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The evolution of mountain landscapes is controlled by complex interactions between large-scale tectonic, surficial and climate conditions. Dominant processes are attributed to creating characteristic features of the landscape, but topographic features are the cumulative result of coupled surficial processes, each locally effective in a different climate or elevation regime. The focus of erosion by glacial, fluvial, or mass wasting processes is highly sensitive to small changes in boundary conditions, therefore spatial and temporal variability can be high when observed over short time scales. This work evaluated methods for dissecting the history of complex alpine landscapes to understand the role of individual processes influenced by changing climate and underlying bedrock. It also investigated how individual and combined mechanisms of surficial processes influenced the evolution of topography in the Teton Range in Wyoming. Detrital apatite (U-Th)/He thermochronology and cosmogenic radionuclide erosion rates were applied to determine spatial and temporal variability of erosion in the central catchments of the range. Spatial variability existed between the glacial and fluvial systems, indicating that sediment erosion and deposition by these processes was controlled by short-term variability in climate conditions. Effective glacial incision also controlled other processes, specifically enhancing rock fall activity and inhibiting fluvial incision. Short-term erosion rates were highly variable and were controlled by stochastic processes, particularly hillslope failures in response to slope oversteepening due to glacial incision and orientation and spacing of bedrock fractures. Erosion rates averaged over 10 ky time scales were comparable to long-term exhumation rates measured in the Teton Range. The similarity of spatial erosion patterns to predicted uniform erosion and the balance between intermediate and long-term erosion rates suggests the landscape of the Teton Range is approaching steady-state, but frequent stochastic processes, short-term erosional variability and coupled processes maintain rugged topographic relief. / Ph. D.

Long, linear, high-relief escarpments mark many of the world's passive margins. These Great Escarpments have been interpreted to be the result of isostatic flexure, parallel slope retreat, and divide migration which accompanies rifting. It is unclear whether all these escarpments share this origin. Also uncertain is whether these features are formed via stable, steady-state processes or by climatic shifts or tectonic rejuvenation. The Blue Ridge Escarpment, eastern North America's great escarpment, is no different. A number of hypotheses attempt to explain the Blue Ridge Escarpment. These include lithologic variation between Blue Ridge and Piedmont rocks, the distance to ultimate base level, as well as, escarpment retreat resulting from post/syn-rift warping or faulting. We approach this problem from two directions. The first involves topographic comparisons and geologic observations to recognize and track divide migration. The second approach uses U-Th/He thermochronometry along two scarp-normal transects. Topographic analysis used data extracted from DEMs to compare three zones - the Upland, the Piedmont and the scarp zone itself. Parameters such as relief, drainage density, hypsometry, and slope are often used as proxies for relative erosion rates and the degree of maturity of a landscape. Results from these analyses indicate that the Upland and Piedmont zones are distinct landscapes, sharing very few topographic similarities, yet neither appears significantly more erodible than the other. Examination of parameters in the proximity of the escarpment point toward more rapid erosion here. Field evidence of this rapid scarp erosion (and thus divide migration) lies in the presence of beheaded stream channels, cobble roundness, and clast provenance. U-Th/He thermochronometry is a low temperature technique that allows us to calculate when rock cooled below 60-70C. Temperature is used as a proxy for depth, from which we can extract an exhumation rate. This method allows us to further test scarp genesis hypotheses. Preliminary results show older ages (~160) from the Upland surface than on the Piedmont lowland (~100 Ma). This confirms that the Piedmont surface is distinct from the Upland and demonstrates that it has experienced greater erosion. There is also some indication that ages "jump" across the Bowens Creek/Brevard fault system. Lastly, the ages appear to become younger approaching the escarpment which is indicative of scarp migration. As these results are preliminary, more data is required to prove or disprove these conclusions. / Master of Science

ABSTRACT Karst regions of the world that receive relatively similar amounts of precipitation display a wide variety of landscapes. It has been suggested (Groves and Meiman, 2005) that climates exhibiting larger discrete storm events have more dissolving power and consequently higher rates of conduit growth than climates with more uniform precipitation distributions. To study this concept, a computer program “Cave Growth” was developed that modeled the growth of a cross-section of a cave passage under dynamic flow and chemical conditions. A series of 46 simulation datasets were created to represent different climatic conditions. These simulations had the same total annual discharge, but demonstrated a range of flow distributions quantified by use of a gamma distribution index, along with two special theoretical cases. After simulating a year of conduit growth for each of the various flow distributions in a series of model runs, and repeating these sets of simulations for three different passage cross-section geometries, it was evident that the annual temporal distribution of flow did indeed impact the amount of cave growth. However, an increase in the “storminess” of the climate did not simply equate to more dissolution and thus conduit growth. Rather, the quantity and duration of surface contact between water and the conduit walls combined with dissolution rates to affect the total growth. The amount of wetted perimeter (contact between fluid and passage floor/walls) generated by specific conduit to capacity were shown to be very effective at growing the cave. Above this level, the dissolving power of additional water was essentially wasted. This investigation suggests that the maximum amount of passage flow levels depended upon the shape of the passage. Flow conditions that filled the growth occurs under flow conditions that result in the most wetted perimeter for the longest period of time at the highest dissolution rate.

Orientador: Jairo Roberto Jiménez-Rueda / Banca: Juércio Tavares de Mattos / Banca: Maria Isabel Castreghini de Freitas / Banca: Pablo Vidal Torrado / Banca: Tomoyuki Ohara / Resumo: Este trabalho teve por objetivo reunir informações sobre o meio físico e estabelecer o zoneamento geoambiental da região do Planalto de Poços de Caldas, localizado na divisa entre os estados de Minas Gerais e São Paulo. O trabalho foi desenvolvido a partir de pesquisa bibliográfica, geoprocessamento e fotointerpretação de imagens de satélite aliadas a pesquisas de campo para o levantamento e caracterização dos solos através da análise fisiográfica e pedoestratigráfica integradas. As paisagens da área de estudo puderam ser divididas em planálticas e aluviais, tendo sido proposta uma evolução e datação relativa destas paisagens. Cada unidade fisiográfica que caracteriza uma paisagem apresenta uma seqüência pedoestratigráfica típica. De forma geral, a região apresenta solos residuais recobertos por materiais alóctones de composição e idades variadas. Propôs-se a utilização do termo regolítico como referente a volumes de materiais discordantes no perfil, sendo estas discordâncias associadas à ocorrência de deposição de materiais alóctones, predominantemente gravitacionais e secundariamente colúvio-aluvionais. Para os materiais autóctones, ou seja, formados a partir da própria rocha do embasamento, sem nunca terem sofrido ação de transporte, cunhou-se o termo saprolítico. Deve-se deixar explícito que os materiais regolíticos são também influenciados pelas condições pedogênicas do ambiente em que foram depositados sendo assim, os materiais regolíticos encontram-se "saprolitizados". Foram identificados três volumes regolíticos concrecionários e dois volumes saprolíticos residuais típicos da área de estudo. Após estas análises, foram estabelecidas seis zonas geoambientais em função da associação pedoestratigráfica reinante em cada unidade fisiográfica em conjunto com os tipos litológicos principais. As subzonas foram definidas em função da altimetria associada à morfoestrutura. / Abstract: The present work aimed to gather mesological information and establish the geoenvironmental zonning of Poços de Caldas plateau region, located on the border of Minas Gerais and São Paulo states. The adopted procedure was bibliographical research, photointerpretation of remote sensing images along with in situ research in order to describe types of soils and the landscape through a physiographical and pedostratigraphical approach. The landscape of the area was able to be divided into the plateaued and the alluvium kinds. It was also proposed the evolution and associated age of these areas. Each unit of the landscape has its own pedostratigraphical sequence. Over all, the area presents residual soils that were buried by alloctonous materials which present different origins and ages. It was proposed the use of the term regolithic to define the alloctonous sequences of soils. To name the authoctonous profiles, those which have never been transported, the term saprolithic was used. It is important to notice that regolithic materials also suffer influence of the environmental conditions they have been deposited under. Being so, regolithic materials is found in a "saprolithical" state. Three regolithic and two saprolithical typical profiles were identified in the studied area. After these analyses, it was established six geoenvironmental zones according to the dominant pedostratigraphical association in each physiographic unit, along with the main lithological type. Subzones were defined by morphostructural and morphometrical analyses. It was considered the primary aspects of each geoenvironmental zone and subzone, corroborating the efficiency of pedostratigraphical and physiographical method in order to establish these zones. / Doutor

Made available in DSpace on 2014-06-11T19:32:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-04Bitstream added on 2014-06-13T20:03:38Z : No. of bitstreams: 1 moraes_ft_dr_rcla.pdf: 4719689 bytes, checksum: 5063fa9a75396bd995dabe8180044343 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve por objetivo reunir informações sobre o meio físico e estabelecer o zoneamento geoambiental da região do Planalto de Poços de Caldas, localizado na divisa entre os estados de Minas Gerais e São Paulo. O trabalho foi desenvolvido a partir de pesquisa bibliográfica, geoprocessamento e fotointerpretação de imagens de satélite aliadas a pesquisas de campo para o levantamento e caracterização dos solos através da análise fisiográfica e pedoestratigráfica integradas. As paisagens da área de estudo puderam ser divididas em planálticas e aluviais, tendo sido proposta uma evolução e datação relativa destas paisagens. Cada unidade fisiográfica que caracteriza uma paisagem apresenta uma seqüência pedoestratigráfica típica. De forma geral, a região apresenta solos residuais recobertos por materiais alóctones de composição e idades variadas. Propôs-se a utilização do termo regolítico como referente a volumes de materiais discordantes no perfil, sendo estas discordâncias associadas à ocorrência de deposição de materiais alóctones, predominantemente gravitacionais e secundariamente colúvio-aluvionais. Para os materiais autóctones, ou seja, formados a partir da própria rocha do embasamento, sem nunca terem sofrido ação de transporte, cunhou-se o termo saprolítico. Deve-se deixar explícito que os materiais regolíticos são também influenciados pelas condições pedogênicas do ambiente em que foram depositados sendo assim, os materiais regolíticos encontram-se “saprolitizados”. Foram identificados três volumes regolíticos concrecionários e dois volumes saprolíticos residuais típicos da área de estudo. Após estas análises, foram estabelecidas seis zonas geoambientais em função da associação pedoestratigráfica reinante em cada unidade fisiográfica em conjunto com os tipos litológicos principais. As subzonas foram definidas em função da altimetria associada à morfoestrutura. / The present work aimed to gather mesological information and establish the geoenvironmental zonning of Poços de Caldas plateau region, located on the border of Minas Gerais and São Paulo states. The adopted procedure was bibliographical research, photointerpretation of remote sensing images along with in situ research in order to describe types of soils and the landscape through a physiographical and pedostratigraphical approach. The landscape of the area was able to be divided into the plateaued and the alluvium kinds. It was also proposed the evolution and associated age of these areas. Each unit of the landscape has its own pedostratigraphical sequence. Over all, the area presents residual soils that were buried by alloctonous materials which present different origins and ages. It was proposed the use of the term regolithic to define the alloctonous sequences of soils. To name the authoctonous profiles, those which have never been transported, the term saprolithic was used. It is important to notice that regolithic materials also suffer influence of the environmental conditions they have been deposited under. Being so, regolithic materials is found in a “saprolithical” state. Three regolithic and two saprolithical typical profiles were identified in the studied area. After these analyses, it was established six geoenvironmental zones according to the dominant pedostratigraphical association in each physiographic unit, along with the main lithological type. Subzones were defined by morphostructural and morphometrical analyses. It was considered the primary aspects of each geoenvironmental zone and subzone, corroborating the efficiency of pedostratigraphical and physiographical method in order to establish these zones.

Orientador: Peter Christian Hackspacher / Banca: Norberto Morales / Banca: Sandro Guedes / Banca: Cláudio Riccomini / Banca: Pedro José Nunes / Resumo: Neste trabalho são apresentados os resultados obtidos por meio de análises geomorfológicas (Mapa de Níveis de Paleosuperfícies) e termocronológicos (traços de fissão em apatitas e U-Th/He em apatitas) ao longo da Serra do Mar nos setores (1), (2), (3) e (4). As correlações entre as analises geomorfológicas e termocronológicas evidenciaram uma geológica e geomorfológica compreendida entre o Cretáceo Superior e Paleoceno, demonstrando que a evolução das morfologias que compõem a área de estudo estiveram associadas a eventos tectônicos e sucedidos por uma intensa atividade erosiva. De acordo com as datações realizadas utilizando termocronômetros com temperatura de fechamento distintas, estes indicaram que as configurações dos relevos que compõem a Serra do Mar não podem ser associadas apenas aos efeitos das atividades erosivas (recuo de escarpa) e isostáticas, para poderem explicar a homogeneidade entre as idades de traços de fissão e (U-Th)/He em apatitas, sem a presença da atuação tectônica soerguendo e desnivelando parte destes relevos. / Abstract: In this paper the results obtained geomorphological analysis (Map of levels of Palaeosurfaces) and thermochronogical analysis (apatite fission-track and UTh/ He). The correlation between the geomorphologica and the thermochronological analysis evidenced a geological and geomorphological evolution from the Upper Cretaceous to the Palaeocene, showing that the evolution of the morpholoies composing the study area were associated to tectonics events and preceded by intense erosive activity. According to the datings done using thermocronometers with distinct closing temperatures the configuration of the relieves that compose the Serra do Mar can not be associated only to the effects of the erosive (escarpment retreate) and isostatic activities but also to the tectonic motion uplifting and unlevelling part such morphologies, in order to explain the homogeneity between the ages of the fission-track and U-Th/He of apatites. / Doutor

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-01-31T13:13:26Z No. of bitstreams: 2 Dissertação - Rosirlene Lopes da Cruz - 2017.pdf: 5933077 bytes, checksum: ce223b771e070a4ac810988b66f749ed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-01-31T14:30:33Z (GMT) No. of bitstreams: 2 Dissertação - Rosirlene Lopes da Cruz - 2017.pdf: 5933077 bytes, checksum: ce223b771e070a4ac810988b66f749ed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-01-31T14:30:33Z (GMT). No. of bitstreams: 2 Dissertação - Rosirlene Lopes da Cruz - 2017.pdf: 5933077 bytes, checksum: ce223b771e070a4ac810988b66f749ed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-12-15 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The Cerrado Biome region has been undergoing an intense process of occupation, structuring of development policies and government investments since the 1950s. Since then, unsustainable exploitation has been expanding, causing several social and environmental impacts. Considering the process of degradation of the Cerrado, it should be noted that agricultural activities pose one of the greatest environmental threats due to the inadequate use of natural resources that lead to severe environmental degradation through the destruction of habitats and imminently useful species. The landscape aspects of the Cerrado are described in order to understand the characterization of vegetation, soils, climate, lithological aspects and geomorphology, specifically in the area of the Municipality of Palmelo (GO), located in the Southeast Goiano, inserted in the Southern Mesoregion Goiana and Microregion of Pires do Rio. The present work studies the Cerrado Biome and its main characteristics, since it plays a fundamental function for the balance of the other Biomes of Brazil, analyzing the dynamics influencing landscape evolution and the main forms of use and occupation of the in the municipality of Palmelo (GO). As for the methodological aspects, the research was based on mechanisms used in the theoretical and documentary field in order to perform the satellite image analysis to obtain information about the respective classes of use, which guided the field research, composed by the survey of the practices in the landscape evolution in the researched area. In this way, it diagnosed the significant suppression in areas of primary vegetation remnants, which loses space for other classes of use, such as cultivated pastures, planting of crops and poultry, which together total 75.12%, while only 16, 33% of the native vegetation is preserved. There is also an exorbitant use of water resources in poultry farms, by means of harvesting in deep wells that do not receive supervision by the competent agencies. In this way, it is necessary to subsidize, elaborate and execute methodologies that allow and reconcile landscape conservation with economic development. / A região do Bioma Cerrado vem passando por um processo intenso de ocupação, estruturação de políticas de desenvolvimento e investimentos governamentais a partir da década de 1950. Desde então, a exploração não sustentável vem se expandindo, ocasionando diversos impactos socioambientais. Considerando o processo de degradação do Cerrado, salienta-se que as atividades agropecuárias exercem uma das maiores ameaças ambientais, em função dos usos inadequados de recursos naturais que propiciam rigorosa degradação ambiental a partir da destruição de habitat e de espécies iminentemente úteis. Os aspectos paisagísticos do Cerrado são descritos de modo a entender a caracterização da vegetação, dos solos, do clima, dos aspectos litológicos e da geomorfologia, mais especificamente da área do Município de Palmelo (GO), situado no Sudeste Goiano, inserido na Mesorregião Sul Goiana e Microrregião de Pires do Rio. O presente trabalho estuda o Bioma Cerrado e suas principais características, visto que desempenha função fundamental para o equilíbrio dos demais Biomas do Brasil, analisando as dinâmicas influenciadoras na evolução paisagística e as principais formas de uso e ocupação do solo no município de Palmelo (GO). Quanto aos aspectos metodológicos, a pesquisa fundamentou-se em mecanismos utilizados no campo teórico e documental a fim de realizar a análise de imagens de satélite para obtenção de informações sobre as respectivas classes de uso, que orientaram a pesquisa de campo, composta pelo levantamento das práticas indutoras na evolução paisagística na área pesquisada. Deste modo, diagnosticou a expressiva supressão em áreas de remanescentes de vegetação primárias, que perde espaço para as demais classes de uso, como as pastagens cultivadas, o plantio de lavouras e avicultura que, juntas, somam 75,12 %, enquanto apenas 16,33% da vegetação nativa encontra-se preservada. Ocorre também exorbitante uso dos recursos hídricos nas granjas de criatórios de frangos, por meio de captação em poços profundos que não recebem fiscalização dos órgãos competentes. Desta forma, torna-se necessário subsidiar, elaborar e executar metodologias que oportunizem e conciliem a conservação da paisagem com o desenvolvimento econômico.

Südostbrasilien war während des Spätpleistozäns und des Holozäns beachtlichen Klimaschwankungen unterworfen, die vielfältige geoökologische Konsequenzen zur Folge hatten. Mit der europäischen Kolonialisierung setzte überdies ab dem frühen 16. Jahrhundert eine anthropogen verursachte Degradation ein, welche zu massiven Veränderungen des Landschaftssystems führte. Trotz einer längeren geowissenschaftlichen Forschungstradition in der Region ist der Kenntnisstand über die Auswirkungen der natürlichen und anthropogenen Veränderungen auf die Geomorphodynamik bis heute vergleichsweise gering. Bereits existierende Vorstellungen zu dieser Thematik erscheinen darüber hinaus zumindest ergänzungswürdig und müssen entsprechend des aktuellen Forschungsstandes erweitert werden. Um einen Beitrag zur Schließung dieser Forschungslücken zu leisten, wurden im Rahmen der hier vorliegenden Arbeit bodengeographische und fluvialmorphologische Untersuchungen im südostbrasilianischen Guapi-Macacu Flusseinzugsgebiet durchgeführt. Im konkreten soll der Frage nachgegangen werden, ob und wie sich klimatische und anthropogene Veränderungen auf die geomorphodynamische Stabilität der Region ausgewirkt haben. Neben dem wissenschaftlichen Erkenntnisgewinn können daraus gesellschaftlich relevante Informationen über zukünftige Umweltveränderungen abgeleitet werden. Zur Beantwortung solcher Fragestellungen werden in den Geowissenschaften Paläoumweltarchive genutzt. Wegen seiner naturräumlichen Gegebenheiten kommen in der Region dabei lediglich Böden oder fluviale Sedimente als Geoarchive in Frage. Folglich widmet sich der erste Teil der vorliegenden Dissertation der Bodenverbreitung und -genese im Vorland der Serra dos Órgãos-Gebirgskette. Neben der feldmethodischen Aufnahme ausgewählter Bodenprofile wurde dafür auch auf klassische physikochemische Labormethoden zurückgegriffen. Die sich daraus ergebenden bodengeographischen Befunde lassen große Übereinstimmungen mit bekannten Arbeiten aus anderen tropischen Regionen der Welt erkennen. So ist der erdoberflächennahe Untergrund an erosionsgeschützten Standorten aus stark verwitterten, (gelb)braunen Böden oder Bodensedimenten aufgebaut, welche fossile rote Bodenhorizonte und/oder einen farblich heterogenen Kristallinzersatz überlagern. An vielen Unterhängen konnten darüber hinaus teils mehrgliedrige, junge Kolluvien beschrieben werden. Um geomorphodynamische Aktivitätsperioden ausweisen zu können war v.a. die zeitliche Stellung der Hangverlagerungsprozesse von Bedeutung. Feo/Fed- und Mno/Mnd-Verhältnisse sowie geomorphologische Feldbefunde erlauben zusammen die Unterscheidung zwischen älteren und jüngeren Hangsedimenten. Die jüngsten Unterhangkolluvien konnten aufgrund eingebetteter moderner Keramik und Holzkohlen sicher in die neuzeitliche Landnutzungsperiode gestellt werden. Insgesamt ist das Archivpotenzial der Böden und Bodensedimente im Untersuchungs-gebiet jedoch gering. Die formulierten Forschungsfragen zu den Folgen von klimatischen und anthropogenen Veränderungen auf die Geomorphodynamik können damit nur unzureichend beantwortet werden. Einen Fortschritt könnten zukünftig evtl. Lumineszenzdatierungen bringen. Im zweiten Teil der Arbeit werden Untersuchungen vorgestellt, die an fluvialen Sedimentsequenzen in der Region durchgeführt wurden. Diese sind über weite Strecken aufgeschlossen und können daher vergleichsweise einfach studiert werden. Arbeiten zum Aufbau fluvialer Sedimente und Ableitungen über Paläoumweltbedingungen sind in Süd- und Südostbrasilien bisher äußerst selten und darüber hinaus ist die chronologische Auflösung meist nur unzureichend. In der vorliegenden Dissertation wurde zunächst aus 13 chronostratigraphisch bearbeiteten Einzelprofilen ein spätpleistozänes und holozänes, fluviales Standardprofil für das Guapi-Macacu Einzugsgebiet abgeleitet, welches sich aus vier deutlich zu unterscheidenden Fazieseinheiten aufbaut. 44 14C-Datierungen liefern hierfür ein solides Zeitgerüst, so dass gesicherte Aussagen über das Verhalten des Guapi-Macacu-Systems während der letzten etwa 13.000 Jahre möglich sind. Zwar stellt auch das fluviale Standardprofil kein hochauflösendes Paläoumweltarchiv dar, jedoch kann daraus ein wissenschaftlich wertvoller Erkenntnisfortschritt über die Geomorphodynamik im Untersuchungsgebiet abgeleitet werden. So weisen die Ergebnisse auf mehrfache Wechsel in der Fluvial- und Hangdynamik hin, die mit sehr hoher Wahrscheinlichkeit durch großklimatische Veränderungen hervorgerufen wurden. Störungen der thermohalinen Nordatlantikzirkulation lösten an der Grenze zwischen Pleistozän und Holozän sowie am Übergang vom Mittel- zum Spätholozän eine Südwärtsverlagerung der innertropischen Konvergenzzone (ITCZ) aus, wodurch sich die Südatlantische Konvergenzzone (SACZ) während der Sommermonate mit dem Südamerikanischen Monsunsystem (SAMS) verbinden konnte. Im Untersuchungsgebiet wurden dadurch feuchtere Bedingungen und gehäuft Starkregen ausgelöst, welche zu geomorphodynamisch aktiven Phasen führten. Vor allem in steilen Hanglagen und unterhalb größerer abflusswirksamer Felsflächen fanden phasenweise erhebliche Bodenabträge statt und ältere Hillwashsedimente wurden an den Unterhängen akkumuliert. In den Talböden sind die natürlichen Instabilitätsphasen durch grobklastische Schotter (Fazieseinheit I, ca. 12.800 cal. BP) sowie mächtige sandig bis kiesige Sedimente (Fazieseinheit III, ab ca. 4.700 cal. BP) dokumentiert. Bei einer vergleichsweise nördlichen Position der ITCZ, während des Früh- und Mittelholozäns, herrschten im Untersuchungsgebiet hingegen trockenere Klimabedingungen, welche zu geomorphodynamischer Stabilität führten. Diese Stabilitätsphase ist durch einen Hiatus bzw. feinkörnige fluviale Ablagerungen (Fazieseinheit II,zwischen 6.600 und 4.300 cal. BP) in den Flusstälern belegt. An den Hängen wurden zeitgleich sehr wahrscheinlich Cambisole gebildet. Mit der europäischen Kolonisation setzte zu Beginn des 16. Jahrhundert in Südostbrasilien die sukzessive Zerstörung des Atlantischen Küstenregenwaldes ein. Zuckerrohr- und Kaffeeplantagen etablierten sich und es wurde großflächig Brandrodungsfeldbau praktiziert. Dadurch wurden die Böden zeitweise entblößt, was in Verbindung mit den ergiebigen Niederschlägen erneut verstärkte Abträge zur Folge hatte. Die korrelaten Sedimente der nutzungsinduzierten Bodenerosion sind in Form von holzkohlehaltigen Unterhangkolluvien und Auenlehmen (Fazieseinheit IV) erhalten geblieben. Die 14C-Datierungen aus den Flusssedimenten belegen einen verstärkten anthropogenen Einfluss in der Region seit maximal 250 Jahren. Die vorliegende Arbeit hat gezeigt, dass Klima- und Nutzungsbedingungen das geomorphodynamische Prozessgeschehen in der Vergangenheit steuerten. Für die Zukunft sind eine Häufung von Starkniederschlägen und ein wachsender Nutzungsdruck in der Region prognostiziert. Die Ergebnisse aus der jüngeren Erdgeschichte lassen vermuten, dass es dadurch zur Landschaftsdestabilisierung verbunden mit großflächigen Hangrutschungen kommen wird. Diese werden v.a. in besiedelten Regionen sehr ernstzunehmende Naturgefahren für die Bevölkerung darstellen. / A growing number of publications from southeastern Brazil points to significant climatic and subsequently substantial geo-ecological changes during the latest Pleistocene and Holocene. Additionally, the European colonization led to anthropogenically triggered landscape degradation since the early 16th century. Even though there has been a long-term geoscientific research tradition in that region, the impacts of these changes on geomorphodynamic processes are not well understood so far. Existing concepts dealing with these topics need to be improved according to the current state of research. Hence, this doctoral thesis attempts to partly close this gap of knowledge. Therefore, pedological and sedimentological investigations were carried out at several outcrops within the Guapi-Macau river basin, SE-Brazil. Especially, this work aims to answer the research question if and how climate changes and increased human impact affected geomorphodynamic stability of this region. In addition to its scientific importance, this topic is of high relevance for the prediction of future environmental changes as well. Geoarchives are used in geosciences for the reconstruction of Quaternary palaeoenvironments. Due to local geographic conditions, only soils and fluvial sediments can be used as palaeoenvironmental archives in the study area. Consequently, the first part of this thesis deals with soil distribution and soil development in the foreland of the Serra dos Órgãos Mountains. Standard field descriptions and physicochemical laboratory methods were applied to characterize the regional soils. The results show that these soils have great similarities with other tropical regions of the world. In the study area a standard soil profile contains of a strongly weathered, (yellowish)brown soil horizon or hillwash sediment, covering a fossil reddish soil horizon and/or a heterogeneous weathering mantel. Additionally, relatively young colluvial soils can be observed in many footslope positions. To identify phases of geomorphic activity, the temporal evolution of hillslope deposition is of great importance. A combination of Feo/Fed- and Mno/Mnd-ratios as well as the assessment of the geomorphic position of the sites allowed a relative distinction of older from younger hillslope deposits in the region. In detail, whereas youngest colluvial layers developed during the modern period of land use intensification, could be identified by embedded modern pottery as well as high amounts of charcoal, a further distinction of older hillslope deposits was not possible with the applied methods. Furthermore, often their preservation state is not sufficient so that their potential as archives for palaeoenvironmental research is very limited. However, future luminescence dating would be an option to establish a late Quaternary chronology of hillslope deposits. In the second part of this thesis, investigations of fluvial sediments of the region will be presented. They are exposed over longer distances of the river courses in the Guapi-Macau catchment so that they could easily be studied. Comparable works on the architecture of fluvial sediments are very rare in SE-Brazil, and furthermore their palaeoenvironmental interpretation often remains doubtful due to insufficient age control. Based on chronostratigraphical investigations of 13 fluvial exposures a latest Pleistocene and Holocene standard profile for the Guapi-Macau catchment were developed. The investigations revealed four different facies units that are clearly distinguishable from each other. 44 14C-datings provide a reliable time frame for the reconstruction of the Guapi-Macacu river system during the last approx. 13.000 cal. years BP. Although the fluvial sediments are discontinuous and thus do not offer high resolution proxy data, important findings concerning geomorphodynamic processes could be extracted from them. The results point on multiple changes of the overall geomorphodynamic conditions, very likely triggered by large-scale climate changes. Disturbances in the thermohaline circulation of the northern Atlantic caused a southwards shift of the Intertropical Convergence Zone (ITCZ) at the Pleistocene/Holocene boundary as well as at the transition from the Mid- to the Late Holocene. Consequently, the South Atlantic Convergence Zone (SACZ) was connected with the South American Monsoon System (SAMS) during summer, producing periods of intense precipitation over large parts of southeastern South America where the study area is located. Especially at steep slopes and below larger areas of bare bedrock phases of geomorphic activity periodically appeared. Significant amount of soil were eroded, and older hillwash sediments were deposited on the footslopes. In the floodplains, coarse grained gravels (Unit I, approx. 12.800 cal. BP) and several meters of planar or cross-bedded sands to fine gravels (Unit III, after approx. 4.700 cal. BP) document periods of natural geomorphodynamic instability. Due to a more northerly position of the ITCZ, the study area was obviously drier and geomorphologically more stable during the Early and Mid-Holocene. This is documented by a hiatus or fine-grained deposits (Unit II, from approx. 6.600 to 4.300 cal. BP), respectively. On the slopes probably (yellowish)brown cambisols developed simultaneously. Since the European colonization starting from the early 16th century large areas of valuable Atlantic rainforest were destroyed. Instead, sugar cane and coffee plantations were established, and slash-and-burn agriculture became a common land use practice. Soils were exposed and prevailing strong rains led to high rates of soil erosion again. Correlate sediments of this man-made soil erosion are preserved as charcoal-containing hillslope colluvium and fine-grained floodplain sediments (Unit IV). Radiocarbon ages from the fluvial loams point on increased human impact for the last max. 250 years. The present doctoral thesis demonstrates that climatic changes and human impact strongly affected geomorphodynamic processes of SE-Brazil during the past. There are predictions of a larger frequency of intense rainfall events and increased land use pressure for the future. The presented results from the geological history suggest that landscape destabilization and large-scale landslides could be direct consequences of such changes. As seen already today, especially in highly populated regions this could be serious natural hazards which can affect human health.