68]. Field relationships and REE patterns [6.96≤(La/Yb)N≤277.8; Eu/Eu*=0.18-0.58] demonstrate that the granitic dykes and sheets are not cogenetically related to the Serra do Caramuru magmatism. The dioritic facies is metaluminous (A/CNK = 0.88-0.74) and shoshonitic, whereas the granitic ones are metaluminous to peraluminous (A/CNK = 1.08-0.93) and high potassium calc-alkaline. Dykes and sheets are strictly peraluminous (A/CNK = 1.01-1.04). Binary diagrams relating compatible and incompatible trace elements and microtextures indicate the fractional crystallization as the dominant mechanism of magmatic evolution of the various facies. The Serra do Caramuru and Tapuio stocks have well preserved magmatic fabric, do not show metamorphic minerals and are structurally isotropic, showing crosscutting contact with the ductile fabric of the basement. These observations lead to interpretate a stage of relative tectonic stability, consistent with the orogenic relaxation period of the Brasiliano / Pan-African orogeny. Chemical plots involving oxides and trace elements indicate late to post-collisional emplacement. In this context, the assumed better mechanism to describe the stocks emplacement within an extensional T Riedel joint, with ENE-WSW extensional vector. The U-Pb zircon age of 553 ± 10 Ma allows correlating the Serra do Caramuru magmatism to the group of post-collisional bodies, equigranular high potassium calc-alkaline granites of the NE of Rio Piranhas-Seridó Domain.

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Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Pós-Graduação em Geologia, 2015.

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A Serra do Espinhaço e a Serra da Mantiqueira são duas cadeias de grande importância para o Brasil. Nas partes mais altas destas serras encontramse ecossistemas com características singulares, associados aos afloramentos rochosos, denominados Complexos Rupestres de Altitude. Esses ambientes apresentam características do solo e da vegetação distintas das áreas adjacentes. Os solos são em geral rasos, arenosos, com alta saturação de alumínio e teores variados de matéria orgânica. Neossolos Litólicos, Cambissolos e Organossolos são as classes de solo dominantes, diretamente associadas aos afloramentos, formando um mosaico de solos. Alguns solos encontrados nestes ambientes são endêmicos, em função das características peculiares da rocha matriz, da topografia e da vegetação, e sua preservação é estratégica por se tratar de solos raros e ameaçados de extinção. A matéria orgânica desses solos apresenta alto grau de humificação, com grande quantidade de frações solúveis, e a presença generalizada de fragmentos de carvão. Horizontes espódicos e rios negros estão tipicamente associados às áreas de afloramento de arenito e quartzito, sendo formados pela iluviação de compostos orgânicos, e sendo menos comuns nas áreas de granito. O oligotrofismo destes solos, associado a outras limitações de ordem química e física, induzem o desenvolvimento de estratégias de adaptação fisiológica e morfológica por parte da vegetação. A maioria destes ecossistemas é instável sob a condição climática atual, e a intervenção antrópica é um fator de aceleração do processo de degradação. A descrição detalhada dos solos nestes ambientes é fundamental para um melhor entendimento do seu papel nos processos ecológicos e para o desenvolvimento de políticas de conservação.

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Proposta metodológica para discussão dos impactos das mudanças climáticas globais sobre doenças de plantas - Raquel Ghini e Emília Hamada. Cenários climáticos futuros para o Brasil - Emília Hamada, Renata Ribeiro do Valle Gonçalves, Jose Antonio Marengo Orsini e Raquel Ghini. Impacto potencial das mudanças climáticas sobre as doenças da batata no Brasil - Carlos Alberto Lopes, Ailton Reis e Natalino Yassushi Shimoyama. Impacto potencial das mudanças climáticas sobre as doenças do tomate no Brasil - Ricardo Gioria, Kátia Regiane Brunelli e Romulo Fujito Kobori. Impacto potencial das mudanças climáticas sobre as doenças do pimentão no Brasil - Romulo Fujito Kobori, Ricardo Gioria e Kátia Regiane Brunelli. Impacto potencial das mudanças climáticas sobre as doenças do melão no Brasil - Kátia Regiane Brunelli, Romulo Fujito Kobori e Ricardo Gioria. Impacto potencial das mudanças climáticas sobre as doenças do arroz no Brasil - Anne Sitarama Prabhu, Silvando Carlos da Silva e Marta Cristina de Filippi. Impacto potencial das mudanças climáticas sobre as doenças de cereais de inverno no Sul do Brasil - Erlei Melo Reis, Ricardo Trezzi Casa e Sandra Maria Zoldan. Impacto potencial das mudanças climáticas sobre as doenças do milho no Brasil - Nicésio Filadelfo Janssen de Almeida Pinto, Elizabeth de Oliveira e Fernando Tavares Fernandes. Impacto potencial das mudanças climáticas sobre as doenças e o desenvolvimento da soja no Brasil - Maria Aparecida Pessôa da Cruz Centurion e Raquel Ghini. Impacto potencial das mudanças climáticas sobre as doenças da bananeira no Brasil - Luadir Gasparotto e José Clério Rezende Pereira. Impacto potencial das mudanças climáticas sobre as doenças da cana-de-açúcar no Brasil - Álvaro Sanguino. Impacto potencial das mudanças climáticas sobre as doenças fúngicas do cafeeiro no Brasil - Edson Ampélio Pozza e Marcelo de Carvalho Alves. Impacto potencial das mudanças climáticas sobre as principais doenças de citros no Estado de São Paulo - Waldir Cintra de Jesus Junior, Marcelo Augusto Boechat Morandi, Rock Seille Carlos Christiano e Pedro Takao Yamamoto. Impacto potencial das mudanças climáticas sobre as doenças da seringueira no Estado de São Paulo - Edson Luiz Furtado. Impacto potencial das mudanças climáticas sobre a ferrugem-do-eucalipto no Estado de São Paulo - Edson Luiz Furtado, Carlos André Gaspar dos Santos e Marcus Vinicius Masson. Impacto potencial das mudanças climáticas sobre a incidência de fitonematóides no Brasil - Mário Massayuki Inomoto. Impacto potencial das mudanças climáticas sobre o controle biológico de doenças de plantas - Wagner Bettiol. Impacto potencial das mudanças climáticas sobre o controle químico de doenças de plantas Raquel Ghini.

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1. Species' distribution modelling relies on adequate data sets to build reliable statistical models with high predictive ability. However, the money spent collecting empirical data might be better spent on management. A less expensive source of species' distribution information is expert opinion. This study evaluates expert knowledge and its source. In particular, we determine whether models built on expert knowledge apply over multiple regions or only within the region where the knowledge was derived. 2. The case study focuses on the distribution of the brush-tailed rock-wallaby Petrogale penicillata in eastern Australia. We brought together from two biogeographically different regions substantial and well-designed field data and knowledge from nine experts. We used a novel elicitation tool within a geographical information system to systematically collect expert opinions. The tool utilized an indirect approach to elicitation, asking experts simpler questions about observable rather than abstract quantities, with measures in place to identify uncertainty and offer feedback. Bayesian analysis was used to combine field data and expert knowledge in each region to determine: (i) how expert opinion affected models based on field data and (ii) how similar expert-informed models were within regions and across regions. 3. The elicitation tool effectively captured the experts' opinions and their uncertainties. Experts were comfortable with the map-based elicitation approach used, especially with graphical feedback. Experts tended to predict lower values of species occurrence compared with field data. 4. Across experts, consensus on effect sizes occurred for several habitat variables. Expert opinion generally influenced predictions from field data. However, south-east Queensland and north-east New South Wales experts had different opinions on the influence of elevation and geology, with these differences attributable to geological differences between these regions. 5. Synthesis and applications. When formulated as priors in Bayesian analysis, expert opinion is useful for modifying or strengthening patterns exhibited by empirical data sets that are limited in size or scope. Nevertheless, the ability of an expert to extrapolate beyond their region of knowledge may be poor. Hence there is significant merit in obtaining information from local experts when compiling species' distribution models across several regions.

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Determining the ecologically relevant spatial scales for predicting species occurrences is an important concept when determining species–environment relationships. Therefore species distribution modelling should consider all ecologically relevant spatial scales. While several recent studies have addressed this problem in artificially fragmented landscapes, few studies have researched relevant ecological scales for organisms that also live in naturally fragmented landscapes. This situation is exemplified by the Australian rock-wallabies’ preference for rugged terrain and we addressed the issue of scale using the threatened brush-tailed rock-wallaby (Petrogale penicillata) in eastern Australia. We surveyed for brush-tailed rock-wallabies at 200 sites in southeast Queensland, collecting potentially influential site level and landscape level variables. We applied classification trees at either scale to capture a hierarchy of relationships between the explanatory variables and brush-tailed rock-wallaby presence/absence. Habitat complexity at the site level and geology at the landscape level were the best predictors of where we observed brush-tailed rock-wallabies. Our study showed that the distribution of the species is affected by both site scale and landscape scale factors, reinforcing the need for a multi-scale approach to understanding the relationship between a species and its environment. We demonstrate that careful design of data collection, using coarse scale spatial datasets and finer scale field data, can provide useful information for identifying the ecologically relevant scales for studying species–environment relationships. Our study highlights the need to determine patterns of environmental influence at multiple scales to conserve specialist species such as the brush-tailed rock-wallaby in naturally fragmented landscapes.

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Numerous expert elicitation methods have been suggested for generalised linear models (GLMs). This paper compares three relatively new approaches to eliciting expert knowledge in a form suitable for Bayesian logistic regression. These methods were trialled on two experts in order to model the habitat suitability of the threatened Australian brush-tailed rock-wallaby (Petrogale penicillata). The first elicitation approach is a geographically assisted indirect predictive method with a geographic information system (GIS) interface. The second approach is a predictive indirect method which uses an interactive graphical tool. The third method uses a questionnaire to elicit expert knowledge directly about the impact of a habitat variable on the response. Two variables (slope and aspect) are used to examine prior and posterior distributions of the three methods. The results indicate that there are some similarities and dissimilarities between the expert informed priors of the two experts formulated from the different approaches. The choice of elicitation method depends on the statistical knowledge of the expert, their mapping skills, time constraints, accessibility to experts and funding available. This trial reveals that expert knowledge can be important when modelling rare event data, such as threatened species, because experts can provide additional information that may not be represented in the dataset. However care must be taken with the way in which this information is elicited and formulated.

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The rock pools, salt pans, cliffs and bluffs, and the banks of the Coorooman and Pumpkin Creeks within Darumbal and Woppaburra Country are used as a backdrop in this paper, which offers an exploration of one woman’s quest to undertake her PhD and develop as an Indigenous scholar. The paper describes this Country and the use of Country to nourish, develop, stimulate and support the intellect. It draws on Australian and international literature to demonstrate the intellectual growth and development of Indigenous scholars. The paper offers a highly personal narrative of intellectual journeying which shows how we can be agents of change and power in our individual lives, even while power is being exercised over us and we are being oppressed and marginalised as Indigenous peoples.

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Genetic variation is the resource animal breeders exploit in stock improvement programs. Both the process of selection and husbandry practices employed in aquaculture will erode genetic variation levels overtime, hence the critical resource can be lost and this may compromise future genetic gains in breeding programs. The amount of genetic variation in five lines of Sydney Rock Oyster (SRO) that had been selected for QX (Queensland unknown) disease resistance were examined and compared with that in a wild reference population using seven specific SRO microsatellite loci. The five selected lines had significantly lower levels of genetic diversity than did the wild reference population with allelic diversity declining approximately 80%, but impacts on heterozygosity per locus were less severe. Significant deficiencies in heterozygotes were detected at six of the seven loci in both mass selected lines and the wild reference population. Against this trend however, a significant excess of heterozygotes was recorded at three loci Sgo9, Sgo14 and Sgo21 in three QX disease resistant lines (#2, #5 and #13). All populations were significantly genetic differentiated from each other based on pairwise FST values. A neighbour joining tree based on DA genetic distances showed a clear separation between all culture and wild populations. Results of this study show clearly, that the impacts of the stock improvement program for SRO has significantly eroded natural levels of genetic variation in the culture lines. This could compromise long-term genetic gains and affect sustainability of the SRO breeding program over the long-term.