234 resultados para Geomorphological facies


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A survey was conducted aiming to recognize and characterize the environments of occurrence of Trichilia species and their geographic distribuition, particulary T. catigua A. Juss, in Santa Catarina State. These informations will support a domestication strategy for agricultural production of this spcies. This species is widely used by traditional communities as dye and tonic beverage, as well as digestive and purgative. Some pharmaceutical and beverage industries in Brasil use bark of this species to prepare a tonic drink. There are several common names reffering the species and this situation can promove mistakes in collecting and selling processes. Termperature, soil, vegetational types and edaphoclimatic aspects have great influence on the occurrence of this species. Plant collection strategu was based on herbaria data and field verification. The vouchers were deposited at the Federal University of Parana herbarium (UPCB). The collection sites were geographically located, by latitude and longitude and these data were crossed with climate, soil, temperature, rainfall, altitude and vegetation maps. Catuaba occurs predominantly on a stational semidecidual forest and also on transitional forest with Araucaria and part of Atlantic forest. It is found growing in lower canopy, with fertile soils, and high content of organic matter. The main geomorphological formation are basaltic and the soil types vary from dark red latossol to yellow red latossol, including structured red latossl and cambissol from basaltic and granitic origin.

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The iron ores of Alegria mine are composed of itabirites enclosing minor bodies of high-grade ores. The itabirites are classified according to mineralogical composition in five types: martite-rich, goethite-rich, specularite-rich, magnetite-rich and anphibolite-rich ores. The hematites are martite-rich, magnetite-rich, specularite-rich and more rarely, amphibolite-rich. Other classification criteria of the ores are based on the physical properties and the degree of compaction. As such, the itabirites and hematites can be classified as hard, friable and soft types. The mineralogical/textural evolution of the ores is linked to the pressure and temperature conditions that accompanied the tectonic processes in anphibolite facies and the different degrees of subsequent surficial weathering processes. Petrographic and microstructural studies indicate that the magnetite and amphibole bearing itabirites represent the parent rocks that created the other itabirites and that the specularite itabirites and the hard martite types are related to silica dissolution and redeposition in zones of high and low strain. Most of itabirites ores correspond to chert oxide facies banded iron formation, except the goethite and amphibole bearing itabirite that resemble a silicate or oxide-silicate facies with minor carbonate impurities. The great mass and pods of soft martite itabirites are probably shaley oxide facies BIFs with little volcanic contribution. Trace element contents of the Alegria's itabirites show strong dissimilarities with BIFs associated with volcanism (Algoma type), but closely ressemble to the Lake Superior type, with high content in Cr, Co and low V, Ni, Cu and Zn. Although the absolute contents of REE present in the Alegria's itabirites are, in general very low, the pattern when normalised by NASC is similar to the great majority of the Archean and Paleoproterozoic BIFs elsewhere in the world, and characterised by positive Eu anomaly.

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The Rio da Batateira e Santana formations, the latter with Crato, Ipubi and Romualdo members (Alagoas Stage, Aptian), were studied in four cored and logged wells from the eastern portion of Araripe Basin, Northeastern Brazil. The investigated section is 230 m-thick, and PS-14 well is the most representative, because it is the only one which sampled the evaporites of Ipubi Member. Nine facies cycles were identified, being formed by siliciclastics (estuarine, deltaic and lacustrine), mixed lithologies (lacustrine), carbonates, black shales and marls (lacustrine), and gypsum-anhydrite (lacustrine evaporite). The ordering of facies cycles furnished six depositional sequences. They were formed by siliciclastic, regressive-transgressive R-T cycles (S1 and S4, corresponding to Rio da Batateira Formation and to Santana Formation/Romualdo Member), by siliciclastics and carbonates, R-T cycles (S2, S3.1 and S3.2, corresponding to Crato Member), and by siliciclastic-carbonate, R-T cycles followed by evaporitic cycles (S3.3, referred to Ipubi Member). The last cycles correspond to concentration-dilution, C-D cycles of marine brines, which precipitated gypsum in the restricted lacustrine basin.

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The objective of this study is the geometric characterization of a fluvial system, exemplified by the Itaquaquecetuba Formation. The studied area is a quarry located in Itaquaquecetuba, distant 35 km from the city of São Paulo, which is inserted in the context of São Paulo Basin. Fluvial systems are important hydrocarbon reservoirs, and this study may contribute with an analogue for ancient reservoirs. It was elaborated ten facies logs along a distance of 200 m (log spacing of 20 m), with a vertical column (thickness) of 40 m for each log. Eight facies cycles, and its lateral chrono-correlation allowed to map the potential reservoir and non-reservoir facies within each cycle. Regarding the depositional model for the studied section, it is assumed an alluvial fan system composed of meandering and ribbon-type fluvial channels.

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The Brazilian Granitic Province from southeastern Mato Grosso do Sul and Mato Grosso region, central western Brazil, can be divided into two major groups and/or magmatic events related to the evolution of the Paraguay Fold Belt. The southern portion crops out in Mato Grosso do Sul State and is constituted by the Taboco, Rio Negro, Coxim and Sonora massifs forming NE-SW oriented, elongated small intrusions. The north portion crops out in Mato Grosso State and is constituted by the São Vicente, Araguaiana and Lajinha batholiths. Lithogeochemical aspects of the northern granites point to Type-I granites ranging from K calc-alkaline to high-K, peraluminous to metaluminous in composition, generated in an environment of continental collision and/or post- collision decompression. The southern granites are Type-I, from K calc-alkaline to high-K, peraluminous to subordinate metalummous, in a syn-collision continental arc environment with the exception of some pre-collisional facies from the Rio Negro Massif. The southern granites have less SiO 2 and K 2O, and are less differentiated and evolved than granites from the northern region. The four southern granites can be grouped into two subordinate sets with the degree of differentiation increasing from South (Taboco and Rio Negro) to North (Coxim and Sonora). The granitic rocks are characterized by a magmatism generated by melting of material from the lower crust which suggests that in this province the formation from non-cogenetic magmas with diversified compositions and distinct degrees of fractioning reaching more steady consolidated environments at the end of the collisional event in the southeastern Amazonian Craton.

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The Rio Branco Rapakivi Batholith belongs to the Cachoeirinha Tectonic Domain, part of the Rio Negro-Juruena Geochronological Province located on the southwestern portion of the Amazonian Craton in Mato Grosso, Central Brasil. A systematic geological mapping on a 1:100.000 scale, coupled with petrographic and geochemical studies allowed to redefine this batholithic unit, to recognize faciological variations and to characterize the geochemical features of this rapakivi magmatism. The batholith is constituted by two major plutonic suites, the first forming a basic suite of fine-grained, equigranular, mesoto melanocratic gray to black lithotypes, with usually discontinuous porphyritic varieties located near the margins of the intrusion. The second one is characterized by acid to intermediate rocks constituted by porphyritic granites, in part granophyric, with rapakivi textures. They have K-feldspar phenocrysts of up to 4cm. Three distinct petrographic facies are recognized in this suite: 1. equigranular to pegmatitic monzogranites; 2. red rapakivi leuco-monzogranites; 3. dark red rapakivi monzogranites to quartz-monzonites. Rocks present SiO2 contents from 67% to 73%, show peraluminous to metaluminous compositions and define a high-K calc-alkaline to shoshonitic magmatism in an I- and A-type, post-orogenic to anorogenic intraplate environment. The magmatic processes are associated with the end of the collisional event that consolidated and stabilized the SW part of the Amazonian Craton.

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Twenty-two 14C datings were performed at the central sector of the Paraná coast to define Holocene regressive barrier evolution. The barrier Pleistocene substratum was ascribed an age between 40 400 and 30 000 yr BP, but it can also represent the penultimate sea level highstand during marine isotope stage 5e. The Holocene barrier samples provided ages between 8542-8279 and 2987-2751 cal yr BP, and showed at least six age inversions that were related to age differences between in situ or low-distance transported shells or trunk fragments, and high-distance transported vegetal debris, wood fragments and organic matter samples. The regressive Holocene barrier age was 4402-4135 cal yr BP near the base, and 2987-2751 cal yr BP near the top. Most of the vegetal remains were transported by ebb tidal currents from the estuaries to the inner shelf below wave base level during the mid-Holocene highstand; they were transported onshore by storm waves and littoral currents during the sea level lowering after the sea level maximum, and were deposited mainly as middle shoreface swaley cross-stratification facies. © 2008.

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Background: Many factors contribute to extend productive life in the modern world. Competition makes people worry about physical appearance, mosftly in respect to facial and skin aging. This has motivated new developments in cosmetic dermatology and the need of evaluating patient satisfaction with the new proposed treatments. Poll questionnaire has been used for such evaluation, and the analysis of the electroencephalogram (EEG) mapping obtained while the patient answers the satisfaction questionnaire may render the results less subjective. Objectives: The purpose of this paper is to study the satisfaction of a group of 33 women (mean age, 44.years) treated with hyaluronic acid filling of nasolabial folding or lips, combining the EEG brain mapping and questionnaire techniques. Methods: At the third month of evaluation, two networked personal computers were used for the EEG recording and for presenting the patient with a questionnaire about her well-being feeling; self-evaluation of her face; her satisfaction with the results of the aesthetic treatment; how the family, friends, and people at work evaluated the result of the treatment; and her decision to repeat the treatment and to recommend it to friends and family. Results: Poll results showed that patients were feeling well and were satisfied with the results of the aesthetic treatment. Furthermore, the regression EEG mappings showed patients to be satisfied with their appearance and with the treatment involving similar brain areas. Conclusion: Patients decided to undergo the treatment because they were already considering it (54%) or because they were dissatisfied with their lips or nasolabial folding (52%). The fact that the treatment was free of charge solidified the decision. Patients consider themselves as good-looking and they wanted to preserve such a condition. © 2008 Wiley Periodicals, Inc.

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The city of Cubatão is a densely populated area with high industrial activity. In the area there are also important linear works as roads, railways, pipelines, aqueducts and lines of transmission of energy. The geological and geomorphological features of the municipality, combined with the human activities, make the site an area heavily prone to the landslides, so a region at high risk. In this work, landslide scars were extracted in aerial photos from 1985 and 1994, years that recorded a high incidence of landslides. Quantitative analysis of the relationship between the occurrence of scars and the forms of tracks were conducted, based on an intensive survey of scars in the region, represented by 2595 extracted scars, with the aim of contributing to a better understanding of the slipping processes in the Serra do Mar paulista and thus to the reduction of risks in the region. Achievements have concluded that the greatest percentage of slides in the region is linked to the strands straitght, followed by convex, which confirms previous studies conducted in the region, in a qualitative way or with a much lower number of scars.

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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.

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Paleogene sediments of this region represent a significant source of water for urban, industrial and agricultural activities. This basin is part of the Southeastern Brazilian Continental Rift, which occupies a large portion of this geographical area. This study aims to present the evolution of the natural Paleogene landscape, through an analysis of its stratigraphic intcrops and underground portions based on the concept of facies and facies associations. A total of nine clastic and separate lithofacies were recognized and grouped into two main facies associations. These data suggest the existence of two depositional interdigitated systems: fluvial braided fans, which were predominant in parts of the northern and central area, and another composed of lacustrine sediments found in its central-south region. The paleogeography herein outlined will help considerably in the detection of new areas for mineral and water resources prospection, as well as in urban planning projects of this region.

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Rio Apa Massif crops out in the Mato Grosso do Sul state and corresponds to the southeastern portion of the Amazonian Craton dominantly Paleoproterozoic in age. Rio Apa Complex is oldest and it is composed mainly by migmatitic orthogneisses, beyond amphybolites, tonalities and granodiorite. Alto Tererê Group is composed by schists, biotitemuscovite gneisses and micaceous quartzites generally rich in garnets, beyond metabasic rocks of low amphibolite facies. The Amoguijá Group is constituted by Alumiador Intrusive Suite, which is represented by a sieno to monzogranitic batholith and Serra da Bocaina Volcanic Suite composed of volcanoclastic rocks of alkali riolites to monzoriolites compositions and pyroclastic products. Overlaying towards East and South occurs Neoproterozoic metasedimentary rocks from the Paraguai Folded Belt (Cuiabá, Corumbá and Jacadigo Groups - Urucum Formation). Structural-metamorphic framewok is identified by five deformational phases but the actual tectonic and metamorphic structure shows the superposed tectonic array of the Paraguai Folded Belt. Rocks from Rio Apa Complex, Alto Tererê Group and Amoguijá Group record an older structural evolution defined by (Dn-1 and Dn). The deformational phases (Dn+1 and Dn+2) are visible mainly in rocks of Paraguai Folded Belt beyond the last deformation (Dn+3) that imprints all sequences.

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The Permian-Carboniferous Itararé Group is one complexe lithostratigraphic unit of the Paraná Basin, southeastern Brazil, typically marked by discontinuity of its lithofacies. Under the exploratory point of view, the unit represents one of the most significant intervals of the basin, since several occurrences of mineral and energetic resources are associated to it, as groundwater, petroleum and coal. The prospection and exploitation of these resources depend on a good understanding of the stratigraphic architecture and the paleogeography. There are many contributions on the specialized literature which deal with this subject, although the regions of Limeira and Piracicaba (superior portion of the unit) still lack new investigations, which may contribute to the understanding of its lithofacies and related sedimentary processes. It was analyzed the sedimentary sets pilling up, followed by stratigraphic correlations between the two regions. Moreover, from sedimentary structures, it was made paleocurrent measurement with the purpose of obtaining indicative patterns of the sedimentary polarity, contributing for the comprehension of the paleogeography. Recent studies in the Domo de Pitanga region (between Rio Claro and Piracicaba cities) and in the Corumbataí river drainage basin, were taken also as basis for possible correlations. It was obtained a frame of the lithofacies arrangement, their vertical and lateral relations, as well as their depositional polarities.

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Metaultramafic bodies tectonically emplaced within the metasedimentary sequence of the Araxá Group are associated with an ophiolitic melange in southeast Goiás. In the region of Crominia - Mairipotaba, they occur as lenticular bodies aligned E-W. Cumulate textures and geochemical data indicate that the parent rocks had harzburgitic to dunitic compositions. Relicts of primary crystals of olivine and orthopyroxene are suggestive of amphibolite facies metamorphic re-equilibration fabrics, even though the paragenesis and mineral associations of these metaultramafic rocks are typical of greenschist facies (T < 550°C and P = 5.5 kbar). The chromitites exhibit massive to breccioid structure and pull-apart texture, with chromite crystals around 0.5 mm in size. Chromite concentrations in the chromitite levels reach 70 to 85% by volume of the rock. The crystals are dispersed in the matrix, which is composed essentially of serpentine, and subordinately of chlorite and talc. The textures and geochemical data (Cr 2O 3 x TiO 2 and Mg x Cr ratios present in the chromitite) are similar to those observed in ophiolitic complexes. Hence, they correspond to allochthonous bodies (Alpine type) associated with an ophiolitic mélange.

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The Neoproterozoic granitogenesis related to the Central Mantiqueira Province comprise the calc alkaline to alkaline granitoid complexes of Sorocaba, San Francisco, São Roque, Ibiúna and Piedade. These complexes occur in a ruptil tectonic to tardi (Sn+3) event. The emplacement of the different facies in transtractives structures of the pull-apart type are characterized in the area by the main transcurrent shear zones of Taxaquara-Pirapora, Itu-Jundiuvira, Moreiras, Cangüera and Caucáia of ENE-WSW general direction. The massifs present complex internal architecture characterized by intrusions in restrict initial phase of intermediate equigranular nature. Also present a main phase of porfiroid monzo and sienogranite that fragments the previous phase, followed by lateral accretion of equi to inequigranular material, and in some cases by the accretion of late phases of circular bodies of porfiroid rapakivi granites, and a late to final phase of aplitic to pegmatitic composition. This magmatism grew with the intrusions of successive magmatic pulses, partially controlled by many reactivations of the shear zones. The REE also suggest that the magmatic phases are similar, synchronous and repetitive in four of the complexes in both domains, present in the São Francisco Complex. The crystallization starts from accretion processes, but compositionally quite different from the others. The variation in compositions and ages (TDM) for these granites reflect the derivation from different sources developed under different magmatic conditions, followed by processes of contamination that frequently occur in the crust.