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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

G?nese e classifica??o de solos em topossequ?ncia de veredas das Chapadas do Alto Vale do Jequitinhonha, MG. / Genesis and classification of soils in toposequence of palm swanp of the chapadas of the Alto Vale do Jequitinhonha, MG.

Bispo, F?bio Henrique Alves 11 February 2010 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T13:30:35Z No. of bitstreams: 5 4.pdf: 3718414 bytes, checksum: f4d04925f023477104d351ad557bc315 (MD5) license_url: 49 bytes, checksum: fd26723f8d7edacdb29e3f03465c3b03 (MD5) license_text: 20626 bytes, checksum: 7851d446050a985bd0603b7c4cee472d (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-27T18:48:03Z (GMT) No. of bitstreams: 5 4.pdf: 3718414 bytes, checksum: f4d04925f023477104d351ad557bc315 (MD5) license_url: 49 bytes, checksum: fd26723f8d7edacdb29e3f03465c3b03 (MD5) license_text: 20626 bytes, checksum: 7851d446050a985bd0603b7c4cee472d (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Made available in DSpace on 2015-02-27T18:48:03Z (GMT). No. of bitstreams: 5 4.pdf: 3718414 bytes, checksum: f4d04925f023477104d351ad557bc315 (MD5) license_url: 49 bytes, checksum: fd26723f8d7edacdb29e3f03465c3b03 (MD5) license_text: 20626 bytes, checksum: 7851d446050a985bd0603b7c4cee472d (MD5) license_rdf: 19710 bytes, checksum: aa65da15f424ff71c620a992a187295c (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) Previous issue date: 2010 / No Alto Vale do Jequitinhonha encontram-se extensas ?reas de relevo aplainado onde predominam as ?Chapadas?, que est?o separadas por ?reas dissecadas pelos afluentes dos rios Jequitinhonha e Ara?ua?. Nessas ?reas encontra-se um sistema de drenagem superficial com uma vegeta??o arb?reo-arbustiva e gram?neas, comumente denominadas de ?veredas?. O objetivo deste trabalho foi caracterizar morfol?gica, micromorfologica, quimica, fisica e mineralogicamente uma topossequ?ncia formada por Latossolo Vermelho Amarelo, Latossolo Amarelo, ?Latossolo Acinzentado? e Gleissolo representativos dos solos da microbacia da Vereda Lagoa do Leandro, localizada no munic?pio de Minas Novas - MG, enfatizando aspectos de sua g?nese e da evolu??o da paisagem nas chapadas do Alto Vale do Jequitinhonha. A topossequ?ncia est? embasada em rochas do Grupo Maca?bas e o clima ? tropical com esta??o seca de inverno. O Cerrado era a cobertura vegetal nativa nas ?reas de entorno da Vereda Lagoa do Leandro e foi substitu?do pelo reflorestamento com Eucaliptus sp. Os perfis ocupam as seguintes posi??es na vertente: topo - Latossolo Vermelho (LVA), ter?o m?dio de vertente - Latossolo Amarelo (LA), sop? - ?Latossolo Acinzentado? (?LAC?) e base da vereda - Gleissolo (GXbd). Esses perfis foram descritos e coletadas amostras deformadas e indeformadas para realiza??o das an?lises f?sicas, qu?micas, mineral?gicas e micromorfol?gicas. A Vereda Lagoa do Leandro ? caracterizada como de superf?cie tabular ocupando uma ?rea de aproximadamente 59 hectares. Os solos das partes mais elevadas da vertente apresentaram atributos morfol?gicos, f?sicos, qu?micos e mineral?gicos t?picos da classe dos Latossolos. No entanto, na base da vereda encontra-se o GXbd apresentando cores acinzentadas, forte gradiente textural e estrutura maci?a. A diminui??o de Fe cristalino e de baixa cristalinidade ao longo da vertente confirmou a perda de Fe e refletiu a cor dos solos. Os teores de Si e Al foram mais baixos no ?LAC?. Houve uma diminui??o da rela??o Fe2O3/TiO2 vertente abaixo, indicando impedimentos ? drenagem ao longo da topossequ?ncia. A mineralogia da fra??o argila em todos os solos ? dominada pela caulinita. Nos LVA e LA foram identificadas goethita, gibbsita e anat?sio, em ?LAC? anat?sio, em GXbd ilita, anat?sio e tra?os de vermiculita. A micromorfologia mostra a predomin?ncia da microestrutura tipo granular ou microagregados e porosidade do tipo empilhamento/empacotamento, t?picos de Latossolos, em LVA, LA e ?LAC?. No GXbd predomina a estrutura maci?a, com a presen?a de cut?s de iluvia??o e ferri-argil?s. Os solos e a paisagem da Vereda Lagoa do Leandro foram formados e evolu?ram juntamente com a instala??o e desenvolvimento da rede de drenagem que, por sua vez, est? relacionada com mudan?as clim?ticas pleistoc?nicas. Paleogleissolos foram latolizados pela a??o da fauna escavadora e deram origem aos atuais ?LAC?. Os GXbd da base da vereda preservaram atributos f?sicos, mineral?gicos e micromorfol?gicos que tiveram suas g?neses em per?odos secos. A g?nese e os atributos dos solos do sop? e da base das veredas das chapadas do Alto Vale do Jequitinhonha - MG s?o fortemente influenciados pela presen?a do len?ol fre?tico na superf?cie ou pr?ximo ? superf?cie o ano todo, no presente e/ou no passado. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2010. / ABSTRACT In the Alto Vale do Jequitinhonha there are large areas of flattened relief dominated by ?chapadas?, that are separated by areas dissected by tributaries of the river Jequitinhonha and Ara?ua?. In these areas there is one surface drainage system with a vegetation of trees and shrubs and grasses, commonly called ?Veredas?. The objective of this study was to characterize morphological, micromorphological, chemical, physical and mineralogically a toposequence formed by a Red Yellow Oxisol, Yellow Oxisol, ?Gray Oxisol? and Haplix Gleisol representative of soils in the watershed Vereda Lagoa do Leandro, located in Minas Gerais State, emphasizing aspects of its genesis and evolution of the landscape in the chapadas of the Alto Jequitinhonha. The toposequence is grounded by Maca?bas Group rocks, the climate is tropical with winter?s dry season. The Cerrado was the native vegetation in areas surrounding the Vereda Lagoa do Leandro and was replaced by the reforestation with Eucalyptus sp. The profiles occupy the following positions in the hillside: top - a Red Yellow Oxisol (LVA), the middle slope ? Yellow Oxisol (LA), the footslope ? ?Gray Oxisol? (?LAC?) and on the basis of the palm swanp ? Hasplic Gleisol (GXbd). These profiles were described and sampled and to carry out the physical analysis, chemical, mineralogical and micromorphological. The Vereda Lagoa do Leandro is characterized as tabular surface covering an area of approximately 59 hectares. The soils of the higher parts of the case showed the morphological, physical, chemical and mineralogical typical of Oxisols. However, at the base of the path is GXbd presenting the colors gray, strong texture gradient and massive structure. The reduction of crystalline Fe and amorphous over the case confirmed the loss of Fe and reflected the color of the soil. The contents of Si and Al were lower in the ?LAC?. There was a decrease in the case Fe2O3/TiO2 below hillside, indicating impediments to drainage along the toposequence. The clay mineralogy in all soils is dominated by kaolinite. In LVA and LA were identified goethite, gibbsite and anatase in ?LAC? anatase in GXbd illite, anatase and traces of vermiculite. Micromorphology shows the prevalence of type or granular microstructure and porosity of the micro-type stacking / packaging, typical of Oxisols, in LVA, LA and ?LAC?. In GXbd dominates the massive structure, with the presence of illuviation cutans and ferriargillans. The soils and the landscape of the Vereda Lagoa do Leandro were formed and evolved along with the installation and development of the drainage network, which in turn is related to Pleistocene climate change. Paleogleissols were latolization the action of the excavator and fauna led to the genesis of the ?LAC?. The GXbd the base of the palm swamp preserved the physical, mineralogical and micromorphological that had their genesis in dry periods. The genesis and characteristics of the soils of the topossequence and on the footslope and the basis of the palm swamp of the Chapadas of the Alto Jequitinhonha - MG are strongly influenced by the presence of ground water on the surface or near the surface all year, in present and/ or in past.
2

Evolu??o morfotect?nica do maci?o estrutural pereiro, Prov?ncia Borborema

Gurgel, Silvana Praxedes de Paiva 06 August 2012 (has links)
Made available in DSpace on 2015-02-24T19:48:44Z (GMT). No. of bitstreams: 1 SilvanaPPG_TESE_pag119_final.pdf: 4384081 bytes, checksum: f4e3889e03bd2b77ef4e8f1b271723a8 (MD5) Previous issue date: 2012-08-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The Northeast relief was described by the Pediplanation Model. This action discards the theoretical basis of post-Cretaceous tectonic evolution of the landscape. Through this model the Massif Pereiro - MP, Borborema Province, was established as part of the Tablelands Area Residual Sertanejos. The present work aims to establish the post- Cretaceous morphotectonic evolution of the MP by geomorphological and geological mapping using Geographic Information System, Remote Sensing and dating of sediments by Single Aliquot Regenerative-dose (SAR). The MP is contained in the core semi-arid, annual precipitation of 600-800 mm / year. The MP is NE-SW, is limited by Shear Zone Jaguaribe (ZCJ) and Portalegre Shear Zone (ZCPa), the same attitude, and crossed by several other shear zones. These shear zones show evidence of brittle Cenozoic reactivation, mostly as normal faults and shallow crustal level. The Quaternary sedimentation around the MP focuses on fault escarpments in a general pattern cascade, where ages decrease from the summits of the steep foothills. The ages of 51 sediment samples indicate a correlation with global climate following pulses: Last Interestadial-UI, the Last Glacial Maximum - LGM and the transition Pleistocene / Holocene, while the latter focus on 18 of 51 samples dated. This study also finds evidence of a new quaternary basin, here called Merejo Basin. Through these results it is concluded that no evidence of post-Cretaceous tectonic evolution of morphological MP, as their retreat along the fault scarps, invariably following the trend of the shear zones. The erosion of cliffs in large time scale is controlled by weakness zones generated by faults on the other hand the erosion of cliffs in short time, with the formation of deposits and colluvial horizons pedogenizados, has climate control. It was also found that in the study area there is a preponderance of past and current tectonic erosion processes on the morphological evolution / O relevo do Nordeste foi descrito por meio do modelo de pediplana??o. Esta base te?rica descarta a atua??o da tect?nica p?s-cret?cea na evolu??o da paisagem. Atrav?s deste modelo o Maci?o do Pereiro MP, Prov?ncia Borborema, foi definido como parte do Dom?nio dos Planaltos Residuais Sertanejos. O presente trabalho tem por objetivo estabelecer a evolu??o morfotect?nica p?s-cret?cea do MP, atrav?s da cartografia geol?gica e geomorfol?gica com uso de Sistema de Informa??o Geogr?fica, Sensoriamento Remoto e data??o de sedimentos por Single Aliquot Regenerative-dose (SAR). O MP est? contido no n?cleo semi?rido, de precipita??o anual entre 600 a 800 mm/ano. O MP tem dire??o NE-SW, ? limitado pela Zona de Cisalhamento de Jaguaribe (ZCJ) e Zona de Cisalhamento Portalegre (ZCPa), de mesma atitude, e atravessado por v?rias outras zonas de cisalhamento. Estas zonas de cisalhamento apresentam evid?ncias de reativa??o fr?gil cenozoica, na sua maioria como falhas normais e de n?vel crustal raso. A sedimenta??o quatern?ria em torno do MP se concentra em escarpas de falhas, em um padr?o geral em cascata, onde as idades diminuem das cimeiras aos sop?s das escarpas. As idades de 51 amostras de sedimentos indicam correla??o com seguintes pulsos clim?ticos globais: ?ltimo Interestadial- UI, o ?ltimo M?ximo Glacial - UMG e a transi??o Pleistoceno/Holoceno, sendo que nesta ?ltima concentram-se 18 das 51 amostras datadas. O presente trabalho tamb?m encontra evid?ncias de uma nova bacia quatern?ria, aqui denominada de Bacia Merejo. Atrav?s destes resultados conclui-se que h? evidencia de tect?nica p?s-cret?cea na evolu??o morfol?gica do MP, pois as suas escarpas recuam paralelamente ?s falhas, seguindo invariavelmente o trend das zonas de cisalhamento. A eros?o das escarpas em grande escala de tempo ? controlada pelas zonas de fraqueza geradas pelos falhamentos, por outro lado ? eros?o das escarpas em curtos espa?os de tempos, com a forma??o dos dep?sitos coluvionares e horizontes pedogenizados, possui controle clim?tico. Concluise ainda que na ?rea de estudo haja a preponder?ncia da tect?nica pret?rita e atual sobre os processos erosivos na evolu??o morfol?gica

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