921 resultados para Mantiqueira mountain range


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Kvavadze et al. 1994: Palynological studies of the deposits of the Luganski bog situated at an altitutde of 2428 m have shown that glacial lakes repeatedly emerged there during the Holocene. They used to exist for rather a long time during the Atlantic. More shortterm lake basins reappeared at the very end of the Subboreal period and during the climatic optimums 1000 BP and 400-500 BP.

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Modern erosion of the Himalaya, the world's largest mountain range, transfers huge dissolved and particulate loads to the ocean. It plays an important role in the long-term global carbon cycle, mostly through enhanced organic carbon burial in the Bengal Fan. To understand the role of past Himalayan erosion, the influence of changing climate and tectonic on erosion must be determined. Here we use a 12 Myr sedimentary record from the distal Bengal Fan (Deep Sea Drilling Project Site 218) to reconstruct the Mio-Pliocene history of Himalayan erosion. We use carbon stable isotopes (d13C) of bulk organic matter as paleo-environmental proxy and stratigraphic tool. Multi-isotopic - Sr, Nd and Os - data are used as proxies for the source of the sediments deposited in the Bengal Fan over time. d13C values of bulk organic matter shift dramatically towards less depleted values, revealing the widespread Late Miocene (ca. 7.4 Ma) expansion of C4 plants in the basin. Sr, Nd and Os isotopic compositions indicate a rather stable erosion pattern in the Himalaya range during the past 12 Myr. This supports the existence of a strong connection between the southern Tibetan plateau and the Bengal Fan. The tectonic evolution of the Himalaya range and Southern Tibet seems to have been unable to produce large re-organisation of the drainage system. Moreover, our data do not suggest a rapid change of the altitude of the southern Tibetan plateau during the past 12 Myr. Variations in Sr and Nd isotopic compositions around the late Miocene expansion of C4 plants are suggestive of a relative increase in the erosion of High Himalaya Crystalline rock (i.e. a simultaneous reduction of both Transhimalayan batholiths and Lesser Himalaya relative contributions). This could be related to an increase in aridity as suggested by the ecological and sedimentological changes at that time. A reversed trend in Sr and Nd isotopic compositions is observed at the Plio-Pleistocene transition that is likely related to higher precipitation and the development of glaciers in the Himalaya. These almost synchronous moderate changes in erosion pattern and climate changes during the late Miocene and at the Plio-Pleistocene transition support the notion of a dominant control of climate on Himalayan erosion during this time period. However, stable erosion regime during the Pleistocene is suggestive of a limited influence of the glacier development on Himalayan erosion.

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The neotropical pioneer species Vochysia ferruginea is locally important for timber and is being increasingly exploited. The sustainable utilisation of this species would benefit from an understanding of the level and partitioning of genetic diversity within remnant and secondary regrowth populations. We used data from total genome (amplified fragment length polymorphism, AFLP) and chloroplast genome markers to assay diversity levels within seven Costa Rican populations. Significant chloroplast differentiation between Atlantic and Pacific watersheds was observed, suggesting divergent historical origins for these populations. Contemporary gene flow, though extensive, is geographically constrained and a clear pattern of isolation by distance was detectable when an inter-population distance representing gene flow around the central Costa Rican mountain range was used. Overall population differentiation was low (F-ST = 0.15) and within-population diversity high, though variable (H-s=0.16-0.32), which fits with the overall pattern of population genetic structure expected for a widespread, outcrossed tropical tree. However genetic diversity was significantly lower and differentiation higher for recently colonised and disturbed populations compared to that at more established sites. Such a pattern seems indicative of a pioneer species undergoing repeated cycles of colonisation and succession.

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Este estudo tem como objetivo verificar se a política educacional do CEU: Centro Educacional Unificado criado e implementado no governo Municipal de Marta Suplicy também apresentado como uma proposta contra-hegemônica de escola inclusiva e cidadã, ainda existe nesta atual administração. Apresenta e identifica os princípios do projeto CEU, bem como suas principais diferenças dentro de duas perspectivas políticas: uma progressista e outra mais conservadora. Com a transição da administração publica através da posse do prefeito eleito José Serra e continuada com o exercício do vice-prefeito Gilberto Kassab, os CEUs ficam sujeitos às mudanças técnico- administrativas e políticas, tornando necessária a análise da continuidade e da auto sustentabilidade destes complexos educacionais face ao alto investimento dos recursos públicos demandados em sua implementação. Apresenta-se um estudo bibliográfico sobre a política neoliberal em educação e também aos documentos oficiais da Rede Municipal de São Paulo. Por meio da pesquisa empírica com protagonista do projeto foram observadas as principais diferenças objetivando a análise do processo instituinte.

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The Alborz Mountain range separates the northern part of Iran from the southern part. It also isolates a narrow coastal strip to the south of the Caspian Sea from the Central Iran plateau. Communication between the south and north until the 1950's was via two roads and one rail link. In 1963 work was completed on a major access road via the Haraz Valley (the most physically hostile area in the region). From the beginning the road was plagued by accidents resulting from unstable slopes on either side of the valley. Heavy casualties persuaded the government to undertake major engineering works to eliminate ''black spots" and make the road safe. However, despite substantial and prolonged expenditure the problems were not solved and casualties increased steadily due to the increase in traffic using the road. Another road was built to bypass the Haraz road and opened to traffic in 1983. But closure of the Haraz road was still impossible because of the growth of settlements along the route and the need for access to other installations such as the Lar Dam. The aim of this research was to explore the possibility of applying Landsat MSS imagery to locating black spots along the road and the instability problems. Landsat data had not previously been applied to highway engineering problems in the study area. Aerial photographs are better in general than satellite images for detailed mapping, but Landsat images are superior for reconnaissance and adequate for mapping at the 1 :250,000 scale. The broad overview and lack of distortion in the Landsat imagery make the images ideal for structural interpretation. The results of Landsat digital image analysis showed that certain rock types and structural features can be delineated and mapped. The most unstable areas comprising steep slopes, free of vegetation cover can be identified using image processing techniques. Structural lineaments revealed from the image analysis led to improved results (delineation of unstable features). Damavand Quaternary volcanics were found to be the dominant rock type along a 40 km stretch of the road. These rock types are inherently unstable and partly responsible for the difficulties along the road. For more detailed geological and morphological interpretation a sample of small subscenes was selected and analysed. A special developed image analysis package was designed at Aston for use on a non specialized computing system. Using this package a new and unique method for image classification was developed, allowing accurate delineation of the critical features of the study area.

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El artículo presenta resultados de investigación realizada en la localidad de San Antonio Juárez, municipio de Tzicatlacoyan, en el estado de Puebla, México. El objetivo fue conocer las estrategias de reproducción de los grupos domésticos campesinos, asentados en entornos ambientales adversos, que presentan restricciones severas para el desarrollo de la agricultura. A partir de técnicas cualitativas y cuantitativas, se pudo constatar la presencia de estrategias de reproducción distinta, a nivel de barrio, basada en el conocimiento local, la división genérica del trabajo y la organización a nivel de grupo doméstico y comunidad.

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El artículo presenta resultados de investigación realizada en la localidad de San Antonio Juárez, municipio de Tzicatlacoyan, en el estado de Puebla, México. El objetivo fue conocer las estrategias de reproducción de los grupos domésticos campesinos, asentados en entornos ambientales adversos, que presentan restricciones severas para el desarrollo de la agricultura. A partir de técnicas cualitativas y cuantitativas, se pudo constatar la presencia de estrategias de reproducción distinta, a nivel de barrio, basada en el conocimiento local, la división genérica del trabajo y la organización a nivel de grupo doméstico y comunidad.

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El artículo presenta resultados de investigación realizada en la localidad de San Antonio Juárez, municipio de Tzicatlacoyan, en el estado de Puebla, México. El objetivo fue conocer las estrategias de reproducción de los grupos domésticos campesinos, asentados en entornos ambientales adversos, que presentan restricciones severas para el desarrollo de la agricultura. A partir de técnicas cualitativas y cuantitativas, se pudo constatar la presencia de estrategias de reproducción distinta, a nivel de barrio, basada en el conocimiento local, la división genérica del trabajo y la organización a nivel de grupo doméstico y comunidad.

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The uniform triangulation of the whole glacierized area of the Eastern Cordillera of Bolivia provided the first comparable geometrie basis for an accurate photogrammetric height evaluation of glaciers in the mountain range from the far south up to the Peruvian border. A total of 1775 glaciers, larger than 0.1 ha, were recorded in 16 mountain ranges ofthe East- ern Cordillera. Snow lines in the outer tropics can now be analysed with an accuracy of European standards. In spite of the widemeshed network of meteorological stations this allows a more pre- eise climatic differentiation to be made, particularly at high altitude sites. The methods and results of the analysis are described. Because of these results it becomes necessary to revise and refine previous concepts of the spatial distribution of climatic phenomena. Characteristics of glaciers in the Bolivian Cordillera obviously depend on the NE to SW decline in precipitation. The snow lines which are found at an altitude of 4500 m on the north- eastern slope directed towards the Yungas climb up to 5200 m on the lee slope towards the Alti- plano. The N to S increase in snowline elevation is not as significant as expected. With some res- ervation a 100 m fall in the snowline elevation in the Bolivian Cordillera can be explained by an increase in precipitation of about 50 mm.

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The Yari-Hotaka Mountain Range is one of the most famous formerly-glaciated areas of Japan. Many glacial landforms remain in three neighbouring U-shaped valleys, named Yarisawa, Yokoo and Migimata. Moraines and outwash terraces can be classified into four groups according to their location and to the amount of glacial quartz grains contained in the deposits. A glaciation is proved for other parts of the Northern Japanese Alps before 100 000 years B.P., but not for the Yari-Hotaka Mountain Range, because the corresponding glacial landforms cannot be found here. The oldest known Ichinomata stage before and after 60 000 years B.P. corresponds to the Yokoo glacial which is proved wirhin the whole Japanese Alps. The three younger stages, Babadaira stage (before 30 000 years B.P.), Yarisawa stage I (about 30000 years B.P.) and Yarisawa stage II (about 15000 years B.P.), belong to the Karasawa glacial. About 10 000 years B.P. the glaciers melted away. At all times the relief-influence was especially important for Ihe mass-balances of Japanese glaciers. Wind-drifted snow from the west-exposed windward slopes to the slopes in eastern (lee) exposition, and a voluminous snow accumulation by avalanches from the high rocky walls onto the glacier surfaces beneath, caused very low situated glaciers as well as low equilibrium-lines. In most cases the snow-lines were situated 100 m or more above the equilibrium-lines. During the Ichinomata stage the snow-line reached an altitude of 2400-2450 m. It rose about 100 m to the Babadaira stage, 300 m to Yarisawa stage I and about 450 m to Yarisawa stage II. At present the snow-line is situated above the Northern Japanese Alps at over 4000 m. Therefore only perennial snow-patches exist. If the snow-line would go down by a few hundred meters, this region would be highly interesting Ifor studies on the beginning of mountain glaciation.

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Previous studies about the strength of the lithosphere in the Iberia centre fail to resolve the depth of earthquakes because of the rheological uncertainties. Therefore, new contributions are considered (the crustal structure from a density model) and several parameters (tectonic regime, mantle rheology, strain rate) are checked in this paper to properly examine the role of lithospheric strength in the intraplate seismicity and the Cenozoic evolution. The strength distribution with depth, the integrated strength, the effective elastic thickness and the seismogenic thickness have been calculated by a finite element modelling of the lithosphere across the Central System mountain range and the bordering Duero and Madrid sedimentary basins. Only a dry mantle under strike-slip/extension and a strain rate of 10-15 s-1, or under extension and 10-16 s-1, causes a strong lithosphere. The integrated strength and the elastic thickness are lower in the mountain chain than in the basins. These anisotropies have been maintained since the Cenozoic and determine the mountain uplift and the biharmonic folding of the Iberian lithosphere during the Alpine deformations. The seismogenic thickness bounds the seismic activity in the upper–middle crust, and the decreasing crustal strength from the Duero Basin towards the Madrid Basin is related to a parallel increase in Plio–Quaternary deformations and seismicity. However, elasto–plastic modelling shows that current African–Eurasian convergence is resolved elastically or ductilely, which accounts for the low seismicity recorded in this region.

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This dissertation present an analysis of the interethnic conflict between Makuxi and Wapixana at the current moment in the Maloca of the Adobe, Aboriginal Land Fox-Mountain range of the Sun, in the State of Roraima. The theoretical field was boarded in the Ethnology, pursuing situations in local history, with edges in ethno-history. The research elapsed of the deepening necessity on the social relations and aboriginal politics, for the intercultural professional exercise of educator, appealing the bibliographical survey and participant comment as method; not directive interviews, photographs, filmings and daily register in of field, as techniques carried through in the period of 2006 to 2007. Although to inhabit in the same area and to establish marriages between itself, individuals and groups express tensions, aggravated with the landmark and legal recognition of the area, which generated inter dispute and intraetnias, mainly with the intrusion of farmers, rizicultores and the form of governmental influence. A relation of rivalry, individual and collective was evidenced, suggesting the strengthenig and not it fractionly, of the fights external politics, interns and in way to the cultural diversity and social adversity

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A zona geográfica circunscrita que abrange este trabalho de investigação encontra-se exígua de pesquisa e trabalhos arqueológicos, sendo no entanto reconhecida como uma zona enxameada de vestígios. Um imenso património por descobrir. Ambiciona-se, por isso clarificar a ocupação, no que respeita ao povoamento do território do actual concelho do Marco de Canaveses, no período cronológico da Proto-História, de forma a contribuir para uma actualização da investigação realizada e procurando novos pontos a desenvolver, alargando-a depois a uma vasta área territorial de serrania que integra o imenso noroeste peninsular. Orientada por um fio condutor sequencial de natureza cronológica, a investigação realizada conta com o contributo da toponímia, análise cartográfica, monografias e resenhas locais para o conhecimento de toda uma realidade patrimonial existente ao longo do território em estudo. A correlação das temáticas de ordem social, como a circulação de pessoas e bens através da rede viária e, por outro lado, de ordem geográfica no que respeita a locais propícios à fixação da população pelas suas características culturais e naturais, permite uma análise geográfica a este nível e a resposta a questões como: “De que forma habitou?” e “Porque habitou?”.

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La falda de la sierra cordobesa forma un espacio unitario íntimamente conectado geográfica, emocional y económicamente con la ciudad. En este espacio se sitúan elementos históricos tan importantes como el heredamiento de la Albaida o, sobre todo, la dehesa de Córdoba la Vieja, que recibe este nombre por encontrarse en su interior las ruinas de la antigua ciudad omeya de Madinat al-Zahra. Tradicionalmente se ha presentado este espacio como una amplia dehesa dedicada a la ganadería extensiva. Sin embargo, un estudio más detallado de las fuentes documentales disponibles nos muestra un paisaje diversificado en el que, junto con los pastos para el ganado, abundan olivares, viñas y huertas que fueron fundamentales para el abastecimiento de los mercados de la ciudad de Córdoba durante la Baja Edad Media.

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This dissertation present an analysis of the interethnic conflict between Makuxi and Wapixana at the current moment in the Maloca of the Adobe, Aboriginal Land Fox-Mountain range of the Sun, in the State of Roraima. The theoretical field was boarded in the Ethnology, pursuing situations in local history, with edges in ethno-history. The research elapsed of the deepening necessity on the social relations and aboriginal politics, for the intercultural professional exercise of educator, appealing the bibliographical survey and participant comment as method; not directive interviews, photographs, filmings and daily register in of field, as techniques carried through in the period of 2006 to 2007. Although to inhabit in the same area and to establish marriages between itself, individuals and groups express tensions, aggravated with the landmark and legal recognition of the area, which generated inter dispute and intraetnias, mainly with the intrusion of farmers, rizicultores and the form of governmental influence. A relation of rivalry, individual and collective was evidenced, suggesting the strengthenig and not it fractionly, of the fights external politics, interns and in way to the cultural diversity and social adversity