No / The Covesea Caves, located on the coast of the Moray Firth in northeastern Scotland, are a series of archaeological cave sites that are hypothesized to be part of a larger mortuary complex used during the Late Prehistoric period. Although much attention has been given to the unusual assemblage of human remains recovered from these sites, there has been less analysis undertaken on the vast amount of archaeofauna from the caves. This is in the process of being rectified through the recent work of the Covesea Cave Project, under direction of Ian Armit and Lindsey Büster and currently being undertaken at the University of Bradford. This report details attempts to confirm species identifications for several faunal bones of interest through various methodologies; unfortunately, not all of the attempts were successful. However, identifications are confirmed for two avian bones using comparative osteological analysis at the Avian Anatomical Collection at the Natural History Museum at Tring, United Kingdom. These species are placed in context through consideration of previous excavations at the Covesea Caves, as well as recent literature on ornithological analyses of ritual and funerary sites in Later Prehistoric Britain.

A dissertation submitted to the Faculty of Arts, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree or Master of Arts. Johannesburg, February 1995. / This study, based on material excavated at Rose Cottage Cave, presents a new theoretical perspective for our understanding of the southern African archaeological record dated to the Pleistocenel Holocene boundary. Over the past twelve years, : NO contesting models for interpreting the Pleistocene! Holocene boundary have been proposed - it has been described as a period of cultural stasis, on the one hand, or, as exhibiting continuous change, on the other hand. This study departs from the position that this debate is at a theoretical impasse. Through the assumption of a theoretical framework that deals concurrently with cultural representation and social strategy, previously unrecognised aspects of the archaeological record are investigated. t explore the r-ctlve constitutive role of material culture and thus remove the false dichotomy between cultural form and functional expediency. In allowing for the active role of human agency, a model for the interpretation of spatial use is developer, through the incorporation of the informative and constraining role of previous spatial patternings. I recognise that meaning is actively created, and exarnple the spatially and chronolcqlcatlv contingent nature of meaning through the unique perspective that deep sequence archaeological deposit offers. / MT2017

Swartkrans Cave, famous for abundant hominin fossils of P. robustus and the site where the first evidence of the co-existence of two hominin species was recovered, has yielded a wealth of information on early hominin behaviour. In 2005 a new program of research and excavation began at the site, and its results form the central part of this thesis. This study has focused on the early Pleistocene Member 1 deposits which include an Earlier Stone Age industry and the late Pleistocene Member 4 Middle Stone Age deposits. The thesis has four areas of focus. First the new work has resulted in clarification and new interpretations for the formation of the hominin rich Hanging Remnant deposit of Member 1, which lacks stone tools. This extensive calcified conglomerate which spans most of the north wall of the cave is now seen as a non-homogenous unit that represents material entering from at least four avens. However, this study also established that the newly exposed central portion of the Hanging Remnant and the hominin fossil-rich northwest corner infill worked by Robert Broom in the 1940s derived from the same depositional episode. Secondly, the new excavations in the Lower Bank of Member 1 have resulted in an enlargement of the previously ambiguous Earlier Stone Age assemblage. Analysis of this new assemblage, in conjunction with recently released dating results, has now confirmed that the artefacts belong to the Oldowan Industrial Complex. Thirdly, new excavations in the Member 4 deposit have resulted in the recovery of over 3,200 Middle Stone Age (MSA) stone tools and a clearer understanding of their context. The stone tool-bearing deposits of Member 4 are now understood to derive from a surface colluvium, rather than a cave infill. This MSA assemblage consists of a high number of retouched pieces that are dominated by steep-sided scrapers and denticulated scrapers with a near-absence of points. The technology of a variety of core types suggests a superior understanding of raw material flaking qualities by the tool makers. The limited types of formal tools suggest that the site was used for one or more specific activities, rather than for a range of activities by the tool makers. Fourthly, excavation of the deposits underlying the Member 4 colluvium has resulted in the discovery of two previously unknown hominin-bearing deposits. It is now established that what was originally called Member 4 is composed of three distinct deposits. The lowest of these is an east extension of the Member 1 Lower Bank (LB East Extension), which has yielded P. robustus fossils. This is overlain by a large talus cone (TCD), which also has yielded P. robustus fossils. The latter is capped by flowstone dated to ~110,000 years, followed by the MSA-tool bearing colluvium.

La position géographique des Comores, lui a permis d’accueillir plusieurs migrations : Bantou, Austronésien, Proto-Malgache, Arabo-Persan. Ces migrants avaient apporté leur croyance et leur culture respective. Comme témoignage de cette civilisation : l’importance sociale des mwalimu, l’existence des séances de possession, la survivance du culte des esprits Djinns, les cultes des ancêtres et cultes de la nature. Trimba à Nyumakele et Nkoma à Ouani (fête agraire et/ou rites de protection), Mudandra (danse des esprits) au village de Ouzini et Mro-Maji organisée à l’intérieur d’une grotte sacrée font partie des rites pré-islamiques à Anjouan ainsi que les cultes des anguilles sacrée « Mwana-Mroni ». Ces rites s’observent dans les régions habitées par les autochtones « Wamatsaha ». Certains de ces pratiques s’exécutent dans des lieux sacrés appelés « Ziara ». En conclusion, nous avons montré que la montée des « islamistes » appelés aussi « Djawula » risque de faire disparaître à jamais ces pratiques ancestrales / The geographical position of the comoros, has enabled to host several migrations: Bantu, Austronesian, Proto-Malagasy, Arabo-Persian. These migrants had brought their respective beliefs and cultures. As a testimony of this civilization:: the social importance of the Mwalimu, the existence of possession seances , the survival of Djinn spirit cult, the ancestors cult and devotoion to nature. Trimba at Nyumakele and Nkoma at Ouani (agrarian festival and / or rites of protection), Mudandra (spirit dance) at the village of Ouzini and Mro-Maji organized inside a sacred cave are part of the pre-Islamic rites in Anjouan than the cults of the sacred eels "Mwana-mroni". These rites are noticed in the areas inhabited by the indigenous "Wamatsaha". Some of these practices are performed in sacred places called "Ziara". In conclusion, we have shown that the rise of the "Islamists" also called "Djawula" risks to destroy forever these ancestral practices.

No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turístico do Alto Ribeira (High Ribeira River Turistic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Água Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005. The 222Rn concentrations lay in a range from 153 Bq.m-3 to 6607 Bq.m-3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a-1 for the Couto cave, strongly ventilated, to 4.0 mSv.a-1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a-1. All assessed effective doses received by the tour guides are bellow 20 mSv.a-1, suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990).

O objetivo do presente trabalho foi analisar os processos que levaram à invenção das práticas espeleológicas e do fenômeno espeleoturístico, sua produção social internacional e inserção no contexto brasileiro. Considera-se que o desenvolvimento da espeleologia como atividade de múltiplo sentido, técnico, esportivo, científico, lazer e contato com a natureza foi determinante para a geração do deslocamento e fluxos de pessoas para regiões onde existam sítios espeleológicos. Considera-se, como ponto de partida, que essa é a base apropriada pelo mercado, visando à implantação do turismo em cavernas. A abordagem teórico-metodológica multirreferencial parte dos conceitos da fenomenologia da imaginação de Bachelard e dos aportes da geopoética e da geografia humanístico-cultural, com contribuições também da percepção ambiental e da topofilia (Tuan). Pretendeu-se estudar o imaginário coletivo e os aspectos simbólicos da relação das sociedades humanas com as cavernas. Procurou-se, ainda, verificar as dinâmicas e fatores determinantes do processo espeleoturístico. Os procedimentos metodológicos enfatizaram uma análise das narrativas visuais e da produção de sentidos a partir das práticas discursivas de percepção da paisagem relativas às cavernas brasileiras, sua visitação turística e a proteção ambiental, destacando um estudo de caso no Vale do Ribeira (SP). Foi realizada uma ampla análise documental, utilizando materiais diversificados (textos filosóficos, religiosos e literários) coletados em bibliotecas, livrarias e alguns casos também em meio eletrônico. As imagens foram recolhidas em websites ligados ao tema caverna ou áreas afins, seja de entidades oficiais ou blogs e fotologs pessoais. Realizou-se também uma análise fílmica de 42 produções cinematográficas. O levantamento fotogeográfico e sociocultural das práticas espeleológicas e espeleoturísticas foi produzido durante as viagens de campo, realizadas entre 2000- 2010 em vários pontos do Brasil, com ênfase para o Alto Ribeira, e também em outros países (Portugal, Cuba), gerando um corpus com milhares de fotografias, acrescidas de outras disponibilizadas por colaboradores. Utilizou-se, ainda, métodos diversificados de entrevista, tais como gravações de depoimentos orais e entrevistas eletrônicas, por meio de questionário próprio, com 21 espeleólogos, sendo que 18 deles propiciaram dados sobre a representação do ser espeleólogo. Questionários sobre as representações sociais de cavernas foram incorporados ao estudo, aproveitando material que vimos produzindo no âmbito da Seção de História da Espeleologia da Sociedade Brasileira de Espeleologia (SBE), desde 1998, envolvendo 461 indivíduos. Os sujeitos principais são estudantes da educação básica ou do ensino superior, contrapondo moradores de áreas urbanas paulistas ou das proximidades das áreas de sítios espeleológicos, como no caso de Iporanga (SP). Os resultados demonstraram as influências do imaginário poético e do conteúdo simbólico das cavernas no desenvolvimento da atividade espeleológica e espeleoturística. As representações da paisagem cárstica e das práticas espeleológicas apareceram com extrema riqueza, tanto nos depoimentos, quanto nos documentos relacionados com temas filosóficos, religiosos, literários ou cinematográficos. É de fundamental importância ampliação dos processos educativos na formação do espeleólogo e dos cavernistas, a difusão das práticas espeleológicas e disseminação da espeleologia, aproximando racionalidades e subjetividades. Isso nos permite repensar sobre nossa relação histórica com o mundo subterrâneo, as interações da espeleologia e do turismo ao longo da trajetória da sociedade contemporânea. / The aim of this study was to analyze the processes that led to the invention of speleological practices and speleotourist phenomenon, and its international social production and its insertion in the Brazilian context. It is considered that the development of speleology as an activity of multiple meaning, technical, sporting, scientific, entertainment and contact with nature was crucial to the generation of movement and flows of people to areas where there are speleological sites. It is, as a starting point, that is the appropriate basis for the market, to the deployment of tourism in caves. The theoretical and methodological approach multi-referential starts of the concepts of the phenomenology of the imagination of Bachelard and the contributions of geopoetic and of the humanistic and cultural geography, with contributions also from the environmental perception and topophilia (Tuan). It was intended to study the collective imaginary and the symbolic aspects of the relationship of human societies with the caves. It is also to verify the dynamics and determinants of the speleotourist process. The methodological procedures emphasized an analysis of visual narratives and the production of senses from the discursive practices of landscape perception relating to Brazilian caves, tourist visitation and environmental protection, highlighting a case study in the Ribeira Valley (SP). It was performed an extensive documentary analysis, using varied materials collected in libraries, bookstores and in some cases also in electronic media. The images were collected from websites on speleology or related areas, or in websites of authorities or personal blogs and fotologs. There was also a film analysis of 42 film productions. The photogeographical and sociocultural survey of the speleological practices and cavingtourism was produced during the field trips, conducted between 2000-2010 in several places in Brazil, with emphasis on the Upper Ribeira Valley, and also in other countries (Portugal, Cuba), generating a corpus with thousands of photos, plus others photos provided by collaborators. It was used, yet, varied methods of interview, such as recordings of oral and electronic interviews, through the questionnaire, with 21 cavers or speleologists, of which 18 propitiated data about representations of to be a speleologist. The questionnaires on the social representations of the cave were incorporated into the study, using material that was produced under the History of Speleology Section of the Brazilian Speleological Society (SBE), since 1998, involving 461 people. The participants involved are students of basic education or university level, contrasting with urban dwellers of São Paulo or nearby places of speleological sites, such as Iporanga (SP). The outcomes they demonstrated the influences of the imaginary poetic and of the symbolic content from the caves into the development from speleological activity and speleotourist. The karst landscape representations and speleological practices appeared with extreme wealth, both in the testimonials and documents of philosophical, religious, literary and film themes. It is essential to increase the educational processes for the formation of cavers and speleologists, the spread of the speleological practices and the dissemination of caving, approaching rationalities and subjectivities. This allows us to rethink our historical relationship with the underworld, the interactions of caving and tourism along de trajectory of contemporary society.

No presente trabalho foram determinadas as concentrações de radônio em seis cavernas do Parque Estadual Turístico do Alto Ribeira (PETAR) e foi estimada a dose efetiva anual recebida pelos guias turísticos da região. O PETAR apresenta quatro núcleos de visitação: Santana, Ouro Grosso, Caboclos e Casa de Pedra e recebe anualmente cerca de 40 mil visitantes. As cavernas escolhidas foram Couto, Água Suja, Laje Branca, Morro Preto e Santana, do núcleo Santana e a caverna Alambari de Baixo do núcleo Ouro Grosso, por receberem o maior número de turistas. Os níveis de radônio foram determinados utilizando detectores de traços nucleares do estado sólido Makrofol E expostos trimestralmente por um período de 26 meses, entre Outubro de 2003 e Novembro de 2005. As concentrações de 222Rn variaram na faixa de 153 Bq.m-3 a 6607 Bq.m-3, sendo observado que, de uma maneira geral, os níveis de radônio diminuem nos períodos frios. A dose efetiva anual, considerando os cenários mais realistas, com média geométrica das concentrações, fator de equilíbrio 0,5 e tempo de exposição anual para cada caverna, variou entre 0,2 mSv.a-1 para a caverna Couto, bastante ventilada e 4,0 mSv.a-1 para a caverna Santana, a mais visitada, com galerias sem comunicação externa. Para o pior cenário, com média aritmética das concentrações, fator de equilíbrio 1 e tempo de exposição anual para todas as cavernas, a dose efetiva anual total foi 16,1 mSv.a-1. Todas as estimativas da dose efetiva anual estão abaixo de 20 mSv.a-1, sugerido como o valor limite para dose efetiva anual para exposição ocupacional pela Comissão Internacional de Proteção Radiológica (ICRP 60, 1990). / In the present work, radon concentrations in six caves of PETAR - Parque Estadual Turístico do Alto Ribeira (High Ribeira River Turistic State Park) were carried out with Makrofol E solid state nuclear track detectors (SSNTD) and used to assess the annual effective dose received by regional tour guides. The park has four visitation centers: Santana, Ouro Grosso, Caboclos e Casa de Pedra and receives nearly 40,000 people annually. The caves evaluated were Couto, Água Suja, Laje Branca, Morro Preto and Santana, from Santana center and Alambari de Baixo from Ouro Grosso center, for being the most frequently visited caves. The exposure period of the SSNTD was, at least, three months, over a period of 26 months, from October 2003 to November 2005. The 222Rn concentrations lay in a range from 153 Bq.m-3 to 6607 Bq.m-3 and we observed that, in general, for chilly weather, the radon levels decrease. The annual effective dose, considering the most realistic scenario, with geometric mean concentrations, an equilibrium factor of 0.5 and annual exposure time for each cave, varied from 0.2 mSv.a-1 for the Couto cave, strongly ventilated, to 4.0 mSv.a-1 for the Santana cave, the most frequently visited and no external communication. For the worst scenario, with arithmetic mean concentrations, equilibrium factor 1 and annual exposure time for all caves, the annual effective dose was 16.1 mSv.a-1. All assessed effective doses received by the tour guides are bellow 20 mSv.a-1, suggested as an annual effective dose limit for occupational exposure by the International Commission of Radiological Protection (ICRP 60, 1990).

Registros das razões isotópicas do oxigênio (d18O) e do carbono (d13C), juntamente com as taxas de crescimento de espeleotemas, precisamente datados pelo método U/Th, foram utilizados para reconstituição das variações de pluviosidade dos últimos 93 mil anos A.P. na região da Chapada Diamantina, porção central do Estado da Bahia. A reconstituição paleoclimática foi apoiada por estudo de calibração realizado em duas cavernas da região estudada, através do qual se obteve boa relação entre a assinatura isotópica da chuva e do d18O dos gotejamentos e evidências de condições ambientais propícias para deposição de espeleotemas em equilíbrio isotópico com a água de gotejamento. A interpretação climática dos dados de d18O dos espeleotemas considera também a análise da composição isotópica da água da chuva em face da pluviometria, a partir de dados de estações do IAEA-GNIP no Brasil e de simulações das variações do d18O da chuva através do modelo climático ECHAM-4. Esses dados indicam o fator amount effect, como relação preponderante na discussão de pluviosidade através dos registros de espeleotemas, a qual é caracterizada pela diminuição dos valores de d18O com o aumento do volume de chuvas. A partir dos registros de d18O dos espeleotemas foi possível reconstituir os padrões regionais de pluviosidade segundo o ciclo de insolação, como também identificar eventos de mudança abrupta de pluviosidade em escala milenar ocorridos durante o último período glacial e Holoceno. Em escala orbital, foi observado aumento (diminuição) da paleoprecipitação na Bahia durante fases de baixa (alta) insolação de verão (10ºS). Essa relação é evidente na maior parte do registro baiano com exceção do período entre 40 e 20 ky A.P., quando houve predomínio de clima seco, mesmo em fases de insolação baixa. No entanto, tal é relação inversa a que foi descrita em estudos paleoclimáticos do Sul/Sudeste do Brasil e dos Andes. Além disso, variações de paleopluviosidade da Chapada Diamantina estão em fase com as registradas nos trópicos do Hemisfério Norte, na China e Venezuela. Esses resultados indicam influência direta do sistema de Monções Sul-americana (MSA) sobre o regime de chuvas do Nordeste em longa escala de tempo, a qual é primariamente modulada pela intensidade da insolação de verão. Aumentos abruptos da paleopluviosidade em escala milenar, indicados por baixos valores de d18O e d13C, como pelas altas taxas de crescimento de espeleotemas, ocorreram durante predomínio de condições frias no Atlântico Norte, em períodos de grandes mudanças nas condições oceânicas, e são concomitantes com os eventos Heinrich e Younger Dryas. Já fortes diminuições foram observadas durante alguns eventos Dansgaard-Oeschger e Bølling-Allerød. Ao contrário do que foi observado durante os ciclos orbitais, o impacto no clima da Bahia atribuído a esses eventos é semelhante em todo país e também nos Andes, de acordo com estudo comparativo entre testemunhos marinhos/lacustres e espeleotemas. Esses eventos produz efeito na pluviosidade de regiões (sub)tropicais do Hemisfério Norte, assim como registrados em arquivos paleoclimáticos da China e Venezuela. O mecanismo mais provável para geração desses eventos está relacionado com mudanças na Atlantic Meridional Overturning Circulation (AMOC). Com a AMOC desintensificada durante eventos Heinrich no Hemisfério Norte, existe predomínio de um gradiente da temperatura da superfície do Atlântico tropical que favorece posicionamento da Zona de Convergência Intertropical mais a sul durante os eventos úmidos na Bahia. / Speleothem records of stable oxygen (d18O) and carbon isotope ratios (d13C) and speleothem growth rates, precisely dated by U/Th method, were used to reconstruct past changes in precipitation in the last 93,000 years B.P. from Chapada Diamantina region, Bahia State. The paleoclimatic reconstruction takes into account results from a calibration study performed in two caves in the Chapada Diamantina region. It was found a robust relationship between isotope signature in precipitation and cave drip water and also evidenced adequate environmental conditions for speleothem deposition in isotopic equilibrium with drip water. The interpretation of the speleothem d18O records is based on the relationship between isotope composition of precipitation and rainfall amount from IAEA-GNIP stations in Brazil and also results from climate experiments coupled with d18O in precipitation using ECHAM-4. These data indicate the amount effect as the dominant isotope fractionation factor controlling the d18O variations in meteoric water forming speleothems, which is characterized by a decrease in the d18O values with an increase in rainfall amount. Speleothem d18O records allow reconstructing the regional paleoprecipitation patterns on both orbital and millennial time-scales during last glacial period and Holocene. These records indicate an increase (decrease) in paleoprecipitation over central Bahia during low (high) summer insolation (10ºS) phases. This relationship is evident is most of this new speleothem record, except in the period between 40 and 20 ka B.P., when dry climate conditions predominate in the region even during the low insolation phases. However, this relationship is exactly the contrary of the one reported from southern/southeastern Brazil and Central Andes paleoclimate studies. Furthermore, the precipitation variations in Chapada Diamantina are in phase with records from Northern Hemisphere on orbital time-scales, particularly from China and Venezuela. These results suggest a direct influence of the South American Monsoon System (SAMS) on long-term changes in precipitation over northeastern Brazil, which is primarily controlled by gradual changes in summer insolation. Abrupt wet events are defined on millennial time-scales in the Chapada Diamantina records by low values of d18O e d13C and high speleothem growth rates. They occurred under prevalence of cold conditions in Northern Hemisphere, triggered by major changes in oceanic circulation in Atlantic Ocean, during Heinrich and Younger Dryas (YD) events. On the other hand, abrupt decreases in regional precipitation are coincident with some of the Dansgaard-Oeschger (D-O) e Bølling-Allerød (B-A), which are typical warm events in Northern Hemisphere. However, differently from the isotope-climate relationship established on orbital times, the impact of these millennial events on the precipitation variations of Bahia is similar to what is documented in speleothem, lake and marine records from Brazil and Central Andes and opposite to changes described in China and Venezuela, among many other records from Northern Hemisphere. The climate mechanism behind the origin of these millennial events is associated with changes in the Atlantic Meridional Overturning Circulation (AMOC). The Heinrich events are linked to periods of weaker AMOC and sea surface temperature gradients that favor a mean southern position of Intertropical Convergence Zone, which results in very wet conditions in Bahia.

Registros das razões isotópicas do oxigênio (d18O) e do carbono (d13C), juntamente com as taxas de crescimento de espeleotemas, precisamente datados pelo método U/Th, foram utilizados para reconstituição das variações de pluviosidade dos últimos 93 mil anos A.P. na região da Chapada Diamantina, porção central do Estado da Bahia. A reconstituição paleoclimática foi apoiada por estudo de calibração realizado em duas cavernas da região estudada, através do qual se obteve boa relação entre a assinatura isotópica da chuva e do d18O dos gotejamentos e evidências de condições ambientais propícias para deposição de espeleotemas em equilíbrio isotópico com a água de gotejamento. A interpretação climática dos dados de d18O dos espeleotemas considera também a análise da composição isotópica da água da chuva em face da pluviometria, a partir de dados de estações do IAEA-GNIP no Brasil e de simulações das variações do d18O da chuva através do modelo climático ECHAM-4. Esses dados indicam o fator amount effect, como relação preponderante na discussão de pluviosidade através dos registros de espeleotemas, a qual é caracterizada pela diminuição dos valores de d18O com o aumento do volume de chuvas. A partir dos registros de d18O dos espeleotemas foi possível reconstituir os padrões regionais de pluviosidade segundo o ciclo de insolação, como também identificar eventos de mudança abrupta de pluviosidade em escala milenar ocorridos durante o último período glacial e Holoceno. Em escala orbital, foi observado aumento (diminuição) da paleoprecipitação na Bahia durante fases de baixa (alta) insolação de verão (10ºS). Essa relação é evidente na maior parte do registro baiano com exceção do período entre 40 e 20 ky A.P., quando houve predomínio de clima seco, mesmo em fases de insolação baixa. No entanto, tal é relação inversa a que foi descrita em estudos paleoclimáticos do Sul/Sudeste do Brasil e dos Andes. Além disso, variações de paleopluviosidade da Chapada Diamantina estão em fase com as registradas nos trópicos do Hemisfério Norte, na China e Venezuela. Esses resultados indicam influência direta do sistema de Monções Sul-americana (MSA) sobre o regime de chuvas do Nordeste em longa escala de tempo, a qual é primariamente modulada pela intensidade da insolação de verão. Aumentos abruptos da paleopluviosidade em escala milenar, indicados por baixos valores de d18O e d13C, como pelas altas taxas de crescimento de espeleotemas, ocorreram durante predomínio de condições frias no Atlântico Norte, em períodos de grandes mudanças nas condições oceânicas, e são concomitantes com os eventos Heinrich e Younger Dryas. Já fortes diminuições foram observadas durante alguns eventos Dansgaard-Oeschger e Bølling-Allerød. Ao contrário do que foi observado durante os ciclos orbitais, o impacto no clima da Bahia atribuído a esses eventos é semelhante em todo país e também nos Andes, de acordo com estudo comparativo entre testemunhos marinhos/lacustres e espeleotemas. Esses eventos produz efeito na pluviosidade de regiões (sub)tropicais do Hemisfério Norte, assim como registrados em arquivos paleoclimáticos da China e Venezuela. O mecanismo mais provável para geração desses eventos está relacionado com mudanças na Atlantic Meridional Overturning Circulation (AMOC). Com a AMOC desintensificada durante eventos Heinrich no Hemisfério Norte, existe predomínio de um gradiente da temperatura da superfície do Atlântico tropical que favorece posicionamento da Zona de Convergência Intertropical mais a sul durante os eventos úmidos na Bahia. / Speleothem records of stable oxygen (d18O) and carbon isotope ratios (d13C) and speleothem growth rates, precisely dated by U/Th method, were used to reconstruct past changes in precipitation in the last 93,000 years B.P. from Chapada Diamantina region, Bahia State. The paleoclimatic reconstruction takes into account results from a calibration study performed in two caves in the Chapada Diamantina region. It was found a robust relationship between isotope signature in precipitation and cave drip water and also evidenced adequate environmental conditions for speleothem deposition in isotopic equilibrium with drip water. The interpretation of the speleothem d18O records is based on the relationship between isotope composition of precipitation and rainfall amount from IAEA-GNIP stations in Brazil and also results from climate experiments coupled with d18O in precipitation using ECHAM-4. These data indicate the amount effect as the dominant isotope fractionation factor controlling the d18O variations in meteoric water forming speleothems, which is characterized by a decrease in the d18O values with an increase in rainfall amount. Speleothem d18O records allow reconstructing the regional paleoprecipitation patterns on both orbital and millennial time-scales during last glacial period and Holocene. These records indicate an increase (decrease) in paleoprecipitation over central Bahia during low (high) summer insolation (10ºS) phases. This relationship is evident is most of this new speleothem record, except in the period between 40 and 20 ka B.P., when dry climate conditions predominate in the region even during the low insolation phases. However, this relationship is exactly the contrary of the one reported from southern/southeastern Brazil and Central Andes paleoclimate studies. Furthermore, the precipitation variations in Chapada Diamantina are in phase with records from Northern Hemisphere on orbital time-scales, particularly from China and Venezuela. These results suggest a direct influence of the South American Monsoon System (SAMS) on long-term changes in precipitation over northeastern Brazil, which is primarily controlled by gradual changes in summer insolation. Abrupt wet events are defined on millennial time-scales in the Chapada Diamantina records by low values of d18O e d13C and high speleothem growth rates. They occurred under prevalence of cold conditions in Northern Hemisphere, triggered by major changes in oceanic circulation in Atlantic Ocean, during Heinrich and Younger Dryas (YD) events. On the other hand, abrupt decreases in regional precipitation are coincident with some of the Dansgaard-Oeschger (D-O) e Bølling-Allerød (B-A), which are typical warm events in Northern Hemisphere. However, differently from the isotope-climate relationship established on orbital times, the impact of these millennial events on the precipitation variations of Bahia is similar to what is documented in speleothem, lake and marine records from Brazil and Central Andes and opposite to changes described in China and Venezuela, among many other records from Northern Hemisphere. The climate mechanism behind the origin of these millennial events is associated with changes in the Atlantic Meridional Overturning Circulation (AMOC). The Heinrich events are linked to periods of weaker AMOC and sea surface temperature gradients that favor a mean southern position of Intertropical Convergence Zone, which results in very wet conditions in Bahia.

En 1994, la découverte de la grotte Chauvet-Pont d'Arc (Ardèche, France) révéla des marquesthermiques, d'origine anthropique, uniques au monde. Elles sont les témoins de feux préhistoriqueseffectués dans la partie profonde de la cavité. La datation par thermoluminescence des chauffes estcohérente avec la première période de fréquentation humaine il y a entre 37 000 et 33 500 ans. Lesarchéologues ont identifié deux types de thermo-altérations : des changements de couleur et desécaillages. Les changements de couleur résultent de réactions chimiques s'opérant à hautetempérature dans le calcaire, rendant la roche rouge ou grise. Des essais ex situ ont montré que lacouleur rouge survient après une chauffe de 10 minutes à 250oC tandis qu'une température minimumde 350oC est nécessaire pour la couleur grise. Le phénomène d'écaillage provient de fortes contraintesmécaniques dans la roche causées par la dilatation thermique et des processus thermo-hydriques. Deplus, des particules de suie recouvrent encore une partie des parois dans les zones altérées. À partirde ces indices, l'objectif de la thèse est de caractériser les feux de la Galerie des Mégacéros qui sesitue dans la partie profonde de la grotte. L'estimation des quantités de bois, du nombre de feux etde la capacité à alimenter les foyers pourrait aider les archéologues à faire des hypothèses sur lafonction de ces feux.Pour des raisons de conservation, seule la simulation peut reproduire des feux dans la géométrie de lagrotte sans nécessiter sa reconstitution. Cette étude consiste à construire une modélisation numériquede feux confinés et des impacts thermiques résultants. Un couplage fluide-structure est donc développéà partir de deux logiciels open source : OpenFOAM et Cast3m. Le premier effectue la simulation descénarios de feux grâce au module FireFOAM. Le second réalise les calculs thermo-mécaniques dansle massif. Afin d'étendre le champ d'application initial de FireFOAM, des modèles numériques ontété implémentés dans le code. Ceux-ci concernent le dépôt de suie, l'évaluation des risques, lacorrection des mesures par thermocouple et une condition limite en température. De plus, quelquesexigences de modélisation améliorant la qualité des résultats sont détaillées dans le manuscrit. Lemodèle ainsi développé est validé sur des feux expérimentaux exécutés dans une ancienne carrière decalcaire dont les dimensions sont proches de celles de la Galerie des Mégacéros. Du pin sylvestre, quicorrespond à l'essence dont sont issus les échantillons de charbon analysés de la grotte, est utilisécomme combustible. La combustion aboutit à des thermo-altérations analogues à celles observéesdans la grotte Chauvet-Pont d'Arc. Des écaillages et des changements de couleur se sont produits auplafond et aux parois de la carrière. La comparaison avec la simulation est effectuée à partir desmesures de températures, de vitesses ainsi que de concentrations de gaz et de particules.Le modèle numérique est ensuite appliqué à la simulation de feux dans la géométrie de la Galerie desMégacéros. Toutes les zones altérées de cette galerie sont traitées et les scénarios qui ont pu se produiresont précisés. Ces travaux fournissent ainsi une vue d'ensemble de la localisation et de l'intensité desfeux dans cette partie de la grotte. De plus, l'adéquation avec les conditions de vie est indiquée pourles feux les plus puissants. Ces informations pourraient aider les archéologues dans la compréhensiondes fonctions de ces feux. / In 1994, the discovery of the Chauvet-Pont d'Arc cave (Ardèche, France) revealed singularanthropogenic thermal marks on walls. They are the witnesses of high intensity prehistorical firescarried out deep in the cavity. The thermoluminescence evaluation of the heating ages is consistentwith the earlier period of human occupation between 37,000 and 33,500 years ago. The archaeologistsidentified two kinds of thermo-alterations : colour changes and spallings. The colour changes resultfrom high-temperature chemical reactions in limestone, turning rock red or grey. Ex situ tests showedthat red colour happens after heating at 250oC for ten minutes while at least 350oC is necessary forgrey. Spalling stems from high stresses in rock due to restrained thermal expansion and thermohydricprocesses. In addition, part of the walls near thermo-altérations is still covered with soot. From theseclues, this investigation aims to characterize the fires of the Megaloceros Gallery which is located inthe deep part of the cave. Estimating the amounts of wood, the fires number and the ability tosupply the hearths could help make assumptions about the function of these fires.For the sake of conservation, only simulation can reproduce fires in the cave geometry withoutrequiring any reconstruction. This study is to set up a numerical modelling of fires in confinedgeometries and the induced thermal impacts on walls. A fluid-structure coupling is then developedfrom two free open source codes : OpenFOAM and Cast3m. The former manages the simulation offire scenarios through the FireFOAM tool. The latter handles the thermo-mechanical calculations inthe rock mass. To extend the initial scope of FireFOAM, some numerical models have beenimplemented in the code. This relates to soot deposit, danger assessment, thermocouple correctionand a thermal boundary condition. In addition, some modelling requirements improving the qualityof the results are detailed in the manuscript. The advanced model is then validated on experimentalfires in a former limestone quarry which has dimensions close to the Megaloceros Gallery ones. Thesame fuel (pinus sylvestris) as the one identified in the cave is burnt. The combustion led to similarthermo-alterations as those observed in the Chauvet-Pont d'Arc cave. Spallings and colour changesoccurred on the ceiling and walls of the quarry. The comparison with simulation is carried out thanksto the measurement of temperatures, velocities, soot deposits, gases and particles concentrations.The numerical model is then applied to the simulation of fires in the Megaloceros Gallery geometry.All the impacted areas of this gallery are considered and the scenarios that may have occurred arespecified. This investigation then provides an overview of the fires locations and intensities in thispart of the cave. Moreover, the compatibility with living conditions is indicated for the most powerfulfires. These information could help for archaeologists in the understanding of the functions of these fires.