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1
Moura-Fé, Marcelo Martins de. "Barreiras: Série, Grupo ou Formação? (Barreiras: Serie, Group or Formation?)". Revista Brasileira de Geografia Física 7, n. 6 (25 febbraio 2015): 1055. http://dx.doi.org/10.26848/rbgf.v7.6.p1055-1061.
Testo completoAbstract (sommario):
A Formação Barreiras se estende por quase todo o litoral brasileiro. Associado a esta amplitude espacial, diversas questões sobre esta formação sedimentar ainda se apresentam, impossibilitando um melhor entendimento sobre sua gênese, estratigrafia e sua denominação. Tais questões, presentes em vários pontos da historiografia científica, ganham status de verdadeiras lacunas, que são ressaltadas, sobretudo, quando se verifica um breve histórico dos estudos sobre a Formação Barreiras, os quais que se iniciaram desde 1902 e, ultrapassados mais de um século, ainda não encontraram respostas substanciais e amplas às indagações supracitadas, deixando vagas as lacunas que serviriam de base para uma melhor compreensão de como se originou, evoluiu e se diversificou essa formação geológica. A metodologia utilizada para a elaboração desse trabalho foi o de um detalhado embasamento teórico acerca da temática abordada. Os objetivos que permeiam este texto são o de apresentar e discutir um histórico sobre os estudos sobre a Formação Barreiras, sobretudo, dos que trataram da estratigrafia e correlatas denominações litoestratigráficas, de forma concomitante à evolução das designações utilizadas e seus significados para a compreensão desse importante substrato geológico de praticamente toda a zona costeira brasileira.
2
Rossetti, Dilce F., e Ana M. Góes. "Marine influence in the Barreiras Formation, State of Alagoas, northeastern Brazil". Anais da Academia Brasileira de Ciências 81, n. 4 (dicembre 2009): 741–55. http://dx.doi.org/10.1590/s0001-37652009000400012.
Testo completoAbstract (sommario):
Tidal processes were important for deposition of the Barreiras Formation located in northern Brazil, while correlatable deposits in northeastern Brazil have been traditionally related to continental environments. Facies analysis in southern Alagoas revealed that the Barreiras Formation consists of cross-stratified conglomerates and sandstones (facies Sx and Cgx), compound cross-stratified sandstones (facies Cx), and heterolithic beddings (facies H). A significant portion of these deposits occurs within channel morphologies displaying fining and thinning upward successions. An abundance of sedimentary features is comparable to those from the northern Brazilian counterpart. These include: tidal bundles; herringbone cross-stratification; heterolithic beddings with sandstone and mudstone beds in sharp contacts; and ichnofossils mostly consisting of Ophiomorpha nodosa, Skolithos and Planolites. Altogether, these features point to a marginal marine depositional setting dominated by tidal processes, which are related to an estuarine system, an interpretation also provided for the Barreiras Formation in northern Brazil. The widespread occurrence of deposits with unambiguous evidence of tidal processes in the Barreiras Formation of northern Brazil, and now in the State of Alagoas, leads to argue that the early/middle Miocene worldwide marine transgression might have left a much more widespread sedimentary record along the Brazilian coast than currently regarded.
3
Guimarães, José Tasso Felix, Afonso César Rodrigues Nogueira, José Bandeira Cavalcante Da Silva, Joelson Lima Soares e Rosemery Silveira. "Fossil Fungi from Miocene Sedimentary Rocks of the Central and Coastal Amazon Region, North Brazil". Journal of Paleontology 87, n. 3 (maggio 2013): 484–92. http://dx.doi.org/10.1666/12-091.1.
Testo completoAbstract (sommario):
Samples from outcrops of the Miocene Solimões and Barreiras formations from the central and coastal Amazon regions of Brazil were analyzed palynologically. Assemblages of fossil fungi were identified, and are described herein, and their relevance to paleoenvironmental and paleoclimatic studies in tropical regions discussed. The fungal assemblage comprises four spore groups, 19 species belonging to 12 genera. Additionally, two new species are proposed. The samples from the Solimões Formation contain the following taxa: Mediaverrunites elsikii, Mediaverrunites mulleri, Monoporisporites sp., Fusiformisporites crabbii, and Multicellites cingulatus. The presence of these suggests river channel margins colonized by freshwater vegetation, where seasonal fluctuations of water table and rainfall produce wetter substrates. The samples from the Barreiras Formation showed higher species and generic diversity than those from the Solimões Formation with Hypoxylonites minutus, Hypoxylonsporites ater, Hypoxylonites sp., the new species Inapertisporites multiporus n. sp., Pluricellaesporites regularis, Lacrimasporonites levis, Monoporisporites annulatus, Spirotremesporites simplex, Dyadosporites novus, Dyadosporites sp., and Multicellaesporites attenuates. All of these correspond to parasitic fungi from a range of from tropical wetlands. Spegazzinites sp. and Dicellaesporites aculeolatus, good indicators of marine influence and mangrove presence, were also identified in the samples from the Barreiras Formation. Furthermore, the fungal spore taxa Inapertisporites multiporus, Mediaverrunites elsikii, Mediaverrunites mulleri, Pluricellaesporites regularis, and Spirotremesporites simplex serve as stratigraphic indicators when combined with miospore index taxa such as Crassoretitriletes vanraadshooveni, Grimsdalea magnaclavata and Fenestrites longispinosus indicating a Miocene age for these sediments in the Amazon region.
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Messias Martins, Ramon, Angélica Fortes Drummond Chicarino Varajão, Fábio Soares de Oliveira, Thierry Allard, Cesar Augusto Chicarino Varajão e Caroline Delpupo Souza. "Degradation systems of ferruginous duricrust in the Barreiras Formation, Southeastern Brazil". CATENA 246 (novembre 2024): 108463. http://dx.doi.org/10.1016/j.catena.2024.108463.
Testo completo
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Ramos, Germano, Osvaldo Correia Filho, Flávia Cabral, Ewerton Bertoldo, Carlos Fabin e Virgínio Neumann. "GEOLOGIA DE SUPERFÍCIE E ASPECTOS ESTRUTURAIS DA REGIÃO DE RIO TINTO, FAIXA COSTEIRA DA BACIA DA PARAÍBA". Estudos Geológicos 31, n. 1 (21 giugno 2021): 44–68. http://dx.doi.org/10.18190/1980-8208/estudosgeologicos.v31n1p44-68.
Testo completoAbstract (sommario):
This work presents a geological 1:50.000 mapping survey for the Rio Tinto region, located in the coastal zone of Paraíba Basin, Miriri Sub-bacia. The mapping was supported by interpretation of satellite imagery, analysis of well lithologs, thin sections, and morphometric patterns. Basement rocks outcrops in approximately 10% of the study area, represented by Neoproterozoic granitoids. About 90% of the region is covered by Miocene-Pleistocene deposits and Quaternary sediments of the Barreiras, post-Barreiras formations, and coastal sandy and mangrove sediments, Pleistocene terraces, and Holocene eluvial-colluvial sediments. Analysis of cartography data and radar images showed that the relief is dominated by small plateaus and valleys formed by the Quaternary erosion of Barreiras Formation deposits, controlled by reactivation of the structural framework of the coastal zone. The Mamanguape River follows the homonymous fault, which trends ENE-WSW. The secondary drainage is also controlled by faults trending ENE-WSW, NW-SE, and N-S. Correlation of lithologs showed the occurrence of grabens and horsts formed during the late structural evolution of the coastal zone of the basin.
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Furrier, Max, e Saulo Roberto de Oliveira Vital. "A Formação de Dolinas em Áreas Urbanas: o Caso do Bairro de Cruz das Armas em João Pessoa-PB (The Formation of Dolines in Urban Areas: The Case of Cruz das Armas in João Pessoa-PB)". Revista Brasileira de Geografia Física 4, n. 1 (5 settembre 2011): 161. http://dx.doi.org/10.26848/rbgf.v4i1.232672.
Testo completoAbstract (sommario):
Evidências de dolinas são bastante comuns na cidade de João Pessoa-PB, mas ainda pouco estudadas. As dolinas são consideradas depressões fechadas, circulares, associadas a rebaixamento topográfico coadjuvado por fenômenos cársticos de sub-superfície, caracterizando um carste inumado. Assim como as encostas e os vales entalhados, as dolinas também são alvo da intensa ocupação nas cidades por parte da camada social menos favorecida, tendo em vista, serem áreas bastante deprimidas e susceptíveis a enchentes. A partir de então, esta pesquisa tem como objetivo, identificar os principais fatores de predisposição do terreno para criação de relevo do tipo carste, exclusivamente as dolinas e os riscos associados. Para isso, foram levantados dados sobre o embasamento geológico a partir do mapa geológico do Estado da Paraíba, e informações sobre a morfologia do terreno, coletadas a partir do radar SRTM (Shuttle Radar Topography Mission), além das observações de campo. Como produto, obteve-se os Modelos Digitais do Terreno, por meio dos quais se tornou possível realçar as evidências de subsidência do relevo local, corroborado pelas informações sobre a geologia local, marcada por uma intensa interação dinâmica entre as Formações Barreiras e Gramame (Sub-bacia Sedimentar Alhandra). Concluiu-se que os planos de falha existentes nos calcários da Formação Gramame contribuem de forma conspícua para percolação da água nessa formação perfazendo uma reação química capaz de dissolver o calcário, rebaixando a Formação Barreiras que se encontra sobreposta, dando origem a depressões circulares.Palavras-Chave: Dolinas, Formação Gramame, Formação Barreiras, João Pessoa. The Formation of Dolines in Urban Areas: The Case of Cruz das Armas in João Pessoa-PB ABSTRACTEvidence of dolines are much common in João Pessoa, the capital of the state of Paraíba, but they are still poorly studied. The dolines are considered to be closed and circled depressions, associated to a topographic smoothing assisted by subsurface karstic phenomenons, characterizing an inhumed karst. As well as the slopes and the carved valleys, the dolines are also intensively occupied in the city by people who are less favoured, what represents a serious problem considering that these are depressed areas and susceptible to flooding. The research aims to verify the major factors of the terrain susceptibility to the karst features formation, exclusively the dolines, and the associated risks. In view of this objective, the geological basement data were gathered from the geological map of the State of Paraíba and the terrain morphological information were collected from the SRTM radar (Shuttle Radar Topography Mission), besides the observations of the fieldwork developed. As result, the Digital Terrain Models were achieved enabling to present the evidences of the local subsidence features, corroborated by the information about the local geography marked by a intense dynamic interaction between Barreiras and Gramame Formation (Alhandra Sedimentary Sub-Basin). The analysis showed that the failed plans presented in the limestones of the Gramame Formation contribute evidently to the percolation of water on this formation totalizing a chemical reaction able to dissolve the limestone, lowering the superposed Barreiras Formation, what give rise to circular depressions. Key-Words: Dolines, Gramame Formation, Barreiras Formation, João Pessoa.
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SANTOS, Josiane, Marcondes COSTA e José Francisco SILVA. "A CONTRIBUIÇÃO DA FORMAÇÃO BARREIRAS COMO FONTE DOS SEDIMENTOS DOS MANGUEZAIS E DE FUNDO DO RIO MARAPANIM NA REGIÃO DE MARAPANIM (PA) COM BASE NA ASSINATURA DE MINERAIS PESADOS". BOLETIM DO MUSEU DE GEOCIÊNCIAS DA AMAZÔNIA 8 (2021), n. 1 (6 maggio 2021): 1–34. http://dx.doi.org/10.31419/issn.2594-942x.v82021i1a3jts.
Testo completoAbstract (sommario):
The techniques of investigation of heavy minerals using new analytical instruments were used to evaluate the contribution of the Barreiras Formation sediments as source material of the sediments of the Marapanim River estuary, in the northeast of Pará: bottom sediments and muddy plains (mangroves, mainly). The most suitable granulometric fraction is very fine sand, where they stood out in decreasing order of abundance: zircon, tourmaline, staurolite, kyanite and rutile, besides sillimanite, andalusite and amphibole. The frequency of these minerals, morphological aspects, inclusions, cavities, fractures indicate that the Barreiras Formation is the main source of these minerals. However, the semi-quantitative chemical data show that there seems to be an external contribution, perhaps from the sediments of the continental platform.
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Oliveira, Aline Pacobahyba de, João Carlos Ker, Ivo Ribeiro da Silva, Maurício Paulo Ferreira Fontes, Alessandra Pacobahyba de Oliveira e Alan Tadeu Goyatá Neves. "Spodosols pedogenesis under barreiras formation and sandbank environments in the south of Bahia". Revista Brasileira de Ciência do Solo 34, n. 3 (giugno 2010): 847–60. http://dx.doi.org/10.1590/s0100-06832010000300026.
Testo completoAbstract (sommario):
Morphologically differentiated Spodosols usually occur in the Coastal Plain of the South of Bahia and North of Espírito Santo. They are found in profiles known as "muçungas", i.e. sandy soils that accumulate water. In these areas, two kinds of Spodosols, different from those in the Restinga area, can be found: Spodosols with E albic horizon (white muçunungas) and without this horizon (black muçunungas). Eight soil profiles with spodic characteristics were collected and described in order to evaluate differences in the formation process of Barreiras and Restinga Spodosols in the South of Bahia. The soil profiles were also characterized chemically, physically and mineralogically. Additionally, texture and chemical analysis, Fe and Al extraction by sodium dithionite-citrate-bicarbonate (DBC), acid ammonium oxalate and sodium pyrophosphate, ammonium oxalate extract optic density (DOox), sulphuric acid attack, and X ray difractometry of the clay fraction were performed. In the Spodosols of the Barreiras area, fragipan was found the spodic layers. Cemented B spodic horizon were observed in the white muçunungas, and granular structure and dark color from the surface in the black muçunungas. There was no fragipan or hard spodic horizon in the Restinga Spodosol. This soil is acid, dystrophic and alic, with sandy texture and high clay percentages in the spodic horizons. The CEC, based on H + Al, is predominantly represented by the organic matter. The most representative components of the mineral phase of the clay fraction are kaolinite and possibly vermiculite traces with interlayered hydroxy. Chemical, physical, morphological and mineralogical differences were observed between the Barreiras and Restinga environments. The black and white muçunungas differ in morphologic and chemical properties only.
9
Rêgo, Lunara G. da S., Jéssia J. A. da Silva, Carolina M. M. Souza, Jeane C. Portela, Isadora N. B. M. de Moura, Ana C. R. da Silva e Neyton de O. Miranda. "Pedogenesis in the Barreiras Formation Under Climates of Rio Grande do Norte, Brazil". Journal of Agricultural Science 11, n. 16 (30 settembre 2019): 19. http://dx.doi.org/10.5539/jas.v11n16p19.
Testo completoAbstract (sommario):
In Brazil, the state of Rio Grande do Norte has an important coastal zone and coastal Tableland areas along the Barreiras Formation, but there are few studies to locate and characterize soils with cohesive character. Therefore, this work was carried out to characterize pedons in the western and eastern mesoregions of the state, located in the Barreiras Formation and with different climatic conditions. The profile description and sample collection were carried out in March and April 2016. The characteristics of the profile identified were the sequence of horizons and their depth, soil color, texture, structure, consistency, and transition between horizons. The physical analyzes were of soil density and texture. The chemical analyzes consisted of: pH in water and in KCl, contents of available P, Na+, K+, Ca2+, Mg2+, potential acidity, and total organic carbon. Indices obtained were: base sum, effective cation exchange capacity, cation exchange capacity at pH 7.0, base saturation, exchangeable aluminum saturation, and exchangeable sodium percentage. The profiles were classified up to the fourth categorical level. The mineralogical assembly was identified in the clay fraction of the diagnostic horizons. The identification of the minerals was performed by X-ray diffraction. The pedons of the two regions presented distinct characteristics and pedogenesis, occurring laterization in the pedons of the western mesoregion and podzolization in the pedons of the eastern mesoregion, both without presence of cohesive character as a diagnostic attribute.
10
Santos Júnior, Olavo Francisco,
Roberto Quental Coutinho e
Ricardo Nascimento Flores Severo. "Geotechnical properties of sediments of the Barreiras Formation in Rio Grande do Norte - Brazil". Geotecnia 134 (luglio 2015): 87–108. http://dx.doi.org/10.24849/j.geot.2015.134.05.
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SOUZA, LENA S. B., DILCE F. ROSSETTI, VAGNER R. ELIAS e RENATO L. PRADO. "Neotectonics in Marajó Island, State of Pará (Brazil) revealed by vertical electric sounding integrated with remote sensing and geological data". Anais da Academia Brasileira de Ciências 85, n. 1 (marzo 2013): 73–86. http://dx.doi.org/10.1590/s0001-37652013000100006.
Testo completoAbstract (sommario):
Studies suggest that the Marajó Island has experienced neotectonic activity during its latest evolution. However, there are no data demonstrating the presence of tectonic structures in its shallow subsurface. This work integrates vertical electric sounding, morphostructural lineaments, and geological data aiming to show fault control on the Late Pleistocene-Holocene sedimentation of this area. Resistivity values were related to mud (< 90 Ωm), clayey sand (90 and 200 Ωm), sand (200 and 500 Ωm), as well as Fe-bearing sand and laterite (> 500 Ωm). The latest values were related to the unconformity with lateritic paleosol at the top of the Barreiras Formation. Despite the values ≤ 500 Ωm of both the Barreiras Formation and the Late Pleistocene-Holocene unit, the latter was distinguished along four electric sections due to the presence of this unconformity, combined with the integration of available 14C, and luminescence ages of Quaternary sediments. The electric sections recorded several places with lateral interruptions of resistivity values within short distances, which were related to faults. The Miocene strata were vertically displaced by normal faults, giving rise to new accommodation space where Late Pleistocene-Holocene sediments were deposited. Fault reactivation was crucial to renew sedimentation in eastern Marajó Island during its latest evolutionary stage.
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Santos, Juciela, Roberto Coutinho e Juliane Marques. "Typical geotechnical profiles of the main soil deposits found in the Maceio city, Alagoas, from SPT boreholes". Soils and Rocks 45, n. 4 (8 novembre 2022): 1–10. http://dx.doi.org/10.28927/sr.2022.000122.
Testo completoAbstract (sommario):
This work had as objective to carry out the construction of typical soil profiles of the main existing deposits in the city of Maceio from a database of SPT boreholes, built in GIS environment. In total, 1,686 records of drilling were specialized in sediments of the Barreiras Formation, Coastal Deposits, and lagoons-river, presenting the most frequent characteristics, exemplified through representative profiles. The Barreiras Formation, which covers about 75% of the urban area of the city, presented profiles with a predominance of clayey, without water level records. The deposits lagoons-river, located in the vicinity of Mundaú lagoon, were characterized by the significant presence of soft and organic clays, sometimes peat, it can reach large thicknesses and with the water table rising in certain regions. In the coastal plain, where the highest vertical construction indices in the city are concentrated, it presented an area with a predominance of fine to medium sand, with or without silt, and a water table varying between 1,00 m and 5,00 m. The analysis also allowed for the identification and mapping of the occurrence of limestone rock, sandstone rock, soft and organic clay rocks in the coastal plain, presenting a typical profile of their occurrence, helping to understand the geotechnical behavior of these materials in the studied region.
13
Terto, Maria Luiza de Oliveira, e Marco Túlio Mendonça Diniz. "Caracterização e evolução da história natural da zona costeira de Tibau, Grossos e Areia Branca/RN". Revista Brasileira de Análise e Planejamento Espacial 1, n. 1 (20 aprile 2022): 4–28. http://dx.doi.org/10.51361/rebrape.v1i1.210.
Testo completoAbstract (sommario):
Geodiversity encompasses several aspects; pedological, hydrological, geological among others, of which we will deal with the geomorphological component, which acts as a record of different evolutionary processes throughout the Earth's natural history. Within this context, the present work aims to define the elements that occurred on the coast of Tibau, Grossos and Areia Branca/RN, serving as basis for undertanding the morphology of the area, serving as a basis for the further study or geodiversity. Recovering natural history, from the formation of the Potiguar Basin, with the separation of the Gondwana Super Continent, to the most recent morphological changes, bringing the constitution and age of constitution of the geological formations, the Tibau Formation, Jandaíra and Barreiras. As for the features, it was identified as barcanoid dunes(active and inactive dunes and sand sheets), marine deposits (Beach rocks), as well as alluvial deposits associated with the Apodi-Mossoró estuary , coastal plains, cliffs and association with coastal plateaus and presence of a reef line (Beach rocks).
14
Terto, Maria Luiza de Oliveira, e Marco Túlio Mendonça Diniz. "Caracterização e evolução da história natural da zona costeira de Tibau, Grossos e Areia Branca/RN". Revista Brasileira de Análise e Planejamento Espacial 1, n. 1 (20 aprile 2022): 4–28. http://dx.doi.org/10.51361/rebrape.v1i1.210.
Testo completoAbstract (sommario):
Geodiversity encompasses several aspects; pedological, hydrological, geological among others, of which we will deal with the geomorphological component, which acts as a record of different evolutionary processes throughout the Earth's natural history. Within this context, the present work aims to define the elements that occurred on the coast of Tibau, Grossos and Areia Branca/RN, serving as basis for undertanding the morphology of the area, serving as a basis for the further study or geodiversity. Recovering natural history, from the formation of the Potiguar Basin, with the separation of the Gondwana Super Continent, to the most recent morphological changes, bringing the constitution and age of constitution of the geological formations, the Tibau Formation, Jandaíra and Barreiras. As for the features, it was identified as barcanoid dunes(active and inactive dunes and sand sheets), marine deposits (Beach rocks), as well as alluvial deposits associated with the Apodi-Mossoró estuary , coastal plains, cliffs and association with coastal plateaus and presence of a reef line (Beach rocks).
15
SUGUIO, KENITIRO, ALCINA MAGNÓLIA FRANCA BARRETO e FRANCISCO HILÁRIO REGO BEZERRA. "Barra de Tabatinga and Touros Formations: evidence of pleistocene hich sea-level stillstands of the Rio Grande do Norte coast". Pesquisas em Geociências 28, n. 2 (31 dicembre 2001): 5. http://dx.doi.org/10.22456/1807-9806.20264.
Testo completoAbstract (sommario):
The Barra de Tabatinga Formation corresponds to the previous informally named Barra de Tabatinga unit, after a homonymous beach name. These marine terrace deposits occur along the present shoreline in patches between Natal and Barra de Sagi (ca. 80km). The summit of those deposits is about 7.5m above m.s.l. at Natal. They are composed of very friable clayey sandstones and conglomerates, exhibiting more-or-less conspicuous hydrodynamic sedimentary structures. The Touros Formation, after a homonymous town name, corresponds to the previous Tertiary Guamaré Formation, found by Petrobras only in subsurface. These marine terrace deposits extend, frequently as steep sea-cliffs along the present shoreline, between São Bento and Zumbi (ca. 120 km). The summit of these deposits reaches to a maximum of 20m above m.s.l., 2km to the N of Zumbi. Deposits are made-up of medium to coarse-grained sanstones, frequently well-cemented due to partial dissolution of biodetrital components. Hydrodynamic sedimentary structures, and trace fossils of Ophiomorpha nodosa, are very conspicuous. Both marine terraces, recently dated by TL and/or OSL methods, indicated Upper Pleistocene ages, and overlie unconformably the Neogene Barreiras Formation. Finally, as they fulfill all the requirements of the Brazilian Stratigraphic Nomenclature Code, as demonstrated in this paper, two new formations are formally proposed here.
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Santos, Marquilene Silva, Gilvonete Maria Araujo Freitas e Max Furrier. "Análise da Relação entre Declividade e Uso da Terra na Área Correspondente à Folha Pitimbu-Litoral Sul da Paraíba (Analysis of the Declivity and Land Use Relation in the Area Correspondent to Pitimbu Leaf-South Coast of Paraíba)". Revista Brasileira de Geografia Física 5, n. 1 (17 maggio 2012): 101. http://dx.doi.org/10.26848/rbgf.v5i1.232786.
Testo completoAbstract (sommario):
Diante do atual quadro de degradação ambiental decorrente do processo de ocupação do Litoral Paraibano, o desenvolvimento de estudos detalhados sobre o meio físico e o uso da terra torna-se essencial. Considerando isso, a presente pesquisa tem como objetivo identificar as formas de ocupação e uso da terra atual e sua relação com a declividade, na área correspondente a porção emersa da folha Pitimbu, localizada no litoral sul do estado da Paraíba. A área encontra-se inserida no domínio geomorfológico dos Tabuleiros Litorâneos, esculpidos, predominantemente, sobre os sedimentos mal consolidados da Formação Barreiras e, na Baixada Litorânea, constituída por depósitos Quaternários recentes. Com base na carta topográfica Pitimbu, escala 1:25.000, com equidistância das curvas de nível de 10 m e uso do Software SPRING 5.1.7, foi elaborada a carta clinográfica, e a interpretação de imagens do Satélite CBERS-2B possibilitou confeccionar a carta de ocupação e uso da terra. A partir dos resultados dessa pesquisa, constatou-se que as formas de ocupação e uso da terra na área, muitas vezes, acontecem em desacordo com a legislação vigente, provocando desequilíbrios ambientais, principalmente no tocante ao relevo e aos seus decorrentes processos.Palavras-chave: Ocupação e uso da terra, Pitimbu, Formação Barreiras, Tabuleiros Litorâneos. Analysis of the Declivity and Land Use Relation in the Area Correspondent to Pitimbu Leaf-South Coast of Paraíba ABSTRACTDue to the present environmental degradation as a result of the process of occupation in the Paraibano Coast, it is essential to develop detailed studies about the physical environment and the land use. Considering this fact, this research aims at identifying the forms of occupation and current land use and its relation with the declivity in the area corresponding to the onshore portion of Pitimbu Leaf, located on the southern coast of the State of Paraíba. The area is inserted in the geomorphologic field of the Coastal Tableland, which are predominantly carved on poorly consolidated sediments of the Barreiras Formation and on the Coastal Lowlands, made of recent Quaternary deposits. Based on Pitimbu topographic map, scale 1:25,000, with 10m equidistance interval of the contour-lines, and the aid of Software SPRING 5.1.7, the clinographic map was elaborated and the interpretation of the images from CBERS-2B satellite made it possible to elaborate the land occupation and use map. It was observed that the forms of occupation and land use in the area usually occur at odds with the current legislation, causing environmental imbalances, mainly with regards to the relief and its resulting processes.Key words: Land occupation and use, Pitimbu, Barreiras Formation, Coastal Tablelands.
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Fontoura, Tahyara, Roberto Coutinho e Bruno Morais. "2D stability and flow analysis of a slope in Recife - PE with Barreiras Formation soil in unsaturated conditions". MATEC Web of Conferences 337 (2021): 03017. http://dx.doi.org/10.1051/matecconf/202133703017.
Testo completoAbstract (sommario):
Due to the increase in the number of mass movements on hillslopes during the rainy season in the city of Recife, the importance of analyzing and understanding the unsaturated behavior of the soil is verified. Therefore, this paper covers the stability analysis of an unsaturated soil belonging to the Barreiras Formation located at an important hillslope of Recife. This area has been affected by landslides in 2000, and about 100 families were left homeless after losing their homes. The slope is approximately 56 m high and 414 m long (lined up with Chagas Ferreira Avenue). The results of physical characterization and parameters from shear resistance of soil obtained in laboratory tests are presented. The modeling work was divided in two parts: (1) transient unsaturated seepage analysis; (2) stability analyses. To achieve this, computational solutions were implemented applying the SLOPE / W and SEEP / W programs, which analyzes the stability and flow of the slope. For analyzes, a rainfall of July / 2019 and pontual leaks was considered in the values of of 0.5, 1.0 and 1.5 m3/day. It was possible to observe that, as the intensity of the leaks increased, the pore water pressure values increased considerably at the deepest levels. The water table was also compatible with the increase in the intensity of water infiltration. In the slope stability analyzes conducted was observed that the increase in moisture content and the decrease in suction during intense precipitation periods combined with leak infiltration reflect in the decrease in the safety factor to values around 1.
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Santiago, Raíssa, Fernanda Boina Marin, Fabrício de Andrade Caxito, Mirna Aparecida Neves, Caio Vinícius Gabrig Turbay Rangel, Salomão Silva Calegari e Cristiano Lana. "Detrital zircon U–Pb analysis indicate a provenance shift on the Neogene Barreiras formation, atlantic coast of Brazil". Journal of South American Earth Sciences 131 (novembre 2023): 104626. http://dx.doi.org/10.1016/j.jsames.2023.104626.
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Costa, Marcondes. "Observações de campo nos materiais lateríticos de Mosqueiro (Belém, Pará) como potenciais pigmentos minerais naturais". Boletim do Museu de Geociências da Amazônia 11, n. 4 (30 settembre 2024): 1–9. http://dx.doi.org/10.31419/issn.2594-942x.v112024i4a9mlc.
Testo completoAbstract (sommario):
Back in the 1980s, when I began exploring the cliffs of Baía do Sol (Mosqueiro, Belém, Pará), carved into immature laterite profiles derived from clayey and sandy sedimentary rocks of the Barreiras Formation, I was very impressed by the colorful tones of the mottled horizon in these profiles. With my children (they were still “children”) we played painting each other and it was really fun. When reading and studying cave paintings in the Amazon and around the world, it was evident, obviously, that these paintings were made with different materials, mainly Fe and Mn oxyhydroxides, coal, ash and organic extracts.
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Rossetti, Dilce F., Ana M. Góes, Francisco H. R. Bezerra, Márcio M. Valeriano, Benjamim B. Brito-Neves e Felipe L. Ochoa. "Contribution to the stratigraphy of the onshore Paraíba Basin, Brazil". Anais da Academia Brasileira de Ciências 84, n. 2 (26 aprile 2012): 313–34. http://dx.doi.org/10.1590/s0001-37652012005000026.
Testo completoAbstract (sommario):
Several publications have contributed to improve the stratigraphy of the Paraíba Basin in northeastern Brazil. However, the characterization and distribution of sedimentary units in onshore areas of this basin are still incomplete, despite their significance for reconstructing the tectono-sedimentary evolution of the South American passive margin. This work provides new information to differentiate among lithologically similar strata, otherwise entirely unrelated in time. This approach included morphological, sedimentological and stratigraphic descriptions based on surface and sub-surface data integrated with remote sensing, optically stimulated luminescence dating, U+Th/He dating of weathered goethite, and heavy mineral analysis. Based on this study, it was possible to show that Cretaceous units are constrained to the eastern part of the onshore Paraíba Basin. Except for a few outcrops of carbonatic rocks nearby the modern coastline, deposits of this age are not exposed to the surface in the study area. Instead, the sedimentary cover throughout the basin is constituted by mineralogically and chronologically distinctive deposits, inserted in the Barreiras Formation and mostly in the Post-Barreiras Sediments, of early/middle Miocene and Late Pleistocene-Holocene ages, respectively. The data presented in this work support tectonic deformation as a factor of great relevance to the distribution of the sedimentary units of the Paraíba Basin.
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Almeida-Filho, Raimundo, Dilce F. Rossetti, Fernando P. Miranda, Francisco J. Ferreira, Clauzionor Silva e Carlos Beisl. "Quaternary reactivation of a basement structure in the Barreirinhas Basin, Brazilian Equatorial Margin". Quaternary Research 72, n. 1 (luglio 2009): 103–10. http://dx.doi.org/10.1016/j.yqres.2009.02.010.
Testo completoAbstract (sommario):
AbstractThe Pirapemas Lineament is a remarkable 200-km-long, NE–SW trending structure in the Barreirinhas Basin, one of the several Brazilian coastal basins. This lineament splits the study area in two sectors of distinctive morphology, drainage patterns, and sedimentary covers. Terrain northward of the lineament presents a smooth topography with sub-parallel to sub-dendritic drainage patterns, whereas a dissected plateau characterized by incised valleys and rectangular drainage pattern occurs southward, suggesting a structural control by joints and faults. Geological field data, crossed with thermal luminescence (TL) and optically stimulated luminescence (OSL) dating, revealed that the surface southward of the lineament consists mostly of Miocene and late Pleistocene sedimentary deposits, represented by the Barreiras Formation and the Post-Barreiras sediments, respectively. In contrast, relatively younger sands mantle most of the northward terrain, as indicated by well-preserved paleodune deposits that grade into active aeolian dunes of the Lençóis Maranhenses National Park. Geomorphological and geological data analysis suggests that the northern sector is under the effect of subsidence, proving that the Pirapemas Lineament is an active agent modeling the landscape in the region. Geophysical data (gravity and seismic) confirm that such a structural feature is the surface expression of an active deep-seated basement fault.
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Nunes, Fábio Carvalho, Geraldo da Silva Vilas Boas, Francisco Ferreira Fortunato, Cláudia Cseko Nolasco de Carvalho, Lander de Jesus Alves e Majeti Narasimha Vara Prasad. "Paleoenvironmental records from the analysis of Barreiras Formation soils and organic matter dating (12 C, 13 C, 14 C)". Soil Advances 2 (ottobre 2024): 100010. http://dx.doi.org/10.1016/j.soilad.2024.100010.
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Heck, R. J., A. R. Mermut e M. C. Santos. "Iron oxides in plinthic soils on sedimentary deposits in northeastern Brazil". Revista Brasileira de Ciência do Solo 23, n. 3 (settembre 1999): 651–60. http://dx.doi.org/10.1590/s0100-06831999000300019.
Testo completoAbstract (sommario):
This study was conducted to examine the distribution and nature of Fe oxides in plinthic soils on the sediments of Barreiras Group (in the state of Piauí) and Itapecuru Formation (in the state of Maranhão) in Northeastern Brazil. Four pedons were selected: a "plinthic, dystrophic, epieutrophic Gray Podzolic with low activity clay" and a "dystrophic Plinthosol with low activity clay" (both Plinthic Kandiustalfs) on the Barreiras sediments, as well as an "eutrophic Plinthosol with low activity clay" and an "allic Plinthosol with low activity clay" (both Plinthustalfs) on the Itapecuru sediments. Soil samples were fractionated into > 2 mm (pisoliths), water-stable aggregates (plinthite) and matrices; the aggregates and matrices were further fractionated into sand, silt and clay sizes. Dithionite extractable iron (Fe d) and aluminum (Al d), as well as oxalate extractable iron (Fe o), were determined for all fractions, and X-ray diffraction analyses were performed on the pisoliths. It was observed that the Plinthustalfs contain more iron oxides, exhibit more extensive plinthite development and have a greater potential for further plinthite development than the Kandiustalfs. The distribution of values for the Fe d indicates that plinthite formation and induration in all soils were accompanied by an enrichment of Fe oxides in all particle size fractions. This Fe segregation was accompanied by aggregation of particles leading to a greater degree of crystallinity, as indicated by analysis of the ratios of Al d:Fe d. Larger ratios of goethite to hematite, and relatively smaller amounts of silicates in the more mature pisoliths were revealed by X-ray diffraction analysis. Ratios of Al d:Fe d were larger in the Kandiustalfs than in the Plinthustalfs, and also larger than expected for Al-substituted Fe oxides. According to ratios of Al d:Fe d, Fe mobilization in all soils has likely occurred under reducing conditions, facilitated by organic matter on the soil surface.
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Balsamo, F., F. Storti, F. Salvini, A. T. Silva e C. C. Lima. "Structural and petrophysical evolution of extensional fault zones in low-porosity, poorly lithified sandstones of the Barreiras Formation, NE Brazil". Journal of Structural Geology 32, n. 11 (novembre 2010): 1806–26. http://dx.doi.org/10.1016/j.jsg.2009.10.010.
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Lomnitz, Cinna, e J. Adauto de Souza. "On: “Observations of the air‐coupled waves as a function of depth,” by R. W. Knapp (GEOPHYSICS, 51, 1853–57, September 1986)". GEOPHYSICS 55, n. 6 (giugno 1990): 791. http://dx.doi.org/10.1190/1.1442893.
Testo completoAbstract (sommario):
Body waves critically refracted at the free surface may be the cause of the poor record quality in dry sandy loams, such as those of the extensive areas covered by the Barreiras formation in northeastern Brazil (Gomes and Souza, 1986). Records in these areas are corrupted by strong noise cones with a velocity of 340 m/s, usually identified as air‐coupled Rayleigh waves. The velocity at the top of the weathered layer should probably be at least 1.78 times the speed of sound in air for effective coupling between air waves and Rayleigh waves to take place. However, these so‐called “no‐record areas” are characterized by P-wave velocities less than the speed of sound in air.
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SOUSA, Cláudio José da Silva de, Welitom Rodrigues BORGES, Marcio Maciel CAVALCANTI e Karina Suzana Feitosa PINHEIRO. "RADAR DE PENETRAÇÃO NO SOLO APLICADO AOS SEDIMENTOS CENOZÓICOS NA ILHA DO MARANHÃO, NORDESTE DO BRASIL". Geosciences = Geociências 42, n. 4 (15 gennaio 2024): 523–36. http://dx.doi.org/10.5016/geociencias.v42i4.17129.
Testo completoAbstract (sommario):
RESUMO: Esse trabalho investiga os sedimentos cenozoicos na Ilha do Maranhão, nordeste do Brasil, a partir de radar de penetração no solo, antena blindada de 200 MHz e unidade de controle SIR3000. Perfis de reflexão obtidos entre a planície litorânea e os tabuleiros costeiros foram processados no módulo 2D data analysis do Reflex-Win. As seções GPR destacam reflexões de alta amplitude, contínuas a moderadamente contínuas, a aproximadamente 4 m de profundidade, separando duas regiões: uma rasa, de baixas amplitudes, com reflexões hiperbólicas a caóticas; e outra profunda, com amplitudes moderadamente altas, descontínuas, sinuosas, entremeadas por feições hiperbólicas a caóticas e por zonas de atenuação. Informações geológicas e de levantamentos regionais fundamentaram a correlação dos sinais de alta amplitude à superfície de descontinuidade sobreposta ao Grupo Barreiras. Ela é marcada por paleossolo laterítico, concreções ferruginosas, relevo erosional e sotoposta aos Sedimentos Pós-Barreiras. Hidrogeologicamente, essa discordância pode se constituir em uma superfície de retenção hídrica, favorável à formação de aquíferos suspensos, bem como de surgências ao longo das falésias costeiras. Feições indicativas de dobras, falhas e fraturas em profundidade, com continuidade nos depósitos rasos, sugerem a ação da tectônica neogênica resultante da reativação de falhas transcorrentes ao longo da margem passiva equatorial brasileira. Palavras-chave: Radar de penetração no solo. Sedimentos cenozoicos. Ilha do Maranhão. ABSTRACT: This work investigates the Cenozoic sediments in Maranhão Island, northeastern Brazil, from ground penetrating radar surveys, using a 200 MHz shielded antenna coupled to a SIR3000 control unit. Reflection profiles obtained between the plain and coastal hills were processed in Reflex-Win using the 2D data analysis module. Radargrams highlight continuous, moderately continuous reflections at approximately 4 m depth, separating two regions: one shallow, low amplitude, with hyperbolic to chaotic reflections; and another deep, with moderately high, discontinuous, winding amplitudes, interspersed with hyperbolic to chaotic features and attenuation zones. Geological information and regional surveys supported the correlation of high amplitude signals to the surface of discontinuity at the top of the Barreiras Group. It is under the Post Barreiras Sediments and is marked by lateritic palaeosol, ferruginous concretions and erosional relief. Hydrogeologically, this unconformity may constitute a water retention surface, favorable for lateral runoff, the formation of suspended aquifers, as well as emergence along the coastal cliffs. Features indicative of folds, faults and deep fractures, with continuity in shallow deposits, suggest the action of neogenic tectonics resulting from the reactivation of current faults along the Brazilian equatorial passive margin. Keywords: Ground penetrating radar. Cenozoic sediments. Maranhão Island.
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Boulet, R., E. Fritsch, H. F. Filizola, J. C. De Araujo Filho, J. C. Leprun, F. Barretto, E. Balan e D. Tessier. "Iron bands, fragipans and duripans in the northeastern plateaus of Brazil — properties and genesis". Canadian Journal of Soil Science 78, n. 3 (1 agosto 1998): 519–30. http://dx.doi.org/10.4141/s98-030.
Testo completoAbstract (sommario):
Iron bands, fragipans and duripans are common in yellow low-activity clay soils developed from the Barreiras Group in coastal plateaus of northeastern Brazil. Such indurated horizons are found in depressions of the plateaus where sugar cane growth is greatly reduced. Little research has being done on the nature of their bonding agents and their genesis. Research carried out in arid zones has frequently attributed duripan consistency to amorphous silica; however, duripans in northeast Brazil occur under higher rainfall (1500–2000 mm). The objective of this work was to study the nature and distribution of soil features in a plateau to better understand the processes associated with soil hardening. Two transects, across a small and a large depression, were investigated using field soil characterisation, micromorphological techniques, and mineralogical and geochemical analyses.The formation of the indurated horizons studied is due to two sequential processes: development of aquic conditions and incipient podzolization. Such processes have affected the upper part of a thin (<0.6 m in small depressions) or thick (>0.6 m in large depressions) compact clay horizon, showing horizontal plans likely inherited from the sediment. Onset of aquatic conditions formed the first fragipans overlying iron bands. Later, aquic conditions are combined with incipient podzolization to produce bleached loose horizons overlying duripans and iron bands. As the bonding agents in the duripans are organo-metallic complexes, these duripans appear to be very different from those described in arid environments. Key words: Low activity clay Ultisols, Barreiras Group, iron bands, fragipans and duripans, organo-metallic complexes
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Amédée Péret, Adriana De Castro, e Maria De Lourdes Rocha de Lima. "Research of the CAPES evaluation criteria and the dental faculty formation in a critical dimension". Revista da ABENO 5, n. 1 (2 febbraio 2005): 46–51. http://dx.doi.org/10.30979/rev.abeno.v5i1.1483.
Testo completoAbstract (sommario):
O presente estudo tem como objetivo analisar nos critérios de avaliação da CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) para a área de Odontologia as diretrizes referentes à pesquisa e sua influência na formação do docente em Odontologia, buscando identificar os limites e as possibilidades para o desenvolvimento de uma formação docente crítica e voltada para o social. Formação essa que contribua para a constituição do docente em Odontologia capaz de formar cidadãos críticos, que lutem por uma Odontologia Social. Para o desenvolvimento desta investigação utilizamos como recurso metodológico o estudo de documentos mediante a análise de conteúdo2 . A análise realizada apontou para a existência de barreiras para o desenvolvimento da formação do professor de Odontologia comprometida com as questões sociais e, conseqüentemente na perspectiva crítica. Isso pode ocorrer, visto que os critérios de avaliação da CAPES apresentam uma forte tendência produtivista, devido à valorização do afastamento do Estado do financiamento das pesquisas e da tendência da internacionalização. Por outro lado, pode-se encontrar nos critérios de avaliação a possibilidade de transpor estes obstáculos mediante a incorporação da pesquisa educativa (pedagógica), por meio da articulação ensino e pesquisa e, assim desenvolver competências como a crítica e a reflexão que podem contribuir para uma formação docente numa dimensão crítica.
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Behling, Hermann, e Marcondes Lima da Costa. "Mineralogy, geochemistry, and palynology of modern and late Tertiary mangrove deposits in the Barreiras Formation of Mosqueiro Island, northeastern Pará state, eastern Amazonia". Journal of South American Earth Sciences 17, n. 4 (dicembre 2004): 285–95. http://dx.doi.org/10.1016/j.jsames.2004.08.002.
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Pereira, Olegário Nelson Azevedo, Maria Antonieta Da Conceição Rodrigues e João Manuel Alveirinho Dias. "AN APPROACH TO THE CONTRIBUTION OF ANTHROPOGENIC ACTIONS FOR THE ARARUAMA LAGOONAL SYSTEM (SE BRAZIL) GEOMORPHOLOGICAL EVOLUTION / UMA ABORDAGEM SOBRE A INFLUÊNCIA ANTROPOGÊNICA NA EVOLUÇÃO GEOMORFOLÓGICA DO SISTEMA LAGUNAR DE ARARUAMA (SE, BRASIL)". Journal of Sedimentary Environments 3, n. 2 (28 giugno 2018): 108–20. http://dx.doi.org/10.12957/jse.2018.35533.
Testo completoAbstract (sommario):
The first studies regarding the constitution of the Araruama lagoonal system, located in the Rio de Janeiro state (SE Brazil), were carried out by Alberto Ribeiro Lamego. This author supported the thesis that it had resulted from the formation of a sand barrier (called Massambaba) due to the longitudinal transport of large quantities of sediments through coastal drift currents, and the growth of spits parallel to the shoreline. However, most recent studies largely rejected it, sustaining that the confinement of these hydric environments was the result of the growth of two sand barriers during the Pleistocene and Holocene times (120.000 to 7.000 years before present - BP) due to the sea level changes. The hypothesis that we suggest, is that both propositions are acceptable and complementary. This study aims to demonstrate that, despite the opinions on the formation of the double sand barrier, deposition of sediments by coastal drift currents at the end of the Holocene, and especially in recent chronologies, also contributed to the establishment of this lagoon system. In our opinion, the increased sediment supplies due to human activities contributed to the formation of the inner spits and the nearby sea sandbar. Its orientation was influenced by the existence of the island of Cabo Frio, that allowed the formation of the tombolo that almost connected it to the continent. Through the analysis of historical and cartographic documents related to the colonization and economic exploitation of the region, it is evident that the anthropogenic actions played a significant role in the sandy spits formation. Of these, special emphasis is placed on the agriculture and deforestation that contributed to the increase of sedimentary accumulation. This work demonstrate that the analysis of historical documents can provide information and contribute to the understanding of recent coastal developments. ResumoOs primeiros estudos sobre a constituição do sistema lagunar de Araruama, localizado no estado do Rio de Janeiro (SE Brasil), foram realizados por Alberto Ribeiro Lamego. Este autor apoiou a tese de que este sistema lagunar resultou da formação de uma barreira arenosa (denominada Massambaba) na sequência do transporte longitudinal de grandes quantidades de sedimentos através das correntes costeiras de deriva litorânea e ao crescimento de flechas arenosas paralelas à linha de costa. No entanto, estudos mais recentes, rejeitaram amplamente esta hipótese, e sugeriram que o confinamento desses ambientes lagunares resultou do crescimento de duas barreiras arenosas na sequência de mudanças no nível do mar ocorridas durante os períodos Pleistocénicos e Holocênico (120.000 a 7.000 anos antes do presente - BP). A hipótese que sugerimos é que ambas as hipóteses são aceitáveis e complementares. Este estudo tem como objetivo demonstrar que, apesar das opiniões sobre a formação da dupla barreira de areia, a deposição de sedimentos por correntes de deriva costeira no final do Holoceno, e principalmente em cronologias recentes, também contribuiu para o estabelecimento deste sistema lagunar. Em nossa opinião, o aumento do fornecimento de sedimentos devido às atividades humanas contribuiu para a formação das flechas arenosas interiores e do banco de areia exterior, próximo do mar. A sua orientação foi influenciada pela existência da ilha de Cabo Frio, que permitiu a formação do tombolo que quase a conectou ao continente.Através da análise de documentos históricos e cartográficos relacionados com a colonização e exploração econômica da região, evidencia-se que as ações antropogênicas tiveram um papel significativo na formação das flechas arenosas. De entre estas, salienta-se especialmente a agricultura e o desmatamento que contribuíram para o aumento da acumulação sedimentar. Este trabalho evidencia que a análise de documentos históricos pode fornecer informações e contribuir para a compreensão da evolução recente do litoral.
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Guedes, Saul, Roberto Coutinho e Antonio Viana da Fonseca. "Effect of Varying The Content And Length Of Fibers In The Behavior of A Cemented Soil Efecto del Contenido de Fibra y la Variación de Longitud en el Comportamiento de un Suelo Cementado". Revista de Geociências do Nordeste 10, n. 1 (9 aprile 2024): 238–54. http://dx.doi.org/10.21680/2447-3359.2024v10n1id33395.
Testo completoAbstract (sommario):
This study presents the results of the effects of variation in the content and length of polypropylene fibers, when inserted into a soil-cement mixture, aiming its use as a primary coating for dirt roads. In this study, the experimental models were used: 5% fast-curing cement, clay sand of the Barreiras geological formation and polypropylene fibers of 6 mm and 24 mm lengths, at levels from 0.25%, 0.50% and 0.75% relative to the total dry soil-cement mass. After completion of the unconfined compression tests and tensile strength by diametrical compression, it was found that increasing fiber content in the soil-cement matrix provides: increase in resistance of the materials, increase on the voids content and the strain, but, significantly reduces the initial tangent modulus making the more ductile material. In the terms of length, it observed clearly that the 24 mm fiber has a stronger influence on the mechanical behavior when inserted into the matrix of the developed composite material.
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Schiavo, Jolimar Antonio, Luiz Carlos Ruiz Pessenda, Antonio Alvaro Buso Júnior, Marcia Regina Calegari, Mileni Fornari, Mateus Luiz Secretti, Marcos Gervasio Pereira e Francis Edward Mayle. "Genesis and variation spatial of Podzol in depressions of the Barreiras Formation, northeastern Espírito Santo State, Brazil, and its implications for Quaternary climate change". Journal of South American Earth Sciences 98 (marzo 2020): 102435. http://dx.doi.org/10.1016/j.jsames.2019.102435.
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Ferreira da Silva, Breno Marques, Osvaldo de Freitas Neto, Olavo Francisco Santos, Nathália Marinho Barbosa, Fagner Alexandre Nunes de França e Eduardo Eiler Batista de Araújo. "Stability Evolution with Basal Erosion Increase in Cliffs on the Coast of Rio Grande do Norte, Brazil". Applied Mechanics and Materials 858 (novembre 2016): 342–47. http://dx.doi.org/10.4028/www.scientific.net/amm.858.342.
Testo completoAbstract (sommario):
The coastline is constantly in undergoing change, in terms of its position (retreat) and form. The retreat of coastal cliffs is a physical, dynamic and complex process that is controlled mainly by the geology of the area, strength properties of materials, marine conditions and climatic aspects of the region. This process is directly related to basal erosion, which is basically the mechanical destruction and/or removal of soil particles from the toe of coastal cliffs, caused mainly by wave action. Basal cliff erosion decreases the stability of the slope and may trigger mass movements and coast retreats. The coastal area of Rio Grande do Norte (Brazil) consists predominantly of sandy beaches and cliffs of Barreiras Formation. In this area, the human occupation has been increasing; therefore, it potentiates the probability of occurrence of mass movement. The objective of this study is to analyze the direct influence of basal erosion on stability of typical cliffs of the district of Tibau do Sul / Rio Grande do Norte - Brazil. The results showed that tensions are generated above the basal erosion as notch extension increases.
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Tenório, M. S. C., Z. V. Batista e G. M. D. Fernandes. "PETROGRAPHIC CHARACTERIZATION AND DIAGENESIS IN SANDSTONES OUTCROPS OF THE NORTHERN MACEIÓ FORMATION: IMPLICATIONS IN RESERVOIR QUALITY". Brazilian Journal of Petroleum and Gas 15, n. 1-2 (25 giugno 2021): 37–52. http://dx.doi.org/10.5419/bjpg2021-0004.
Testo completoAbstract (sommario):
The acquisition of geological data is of fundamental importance for the study of areas potentially relevant to the occurrence of petroleum systems. In this context, the development of research in outcropping rock formations has proven to be a potential method to investigate the geology of the geological unit studied in subsurface. One of several examples found in Brazil are the outcrops Barreiras do Boqueirão and Praia de Japaratinga, belonging to the Maceió Formation, located in the northern coast of Alagoas State. The Maceió Formation has the lowest cretaceous sedimentation record within the Alagoas Basin. This sedimentation, present almost in the entire basin, is located mainly in its subsurface. This geological unit is composed of several lithologies, including a turbiditic sequence predominantly formed by shales, sandstones and conglomerates. This environment makes it possible the occurrence of a petroleum system. Our research group chose to investigate this environment because turbiditic sandstones are excellent petroleum reservoirs, and they have a great economic relevance in the Brazilian petroleum scenario. To develop this research, a petrographic characterization of the Maceió Formation sandstones was conducted to help determine the compositional and diagenetic aspects of these rocks and infer the influence of diagenetic processes on the quality of these sandstones as reservoirs. The petrographic analysis showed that the studied sandstones can be classified as arkose and quartzenite, present moderate porosity and good permeability, observed through the predominant presence of floating contacts between the grains. The porosity is predominantly primary intergranular, averaging 15%, but secondary porosity by fracture and dissolution of primary grains also occurs. The sandstones of the Maceió Formation are poorly and moderately selected, with angular, sub-angular and sub-rounded grains, showing low to medium textural maturity, which may also influence the quality of the reservoir, impairing the primary porosity in the samples. The three diagenetic stages were identified as: eodiagenesis, mesodiagenesis, and telodiagenesis. The diagenetic processes found were: mechanical compaction, beginning of chemical compaction, clay infiltration, pyrite cementation, grain dissolution, chlorite cementation, quartz sintaxial growth, and mineral alteration and replacement. Mineral replacement was a phenomenon observed quite expressively in the samples analyzed. This event was evidenced, particularly, by the substitution of muscovite and feldspar for kaolinite, the alteration of biotite was also identified in the samples. Therefore, one can infer that the diagenetic processes had little influence on the reduction of the original porosity in the samples studied. In general, considering all the analyses performed in this research, one can see that the sandstones of the Maceió Formation (northern portion) present a good reservoir quality.
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COSTA, JOÃO B. S., YOCITERU HASUI, RUTH L. BEMERGUY, ADILSON V. SOARES-JÚNIOR e JAVIER M. C. VILLEGAS. "Tectonics and paleogeography of the Marajó Basin, northern Brazil". Anais da Academia Brasileira de Ciências 74, n. 3 (settembre 2002): 519–31. http://dx.doi.org/10.1590/s0001-37652002000300013.
Testo completoAbstract (sommario):
The Marajó Basin area presents geologic and geomorphologic features chiefly due to the Mesozoic extension and post-Miocene neotectonics. The extension event with an Early and a Late Cretaceous phases originated four sub-basins that constitutes the Marajó Basin, with a thick continental clastic sequence showing marine influence. NW and NNW normal faults and NE and ENE strike-slip faults controlled the basin geometry. The extension, related to the Equatorial Atlantic opening, propagated into the continent along crustal weakness zones of the Precambrian Tumucumaque, Amapá and Araguaia orogenic belts. The neotectonic event is a strike-slip regime which developed transtensional basins filled in by Upper Tertiary shallow marine (Pirabas Formation) and transitional sequences (Barreiras Group), followed by Quaternary fluvial deposits and transitional sequences derived from the Amazon and Tocantins rivers and the Marajoara estuary. The current landscape has a typical estuarine morphology. The coast morphology presents sea-cliffs on transitional Upper Tertiary sequences, while inwards dominate hills sustained by Mid-Pleistocene lateritic crust, with a flat erosive surface at 70 m. In the eastern Marajó Island several generations of paleochannels associated with fluvial-estuarine sequences are recognized, while a fluvial-marine plain is widespread on its western side.
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Nascimento, Vandetania Xavier, Claúdia Maria Salvador Vasconcelos e Marcela Rejane Silva Ferreira. "ESTUDO DA EROSÃO MARINHA NA PRAIA DE BARRA DE MAXARANGUAPE/RN". Revista da Casa da Geografia de Sobral (RCGS) 21, n. 2 (30 settembre 2019): 33–37. http://dx.doi.org/10.35701/rcgs.v21n2.598.
Testo completoAbstract (sommario):
A zona costeira é uma área que está em um equilíbrio dinâmico em decorrência da intermediação de fatores naturais e antrópicos, no entanto as consequências nocivas promovidas pelos agentes naturais tem sua dinâmica própria, e causa múltiplas reações que independem da ação humana, contudo, muitas vezes acelerados ou aumentados pela intervenção do homem. Geologicamente, toda faixa costeira do estado potiguar é constituída por rochas sedimentares de idade Cretácea, recoberta por rochas da Formação Barreiras e sedimentos Quaternários, como dunas, rochas praiais, terraços marinhos e aluvionares com coberturas arenosas diversas. Este trabalho busca entender os efeitos causados pela erosão costeira na vida dos moradores locais. Para atingir os objetivos propostos foi realizado uma visita in loco, onde aplicamos uma entrevista com 10 pescadores da área, os resultados obtidos demostram que a erosão da praia tem provocado o desequilíbrio na economia local, desapropriação de residências e pousadas, desemprego e a ausência de turismo. O assoreamento no estuário do rio Maxaranguape, tem alterado a dinâmica das embarcações pesqueiras que ali ficam atracadas, prejudicando os rendimentos financeiros dos pescadores.Palavras-chave: Maxaranguape; Zona costeira; Erosão ABSTRACT The coastal zone is an area that is in a dynamic equilibrium due to the effect of natural and anthropic factors; however, the harmful consequences promoted by natural agents have their own dynamics, and cause multiple reactions that are independent of human action, many times increased by man's intervention. Geologically, all the coastal zone of the Potiguar state is constituted by sedimentary rocks of Cretaceous age, covered by Rocks of the Barreiras Formation and Quaternary sediments, like dunes, beach rocks, marine and alluvial terraces. This work want to understand the effects caused by coastal erosion on the lives of local residents. To achieve the proposed objectives, an on-site visit was carried out, where we interviewed ten fishermen from the area. The results show that beach erosion has caused an imbalance in the local economy, expropriation of homes and inns, unemployment and lack of tourism. The siltation in the estuary of the Maxaranguape river has altered the dynamics of the fishing boats that are there, damaging the financial income of the fishermen.Keywords: Maxaranguape; Coastal zone; Erosion.
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ANDRÉ, Jefferson Lima Fernandes, Luiza Alves GARCIA, Lucas Dias SANTIAGO e Aurélio Fagundes SILVA. "FÁCIES SEDIMENTARES DAS ROCHAS AFLORANTES NO NORTE DO ESTADO ESPÍRITO SANTO, PORÇÃO ONSHORE DA BACIA SEDIMENTAR DO ESPÍRITO SANTO". Geosciences = Geociências 43, n. 4 (19 dicembre 2024): 497–514. https://doi.org/10.5016/geociencias.v43i4.18373.
Testo completoAbstract (sommario):
RESUMO - No presente estudo pretende-se contribuir sobre a compreensão geológica da porção onshore Bacia Sedimentar do Espírito Santo, onde há poucos estudos publicados. Identificaram-se fácies sedimentares de maior ocorrência como fácies rudáceas, areníticas e lamíticas, com cores branca a cinza claro, formando depósitos tabulares com gradação normal e interacamadados. Estratificações acanaladas incipientes foram observadas, assim como feições de acresção lateral, escavação e preenchimento de canais. As fácies areníticas e rudáceas são mal selecionadas, matriz-suportadas, constituídas principalmente de quartzo, feldspato (alguns bem preservados) e argilominerais diagenéticos e, também fragmentos do embasamento, rochas sedimentares e uma possível contribuição de material vulcanossedimentar. Os lamitos são pouco espessos, tabulares e raramente bioturbados. Além dessas fácies, foi identificado um espesso depósito conglomerático de matriz areno-argilosa, possivelmente decorrente de um fluxo de alta densidade, já que contêm blocos dispersos de argilito na porção basal e, mais ao topo, seixos orientados e estratificação plano-paralela, indicando corrente unidirecional de alta velocidade. Faz contato erosivo na base com um arenito fino e bem selecionado, que está depositado próximo ao embasamento. Considerando as formas de ocorrência, estruturas e características faciológicas, sugere-se a evolução em ambiente fluvial entrelaçado, em condição de aporte/nível de base que permitiu a deposição próximo à área fonte. Palavras chaves: Fácies sedimentares. Porção onshore da Bacia Sedimentar do Espírito Santo. Formação Rio Doce. Formação Barreiras. ABSTRACT - In the present study, the aim is to contribute to the geological understanding of the onshore portion of the Espírito Santo Basin. The most common sedimentary facies were identified, such as rudaceous, arenitic, and lamitic facies, with colors ranging from white to light gray, forming tabular deposits with normal grading and interbedded layers. Incipient cross stratifications and lateral accretion, channel excavation, and filling features were observed. The arenitic and rudaceous facies are poorly sorted, matrix-supported, and consist mainly of quartz, feldspar (some well-preserved), diagenetic clay minerals, and fragments from the basement, sedimentary rocks, and possibly some contribution of volcanosedimentary material. The lamites are thin, tabular, and rarely bioturbated. Different of these facies, a thick conglomerate deposit with a sandy-clay matrix was identified, possibly resulting from a high-density flow, as it contains dispersed claystone blocks in the basal portion and upward, oriented pebbles and planar-parallel stratification, indicating a high-velocity unidirectional current. It has an erosive contact at the base with a fine and well-sorted sandstone deposited near the basement. Considering the occurrence forms, structures, and facies characteristics, an evolution in a braided fluvial environment is suggested, in a condition of sediment supply/base level that allowed continental deposition. Keywords: Sedimentary facies. Onshore portion of the Espírito Santo Sedimentary Basin. Rio Doce Formation. Barreiras Formation.
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Coutinho, Roberto, Bruno Morais, Rodolfo Mendes e Marcio Andrade. "Alert scenarios for the Metropolitan Region of Recife-PE based on monitoring of rainfall and soil humidity – a case study". Soils and Rocks 46, n. 4 (23 novembre 2023): e2023008323. http://dx.doi.org/10.28927/sr.2023.008323.
Testo completoAbstract (sommario):
In Brazil, landslides are frequent, causing deaths and property damage, and occur under the influence of natural and/or anthropic conditions. Rain acts as the main non-anthropic agent in triggering this phenomenon. Because of this, the prediction of landslides becomes an essential tool for managing high-risk areas. The Metropolitan Region of Recife (MRR) has a large history with numerous cases of mass movements over the years. Currently, research points out improvements in the quality of forecasts by including hydrological information, such as soil moisture, in warning systems. Given the importance of measuring soil moisture in situ, a network of equipment consisting of rain gauges and capacitive moisture sensors was installed in the MRR, to monitor rainfall and soil moisture in an integrated manner. The objective of this article is to understand the hydrological conditions of the soil in two high-risk areas of the MRR, built over the Barreiras Formation to set the foundations for the development of a Landslide Early Warning System (LEWS) that integrates rain and humidity. The data showed that the variation in soil moisture is very dependent on rainfall and presents sudden variations in moisture with increasing hourly rainfall. The data also revealed that the monitored soils remained wet for approximately six months in the year 2022, highlighting the potential for moderate rainfall during this period to trigger landslides.
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Sousa, Jefferson Lucas Matias, e Francisco Soares Santos-Filho. "Estudos Botânicos nos Tabuleiros Litorâneos do Brasil". Revista Brasileira de Geografia Física 13, n. 3 (7 giugno 2020): 1335. http://dx.doi.org/10.26848/rbgf.v13.3.p1335-1347.
Testo completoAbstract (sommario):
Estudos que visam conhecer a vegetação de tabuleiros são cruciais para a compreensão da distribuição das espécies, identificação de possíveis áreas de endemismo e relações ecológicas. O objetivo do trabalho foi realizar uma análise cienciométrica de trabalhos científico sobre a flora dos tabuleiros do Brasil nas últimas duas décadas, tais informações serão importantes para elucidar de que forma esse ambiente está sendo estudado, bem como para apontar possíveis lacunas e onde os esforços de pesquisadores precisam ser aplicados. Nas principais bases de dados, foram feitas pesquisas utilizando as palavras “tabuleiro” e “tableland” associado aos nomes dos 13 Estados que apresentam esse tipo de formação. Foram selecionados então produções dos campos da botânica e da ecologia vegetal. A fim de permitir uma comparação da representatividade dos estudos frente à dimensão das áreas litorâneas dos Estados propôs-se um Índice de Cobertura de Estudos Ambientais (ICEA). Nos 13 estados que apresentam a Formação Barreiras, foram encontrados 23 estudos. Artigos científicos (65,2%) e capítulos de livros (21,7%) foram o principal meio utilizado pelos pesquisadores para divulgarem seus resultados. Constatou-se a existência de estudos apenas nas regiões Nordeste e Sudeste do Brasil. Alagoas, Piauí e Espírito Santo foram os Estados que apresentaram o maior ICEA. O presente estudo demonstrou através de seus resultados que esse ecossistema não está recebendo a atenção que merece, sobretudo da comunidade científica voltada para a pesquisa ambiental. É recomendado um esforço maior, principalmente na região Norte, onde jamais uma pesquisa botânica foi feita tendo os tabuleiros daquela região como foco. Botanical Studies in Brazilian Coastal TraysA B S T R A C TStudies aimed at knowing the vegetation of trays are crucial for understanding species distribution, identifying possible areas of endemism and ecological relationships. The objective of this work was to perform a scientific analysis of scientific work on the flora of the Brazilian trays over the last two decades, such information will be important to clarify how this environment is being studied, as well as to point out possible gaps and where researchers need to be applied. In the main databases, searches were made using the words “board” and “tableland” associated with the names of the 13 states that present this type of formation. Productions from the fields of botany and plant ecology were then selected. In order to allow a comparison of the representativeness of studies in relation to the size of the coastal areas of the States, an Environmental Studies Coverage Index (ESCI) was proposed. In the 13 states that present the Barreiras Formation, 23 studies were found. Scientific articles (65.2%) and book chapters (21.7%) were the main means used by researchers to disseminate their results. Studies were found only in the Northeast and Southeast regions of Brazil. Alagoas, Piauí and Espírito Santo were the states that presented the largest ESCI. The present study demonstrated through its results that this ecosystem is not receiving the attention it deserves, especially from the scientific community focused on environmental research. A larger effort is recommended, especially in the Northern region, where botanical research has never been done.Keywords: Coastal tray, botanic studies, scientometry.
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Gomes, Maria Da Conceição Rabelo, Adryane Gorayeb, Dimas De Brito Souza e Raquel Morais Silva. "Analysis of the Levels of Alteration of Aquifers Caused by the Installation of Wind Farms on Dunes on the Coast of Ceará, Brazil". Ambiente e Agua - An Interdisciplinary Journal of Applied Science 14, n. 6 (30 ottobre 2019): 1. http://dx.doi.org/10.4136/ambi-agua.2430.
Testo completoAbstract (sommario):
This research evaluated the levels of alteration of aquifers caused by installation of wind farms on dunes on the coast of Ceará, using the GOD and POSH methods of vulnerability, underground flow, and the application of multivariate analysis to subsidize the monitoring of groundwater quality in the area. There were three stages of field study: registering the wells and pollution sources, measuring the water levels, and groundwater sampling for laboratory analysis. The results obtained with the GOD method demonstrate the predominance of moderate- to high natural vulnerability of the aquifer to pollution in the areas close to the wind park in the district of Amarelas (Xavier and Ziu beach) and revealed high pollution loads according to the POSH method. The directional vectors of the underground flow are meaningful for Xavier Beach (high vulnerability), the center of Amarelas (moderate vulnerability), Tapuiu and Montevideo (low vulnerability). This indicated that the wind farm may have a potential impact on the lowering of groundwater in the area. From the multivariate analysis, it is evident that the groundwater characteristics are strongly related to the geological formation of the wells (Dunas and Barreiras), showing all samples within the Tolerable Maximum Value for human consumption for TDS, hardness, turbidity, and pH. It is vital to carry out preliminary studies of the aquifers underlying the areas where wind farms are to be installed, considering the levels of vulnerability and the risks of pollution and alteration of the water supply.
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Medeiros, Allan, Romário Silva, Valteson Santos, Olavo Santos Junior, Ricardo Severo, Osvaldo Freitas Neto e Bruna Lira. "Influence of the degree of saturation and the wetting front on the stability of cliffs: a case study on a cliff located on the beach of Tabatinga-RN-Brazil". Soils and Rocks 46, n. 4 (22 novembre 2023): e2023005423. http://dx.doi.org/10.28927/sr.2023.005423.
Testo completoAbstract (sommario):
Coastal zones are of great interest in civil engineering due to their economic relevance and active geological dynamics. In Brazil, the development of these regions is related to the use of their geomorphological features in the landscape, among which the cliffs stand out. Although there are studies that consider the influence of the wetting front in stability analysis with cliffs, in general, the studies only consider extreme saturation situations (dry and saturated). In this sense, the present study aims to understand the influence of the wetting front and the degree of saturation reached by the materials in the stability of cliffs composed of Barreiras Formation soil. The stability analyses were carried out using the limit equilibrium method and stress analysis, varying the degrees of saturation of the materials and wetting fronts of a model of a cliff located at Praia de Tabatinga, State of Rio Grande do Norte, Brazil. Failures were identified, in different wetting fronts, by the limit equilibrium method from degrees of saturation around 20%, and by the stress analysis method around 40%. Thus, it was concluded that the variation in the degree of saturation has a preponderant effect on the destabilization of a cliff, since partial saturations are already enough to trigger significant mass movements. It was also noticeable that the wetting front is a relevant effect on instability, although conditioned to the degree of saturation reached, which may enhance the order of magnitude of the identified failures.
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Rocha, Gustavo Rodrigues da, e Helenice Vital. "MORPHOLOGICAL CHARACTERIZATION OF THE POTENGI RIVER ESTUARINE SYSTEM, NATAL (BRAZIL)". Revista Brasileira de Geofísica 33, n. 1 (1 marzo 2015): 141. http://dx.doi.org/10.22564/rbgf.v33i1.649.
Testo completoAbstract (sommario):
ABSTRACT. This study mapped the Potengi estuary riverbed (Natal-RN), located in northeastern Brazil, using high-resolution geophysics (single beam and side-scan sonar) associated with sediment samples. The imaging of subaqueous features allowed to identify the bedforms and submerged rocky outcrops. Four main groups of bedforms were identified: large 2-D and 3-D dunes, ripples and flat bottom, as well as rocky outcrops. Rocky outcrops were correlated to Barreiras Formation and beachrocks. The estuarine channel is filled mainly by Holocene sandy sediments in the main channel ranging from well-sorted to sorted grains, and silty sediments in the river margins. The integration and analysis of these results contribute to a better understanding of tropical estuaries.Keywords: high-resolution geophysics, bathymetry, side scan sonar, bed forms.RESUMO. Este estudo teve como principal objetivo o mapeamento do substrato do estuário do Rio Potengi (Natal-RN), localizado no Nordeste do Brasil, utilizando geofísica de alta resolução (dados batimétricos monofeixe e sonográficos) associada à amostragem de sedimentos. O imageamento das feições subaquáticas permitiu a identificação das formas de leito, bem como de afloramentos rochosos submersos. Foram identificados quatro grupos principais de formas de leito: dunas 2D e 3D de grande porte, ripples e fundo plano, além de afloramentos rochosos. Quanto à composição dos sedimentos holocênicos que preenchem o rio, estes são predominantemente arenosos (canal principal), variando de selecionados a bem selecionados, por vezes siltosos (margens do rio). Os resultados obtidos contribuem para uma melhor compreensão dos estuários tropicais.Palavras-chave: geofísica de alta resolução, batimetria, imageamento sonográfico, formas de leito.
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Silva, Elidiane da, Nilton Curi, Mozart Martins Ferreira, Margarete Marin Lordelo Volpato, Walbert Júnior Reis dos Santos e Sérgio Henrique Godinho Silva. "PEDOTRANSFER FUNCTIONS FOR WATER RETENTION IN THE MAIN SOILS FROM THE BRAZILIAN COASTAL PLAINS". Ciência e Agrotecnologia 39, n. 4 (agosto 2015): 331–38. http://dx.doi.org/10.1590/s1413-70542015000400003.
Testo completoAbstract (sommario):
Pedotransfer functions (PTFs) are equations used to estimate soil characteristics difficult to determine from other easily obtained ones. Water retention in soil is used in several agronomic and environmental applications, but its direct determination is time consuming and onerous, therefore PTFs are alternatives to obtaining this information more quickly and economically. The aims of this study were to generate a database and develop PTFs for water retention at potentials of -33 kPa (field capacity) and -1500 kPa (permanent wilting point) for Yellow Argisol and Yellow Latosol from the Brazilian Coastal Plains region. The Coastal Plains soils are mostly developed from Barreiras formation (pre-weathered sediments) and their main uses are sugarcane, livestock, forestry and fruticulture. The database to generate the PTFs was composed from the selection of information derived from scientific works and soil survey reports of the region. Specific PTFs were generated for each soil class, in their respective A and B horizons and for solum, through multiple regression by stepwise package of R language programming. Due to the small pedological variability (small number of soil classes containing great geographical expression) and mineralogical uniformity, usually observed in this environment, non-stratification of soil classes to create general PTFs presented similar or superior results compared to equations for each soil class. The adjustment of data demonstrated that water retention values at -33 kPa and -1500 kPa potentials can be estimated with adequate accuracy for the main soils of the Brazilian Coastal Plains through PTFs mainly from particle size distribution and secondarily from organic matter data.
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Campos, Thomas Ferreira da Costa, Kenji Freire Motoki, Valéria Fonsêca da Silva Pastura, Susanna Eleonora Sichel e Estefano Monteiro Fonseca. "Gamma radiation of the street corners from South zone of Natal city, Rio Grande do Norte, Brazil". Brazilian Journal of Radiation Sciences 10, n. 4 (20 dicembre 2022): 1–23. http://dx.doi.org/10.15392/2319-0612.2022.2053.
Testo completoAbstract (sommario):
This research had the objective of studying the absorbed dose of the street corner intersections from the South zone of Natal city, Brazil. This city grew up on dune lands, on siliciclastic rocks from Barreiras Formation, these dunes are quartz-sand and have heavy mineral layers bearing uranium and thorium (monazite, xenothymeo, thorianite, ilmenite, rutile, zircon, magnetite and columbite-tantalite). Not all streets in Natal city have paving, in the part with more movement they have asphalt covering over cobblestone, in the less busy have cobblestone covering, and in the quiet streets are in natural dune sand. In situ Gamma radiation measurements were performed with three portable spectrometers model RS-230 with BGO crystal, about 1 meter above the ground. The absorbed dose ranged from 11 to 150 ƞGy/h (MG: 40; Median: 39; SD: 18). In gamma spectrometry measure, Uranium varied between 0.1 to 6.2 Eq.A. ppm (MG: 1.6; Median: 1.4; SD: 1), Thorium between 0.7 to 32 Eq.A. ppm (MG: 6; Median: 5; SD: 3.3), Potassium ranged between 0.1 to 3.9 Eq.A. % (MG: 1.2; Median: 1.2; SD: 0.7). The values of the absorbed dose of external radiation measured in the studied street corners show values lower than the world average of 59 ƞGy/h, and annual effective dose is also lower than the global average value of 0.48 mSv/a. Areas with higher U-K contents correspond to areas with asphalt/cobblestone capping, while areas with higher Th contents correspond to sandy streets and dunes in protected areas. This fact denote a lower radiometric risk to the population.
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Silveira, Vitor E. P., Natália B. dos Santos, Daniel R. Franco, Emanuele F. la Terra, Joshua M. Feinberg, R. B. Scorzelli, Magda B. Fontes et al. "Environmental magnetism evidence for longshore drift distribution of Fe-bearing phases: An example from the Brazilian southeastern coastal region". Journal of Sedimentary Research 91, n. 11 (5 novembre 2021): 1133–50. http://dx.doi.org/10.2110/jsr.2020.089.
Testo completoAbstract (sommario):
ABSTRACT The accumulation of heavy minerals along a part of the southeastern Brazilian coast (northern coast of Rio de Janeiro State, Brazil) provides insight into sedimentary provenance and transport by longshore drift. In particular, recent work has focused on heavy minerals as tracers to determine sedimentary sources and transport pathways, indicating a mineral distribution according to the northward and southward coastal transport cells. There is also evidence of heavy-mineral transport by the Paraíba do Sul River. However, research has not been done in this area on the opaque fraction (iron oxides and oxyhydroxides), which are good tracers for provenance and distribution processes. Here we intend to: 1) characterize the spatial variation of the magnetic properties of heavy-mineral contents throughout a coastal area of the Itabapoana and Paraíba do Sul River mouths (state of Rio de Janeiro), 2) evaluate the contribution of coastal dynamics on the mineral distribution along this coastal area, 3) provide contributions on the provenance of iron-bearing minerals. Results indicate that a bimodal pattern was observed for the magnetic remanence of magnetite and hematite near the Paraíba do Sul River. For the northernmost section, goethite exhibits a gradual increase in concentration towards the central part of the study area. Additionally, higher heavy-mineral content is observed at the northern coastal section, which may be related to coastal morphology, which is exposed to high-energy beach processes. It is possible to verify three sampling groups in accordance with their magnetic properties: 1) the “southernmost” and 2) the “northernmost” groups, suggesting a mineral provenance related to the Paraíba do Sul and Itabapoana rivers, respectively, as possible major sources, and 3) another at the intermediate section of the area, possibly linked to the erosion of the Barreiras Formation bluffs. Results also show a correspondence between the variability of magnetic parameters and the main directions of the coastal transport cells.
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Santos, Joildes Brasil dos, e Selma Simões de Castro. "PARÂMETROS FÍSICO-AMBIENTAIS EM ÁREAS COM POSSIBILIDADE DE OCORRÊNCIA DE SOLOS COESOS DA DEPRESSÃO DO SÃO FRANCISCO-BA: O Caso da Fazenda Caracol-BA (Physical and environmental parameters of the areas with possibility of cohesive soils in the ...)". Revista Brasileira de Geografia Física 9, n. 6 (8 novembre 2016): 1690. http://dx.doi.org/10.26848/rbgf.v9.6.p1690-1702.
Testo completoAbstract (sommario):
O caráter coeso do solo é utilizado pelo SiBCS - Sistema Brasileiro de Classificação de Solos, para solos que apresentam horizonte extremamente endurecido entre 30-70cm de profundidade, caracterizado por forte adensamento natural, cuja a origem ainda não é conclusiva, embora se destaque o processo de silicificação e de argiluviação como as principais. Ocorrem em regiões semiáridas e áridas, como no NE brasileiro, onde estão associados aos tabuleiros costeiros sustentados por sedimentos terciários e quaternários, como os do Grupo Barreiras, onde são mais estudados. Fora dessa Formação são pouco conhecidos, como na Depressão do São Francisco-BA onde solos com horizontes endurecidos sugerem presença de solos coesos. Nesse sentido, o presente artigo se propõe a discutir a relação entre o caráter coeso nos solos e os parâmetros físico-ambientais da paisagem, mais especificamente da Fazenda Caracol-BA, em que tais horizontes vêm dificultando a atividade agrícola. A pesquisa foi realizada a partir da construção de um banco de dados georreferenciados no software Arcgis 10.1 relativos a altitude e declividade gerados a partir de imagens SRTM (TOPODATA), os dados de solos foram do Relatório de Levantamento Pedológico da própria fazenda e os dados de uso e cobertura foram gerados a partir da classificação das imagens Landsat-8 segundo as normas do IBGE. Entre os parâmetros analisados, destaca-se o papel da sílica e da argila, que a partir de interpolações dessas variáveis foram núcleos de acumulação de argila entre 0-20 e 20-40cm, e de sílica a partir de 100cm de profundidade, indicando possível ocorrência do caráter coeso nos solos estudados, embora diferente do preconizado pelo SiBCS. A B S T R A C T The cohesive nature of the soil is used by the Brazilian System of Soil Classification, for soils with extremely hardened horizon between 30-70cm deep, characterized by strong natural densification, whose origin is still not conclusive, although it highlighted the process of silicification and Argilluviation as the main. Occur in semi-arid and arid regions, such as the Brazilian NE, which are associated with coastal tablelands supported by tertiary and quaternary sediments, such as the Barreiras Group. Out of this formation are not well known, as in the Depression of the San Francisco-BA where soils with hardened horizons suggest the presence of cohesive soils. In this sense, this article aims to discuss the relationship between the cohesive character in the soil and the physical and environmental parameters of the landscape, specifically the Treasury Snail-BA, where these horizons have hindered agricultural activity. The survey was conducted from building a georeferenced database on 10.1 Arcgis software for the altitude and steepness generated from SRTM images (TOPODATA) .The soil data were from the farm itself Pedological Survey Report and data use and coverage were generated from the Landsat-8 image classification. Among the analyzed parameters, there is the role of silica and clay. From the interpolations of both variables were identified clay accumulation cores between 0-20 and 20-40cm deep, and silica from 100cm depth, indicating possible occurrence of cohesive character in the soils, although different from recommended by SiBCS.. Keywords: Character Cohesive, Physical Environmental Parameters, cementing agents
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Madeira, Viviane. "Associativismo, correspondência e periodismo: tecendo uma rede de intelectuais feministas de língua portuguesa/ Associations, Letters and the Periodic Press: Weaving a Network of Portuguese-Speaking Feminist Intellectuals". Revista do Centro de Estudos Portugueses 42, n. 67 (27 ottobre 2022): 161. http://dx.doi.org/10.17851/2359-0076.42.67.161-180.
Testo completoAbstract (sommario):
Resumo: O presente artigo estuda e descreve algumas das cartas que fazem parte do Espólio Osório de Castro (N12) e do Fundo da Federação Brasileira para o Progresso Feminino (BR RJANRIO Q0) com o intuito de mapear a formação de uma rede intelectual transnacional que conta com a escritora, ativista feminista e professora goesa Maria Ermelinda dos Stuarts Gomes (1889-1937) e a ativista feminista e escritora portuguesa Ana de Castro Osório (1872-1933). A partir da análise das cartas e de sua ação nas associações de que faziam parte, observamos a prevalência de um ideal emancipatório pautado pela missão civilizatória, a que Françoise Vergès (2020) chama de feminismo civilizatório. As estratégias de propagação dessas ideias, proporcionadas pela mobilização de uma rede intelectual de mulheres, culminaram em publicações que superam as barreiras nacionais, já que ambas as autoras publicaram seus textos em periódicos tanto em Portugal, quanto no Brasil e em Goa, na Índia.Palavras-chave: Correspondência; imprensa periódica; feminismo; Brasil; Portugal; Goa.Abstract: This article studies and describes some of the letters that are part of the Espólio Osório de Castro (N12) and the Fundo da Federação Brasileira para o Progresso Feminino (BR RJANRIO Q0) in order to map the formation of a transnational intellectual network. The feminist activist and Goan teacher Maria Ermelinda dos Stuarts Gomes (1889-1937) and the Portuguese feminist activist and writer Ana de Castro Osório (1872-1933) are part of such a network. By analyzing their letters and their action in the feminist associations, we can observe the prevalence of an emancipatory ideal guided by the civilizing mission, which Françoise Vergès (2020) calls civilizing feminism. The strategies they adopted to propagate these ideas were put into action by mobilizing an intellectual network of women and culminated in the authors publishing their texts beyond national borders, which is reflected in their writings in the periodical press from Brazil, Portugal, and Goa, in India.Keywords: Correspondence; Periodical Press; Feminism; Brazil; Portugal; Goa.
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Mirta María Robles Anaya. "Formación de calidad desde la virtualidad del aprendizaje post pandemia COVID-19 en instituciones públicas". GACETA DE PEDAGOGÍA, n. 45 (30 aprile 2023): 314–34. http://dx.doi.org/10.56219/rgp.vi45.1904.
Testo completoAbstract (sommario):
Con la evolución de las TIC, las instituciones educativas apoyándose en modelos de transformación pedagógica, buscan estrategias para una formación de calidad. El objetivo de este artículo fue analizar la formación de calidad desde la virtualidad del aprendizaje post pandemia en la educación pública. A través de un diseño documental, se desarrolló esta investigación bajo la premisa, que los docentes presentan bajo dominio de las TIC, limitante para ofrecer una formación de calidad desde la virtualidad. Las 17 unidades de estudio seleccionadas sobre virtualidad, en el ejercicio de la educación de calidad en tiempos de pandemia, aportaron como resultado unas categorías de estudio. Concluyendo que la formación de calidad desde la virtualidad post pandemia en estas instituciones educativas, reduce las barreras de aprendizaje, y permite a los discentes asumir los retos de las nuevas TIC, así como la necesidad de generar nuevas políticas educativas para mejorar la calidad de la enseñanza.
Palabras clave: Formación de Calidad; Virtualidad del Aprendizaje; Post pandemia
ABSTRACT
With the of ICT, educational institutions, relying on models of pedagogical transformation, seek strategies for quality training. The objective of this article was to analyze quality training from the virtuality of post-pandemic learning in public education. Through a documentary design, this research was developed under the premise that teachers have a mastery of ICT, limiting to offer of quality training from virtuality. The 17 selected study units on virtuality, in the exercise of quality education in times of pandemic, provided study categories as a result. Concluding that quality training from the post-pandemic virtuality in these educational institutions reduces learning barriers, and allows students to assume the challenges of new ICTs, as well as the need to generate new educational policies to improve the quality of education teaching.
Key words: Quality Training; Virtuality of Learning; Post pandemic
RESUMO
Com a evolução das TIC, as instituições de ensino, apoiando-se em modelos de transformação pedagógica, buscam estratégias para uma formação de qualidade. O objetivo deste artigo é analisar a formação de qualidade a partir da virtualidade do aprendizado pós-pandemia no ensino público. Por meio de um desenho documental, esta pesquisa foi desenvolvida sob a premissa de que os professores possuem domínio das TIC, limitando-se a oferecer formação de qualidade a partir da virtualidade. As 17 unidades de estudo selecionadas sobre a virtualidade, no exercício da educação de qualidade em tempos de pandemia, proporcionaram como resultado categorias de estudo. Concluindo que a formação de qualidade a partir da virtualidade pós-pandemia nessas instituições de ensino reduz as barreiras de aprendizagem, e permite aos alunos assumir os desafios das novas TIC, bem como a necessidade de gerar novas políticas educacionais para melhorar a qualidade do ensino.
Palavras-chave: Treinamento de Qualidade; Virtualidade da Aprendizagem; Pós pandemia
RÉSUMÉ
Avec l'évolution des TIC, les établissements d'enseignement, s'appuyant sur des modèles de transformation pédagogique, recherchent des stratégies de formation de qualité. L'objectif de cet article est d'analyser une formation de qualité à partir de la virtualité des apprentissages post-pandémie dans l'enseignement public. A travers une conception documentaire, cette recherche a été développée sous le postulat que les enseignants ont une maîtrise des TIC, limitant à proposer une formation de qualité à partir de la virtualité. Les 17 unités d'études sélectionnées sur la virtualité, dans l'exercice d'une éducation de qualité en temps de pandémie, ont ainsi fourni des catégories d'études. Concluant qu'une formation de qualité issue de la virtualité post-pandémique dans ces établissements d'enseignement réduit les barrières à l'apprentissage, et permet aux étudiants d'assumer les défis des nouvelles TIC, ainsi que la nécessité de générer de nouvelles politiques éducatives pour améliorer la qualité de l'enseignement.
Mots clés : Formation Qualité ; Virtualité de l'apprentissage ; Post-pandémie
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Engelman, Raquel, Rubia Marcondes Guisso e Edi Madalena Fracasso. "AÇÕES DE GESTÃO AMBIENTAL NAS INSTITUIÇÕES DE ENSINO SUPERIOR: O QUE TÊM SIDO FEITO POR ELAS?" Revista de Gestão Social e Ambiental 3, n. 1 (1 aprile 2009): 22–33. http://dx.doi.org/10.24857/rgsa.v3i1.115.
Testo completoAbstract (sommario):
Nas últimas décadas as questões ambientais estão gerando mudanças nos processos econômicos e produtivos mundiais como reflexos das exigências da sociedade em relação a valores e um crescente processo de conscientização ecológica, onde já é possível entrever um número crescente de universidades em várias partes do mundo desenvolvendo estudos e implementando práticas ambientais nos seus campi. Nesta vertente, as Instituições de Ensino Superior desempenham um importante papel, ao serem fonte de conhecimento e exemplo para a sociedade. Esse artigo trata das ações ambientais oriundas das IES, visando identificar se há um comprometimento por parte das instituições com uma gestão ambiental e quais as práticas realizadas neste sentido não só porque atuam na formação dos valores da comunidade, mas também por servirem de modelo, influenciando a sociedade. Práticas ambientais visando o desenvolvimento sustentável têm sido realizadas pelas universidades pesquisadas e há inclusão de objetivos ambientalmente sustentáveis em seus programas de difusão de conhecimentos e em suas próprias políticas internas. Os resultados mostram que apesar de barreiras financeiras, muitas iniciativas são tomadas nesse sentido e há um processo crescente de conscientização em todas as pessoas envolvidas com as IES.Palavras-chave: Instituições de Ensino Superior (IES); Comprometimento; Práticas Ambientais.AbstractIn the last decades environmental issues are leading to changes in productive and economic global processes as reflections on society’s demand related to values and to a growing ecological awareness, where it is possible to identify a growing number of universities in various parts of the world developing studies and implementing environmental practices on their campuses. According to these aspects, higher education institutions (IES) play an important role, as source of knowledge and example for society. This article is about the environmental practices of IES, and it aims to identify if there is a commitment by the institutions with environmental management and what practices are being taken in this direction, not only because they participate in the formation of community’s values but also serving as a model, influencing society. Environmental practices aiming sustainable development are part of the reality of the surveyed universities, and there is an inclusion of environmentally sustainable goals in their programs of knowledge dissemination and in their own internal policies. The results show that despite financial barriers, many initiatives are taken in this direction and there is a growing awareness process with all individuals involved with the IES.Keywords: Higher Education Institutions (IES); Commitment; Environmental Practices.
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VIANA, Vânia, Marcondes COSTA, Darilena PORFÍRIO e Glayce VALENTE. "FÍSICO-QUÍMICA DE ÁGUAS E GEOQUÍMICA DE SEDIMENTOS EM SUSPENSÃO DE RECURSOS HÍDRICOS SUPERFICIAIS DO MUNICÍPIO DE BELÉM, ESTADO DO PARÁ". BOLETIM DO MUSEU DE GEOCIÊNCIAS DA AMAZÔNIA 8 (2021), n. 1 (6 maggio 2021): 1–20. http://dx.doi.org/10.31419/issn.2594-942x.v82021i1a4vrv.
Testo completoAbstract (sommario):
The municipality of Belém is installed on low ground under a rich and immense system of surface waters that converge for the most part directly into the Pará River system, Marajó Bay, northern fathom of the Amazon River and then the Atlantic Ocean. The Guamá river (estuary) and Guajará bay stand out, bathing its western, north and northeast portions, and numerous tidal channels, as well as several streams converge on the former, as well as several swamps and temporary wetlands. The main urban nucleus, the city of Belém, was installed and continues to do so, along the tidal and igarapé channels, modifying its courses, and polluting them brutally, either by solid waste or by domestic effluents of all kinds without any treatment, in addition to industrial contributions, becoming more serious as the city moves forward in horizontal and vertical buildings. The tides partially assist in this cleaning, by carrying a large part of these pollutants daily to the Guamá River, from this one to the Guajará Bay and then Marajó and Atlantic. Beautiful beaches in the north and northeast of the municipality (Outeiro, Mosqueiro, Farol, Ariramba, Carananduba, Paraíso and Baía do Sol) attract thousands of visitors, which further contribute to general pollution. Although several surveys have already been carried out to assess these impacts and its dilution, it was decided to try a new attack, emphasizing the Tucunduba stream and its drainage in the Guamá river, the Guajará bay on its margin of strong industrial-port impact and then the beaches of the Baía do Sol. Water and solid sediment in suspension (suspended) were collected in three different periods, considering the two tidal cycles, in eight seasons. Measurements of the main physical parameters were made in loco. Next, cations and anions in the waters analyzed, mineralogical identification and chemistry of the suspensates, in addition to micromorphological analyzes were carried out. The results show that the Guamá river and Guajará bay can be still classified as unpolluted natural waters, similar to the white waters of the Amazon region. Tucunduba and the waters of the Baía do Sol, mainly those restricted (swamps and manholes) are strongly altered by human occupation. Cations and anions, as well as microplankton from the suspension sediments, also allow identify the seasonal interference of oceanic interference during the dry season. The suspension materials of these rivers are dominated by quartz, kaolinite, partly muscovite / illite, demonstrating a strong relationship with the sediments of the margins, gullies and flood plains, and also of the Barreiras Formation, Neogene in age, the geological unit that serves as a substrate for the lands of Belém municipality. However, for a more informed assessment, a systematic and much more comprehensive study is recommended from the chemical, biological, mineralogical point of view and still under strong seasonal and tidal cycle controls, preferably for a continuous decade.