Susceptibilidade erosiva do baixo curso do rio Acaraú-CE

The inadequate land use in the low course of the river Acaraú is speeding up processes of erosion in some degrees. This process is accented in the areas where caatinga was removed for implantation of pastures and agriculture. Concomitantly, the plain of flooding of the river Acaraú an accumulation of sand with the carry of these sediments, resulting in the widening of the fluvial plain and reduction of the shape water, with increase of the evapotranspiration and consequence salinization, proceeding from the local substratum. This paper aimed at the crossing of diverse space information (geomorfology, soil, declivity, geology and land use) in environment SIG, for determination of the susceptible areas to the erosion and an accumulation of sand in the low course of the Acaraú river, north of the State of the Ceará, Brazil. The results allow to evaluate the application of this tool in the planning and management of the environment, from the crossing of the type of use with the used environment and the consequent impact to the ecosystem.

Capacidade de carga real (ccr) da caverna de santana, parque estadual turístico do alto ribeira (Petar) - sp, e indicações para o seu manejo turístico

The tourist use of Santana cave provides a row of environmental damages, compromising partially the pristine conditions. Among the measures adopted to avoid this situation, this issue presents a contribution for the physical limits to tourist visitation and the indications for speleotouristic management. It was used the Cifuentes Carrying Capacity method and some basic principles of Visitors Impact Management Framework - VIM. The results show a Real Carrying Capacity (CCR) about 120 visits daily on the cave. The discussions raise a few hypotheses about the alteration in the method used and the temporal frequency between visitors groups, suggesting a provisional CCR of 117 and 135 visitors daily, respectively, during the week and in the weekends and holidays. The conclusions appoint the necessity of a conceptual revision in the Carrying Capacity methods, mainly about its adaptation for tourist management in caves. In the case studied, it is suggested the immediate beginning of environmental monitoring of the cave, to verify the plausibility from proposed visitation limits and the possible contributions for to mitigate the environmental impacts from speleotourism.

Evolução da margem atlântica equatorial do Brasil: Três fases distensivas

The extension of the Pangaea started in the Upper Triassic and evolved to uplifts, magmatism and development a triple junction during the Mesozoic, and opening the Central Atlantic Ocean. The Brazilian Equatorial Atlantic margin was formed in three Mesozoic extensional events. The first event is recorded by the Calçoene Graben of the Foz do Amazonas Basin. The second event started in the Valangian and is recognized by the enlargement of the Foz do Amazonas Basin, formation of the Marajó and Grajaú basins, and the Gurupi Graben System. The third event commenced in the Albian related to northwestward progression of the rift system, which enlarged the Foz do Amazonas and formed the Potiguar, Ceará, Barreirinhas and Pará-Maranhão basins. At the end of the Lower Cretaceous the movements attenuated in the Marajó Basin and Gurupi Graben System; the extension concentrated in the Foz do Amazonas, Pará-Maranhão and Barreirinhas basins, and evolved to continental rupture of northern South America and western Africa opening of the Equatorial Atlantic Ocean.

Batimetria fluvial estimada com dados orbitais: Estudo de caso no alto curso do rio Paraguai com o sensor ASTER

The Paraguay River is the main tributary of the Paraná River and has an extension of 1.693 km in Brazilian territory. The navigability conditions are very important for the regional economy because most of the central-west Brazilian agricultural and mineral production is transported by the Paraguay waterway. Increased sedimentation along the channel requires continuous dredging to waterway maintenance. Systematic bathymetric surveys are periodically carried out in order to check depth condition along the channel using echo-sounding devices. In this paper, digital image processing and geostatistical analysis methods were used to analyze the applicability of the ASTER sensor to estimate channel depths in a segment of the upper Paraguay River. The results were compared with field data in order to choose the band with better adjustment and to evaluate the standard deviation. Comparing the VNIR bands, the best fit was presented by the red wavelength (band 2; 0,63 - 0,69 μm), showing a good representation of the channel depths shallow than 1,7 m. Applying geostatistical methods, the model accuracy was enhanced from 43 cm to 36 cm and undesired components were slacked. It was concluded that the digital number of band 2, converted to bathymetry information allows a good estimation of river depths and channel morphology.

Análise de superfície de tendência aplicada à chuva, medida por radar meteorológico, nas regiões de Assis e Piracicaba, SP

This paper presents the results from lineal trend surface analysis technique application. The purpose was to detect positive and negative anomalies in the rain measure distribution obtained by the meteorological radar Doppler, band S, located in Bauru, during the period of 21 of October/2004 to 29 of April/2005 in the areas of Assis and Piracicaba. Using three Z-R radar relations for rain quantification was chosen the specific equation Z = 32R1,65, as the best one. The results showed that the applied methodology was able to indicate the space distribution of the rain accumulated, identifying and locating the regions where there was rainy excess and rainy lack during each analyzed period. Such results indicate areas with larger pluvial impact and consequently more favorable for environmental damages.

Diques clásticos na formação corumbataí (p) no nordeste da bacia do paraná, SP: Análise sistemática e significações estratigráficas, sedimentológicas e tectônicas

This paper aims to present the results of systematic survey on clastic dykes in the Corumbataí Formation (Permian), in the northeast region of the State of São Paulo. Besides this, the paper analyses genetic aspects of those features as well as their stratigraphic and sedimentologic implications in terms of geologic evolution of the northeastern Paraná Sedimentary Basin during Permian times. The field works had been developed in 3 main Corumbataí Formation outcrops (2 road cuts and a quarry) supposed to show the most important clastic dikes occurrences in the studied area. Basically, the sedimentary intrusions are formed by fine sand or silt size particles and had penetrated host rocks as near-vertical, centimeter thick, dykes (most common form) or as horizontal sheets, forming clastic sills (subsidiary form), both with variable geometric forms and dimensions. A lot of dyke walls show undulations suggesting pre-diagenetic clastic intrusions, probably near the ancient depositional surface. Almost all intrusions occur in the superior third portion of the Corumbataí Formation and some similar features seem to appear in the adjoining superposed Pirambóia Formation base. In this article the authors defend a seismic origin hypothesis for the clastic intrusions. It is important to mention that clastic intrusions tend to occur linked to expressive seismic events, with magnitude upper to 5. The analysis of isopach maps of the Permian and Mesozoic units of the Paraná Sedimentary Basin in the study area suggests a depositional system changing, from epicontinental sea conditions to shallow platform and, finally, to coastal deserts. Probably, this environmental change was driven by regional uplift accompanied by seismic events. It is possible that ancient seismicity triggered liquefaction processes and the resulting clastic intrusions. In this sense, those clastic features might be properly namedseismites.

Contexto tectônico dos granitóides neoproterozóicos da faixa de dobramentos paraguai, MS e MT

The Neoproterozoic Granitic Province from the southeast of Mato Grosso and Mato Grosso do Sul region is constituted by seven distinctive granitic bodies, emplaced in the epimetamorphic rocks of the Cuiabá Group and related to the evolution of Paraguai Folded Belt. The Northern portion crops out in Mato Grosso State and is constituted by São Vicente, Araguaiana and Lajinha batholiths; the Southern portion crops out in the Mato Grosso do Sul State and is represented the Sonora, Coxim Rio Negro and Taboco massifs. The structural evolution is evidenced by the presence of three deformational phases, the first one is characterized by axial planar foliation (S 1), parallel or sub parallel to S 0, with attitude N60E/70NW; the second constitutes the most important phase for the tectonic arrangement and is defined by a slaty and/or crenulation cleavages (S 2), with attitude N10W/30SW and contact metamorphism associated to the emplacement of granitic bodies, the third phase is characterized by a weak retrometamorphic cleavage (S 3) with attitude N10E/ 80NW, that evolves local and gradually to strike-slip shear zones. The geological data suggest that this province was formed syn- to post tectonic to the D2 deformational set associated to the end of the collisional event in the Southeastern of the Amazonian Craton.

Variação temporal da resistividade elétrica em contaminação por gasolina

The definition of models and base parameters for application of investigation tools in environment with high complexity are a basic premise to any sciences. The geophysics is a science with solid theoretical base and applications in diversified areas of the sciences geological, astronomical, meteorological, among many others. Its application in environmental studies is relatively recent and needs further research. To understand the behavior of resident contaminants in a dynamic and complex environment as the geological, it requests studies in scale laboratorial, under control of factors seasonality variable. This work simulates a leak of gasoline in soil, under conditions and in laboratory scale, with the objective of monitoring the temporary behavior of the hydrocarbon under the optics of variation of the parameter physical electric resistivity. The results indicate increase of the resistivity in recent periods the contamination, followed for stability in the values and finally fall and return tendency to the natural conditions.

Análise da evolução da paisagem no entorno da represa dos rios jaguari e jacareí, estado de são paulo, com base em sensoriamento remoto e SIG

The primary objective of this study is to evaluate by means of remote sensing and GIS, the landscape evolution around the Jaguari and Jacareí River Dam, located in the eastern section of the State of São Paulo, Brazil. For this purpose we used LANDSAT 5/YM and CBERS-2/CCD images from 1984/1985 and 2006, respectively, considering the following classes of land use: forest, cultivated forest, agriculture, urban areas and water bodies. The two selected dates reflect important changes in the region such as the installation of the dam and subsequent urbanization of parts of its margins and the enlargement of the Fernão Dias Federal Highway, which contributed to an increase of areas of anthropic activities in the studied region. The results also indicate an increase in areas covered by native and planted forests, thus confirming a similar trend in other areas of the State of São Paulo.

Propriedades químicas de um latossolo vermelho de cerrado cultivado com algodão sob diferentes preparos e adubações

The high rate of mineralization of organic matter on savannah soils, which is reached fi ve times faster than in temperate regions, leads us to the challenge of electing the best system of management that maintains and/or increase it in soil, guaranteeing its quality and sustainability. In this sense the present research aimed to study the effects of green, organic and mineral manure on the chemical properties on the chemical properties of an Oxisol, on Savannah area, cultivated with cotton (Gossypium hirsutum) under conventional tillage and no-tillage in the pasture fi eld (Brachiaria decumbens) for 20 years. The experimental design was a randomized block design with split plots. The main plots consisted of two treatments: conventional tillage and no-tillage, and the subplots of six treatments: control (no fertilizer), mineral fertilizer recommended for the crop, according to the soil chemical analysis, organic fertilizer (cattle manure - 20 t ha-1), organic fertilizer (cattle manure - 20 t ha-1) + 1/2mineral fertilization recommended according to the analysis of soil, green manure-1 (Crotalaria juncea) and green manure-2 (Pennisetum americanum). There were studied the following soil chemical properties: P, OM, pH, K, Ca, Mg, Al, Al + H, S, exchange capacity cations and base saturation. The soil samples for the analysis were performed on layers of 0,00-0,05 m, 0,05-0,10 and 0,10-0,20 m. Then it came the following conclusions: the fertilization interfere in soil chemical properties and the preparation did not interfere, the cattle manure and its association with the mineral fertilizer caused increasing level elements in the soil, Crotalaria juncea and Pennisetum americanum did not infl uence on soil chemical properties.

Hidrogeoquímica do aqüífero guarani na área urbana de ribeirão preto (SP)

This work evaluated the hydrogeochemistry of the Guarani Aquifer in the urban area of Ribeirão Preto, São Paulo State. Thirty one sampling points were established and it was carried out field campaigns in 7 and 8 July 2005, analyzing the following parameters: conductivity, temperature, pH, turbidity, color, dry residue, dissolved oxygen, Ca2+, Mg2+, Na+, K+, Fe3+, Al3+, HCO3-, SO42-, PO43-, NO3-, Cl- and F-. The results indicated that the groundwaters in the urban area of Ribeirão Preto pH possess slightly acid, low conductivity, turbidity, color and dissolved oxygen inside the limits established for drinking waters. The ionic composition indicated that the groundwaters have low cations and anions concentration, being they classified as soft water and calcium-bicarbonated. Statistical tests suggested that conductivity and pH are controlled for the calcite dissolution (CaCO3) during the water/rock interaction process. Besides, it is possible to conclude that the high NO3- and PO43- concentrations found in the groundwater in the urban area of Ribeirão Preto are originated due to anthropogenic activities.

Litogeoquímica E aspectos Petrogenéticos dos basaltos da Província Magmática do Paraná na porção centro-norte do Estado de São Paulo

The petrographic and geochemical characterization of flood basalts of Serra Geral Formation are here presented. The investigated areas are situated in four different regions of São Paulo state: Jaú, Ribeirão Preto, Franca and Fernandópolis. They represent almost the total area of outcrops of basalts in the São Paulo State. The petrographical data reveals that these rocks are constituted mainly by plagioclase (30-40%), pyroxenes, augite and pigeonita (20-30%) and magnetite (5-15%), and show a intergranular texture and its varieties intersertal, hialophitic and pilotaxitic. The geochemical data show a basic and tholeiitic affinity of the studied basalts, with high-Ti content (TiO2 > 1.8%), typical of the northern region of Paraná Basin. Three different magma-types were recognized: Paranapanema, Urubici and Pitanga. The first magma-type is concentrated in the Fernandópolis region, the second in the Franca region, and the Pitanga occurs in the Ribeirão Preto and Jaú regions. The distribution patterns of these magma-types and the detailed study of geochemical data showed that they are, probably, generated by a melting of a continental lithospheric mantle.

Geocronologia do maciço Granítico Sararé no SW do Cráton Amazônico

Sararé Massif occurs in the southwest Mato Grosso state intruded into Mesoproterozoic units of the Jauru Block inside the Amazonian Craton. It presents an extension of approximately 80 km2 and NW-SE tectonic structures control the elongated shape. It is constituted by three major monzogranitic petrographic facies, represented by leucocratic, reddish, isotropic, equi-inequigranular to locally porphyritic rocks. The composition indicates S-type, peraluminous, with indicatives of late- to post-kinematic magmatism. Geochronological studies with 40Ar/39Ar in biotites and muscovites resulted in ages of 903 to 906 Ma was interpreted as massif rocks cooling period and U-PB 917 ± 18 Ma. ages points to the crystallization of the intrusive body. The massif is formed by melting of material of the upper crust, in an environment of continental collision and/or of post-collisional decompression at the ending of the Aguapeí-Sunsás event, in more stable environments of consolidation and tectonic stabilization of the Amazonian Craton.

Índice de Qualidade da Água (IQA) do reservatório Tanque Grande, Guarulhos (SP): Análise sazonal e efeitos do uso e ocupação do solo

The Tanque Grande Reservoir is located at the Serra da Cantereira, Guarulhos (SP), and provides 3% of the municipal drinking water. In the last years, the urban zone has expanded towards the reservoir and has significantly altered the land use. In this work, water samples from three stations were monitored from August/2007 up to July/2008 in terms of the Water Quality Index (IQA) adopted by CETESB. The waters were usually classified in the band Good during the study period. Nevertheless, termotolerants coliforms, BOD and total phosphorus have exceeded the legal limits several times. Such occurrences may be related to the economical activities at the sub-watersheds in addition to changes in the land use of the surroundings of the reservoir.

Análise morfotectônica da Bacia do rio Santo anastácio, sp, através de parâmetros fluviomorfométricos e de registros paleossísmicos

Fluvial morphometry is method of great value regarding neotectonic analysis of extensive areas because streams, besides representing one of the main agents in the relief modeling, quickly adjust their thalwegs to even the most gentle crustal deformations. The purpose of this paper is to present the application of some morphometric techniques in the Santo Anastácio River hydrographic basin in order to identify recent tectonic deformations. Additionally, we show liquefaction structures identified in the basin and interpreted here as seismites linked to ancient earthquakes (magnitudes greater than 5). The morphometric survey includes longitudinal stream profile analysis, RDE (declivity versus stream length) index application, and the sinuosity study of the Santo Anastácio River channel. Geologic substrate comprises Cretaceous siliciclastic rocks of the Caiuá and Bauru groups, locally covered by Cenozoic sediments (alluvial plains, terrace deposits, colluvial aprons, as well as in situ regoliths). Considering that liquefaction structures affect dark clay layers of 32.340±320 year BP age (14C dating), a lower age limit for the ancient earthquake is triggered in that region. The authors believe that neotectonic understanding of the Western São Paulo State Plateau is important to the geologic and geomorphologic evolution of that landscape and to the consequent territorial planning and occupation.