L'altération des lithologies himalayennes a potentiellement impacté le cycle global du carbone. Pour pouvoir contraindre et comprendre les processus qui se sont produits dans l'Himalaya et qui ont affecté ces cycles, nous devons être distinguer les signatures de l'altération du silicate et du carbonate dans la charge dissoute des fleuves de l'Himalaya. Des études antérieures ont tenté de le faire en utilisant diverses méthodes mais il n’existe toujours pas de consensus clair sur l’ampleur et le flux de l’altération du silicate dans l’Himalaya. Cette thèse propose l'utilisation du 40Ca comme traceur pouvant améliorer la quantification du flux d'altération du silicate et du carbonate dans la charge dissoute des rivières himalayennes. Des travaux antérieurs ont montré que le budget de l'eau de mer 40Ca est dominé par une source de manteau, de sorte que les carbonates marins ont une signature homogène de 40Ca indiscernable par rapport à la valeur du manteau. En revanche, la croûte supérieure de silicate devrait avoir développé une composition radiogénique. La différence entre la signature en Ca radiogénique des lithologies de carbonate et de silicate peut donc être utilisée pour différencier l’altération du carbonate et du silicate dans la charge dissoute des rivières. Nous présentons ici une étude géochimique comprenant des analyses de Ca radiogénique des rivières drainant les principales unités lithologiques de l'Himalaya, ainsi que des résultats provenant de sédiments, de substrat rocheux, de sol et de gravier. Nos résultats montrent que les carbonates de l’Himalaya ne présentent pas d’excès de 40Ca radiogénique malgré des signatures très variables 87Sr/86Sr, alors que les sédiments sont radiogènes (+0.9 à +4). Ceci suggère que pour Ca, contrairement à Sr, l'échange isotopique entre les lithologies silicate et carbonate a été minime. La composition en Ca radiogène de l'eau des rivières va de +0.1 dans les captages à prédominance carbonatée à +11 dans les rivières drainant des bassins versants silicatés. Pour les grandes rivières, les estimations du budget relatives à l’altération du silicate et du carbonate sur la base des éléments principaux et la composition en Ca radiogénique tendent à concorder. Cependant, pour certaines rivières plus petites, en particulier celles drainant des bassins à dominance silicatée dans les formations cristallines de HHC et du LH, certaines divergences sont observées. Celles-ci ne peuvent pas être attribuées à une définition imprécise de la composition chimique ou radiogénique en Ca des pôles de mélange utilisés pour la modélisation budgétaire, car les valeurs requises pour résoudre le modèle ne sont pas raisonnables. Ils ne peuvent pas non plus être expliqués par la précipitation de carbonates secondaires dans les rivières car la composition non radiogénique de carbonates suggère que ce processus n'est que mineur. Au contraire, ces différences peuvent être dues à la dissolution des traces de calcite radiogénique contenues dans les lithologies de silicate HHC et LH. Le vieillissement de ce matériau, qui ne représente qu'une infime partie de la surface du captage du silicate, pourrait produire une proportion substantielle du Ca radiogénique et pourrait ainsi avoir une influence significative sur le calcul des budgets de ces bassins à partir des données isotopiques. Néanmoins, comme cet effet est observé principalement dans les bassins à faible taux d’érosion des silicates, son influence sur les estimations du flux global de vieillissement du silicate sera mineure. Plus généralement, les résultats de cette thèse impliquent que le système 40Ca permet une résolution de problématiques qui ne peuvent pas être approfondies avec succès à l'aide d'isotopes Sr dans l'Himalaya. Des travaux supplémentaires sont nécessaires pour définir la gamme complète des compositions de Ca radiogénique dans l’Himalaya afin de répondre clairement aux questions concernant les flux d’altération des silicates / Weathering of Himalayan lithologies has had a potential impact on the global carbon cycle. To be able to constrain and understand the processes that occurred in the Himalayas that affected these cycles, we must be able to distinguish the signatures of silicate and carbonate weathering in the dissolved load of Himalayan rivers. Previous studies have attempted to do this using a variety of methods but there is still not a clear consensus on the magnitude and flux of silicate weathering in the Himalaya. This thesis proposes the use of 40Ca as a tracer that could improve the quantification of the silicate and carbonate weathering flux in the dissolved load of Himalayan rivers. Previous work has shown that the 40Ca budget of seawater is dominated by a mantle source, such that marine carbonates have a homogeneous 40Ca signature indistinguishable from the mantle value. In contrast, the upper silicate crust is expected to have developed a radiogenic composition. The difference between the radiogenic Ca signature of carbonate and silicate lithologies can be therefore used to differentiate between carbonate and silicate weathering in the dissolved load of rivers. Here, we present a geochemical survey, including radiogenic Ca analyses, of rivers draining the main lithological units of the Himalaya, as well as results from sediments, bedrock, soil and gravel. Our results show that Himalayan carbonates exhibit no radiogenic 40Ca excesses despite highly variable 87Sr/86Sr signatures, whereas sediments are variably radiogenic (+0.9 to +4). This suggests that for Ca, unlike for Sr, isotopic exchange between the silicate and carbonate lithologies has been minimal. The radiogenic Ca composition of river water ranges from +0.1 in carbonate dominated catchments to +11 in rivers draining silicate catchments. For large rivers, silicate and carbonate weathering budget estimates based on major elements and radiogenic Ca compositions tend to agree. However, for some smaller rivers, especially those draining silicate dominated basins in the HHC and LH formations, some discrepancies are observed. These cannot be attributed to poor definition of the chemical or radiogenic Ca composition of the endmembers used for budget modeling, as the values required to bring the estimates into agreement are unreasonable. They also cannot be explained by precipitation of secondary carbonates in the rivers as the non-radiogenic composition of the carbonate fraction of sediments suggests that this process is only minor. Rather, these discrepancies may be due to the dissolution/weathering of trace amounts of radiogenic calcite contained within HHC and LH silicate lithologies. The weathering of such material, which represents only a tiny fraction of the area of the silicate catchment, could yield a substantial proportion of the radiogenic Ca and may thus have a significant influence on the isotopically based weathering budgets of these basins. Nevertheless, as this effect is observed primarily in basins with low silicate erosion rates, its influence on estimates of the overall silicate weathering flux will be minor. More generally, the results of this thesis imply that the 40K–40Ca system can resolve issues that cannot be successfully addressed using Sr isotopes in the Himalaya. Further work is needed to define the full range of radiogenic Ca compositions in the Himalaya in order to clearly answer questions regarding silicate weathering fluxes

Les biocomposites sont des matériaux renforcés de fibres issues de ressources renouvelables. Ces matériaux sont une solution alternative aux composites renforcés de fibres de verre ou de carbone. En effet, leur légèreté et leurs propriétés mécaniques intéressantes leur confèrent un intérêt grandissant dans les secteurs tels que la construction (terrasse, meubles de jardin) ou l’automobile (panneaux de porte, tableaux de bord). Toutefois, les milieux humides, la température et le rayonnement UV sont des paramètres pouvant compromettre la stabilité physico-chimique des biocomposites. L’objectif principal de cette thèse a été d’évaluer la durabilité des biocomposites sous leurs conditions d’usage principales. Pour cela, ces matériaux ont été exposés pendant une année à l’extérieur (lames de terrasse) et sous vitre pare-brise (tableaux de bord). Les résultats ont montré que, bien que la performance mécanique des biocomposites ait été affectée, celle-ci n’a pas été grandement influencée par le type d’exposition. Par contre, les différences de variations de couleur et de cristallinité différant entre les deux expositions suggèrent des mécanismes de dégradation différents et très dépendants des conditions d’usage.Puisque les biocomposites peuvent être utilisés dans des environnements clos tels que les habitacles d’automobile, ils peuvent être également des sources de polluants dans l’air intérieur. L’étude des émissions de composés organiques volatils (COV) par les biocomposites au cours de leur vieillissement sous vitre pare-brise, a permis de générer des données nécessaires à l’évaluation de l’impact sur la qualité de l’air intérieur de véhicule de ces nouveaux matériaux. Cependant, l’augmentation drastique de la concentration de surface en COV au cours du vieillissement suggère que l’exposition a fortement affecté les biocomposites à cause de la sensibilité des composants structurant les fibres végétales face aux conditions d’exposition.La compréhension des mécanismes de dégradation peut s’effectuer à travers l’interprétation des liens de causalité entre les propriétés mécaniques et de microstructure, les émissions de COV, et l’apparence visuelle. Un traitement statistique par analyse en composantes principales (ACP) a ainsi permis de dégager les relations entre les paramètres quantitatifs.Le vieillissement naturel nécessite souvent une durée d’exposition longue pour apercevoir une dégradation effective des matériaux. De ce fait, le vieillissement accéléré en enceinte de laboratoire est de plus en plus réalisé en industrie permettant un gain de temps. Afin de vérifier la représentativité des mécanismes de dégradation en environnement extérieur par l’enceinte, une étude comparative entre le vieillissement naturel extérieur et un vieillissement accéléré en enceinte a été menée. / Biocomposites are fiber-reinforced materials from renewable resources. These materials are an alternative to fiberglass or carbon reinforced composites. Indeed, their lightweight and interesting mechanical properties give them a growing interest in sectors such as building (decking, garden furniture) or automobile (door panels, dashboards). However, humidity, temperature and UV radiation are parameters that can compromise the physicochemical stability of biocomposites.The main objective of this thesis is to assess the biocomposites durability in their main conditions of use. For this purpose, these materials have been exposed for one year outdoors (deck boards) and under windshield glass (dashboards). The results showed that the mechanical performance of biocomposites was affected and greatly influenced by the type of exposure. On the other hand, the differences in color and crystallinity variations that differ between the two exposures suggest different degradation mechanisms that are very dependent on the conditions of use.Since biocomposites can be used in environments such as the passenger cabin, they can also be sources of pollutants in indoor air. The study of emissions of volatile organic compounds (VOCs) by biocomposites during their ageing under windshield glass allowed generating data necessary for the evaluation of the impact on the car indoor air quality of these new materials. However, the drastic increase of VOCs surface concentration during exposure suggests that weathering strongly affected biocomposites due to the sensitivity of the structural components of plant fibers to exposure conditions.Understanding of the degradation mechanisms can be carried out through the interpretation of the causal links between mechanical and microstructural properties, VOC emissions and visual appearance. Statistical treatment by Principal Component Analysis (PCA) revealed the links and relationships existing between the quantitative parameters.Natural weathering often requires long time of exposure for an efficient perception of the materials degradation. Thus, accelerated ageing in laboratory is more and more carried out in industry for time saving. In order to verify the representativeness of the degradation mechanisms occurring during exterior weathering by weathering chambers, a comparative study between the exterior aging and the artificial aging was carried out.

O saprolito é um corpo geológico constituído pela mistura de minerais primários e secundários resultantes do intemperismo físico e químico, o qual mantém vestígios da estrutura original da rocha. Difere do solo pela evidente filiação litogenética e insignificante atividade biológica. Apesar das definições, no entanto, o limite e a distinção entre solo e saprolito nem sempre são claros, devido a continuidade entre estes corpos em termos de processos hidrológicos e geoquímicos, bem como de suas composições físicas e mineralógicas, o que gera grande confusão nas descrições morfológicas e na organização de informações. Devido ao caráter multidisciplinar das ciências envolvidas no estudo do saprolito e a dedicação parcial de todas elas, há uma grande carência de padronização de termos e procedimentos para sua caracterização e análise. O objetivo geral desta tese é a caracterização de saprolitos desenvolvidos a partir de variadas litologias, no intuito da elaboração de procedimentos para a descrição, classificação e análise de saprolitos. Especificamente objetivou-se avaliar detalhadamente os padrões de alteração física, mineralógica e geoquímica em materiais, influenciados por atributos litológicos relativos a composição mineralo-química e estrutural do material parental. Para tanto foram descritos e amostrados 15 perfis de alteração; compostos por solo, saprolito e rocha, derivados de rochas sedimentares e metamórficas na região Sudeste do Brasil, nos estados de São Paulo e Minas Gerais. As descrições demonstraram que os corpos saprolíticos avaliados podem ser agrupados em quatro tipos morfológicos principais, sendo propostas as seguintes categorias estruturais: contínua, fraturada, fragmentada e terrosa. Dentre todos saprolitos avaliados, aqueles derivados de rochas metamórficas apresentaram maior complexidade morfológica. Deste modo, 9 perfis filiados a xistos e gnaisses foram submetidos a análises físicas, geoquímicas e mineralógicas para avaliação dos processos de alteração e desenvolvimento de sistema de classificação. A composição mineralógica de solos e saprolitos se mostrou semelhante, entretanto, ocorreram dissimilaridades geoquímicas entre estes corpos. Atributos físicos como densidade e porosidade total não demonstraram diferenças significativas entre solo e saprolito, entretanto, ao se considerar isoladamente amostras de saprolito, houve correlação positiva entre a perda de massa e a porosidade total, tornando este último atributo útil `a proposta de classificação de saprolitos. / The saprolite is a geological body constituted by the mixture of primary and secondary minerals resulting of physical and chemical weathering, which retains traces of the original rock structure. It differs from the soil by the evident litogenetic affiliation and insignificant biological activity. Although the definitions, however, the limit and the distinction between soil and saprolite are not always clear, because the continuity between these bodies in terms of hydrological and geochemical processes, as well as their physical and mineralogical compositions, which creates great confusion in morphological descriptions and information network. Due to the multidisciplinary nature of the sciences involved and the partial dedication of all of them in the saprolite investigations, there is a great lack of standardization of terms and procedures for characterization and analysis. The overall objective of this thesis is the characterization of saprolite developed from various lithologies in order to draw up procedures for the description, classification and saprolite analysis. Specifically aimed to evaluate in detail the patterns of physical, mineralogical and geochemical changes in some materials influenced by lithological attributes how the mineralogical and chemical composition, as well as the structure of parental material. For this were described and sampled 15 weathering profiles, composed of soil, saprolite and rock derived from sedimentary and metamorphic rocks in southeastern Brazil, in the states of São Paulo and Minas Gerais. The descriptions shown that saprolite evaluated can be grouped into four main morphological types, proposed the following structural categories: continuous, fractured, fragmented and earthy. Among all evaluated saprolite, those derived from metamorphic rocks showed higher morphological complexity. Thus, 9 affiliated profiles schists and gneisses to have been subjected to physical, geochemical and mineralogical analyzes to evaluate the change processes and to developing the classification system of saprolites. The mineralogical composition of soils and saprolite was similar, however, there were dissimilarities regard geochemical attributes between this bodies. Physical properties such as density and porosity showed no significant differences between soil and saprolite, however, when considered in isolation saprolite samples, there was a positive correlation between weight loss and total porosity, making this last attribute able to integrate the proposed saprolite classification.

Made available in DSpace on 2017-07-10T17:30:32Z (GMT). No. of bitstreams: 1 ELIZANDRA_BERTUOL.pdf: 4697203 bytes, checksum: 4058cf1fefa0969edd3033b8a4d60c1f (MD5) Previous issue date: 2014-07-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study examined the stage of weathering of the surface coverage for the geomorphologic surface V, located in Clevelândia (PR) in the field of the Araucária Plateau. To this end, we analyzed the characteristics of the physical and chemical properties of materials in the profile; was determined from the free, total, and the crystalline iron and the total chemical ten (10) major oxides by X-ray fluorescence finally, there is the micro morphology organization of materials. The weathering profile presented more than 710 cm of exposed material, with gradual transition horizons: A (0-20 cm), AB (20-60cm), BA (60-110 cm), Bw1 (110-210 cm), Bw2 (210-350 cm), BC (350-470 cm) and CB (470- 540 cm) and C (540 - 710+ cm). The characterization of physical and chemical attributes of the weathering profile showed native soil cover, with features Oxisols red with acric character. The mineralogical analysis of the material indicated weathering stage characterized by partial hydrolysis environment, the monossialitization type. Associating soil and geochemical characteristics, one realizes that it is weathering profile whose evolutionary process is to ferruginization. The results confirm the hypothesis that the surface V was prepared by the action of etchplanation from the lowering of the substrate by isovolumetric loss generating planing. / O presente trabalho verificou o estágio de intemperismo da cobertura superficial para a superfície geomorfológica V, localizado em Clevelândia (PR), no domínio do Planalto das Araucárias. Para tal, analisou-se as características dos atributos físicos e químicos dos materiais no perfil; determinou-se o ferro livre, total e amorfo e a química total dos dez (10) principais óxidos por fluorescência de raios-X e, por fim, verificou-se a organização micromorfológica dos materiais. O perfil de intemperismo apresentou mais de 710 cm de material exposto, com transição gradual de horizontes: A (0 20 cm), AB (20- 60 cm), BA (60 110 cm), Bw1 (110 - 210 cm), Bw2 (210 350 cm), BC (350 470 cm), CB (470- 540 cm) e C (540 710+ cm). A caracterização dos atributos físicos e químicos do perfil de intemperismo mostrou cobertura pedológica autóctone, com características de Latossolo Vermelho Distroférrico com caráter ácrico. A análise mineralógica dos materiais indica estágio de intemperismo avançado, caracterizado pelo ambiente de hidrólise parcial, do tipo monossialitização. Associando caraterísticas pedológicas e geoquímicas, percebe-se que se trata de perfil de intemperismo cujo processo evolutivo é o de ferruginização. Os resultados confirmam a hipótese de que a superfície V foi elaborada pela ação da etchplanação, a partir do rebaixamento do substrato por perda isovolumétrica gerando o aplainamento.

Made available in DSpace on 2017-07-10T17:30:41Z (GMT). No. of bitstreams: 1 Luciane_Marcolin.pdf: 2229524 bytes, checksum: cfa5a592966f92c513c066d150d08843 (MD5) Previous issue date: 2015-05-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The following work had as its goal to comprehend the evolution of the pedological cover and the active pedogenetic processes in the landscape unities in Marechal Cândido Rondon/PR. It has been selected two profiles of Oxisol, one under native vegetation and the other under agriculture. Through mineralogical analyses, allied with chemical, physical and morphological data, it was possible to interpret the current level of weathering of the soil profiles. Also, aiming to contribute with the studies about the geomorphic surfaces in the southwest of Paraná, it has been investigated the hypothesis of these surfaces' continuities in the west region of Paraná. The correlation between the results of this research and those from the studies which have already been done by the Grupo Gênese e Evolução de Superfícies Geomórficas e Formações Superficiais (GESGFS) point out that the studied soils in the west of Paraná are in advanced stage of weathering, presenting a mineralogy composed mainly by minerals 1:1 (Kaolinite), the minerals 2:1 (Vermiculite with hydroxy-interlayered). The mineralogy and other Oxisols attributes studied indicate that it has been occurred a process of monossialitization with partial hydrolysis along the pedogenesis. Considering the local landscape, the soil is in accordance with the formation environment in subtropical climate and in relation to the regional landscape they present the same pedological characteristics of the soils in the Incompletely Planed Surfaces V and VI in the southwest of PR, indicating that there is pedogenetic similarity between the soils from these surfaces and the studied soils. / O trabalho exposto teve como objetivo compreender a evolução da cobertura pedológica e os processos pedogenéticos atuantes nas unidades de paisagem de Marechal Cândido Rondon/PR. Foram selecionados dois perfis de LATOSSOLO, um sob vegetação nativa e outro sob agricultura. Através de análises mineralógicas, aliadas a dados químicos, físicos e morfológicos do solo foi possível interpretar o atual estágio de intemperismo dos perfis de solos. Visando também contribuir com os estudos sobre as superfícies geomórficas no sudoeste do Paraná, investigou-se a hipótese de continuidade dessas superfícies para região oeste do Paraná. A correlação entre os resultados dessa pesquisa e aqueles dos estudos já realizados pelo Grupo Gênese e Evolução de Superfícies Geomórficas e Formações Superficiais (GESGFS), apontam que os solos estudados no oeste paranaense estão em avançado estágio de intemperismo apresentando uma mineralogia composta predominantemente por minerais 1:1 (Caulinita), e minerais 2:1 (Vermiculita com hidroxi-entrecamadas). A mineralogia e demais atributos dos LATOSSOLOS estudados indicam que ocorreu um processo de monossialitização com hidrólise parcial ao longo da pedogênese. Considerando a paisagem local o solo esta em concordância com o ambiente de formação em clima subtropical e em relação à paisagem regional apresenta as mesmas características pedológicas dos solos nas Superfícies Incompletamente Aplainadas V e VI, no sudoeste do PR, indicando haver similaridade pedogenética entre os solos dessas superfícies e os solos estudados.

Made available in DSpace on 2017-07-10T17:31:16Z (GMT). No. of bitstreams: 1 Rafaela_Ana_Rech_Rodrigues.pdf: 3839276 bytes, checksum: 0e4c44f90332130f089ffc46bdc0853a (MD5) Previous issue date: 2011-08-03 / Planation surfaces mean the last stage in the reliefs evolution. In order to understand how was the evolution process and formation of the surfaces it becomes necessary to looking for information about the process soil formation related to the climate regime and the bedrock. The Southwest region of Parana and Northwest of Santa Catarina are characterized by a succession of remains of incompletely flattened surfaces, in which one of them stood out for having more than nine meters of weathered material. This study sought to characterize this remaining flat surface by its determining the weathering stage, macro and micromorphological characteristics of the pedon. In addition, there was the possibility of relating the evolution that surface with the etchplanation theory proposed by previous research. Physical analyses were carried as the, granulometry and tipics chemical, micromorphology, clay mineralogy, iron content and analytical chemistry. Therefore, the soil profile presented itself with more than nine meters of material exposed with diffuse transition and moderate A horizon (0 0,20 m), BW1 (0,20 to 1,40 m), Bw2 (1,40 2,50 m), B nític 1 and B nític 2 (2,50 to 8,70 m), BC (8,70 to 9,50 m) and CB (from 9,50 m). Through the microstructure it was observed the vertical transformation of the B horizon latosolic from nític B horizon. In the stage of weathering, mineralogical analysis, chemical and iron content have revealed that the soil profile studied is evolving to an advanced stage, in other words, from ferruginous to ferralitic. Such analysis, especially mineral, allowed to define the partial hydrolysis as the main process related to the formation and evolution of the soil. In this, there is a predominance of kaolinite (1:1), characterized by partial loss of silica (monossialitization) and by the vertical movement of materials. Therefore, we can confirm evolutionary compatibility with etchplanation theory. The occurrence of chemical weathering was possible due to weather conditions and rocky soil, basalt, promoting the vertical movement of materials, causing isovolumetric loss and thus the planation. / Superfícies aplainadas significam a última etapa da evolução de relevos. Para que se possa entender como foi o processo de gênese e evolução das mesmas se torna necessário buscar informações sobre os processos de formação dos solos relacionados ao regime climático e o substrato rochoso. As regiões Sudoeste do Paraná e Noroeste de Santa Catarina se caracterizam por uma sucessão de remanescentes de superfícies incompletamente aplainadas, no qual uma delas destaca-se por apresentar perfis de alteração com mais de nove metros de profundidade. Esse trabalho buscou caracterizar este remanescente de superfície aplainada através do seu estágio de intemperismo determinando, características macro e micromorfológicas do perfil de solo. Além disso, verificou-se a possibilidade de relacionar a evolução dessa superfície com a teoria da etchplanação proposta por pesquisas anteriores. Foram realizadas descrições macromorfológicas, granulometria, caracterização química de rotina, micromorfologia, mineralogia da fração argila, teores de ferro e química analítica. O perfil de alteração apresentou-se com mais de nove metros de material exposto com transição difusa e horizonte A moderado (0 0,20 m), Bw1 (0,20 1,40 m), Bw2 (1,40 2,50 m), B nítico 1 e B nítico 2 (2,50 8,70 m), BC (8,70 9,50 m) e CB (a partir de 9,50 m). Através da microestrutura verificou-se a transformação vertical do horizonte B latossólico a partir do horizonte B nítico. Quanto ao estágio de intemperismo, as análises mineralógica, química e teor de ferro permitiram afirmar que o perfil de solo estudado está evoluindo para um estágio avançado, ou seja, evoluindo de ferruginoso para ferralítico. Tais análises, principalmente a mineralógica, permitiram definir a hidrólise parcial como principal processo relacionado à formação e evolução deste solo, que apresenta predomínio de caolinita (1:1), caracterizando-se pela perda parcial de sílica (monossialitização) e pelo movimento vertical dos materiais. Diante disso, podese confirmar a compatibilidade evolutiva com a teoria da etchplanação. A ocorrência do intemperismo químico foi possível devido às condições climáticas e ao substrato rochoso, o basalto, promovendo a movimentação vertical dos materiais, gerando perda isovolumétrica e assim o aplainamento.

Made available in DSpace on 2017-05-12T14:42:48Z (GMT). No. of bitstreams: 1 Rafaela_Ana_Rech_Rodrigues.pdf: 3839276 bytes, checksum: 0e4c44f90332130f089ffc46bdc0853a (MD5) Previous issue date: 2011-08-03 / Planation surfaces mean the last stage in the reliefs evolution. In order to understand how was the evolution process and formation of the surfaces it becomes necessary to looking for information about the process soil formation related to the climate regime and the bedrock. The Southwest region of Parana and Northwest of Santa Catarina are characterized by a succession of remains of incompletely flattened surfaces, in which one of them stood out for having more than nine meters of weathered material. This study sought to characterize this remaining flat surface by its determining the weathering stage, macro and micromorphological characteristics of the pedon. In addition, there was the possibility of relating the evolution that surface with the etchplanation theory proposed by previous research. Physical analyses were carried as the, granulometry and tipics chemical, micromorphology, clay mineralogy, iron content and analytical chemistry. Therefore, the soil profile presented itself with more than nine meters of material exposed with diffuse transition and moderate A horizon (0 0,20 m), BW1 (0,20 to 1,40 m), Bw2 (1,40 2,50 m), B nític 1 and B nític 2 (2,50 to 8,70 m), BC (8,70 to 9,50 m) and CB (from 9,50 m). Through the microstructure it was observed the vertical transformation of the B horizon latosolic from nític B horizon. In the stage of weathering, mineralogical analysis, chemical and iron content have revealed that the soil profile studied is evolving to an advanced stage, in other words, from ferruginous to ferralitic. Such analysis, especially mineral, allowed to define the partial hydrolysis as the main process related to the formation and evolution of the soil. In this, there is a predominance of kaolinite (1:1), characterized by partial loss of silica (monossialitization) and by the vertical movement of materials. Therefore, we can confirm evolutionary compatibility with etchplanation theory. The occurrence of chemical weathering was possible due to weather conditions and rocky soil, basalt, promoting the vertical movement of materials, causing isovolumetric loss and thus the planation. / Superfícies aplainadas significam a última etapa da evolução de relevos. Para que se possa entender como foi o processo de gênese e evolução das mesmas se torna necessário buscar informações sobre os processos de formação dos solos relacionados ao regime climático e o substrato rochoso. As regiões Sudoeste do Paraná e Noroeste de Santa Catarina se caracterizam por uma sucessão de remanescentes de superfícies incompletamente aplainadas, no qual uma delas destaca-se por apresentar perfis de alteração com mais de nove metros de profundidade. Esse trabalho buscou caracterizar este remanescente de superfície aplainada através do seu estágio de intemperismo determinando, características macro e micromorfológicas do perfil de solo. Além disso, verificou-se a possibilidade de relacionar a evolução dessa superfície com a teoria da etchplanação proposta por pesquisas anteriores. Foram realizadas descrições macromorfológicas, granulometria, caracterização química de rotina, micromorfologia, mineralogia da fração argila, teores de ferro e química analítica. O perfil de alteração apresentou-se com mais de nove metros de material exposto com transição difusa e horizonte A moderado (0 0,20 m), Bw1 (0,20 1,40 m), Bw2 (1,40 2,50 m), B nítico 1 e B nítico 2 (2,50 8,70 m), BC (8,70 9,50 m) e CB (a partir de 9,50 m). Através da microestrutura verificou-se a transformação vertical do horizonte B latossólico a partir do horizonte B nítico. Quanto ao estágio de intemperismo, as análises mineralógica, química e teor de ferro permitiram afirmar que o perfil de solo estudado está evoluindo para um estágio avançado, ou seja, evoluindo de ferruginoso para ferralítico. Tais análises, principalmente a mineralógica, permitiram definir a hidrólise parcial como principal processo relacionado à formação e evolução deste solo, que apresenta predomínio de caolinita (1:1), caracterizando-se pela perda parcial de sílica (monossialitização) e pelo movimento vertical dos materiais. Diante disso, podese confirmar a compatibilidade evolutiva com a teoria da etchplanação. A ocorrência do intemperismo químico foi possível devido às condições climáticas e ao substrato rochoso, o basalto, promovendo a movimentação vertical dos materiais, gerando perda isovolumétrica e assim o aplainamento.

Made available in DSpace on 2017-05-12T14:42:06Z (GMT). No. of bitstreams: 1 ELIZANDRA_BERTUOL.pdf: 4697203 bytes, checksum: 4058cf1fefa0969edd3033b8a4d60c1f (MD5) Previous issue date: 2014-07-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present study examined the stage of weathering of the surface coverage for the geomorphologic surface V, located in Clevelândia (PR) in the field of the Araucária Plateau. To this end, we analyzed the characteristics of the physical and chemical properties of materials in the profile; was determined from the free, total, and the crystalline iron and the total chemical ten (10) major oxides by X-ray fluorescence finally, there is the micro morphology organization of materials. The weathering profile presented more than 710 cm of exposed material, with gradual transition horizons: A (0-20 cm), AB (20-60cm), BA (60-110 cm), Bw1 (110-210 cm), Bw2 (210-350 cm), BC (350-470 cm) and CB (470- 540 cm) and C (540 - 710+ cm). The characterization of physical and chemical attributes of the weathering profile showed native soil cover, with features Oxisols red with acric character. The mineralogical analysis of the material indicated weathering stage characterized by partial hydrolysis environment, the monossialitization type. Associating soil and geochemical characteristics, one realizes that it is weathering profile whose evolutionary process is to ferruginization. The results confirm the hypothesis that the surface V was prepared by the action of etchplanation from the lowering of the substrate by isovolumetric loss generating planing. / O presente trabalho verificou o estágio de intemperismo da cobertura superficial para a superfície geomorfológica V, localizado em Clevelândia (PR), no domínio do Planalto das Araucárias. Para tal, analisou-se as características dos atributos físicos e químicos dos materiais no perfil; determinou-se o ferro livre, total e amorfo e a química total dos dez (10) principais óxidos por fluorescência de raios-X e, por fim, verificou-se a organização micromorfológica dos materiais. O perfil de intemperismo apresentou mais de 710 cm de material exposto, com transição gradual de horizontes: A (0 20 cm), AB (20- 60 cm), BA (60 110 cm), Bw1 (110 - 210 cm), Bw2 (210 350 cm), BC (350 470 cm), CB (470- 540 cm) e C (540 710+ cm). A caracterização dos atributos físicos e químicos do perfil de intemperismo mostrou cobertura pedológica autóctone, com características de Latossolo Vermelho Distroférrico com caráter ácrico. A análise mineralógica dos materiais indica estágio de intemperismo avançado, caracterizado pelo ambiente de hidrólise parcial, do tipo monossialitização. Associando caraterísticas pedológicas e geoquímicas, percebe-se que se trata de perfil de intemperismo cujo processo evolutivo é o de ferruginização. Os resultados confirmam a hipótese de que a superfície V foi elaborada pela ação da etchplanação, a partir do rebaixamento do substrato por perda isovolumétrica gerando o aplainamento.

Made available in DSpace on 2017-05-12T14:42:13Z (GMT). No. of bitstreams: 1 Luciane_Marcolin.pdf: 2229524 bytes, checksum: cfa5a592966f92c513c066d150d08843 (MD5) Previous issue date: 2015-05-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The following work had as its goal to comprehend the evolution of the pedological cover and the active pedogenetic processes in the landscape unities in Marechal Cândido Rondon/PR. It has been selected two profiles of Oxisol, one under native vegetation and the other under agriculture. Through mineralogical analyses, allied with chemical, physical and morphological data, it was possible to interpret the current level of weathering of the soil profiles. Also, aiming to contribute with the studies about the geomorphic surfaces in the southwest of Paraná, it has been investigated the hypothesis of these surfaces' continuities in the west region of Paraná. The correlation between the results of this research and those from the studies which have already been done by the Grupo Gênese e Evolução de Superfícies Geomórficas e Formações Superficiais (GESGFS) point out that the studied soils in the west of Paraná are in advanced stage of weathering, presenting a mineralogy composed mainly by minerals 1:1 (Kaolinite), the minerals 2:1 (Vermiculite with hydroxy-interlayered). The mineralogy and other Oxisols attributes studied indicate that it has been occurred a process of monossialitization with partial hydrolysis along the pedogenesis. Considering the local landscape, the soil is in accordance with the formation environment in subtropical climate and in relation to the regional landscape they present the same pedological characteristics of the soils in the Incompletely Planed Surfaces V and VI in the southwest of PR, indicating that there is pedogenetic similarity between the soils from these surfaces and the studied soils. / O trabalho exposto teve como objetivo compreender a evolução da cobertura pedológica e os processos pedogenéticos atuantes nas unidades de paisagem de Marechal Cândido Rondon/PR. Foram selecionados dois perfis de LATOSSOLO, um sob vegetação nativa e outro sob agricultura. Através de análises mineralógicas, aliadas a dados químicos, físicos e morfológicos do solo foi possível interpretar o atual estágio de intemperismo dos perfis de solos. Visando também contribuir com os estudos sobre as superfícies geomórficas no sudoeste do Paraná, investigou-se a hipótese de continuidade dessas superfícies para região oeste do Paraná. A correlação entre os resultados dessa pesquisa e aqueles dos estudos já realizados pelo Grupo Gênese e Evolução de Superfícies Geomórficas e Formações Superficiais (GESGFS), apontam que os solos estudados no oeste paranaense estão em avançado estágio de intemperismo apresentando uma mineralogia composta predominantemente por minerais 1:1 (Caulinita), e minerais 2:1 (Vermiculita com hidroxi-entrecamadas). A mineralogia e demais atributos dos LATOSSOLOS estudados indicam que ocorreu um processo de monossialitização com hidrólise parcial ao longo da pedogênese. Considerando a paisagem local o solo esta em concordância com o ambiente de formação em clima subtropical e em relação à paisagem regional apresenta as mesmas características pedológicas dos solos nas Superfícies Incompletamente Aplainadas V e VI, no sudoeste do PR, indicando haver similaridade pedogenética entre os solos dessas superfícies e os solos estudados.

Experiments with microbial biofilms in microgravity and simulated microgravity have revealed altered growth kinetics, but geomicrobial biofilms have not yet been studied in low gravity environments. No characterisation of biofilms, geomicrobial or otherwise, have been conducted at hypergravity. This thesis explores factors affecting microbe-mineral interactions under terrestrial conditions, lays the groundwork for a scheduled microgravity experiment, and provides the first data on biofilms grown at hypergravity. As a first step in understanding microbe-mineral interactions in altered gravity environments, experiments were undertaken to identify factors that constrain attachment in a terrestrial environment. The model organism Sphingomonas desiccabilis and basaltic rock from Iceland were selected, and the minerals that make up the basalt were identified and procured in their pure form. The relative significance of physical factors such as hydrophobicity, surface charge, porosity and nutritional value were examined in relationship to the success with which biofilms colonised the mineral surfaces. Growth was measured by the quantity of biofilm biomass after a ifxed time period, using Crystal Violet stain, in order to draw conclusions about the most influential physical conditions on biofilm attachment to a substrate. It was found that mineral attachment is influenced more by porosity and nutritional value than by hydrophobicity or surface charge. To explore how reduced gravity affects biofilm formation and weathering rates, a European Space Agency experiment, BioRock, is underway. Samples of basalt, with monocultures of three different organisms, will be sent to the International Space Station in 2019 for long-term exposure to Martian and micro-gravity. Research testing proof of concepts, material compatibility, and experimental procedure and equipment is described. Confocal laser scanning microscopy (CLSM) was used to image the biofilms, and inductively coupled plasma mass spectroscopy (ICP-MS) experiments were conducted to compare biotic and abiotic elemental release rates from basalt. Both of these methods will be employed for post-flight analysis of BioRock. Preliminary terrestrial ICP-MS experiments indicated that rare Earth elements (REEs) showed the most reliable reflection of leaching patterns overall, as a consequence of their high molecular weight and low volatility during the ashing procedure. To fully understand gravity's effect on microbiological processes it is important to investigate what occurs when its influences are removed, but also to establish what occurs when extra gravitational force is applied. Using simulated hypergravity, achieved through hyper-acceleration on a geotechnical centrifuge, the effects of 10 x g on biofilm development and the leaching of basalt were investigated. As this was the first time that biofilms had been studied under hypergravity, additional substrates were included with the basalt, to enable characterisation of the more general response of biofilms to hypergravity. In contrast to previous experiments conducted on planktonic bacteria, which found decreased population sizes, the biofilms grown at 10 x g showed greater biomass than the 1 x g samples. ICP-MS showed no difference in the average weathering rates, but greater variability in the higher gravity samples. The data collected here advances our understanding of microbial interactions with geologically important substrates, with implications for an ISS microgravity experiment and future human space exploration. It also presents new intelligence on the previously unstudied effects of hypergravity on biofilms and rock weathering.