Condiçőes de cristalização dos charnockitos ígneos no nordeste do brasil

Las rocas máficas y félsicas con ortopiroxeno (hiperstena) son los componentes importantes de la zona de transición que separa el Cratón Arqueano de San Francisco y el Cinturón Móvil Costero Neoproterozóico, en el extremo sur del estado de Bahía, Brasil.  Las charnockitas presentan texturas relictas magmátlcas. Los cálculos termobarométricos hacen pensar en temperaturas entre 700 - 800oC y presiones de 4,5 a 5,5 kbar (12 a 17 km de profundidad) para la generación de estas rocas. Evidencias de campo, complementadas por datos mineralógicos y texturales, hacen pensar en un origen asociado a la fusión parcial de corteza continental en las condiciones de la facies granulita / Abstract.  Orthopyroxene-bearing felsic and mafic rocks are important components of the transition zone between the Archean São Francisco Craton and the late proterozoic Coastal Mobile Belt in southeastern Bahia, Brazil. The charnockites have relict magmatic textures. Thermobarometic calculations based on several Exchange thermometers and one barometer suggest temperatures between 700 and 800oC and a pressure of 4,5 and 5,5 kbar (-12-17 km depth) for the generation of these rocks.  In the studied rocks there are many textural indications for the instability of minerals used in the exchange thermobarometers, suggesting that the interpretation of temperature and pressure conditions of granulite facies rocks is more accurate when based on the principles of the equilibrium of phases.  Field evidence, supplemented by mineralogical and textural data suggests an origin by partial melting of deep continental crust under the dry conditions of granulite facies.Orthopyroxene-bearing felsic and mafic rocks are important components of the transition zone between the Archean São Francisco Craton and the late proterozoic Coastal Mobile Belt in southeastern Bahia, Brazil. The charnockites have relict magmatic textures. Thermobarometic calculations based on several Exchange thermometers and one barometer suggest temperatures between 700 and 800oC and a pressure of 4,5 and 5,5 kbar (-12-17 km depth) for the generation of these rocks.  In the studied rocks there are many textural indications for the instability of minerals used in the exchange thermobarometers, suggesting that the interpretation of temperature and pressure conditions of granulite facies rocks is more accurate when based on the principles of the equilibrium of phases.  Field evidence, supplemented by mineralogical and textural data suggests an origin by partial melting of deep continental crust under the dry conditions of granulite facies.Las rocas mancas y felsicas con ortopiroxeno (hiperstena) son los componentes importantes de la zona de transicion que separa el Craton Arqueano de San Francisco y el Cinturon Movil Costero Neoproterozoico, en el extremo sur del estado de Bahia, Brasil. Las charnockitas presentan texturas relictas maqrnatlcas. Los calculos terrnobarornetricos hacen pensar en temperaturas entre 700 - BOOoCy presiones de 4,5 a 5,5 kbar (12 a 17 km de profundidad) para la generacion de estas rocas. Evidencias de campo, complementadas por datos rnineraloqicos y texturales, hacen pensar en un origen asociado a la fusion parcial de corteza continental en las condiciones de la facies granulit

ESPECTROGRAFIA DE EMISSÃO ÓPTICA VERSUS ESPECTROGRAFIA DE ABSORÇÃO ATÔMICA NA DETERMINAÇÃO DE METAIS TRAÇOS EM SEDIMENTOS DE CORRENTE.

Técnicas de estatística multivariada foram aplicadas a um conjunto de dados geoquímicos composto de 634 amostras de sedimentos de corrente, coletados em uma área semi-árida de cerca de 3000km2 no Estado da Bahia, Brasil. A Fração menor de 80 mesh de todo o conjunto de dados e 108 amostras da fração de minerais pesada foram analisados ​​por espectrografia de emissão óptica e espectrografia de absorção atômica. A análise de agrupamento hierárquico foi aplicada em busca de associações estatísticas dos elementos

A POLÍTICA EDUCACIONAL NO BRASIL: O ENSINO MÉDIO E O LIVRO DIDÁTICO NO ÂMBITO DAS CIÊNCIAS DA TERRA.

A democratização do ensino, defendida em vários momentos históricos, conviveu com a dissociação de duas classes profissionais, os trabalhadores braçais e os dirigentes técnico-científicos. Apesar das reformas educacionais do século passado até a vigência da atual LDB, a política do Estado ainda determina e centraliza as decisões da educação no país. Diante deste quadro, livros didáticos são colocados no mercado para corresponder a uma demanda com tais características. O conteúdo de geologia continua prevalecendo na disciplina Geografia, assumindo um espaço ainda muito menor do que o reservado para os temas sócio-econômicos. O fato de estar presente neste currículo, não garante que o conteúdo de geologia seja abordado com a qualidade e a quantidade dos seus temas

NATURAL ATTENUATION OF BTEX CONTAMINANTS IN THE GROUNDWATER OF THE MOST POPULOUS CITY IN NORTHEASTERN BRAZIL

In order to investigate the contamination and attenuation of BTEX compounds from fuel tank leaks into the Basin of Lucaia’s river aquifer, Salvador, Bahia (Brazil), it was determined in samples of groundwater concentrations of volatile aromatics benzene, toluene, ethylbenzene and xylenes (BTEX), sulfate, nitrate and iron (II) in two distinct periods. The concentrations of compounds were compared to ascertain the yield reduction of BTEX in the sampling points up to 82%. Isotenor curves were generated by observing the behavior of composites and the relation of Eh and nitrate consumption with natural attenuation of BTEX, verifying that it does not occur in a wide spread critical levels and dangerous for the population

VARIAÇÃO ESPACIAL DE SULFETOS VOLÁTEIS ACIDIFICADOS E BIODISPONIBILIDADE DE METAIS EXTRAÍDOS SIMULTANEAMENTE EM SEDIMENTOS AO NORTE DA BAÍA DE TODOS OS SANTOS, BAHIA.

A distribuição espacial de sulfetos volatilizáveis em ácido (SVA) e metais (Cd, Cu, Pb, Ni e Zn) extraídos simultaneamente (MES) no substrato lamoso do sedimento de manguezal na porção norte da Baía de Todos os Santos (Bahia-Brasil) foram estudados em oito estações sob possível efeito urbano, industrial e portuário. O SVA foi extraído do sedimento anaeróbio com ácido clorídrico 1 mol L-1, a frio, enquanto os metais extraídos simultaneamente (MES) bivalentes são liberados. Não houve diferença estatística entre as estações. A razão MES/SVA, correlacionaram-se com as frações granulométricas, matéria orgânica (3.5%), carbono orgânico total (2.4%), nitrogênio total (0.25%), metais (mg Kg-1): Cd, Cu, Pb, Ni e Zn.  Comparando-se com valores de referência internacionais estão abaixo dos limites estabelecidos, mesmo em outras regiões do Brasil. Os valores < 1 para a relação [MES]/[SVA], sugere a não disponibilidade desses metais, o que indicam a ausência de efeitos adversos à biota

Produção fotossintética da macroalga Ulva lactuca Linnaeus (Chlorophyceae) cultivada em efluentes de uma fazenda de camarões marinhos

This study aimed to evaluate the demand for oxygen through the photosynthetic production of macroalgae Ulva lactuca, shrimp cultivated in the effluent, submitted directly to the intensity of natural light in a photoperiod of 14/10 for the latitude of 27 ºS in December, and show the potential for cultivation of this kind of integrated systems, the recirculation in marine shrimp farms. Specimens were collected in Lagoa da Conceição, Florianopolis (Brazil), and transported to the laboratory for selection of the stems. These were washed with fresh water running and then extracted several discs with a diameter of 5cm, which were dry on paper towel and weighed on electronic scales. We used 30 of 500mL Erlenmeyer flasks, previously washed with distilled water with 10% hydrochloric acid. Each received 500mL bottle of water from the canal despesca a marine shrimp farm, containing 32 of salinity and approximately 40 and 5μM ammonia and orthophosphate, respectively. The experiment included four treatments with seaweed and algae without one, as well as their respective controls, all composed of three replications. Controls were involved with laminated paper. The treatments received the following material algal densities of 1 = 1 L-1, 2 = 2 L-1, 3 = 3 L-1 and 4 = 4 L-1. The bottles were covered with paper control rods. On a plastic tank with 1000L of water, the treatments were distributed randomly on a table submerged, allowing 90% of the volume of bottles were submerged. The experiment was kept under constant renewal of water, keeping the temperature uniform, around 26, all in containers. Each time, temperature, light and dissolved oxygen were measured in all bottles, in a period of 27 hours. The photosynthetic production began from 6:30 pm, where they saw an initial increase of the oxygen concentrations in treatments with algae, while all controls remained low until the end of the experiment. There was a first photosynthetic peak around 12:30 pm, where the maximum light intensity was 1,424 lux, and a photoinhibition of algae to UV exposure of between 12:30 and 15:30 h. It was a possible excretion of UV-B at densities of 3 and 4 L-1 arising from the excess of solar irradiation. A second peak production of O2, between 18:30 and 20:30 in the four treatments with algae, resulting in higher rates to 564% of supersaturation, 490% on its photorrespiration and 150% on supersaturation of phitoplancotn showing its potential for cultivation integrated with marine shrimp in a closed system of recycling