xxi, 541 p. : ill. (some col.), maps. A print copy of this title is available through the UO Libraries under the call number: KNIGHT E78.O6 O37 2006 / Many archaeological researchers that have conducted investigations in the Harney Valley of southeastern Oregon use the ethnographic description of the seasonal round of the Harney Valley Paiute reported by Beatrice Blyth Whiting in her 1950 work Paiute Sorcery as a framework for discussions of prehistoric human use of the area. Archaeological investigations of seven sites, situated in areas identified as having been utilized by the Harvey Valley Paiutes, were conducted to test the relationship between Whiting's ethnographic account and the archaeological record. Data recovery excavations occurred at the Hoyt (35HA2422), Morgan (35HA2423) and Hines (35HA2692) sites near Burns, and test excavations occurred at the Knoll (35HA2530) site in the Silvies Valley, the RJ site (35HA3013) in the Stinkingwater Mountains, and the Broken Arrow (35HA2735) and Laurie's (35HA2734) sites near Malheur Lake. Studies of the cultural materials recovered during the excavations were undertaken to evaluate the content and complexity of each site. Analyses included typological considerations of the chipped stone tools, ground stone, bone tools, and shell, bone, and stone beads. Radiocarbon dating, obsidian sourcing and hydration, and zooarchaeological and paleobotanical analyses were also conducted when possible. Based on the results of the analyses, the seven sites reported herein were primarily used during the past 2000 years, with periods of less intensive use extending beyond 4000 BP. The results of the archaeological investigations indicate that there is a strong correlation between the late Holocene prehistoric record and Whiting's ethnographic description. However, the relationship between human use of the centrally-located lakes and wetlands and the neighboring uplands is clearly more complex than the ethnographic record suggests. Patterns of settlement and mobility revealed through the archaeological record indicate that central places, located closer to wetlands and lacustrine settings but within relatively easy reach of the uplands, may have figured more prominently in the behavior of prehistoric populations than the seasonal round as described by Whiting. Future research will benefit from explorations of central place foraging, emphasizing the role of behavioral ecology in the placement of sites and patterns of site use within the Harney Valley and the northern Great Basin at large. / Committee in Charge: Dr. C. Melvin Aikens, Chair; Dr. Dennis L. Jenkins; Dr. Douglas J. Kennett; Dr. Esther Jacobson-Tepfer

xv, 296 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries under the call number: KNIGHT E78.O6 H44 2001 / This study analyzes the botanical and archaeological material from a Middle Holocene occupation at the Bergen site, located in the Fort Rock Basin, Oregon. It serves to complement and enhance over a decade of research focused on regional settlement patterns in the Northern Great Basin. While previous studies in the region have focused on broadly based settlement patterns, this study shifted the interpretive lens toward an in-depth analysis of a single family dwelling, which was occupied some 6000 years ago. It thus introduces the domain of "household archaeology" into the practice of archaeological research in the Northern Great Basin for the first time. Macrobotanical analysis was conducted on 215 soil samples collected on a 50cm grid from this house. An additional 20 samples were analyzed from a second house structure at the site. These analyses have provided evidence of diet, environment, and social behavior associated with the prehistoric occupants of the house. The abundance of charred bulrush (Scirpus ), goosefoot (Chenopodium ), and waada (Suaeda ) seeds in the deposits indicate that small seeds of wetland-adapted plants were an important dietary resource during the Middle Holocene in the Fort Rock Basin. The patterned distribution of botanical material in 215 soil samples across the floor of the house provide strong evidence of prehistoric human activity areas. The highest concentration of seeds and charcoal in the house was located near the central fire hearth, where cooking and food preparation took place. An east-facing entryway is suggested by the presence of a secondary concentration of seeds and charcoal on the eastern edge of the structure. Analysis also revealed a differential distribution of seed types across the house floor. Higher concentrations of bulrush in the northern area of the floor, away from the hearth, suggest the presence of sleeping mats. Results of this study indicate that plant remains are not evenly distributed through archaeological deposits, therefore care must be taken when sampling for macrobotanical remains. Research at the Bergen site provides the basis for recommendations to assist future archaeologists in determining the best and most cost-effective locations within excavations to take macrobotanical samples. / Committee in charge: Dr. C. Melvin Aikens, Chair; Dr. Theresa O'Neil; Dr. Dennis Jenkins; Dr. Daniel Close

O objetivo da presente tese é o de documentar, em escala milenar, as variações paleoclimáticas e paleoceanográficas superficiais do Atlântico Sul Ocidental desde o Último Máximo Glacial. Com esta finalidade, foram obtidas estimativas de paleotemperatura, paleossalinidade e paleoprodutividade baseadas na análise de fauna de foraminíferos planctônicos, isótopos estáveis de oxigênio e carbono em Globigerinoides ruber e nove datações de radiocarbono em amostras de um testemunho coletado na Bacia de Santos. Os dados foram complementados com a reanálise de outro testemunho previamente coletado em outro setor da mesma Bacia. Os resultados demonstram que as mudanças paleoceanográficas registradas no período analisado podem ser parcialmente explicadas por variações na exportação de calor e sal para o hemisfério norte relacionadas à atividade da célula de transporte meridional e à configuração das correntes superficiais associadas à circulação atmosférica. Outra parte significativa da variabilidade parece estar relacionada à intensidade do Sistema de Monção da América do Sul resultante de variações na insolação de acordo com o ciclo de precessão. Os principais desvios da tendência de variação da composição isotópica da água do mar esperada em função das mudanças de insolação coincidem com os grandes pulsos de degelo ocorridos em torno de 19, 14 e 8,2 mil anos AP. / The goal of this thesis is to document the paleoclimatic and paleoceanographic changes occurred at the millennial scale since the Last Glacial Maximum at the surface Western South Atlantic. Paleotemperature, paleosalinity and paleoproductivity estimates were obtained for this purpose based on faunal changes of foraminifera assemblages, carbon and oxygen stable isotopes in Globigerinoides ruber and nine radiocarbon datings in a core retrieved at Santos Basin. These data were supplemented by the reanalysis of a second core previously analyzed from a different sector of the same basin. The results demonstrate that paleoceanographic changes recorded in the analyzed period may be partially explained by changes in the heat and salt export to the northern hemisphere related to the meridional overturning cell and the surface currents related to atmospheric circulation. Another significant portion of the observed variability seems to be related to changes in the strength of the South American Monsoon System resulting from insolation changes according to the precessional cycle. The main departures from the expected trend of variation in the isotopic composition of seawater related to insolation changes coincide with great meltwater pulses occurred around 19, 14, and 8.2 kyr BP.

Com base em um estudo interdisciplinar, os objetivos deste trabalho foram: estudar a dinâmica da vegetação e do nível relativo marinho e inferir o clima, durante o Holoceno, na região nordeste do estado do Espírito Santo. Para tanto foram analisados: (i) vegetação atual (caracterização botânica e \'delta\'13C e \'delta\'15N); (ii) matéria-orgânica do solo (\'delta\'13C, C elementar e datação 14C); (iii) sedimento lacustre (litologia, C e N elementar, \'delta\'13C e \'delta\'15N, datação 14C da matéria-orgânica, pólen e diatomáceas). Os pontos de amostragem estão localizados na Reserva Natural Vale e na Reserva Biológica de Sooretama, região de predomínio de Floresta Ombrófila Densa das Terras Baixas, com fragmentos de Savana e áreas ocupadas por vegetação pioneira. As principais conclusões foram: (i) o local de estudo não apresentou retração florestal durante o Holoceno; (ii) o clima foi inferido como predominantemente úmido; (iii) a dinâmica da vegetação durante o Holoceno no interior e nas proximidades do vale do Rio Barra Seca foi influenciada pelas flutuações do nível relativo marinho: com a transgressão marinha (há aproximadamente 7700 anos cal. A.P.) iniciou-se o deslocamento da vegetação florestal e a instalação do manguezal; entre aproximadamente 4700 até 3000 anos cal. A.P., o período de maior influência marinha, ocorreu o maior distanciamento do manguezal em relação ao ponto estudado; com a regressão marinha, a colonização do vale por vegetação pioneira ocorreu a partir de, aproximadamente, 2300 anos cal. A.P.; há cerca de 1200 anos cal. A.P. ocorreu a instalação do atual ambiente lacustre com a floresta em seu entorno; (iv) o local atualmente ocupado pela Lagoa do Macuco, no interior do vale do Rio Barra Seca, foi caracterizado por um ambiente estuarino durante o período aproximado de 7700 a 3000 anos cal. A.P / Based on an interdisciplinary study, the objectives of the present work were to study the vegetation and relative sea-level dynamics and to infer the climate during the Holocene, at northeastern region of Espírito Santo State. The materials and respective analyses were: (i) modern vegetation (botanic identification, \'delta\'13C and \'delta\'15N); (ii) soil organic matter (total organic carbon, \'delta\'13C and 14C dating); (iii) lake sediment (lithology, total organic carbon and total nitrogen, \'delta\'13C and \'delta\'15N, 14C dating, pollen and diatoms). The sampling points were located at Vale Natural Reserve and Sooretama Biologic Reserve, region of tropical rainforest vegetation dominance, with savanna fragments and pioneer vegetation patches. The main conclusions were: (i) the forest retreatment was not observed in the study site during the Holocene (ii) the climate was predominantly humid (iii) vegetation dynamics inside the Barra Seca River valley and surroundings were influenced by relative sea-level fluctuations: at ca. 7700 cal. yr B.P., the forest vegetation started its retreatment and the mangrove ecosystem was installed; from ca. 4700 to ca. 3000 cal. yr B.P., the period of higher marine influence, occurred the higher mangrove detachment from the sampling point; with the marine regression, the valley colonization by the pioneer vegetation started at ca. 2300 cal. yr B.P.; at ca. 1200 cal. yr B.P. started the installation of modern lacustrine environment, with the Forest in the surroundings; (iv) the present location of Lagoa do Macuco was characterized by na estuarine environment during the period from ~7700 to ca. 3000 cal. yr B.P

A sismoestratigrafia, em geral, não é utilizada em estudos de curto espaço de tempo geológico, como os de quinta e sexta ordem. Entretanto, o estudo da Baía do Araçá, no Canal de São Sebastião, no litoral norte do estado de São Paulo mostrou que este tipo de abordagem é possível para ciclos desta magnitude. Utilizando um sistema de aquisição de dados sísmicos, composto por uma fonte boomer, um pinger e um chirp, foi feito um levantamento da região, que resultou em cerca de 60 km de perfis sísmicos de alta resolução, foi possível reconhecer um conjunto de unidades sísmicas que pode ser entendida no conceito de tratos de sistema. Com a interpretação destes sismogramas, gerou-se um modelo evolutivo para a sedimentação no Araçá tendo sido encontrados tratos de sistemas de mar alto, de mar baixo e transgressivo muito bem definidos. Estes tratos foram relacionados com as curvas de variações eustáticas do Pleistoceno Superior e Holoceno conhecidas, possibilitando a proposição de duas hipóteses distintas: a primeira considerando um período de mar alto no Estágio Isotópico 5e e a segunda com um período de mar alto no Estágio Isotópico 3, em uma posição superior àquela considerada pela maioria dos autores, mas corroborada por outros. Além disso, foram encontradas evidências claras de tectônica Neoquaternária na região. / It is not that common to use the seismic stratigraphy in studies of short geological time as those from fifth and sixth orders. However, the study of Araça\'s Bay, at São Sebastião Channel, at the north coast of São Paulo State, showed that this kind of approach is in fact possible for cycles of this magnitude. Using a seismic setup composed with one boomer seismic source, as well as one pinger and one chirp, a seismic survey was taken in the area, which resulted in about 60 km of seismic profiles of high resolution. Analyzing those seismograms, we propose an evolution model for the sedimentation at Araçá area, and we found records of highstand systems tract, lowstand systems tract and transgressive systems tract very well marked. These tracts were then related to the known sea level change curves for Late Pleistocene and Holocene, allowing a proposition of two distinct hypothesis: the first one considers a highstand period at Isotopic Stage 5e and the second one a highstand period at Isotopic Stage 3, in a higher position than that considered for most authors, but corroborated for some others. Also, it was found clear evidences of Neoquaternary tectonics at the area.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-03-22T19:15:25Z No. of bitstreams: 1 Dissertação Mestrado_ Angélica Blanco_FINALCORRIGIDA.pdf: 3674860 bytes, checksum: 71cb912a535da66b5045cc37b27095b1 (MD5) / Made available in DSpace on 2016-03-22T19:15:25Z (GMT). No. of bitstreams: 1 Dissertação Mestrado_ Angélica Blanco_FINALCORRIGIDA.pdf: 3674860 bytes, checksum: 71cb912a535da66b5045cc37b27095b1 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ / O desenvolvimento de planícies costeiras e a evolução de ambientes deposicionais Fúlviolagunares e depósitos praias deu origem a diversas lagoas ao longo da costa do Estado do Rio de Janeiro. Os sistemas lagunares estiveram influenciados pelas variações do nível do mar com sedimentos oriundos de diversas fontes. Como consequência das flutuações do nível do mar, os sistemas lagunares formados apresentaram características especiais como mistura de águas continentais e marinhas, geralmente com alta salinidade. Este trabalho caracteriza a sedimentação do paleoambiente da lagoa Salgada com uso de isótopos 13C, 15N, do 14C e C:N na matéria orgânica (MO) do testemunho S15. Foi construído um modelo cronológico, através de regressão linear resultando em um período compreendido entre 6.300 e 1.300 anos cal. AP. Devido à complexidade nas interpretações paleoambientais e sedimentológicas de ambientes de planícies deltáicas, assim como a identificação das fontes de MO, os processos de sedimentação foram analisados através da litologia e história evolutiva do lago. O testemunho S-15 foi dividido em três unidades (I, II e III) e nove sub-unidades litológicas (A, B, C, D, E, F, G, H e I) de modo a correlacionar os sedimentos e a MO e assim compreender os processos de sedimentação na lagoa nos últimos 7.000 anos. Os sedimentos são siliciclásticos com fases intercaladas de lama arenosa e lama síltico-argilosa, isto sugere uma sedimentação lacustre num sistema com variações de energia. A geoquímica isotópica do testemunho S-15 mostrou pouca variação ao longo da sucessão sedimentar. A variabilidade dos valores do 13C e do 15N ao longo do testemunho sugere três fases de sedimentação orgânica (fluvial, estuarina e lagunar) devido à transição do ambiente marinho a lagunar, influenciado pela evolução deltáica. Os valores C:N sugerem mistura de fontes de MO alóctone e autóctone (plantas terrestres C3, bactérias e fitoplâncton). O clima semiárido na região, em consequência da ressurgência costeira e fechamento do sistema lagunar, favoreceu a precipitação de sais e carbonatos uma vez que a lagoa ficou isolada na planície costeira. Assim, a geoquímica e os processos de sedimentação mudaram gerando condições específicas para o desenvolvimento de tapetes microbiais e, posteriormente para o topo da sucessão, os estromatólitos. / The development of coastal plains and the evolution of fluvial-lagoonal depositional environments and beach deposits gave rise to several lakes along the Rio de Janeiro State coast. The lagoonal systems were influenced by the sea level variations with sediments from different sources. As a consequence of the fluctuations in sea levels, the lagoonal systems presented special features as a mixture of continental and marine waters, usually with high salinity. This study characterizes the sedimentation of the paleo-environment of Salgada lake, using 13C, 15N isotopes, 14C and C:N in the organic matter (OM ) of the core S-15. It was constructed a chronological model based on linear regression resulting in a period between 6.300 and 1.300 yrs cal. BP. Due to the complexity on paleoenvironmental and sedimentological interpretations in delta plain environment as well the identification of OM sources, the sedimentation processes were analyzed trough the lithology and evolutionary history of the lake. The S-15 core was divided into three units (I , II, and III) and nine lithological sub-units (A, B, C , D, E , F, G , H and I) in order to correlate the sediments and the OM and therefore to understand the lake sedimentation processes in the last 7.000 years. The sediments are siliciclastic with intercalated phases of sandy mud- and clay silt mud -. This suggests a lacustrine system with variations in energy. The isotopic geochemistry of S- 15 core showed little variation throughout the sedimentary succession. The variability of 13C and 15N values along the core suggests three phases of organic sedimentation (fluvial, estuarine and lagoonal) due to the transition from the marine to lagoonal environment, influenced by the deltaic evolution. The C:N values suggests mixing sources of allochthonous and autochthonous OM (C3 terrestrial plants, bacteria and phytoplankton). The semiarid weather in the region, as a consequence of coastal upwelling, and closure of the lake system favored the precipitation of salts and carbonates, since the lagoon was isolated in the coastal plain. Therefore the geochemistry and the sedimentation processes changed generating specific conditions for the development of microbial mats and further, to the top of the succession, the stromatolites.

Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-04-03T16:44:03Z No. of bitstreams: 1 THIAGO ANDRADE DE SOUSA .pdf: 5768772 bytes, checksum: b3c4e1c52ed521e2c3772627711af6fa (MD5) / Made available in DSpace on 2017-04-03T16:44:03Z (GMT). No. of bitstreams: 1 THIAGO ANDRADE DE SOUSA .pdf: 5768772 bytes, checksum: b3c4e1c52ed521e2c3772627711af6fa (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica Ambiental. Niterói, RJ / Os sedimentos continentais depositados no fundo oceânico estão condicionados, majoritariamente, a evolução do clima, ao substrato geológico e ao tipo de transporte, sendo o transporte fluvial o de maior magnitude. Uma vez depositado, os sedimentos tornam-se registros do passado e carregam informações sob a forma de assinatura geoquímica. Os Elementos Terras Raras (ETR) apresentam um comportamento coerente ao longo de uma coluna sedimentar tornando-os útil nos estudos de proveniência sedimentar. Razões entre elementos maiores (Fe/Ca, por exemplo) são descritos na literatura como indicadores de reconstrução do aporto terrígeno. A geoquímica dos ETR e elementos maiores são determinados neste trabalho para o entendimento da dinâmica paleoclimática sobre o aporte e proveniência dos sedimentos da margem leste (Bacia de Santos) do Brasil, e as anomalias do Ce e Eu, confrontando técnicas analíticas distintas (ICP-MS e XRF core scanner) nos principais eventos abruptos (Younger Dryas e Heinrich events) ao longo dos últimos 45.000 anos. Igualmente é discutido a proveniência do material sedimentar por meio de razões entre Elementos Terras Raras leve (ETRL) e Elementos Terras Raras pesado (ETRP) comparando possíveis fontes disponíveis na literatura. O padrão de distribuição indica enriquecimento em ETRM sobre ETRL e ETRP em todos os eventos. Isso significa que a proveniência deste material, provavelmente, deve-se a uma única fonte. As concentrações dos ETRL são sempre maiores que ETRM e ETRP. Esse padrão é outro indicativo de fonte única do material sedimentar. O somatório das concentrações dos ETR durante o MIS 2 é sempre maior do que o MIS 1. O comportamento dos ETR durante os eventos Heinrich são bem similares. A média das concentrações dos ETR nestes eventos são superiores aos encontrados no MIS 1 – Interglacial. As análises das razões Fe/Ca e Ti/Ca pelas duas técnicas mostram-se coerentes e indicam maiores durante o MIS 2. Isto é devido ao aumento de chuvas na região (intensificação do SMAS), nível do mar regressivo (plataforma continental exposta) e por efeitos de diluição do carbonato marinho estimulada pela entrada de matéria orgânica. As razões Al/Si e Fe/K apresentam sinais distintos ao longo do testemunho deste estudo. O aumento de Si durante o MIS 2, em relação aos outros períodos, indica que o glacial foi menos úmido que o interglacial. O aumento de K dentro dos eventos Heinrich indica mudança no padrão de intemperismo continental devido aos episódios de chuvas e aumento no intemperismo químico nas bacias de drenagens. A anomalia do Ce é negativa em todos os períodos e indica condições oxidantes no ambiente deposicional ou oriundas de uma porção detrítica continental. A anomalia do Eu é ligeiramente positiva para todos os períodos. Isto é um indicativo de assimilação ou acúmulo de feldspato. Dados de cinco possíveis fontes para a proveniência do material foram extraídos da literatura. Os sedimentos de Cabo Frio apresentam fracionamento entre ETRL e ETRP próximos aos dados deste estudo. Entretanto, para a razão (Eu/Sm) observa-se boa correlação com fontes vindas da Patagônia e do Rio da Prata. Alguns autores apontam a pluma do Rio da Prata na contribuição sedimentar na região da Bacia de Santos. / The continental sediments deposited in the ocean floor are conditioned, mainly, to the evolution of the climate, the geological substrate and the type of transport, being the fluvial transport of the greater magnitude. Once deposited, the sediments become records of the past and carry information in a form of geochemical signature. Rare Earth Elements (REE) present a coercive behavior along a sedimentary column making them useful for studies of sedimentary origin. Ratios for larger elements (Fe/Ca, for example) are indicators of the reconstruction of the terrigenous port. The geochemistry of the ETR and major elements are determined in this work to understand the paleoclimatic dynamics on the contribution and provenance of the sediments of the eastern margin (Santos Basin) of Brazil, and the anomalies of the Ce and Eu, confronting different analytical techniques (ICP- MS and XRF core scanner) in the main abrupt events (Younger Dryas and Heinrich events) over the last 45,000 years. The origin of the sedimentary material is also discussed by means of ratios between Light Rare Earth Elements (LREE) and Heavy Rare Earth Elements (HREE) comparing possible sources available in the literature. The distribution pattern indicates MREE enrichment over LREE and HREE in all events. This means that the origin of this material, probably, is related to a single source. LREE concentrations are always higher than MREE and HREE. This pattern is another indicative of a single source of sedimentary material. The sum of REE concentrations during MIS 2 is always greater than MIS 1. The behavior of REE during Heinrich events is very similar. The mean REE concentrations in these events are higher than those found in MIS 1 - Interglacial. The analyses of Fe/Ca and Ti/Ca ratios are stronger than those observed during the investigation period (MIS) due to the regressive margin level (continental shelf exposed), and the effects of dilution of the marine carbonate stimulated by imput of organic matter. The Al/Si and Fe/K ratios show distinct signals over time during this study. The increase of Si during MIS 2, in relation to the other periods, indicates that the glacial was less humid than the interglacial. The increase of K within the Heinrich events indicates a change in the continental weather pattern due to rainfall episodes and increase in chemical weathering in the drainage basins. The Ce anomaly is negative at all periods and indicates oxidizing conditions in the depositional environment or from a continental detrital portion. The Eu anomaly is slightly positive for all periods. This is an indicative of assimilation or accumulation of feldspar. Data from five possible sources for a sample of the material was extracted from the literature. The Cabo Frio sediments show the fractionation between LREE and HREE. However, for a (Eu / Sm) ratio a good correlation is observed with sources coming from Patagonia and Rio de la Plata. Some authors point out a region of the River Plate and a sedimentary region in the region of the Santos Basin.

Abstract In this Ph.D. thesis sediment cores from the central Arctic Ocean, southwestern Barents Sea and sediment exposures from the Kola Peninsula were investigated in order to reveal interactions between the late middle Pleistocene and late Pleistocene Arctic ice sheets, between Marine Isotope Stages 6 and 1 (MIS 6 and MIS 1). One of the main objectives of this work is to establish provenance areas for the sediments studied in the central Arctic, the southwestern (SW) Barents Sea and the Kola Peninsula, their transport mechanisms and through that their relationship to glaciations in the Arctic and to development in the Kola Peninsula during the late middle and late Pleistocene. Mineralogical and geochemical data from the core 96/12-1pc on the Lomonosov Ridge, central Arctic Ocean was studied to evaluate ice transport from circum-Arctic ice sheets and variability in sediment drainage systems associated with their decay. SW Barents Sea sediments contain important information on Late Glacial and Holocene sediment provenance characteristics in relation to ice flow patterns and ice rafting from different regional sectors. The studied SW Barents Sea sediment cores show that sediments were most likely derived from a combination of far-field Fennoscandian sources, local subcropping Mesozoic strata below the seafloor and sea ice transport. The investigation carried out on the Kola Peninsula indicates that the Eemian (MIS 5e) marine environment in the White Sea Basin and onshore coastal areas gradually changed into a glaciolacustrine environment during MIS 5d to MIS 5a. Subsequently, the Scandinavian Ice Sheet (SIS) covered the Kola Peninsula, most probably during MIS 4. The final deglaciation of the SIS on the Kola Peninsula took place, however, during the late Weichselian (MIS 2) between 16–12 ka. / Tiivistelmä Tässä väitöstutkimuksessa tutkittiin sedimenttikairanäytteitä keskeiseltä Jäämereltä ja Lounais-Barentsinmereltä sekä tarkasteltiin sedimenttiseurantoja Kuolan niemimaalla tarkoituksena selvittää myöhäisen keskipleistoseeni- ja myöhäispleistoseeniajan Arktisten jääkenttien keskinäiset vuorovaikutukset erityisesti merellisten isotooppivaiheiden 6 ja 1 (MIS 6 ja MIS 1) välillä. Tämän työn yhtenä päätavoitteena on määritellä sedimenttien lähdealueet keskeisellä Arktiksella, lounaisella Barentsinmerellä ja Kuolan niemimaalla, sedimenttien kuljetusmekanismit ja näiden perusteella riippuvuudet Arktisiin jäätiköihin ja Kuolan niemimaalla tapahtuneeseen myöhäiskeski- ja myöhäispleistoseenin kehitykseen. Mineraloginen ja geokemiallinen tieto Lomonosovin harjanteen kairauksesta 96/12-1pc, keskeisellä Jäämerellä on perusta arvioitaessa jääkuljetusmekanismeja ympäröiviltä sirkum-Arktisilta jäätiköiltä ja arvioitaessa valuma-alueiden osuutta suhteessa näiden jäätiköiden häviämiseen. Lounaisen Barentsinmeren sedimentit sisältävät tärkeätä tietoja viimeisen jäätiköitymisen loppuvaiheen ja holoseeni-ajan sedimenttien lähdealueista ja suhteista jäävirtauksiin ja jääkuljetukseen eri aluesektoreilta. Tutkitut Lounais-Barentsinmeren sedimentit osoittavat, että sedimentit olivat todennäköisimmin peräisin suhteellisen kaukaisilta Fennoscandian lähdealueilta, paikallisista mesotsoosista merenpohjan kerrostumista ja merijään kuljettamasta materiaalista. Kuolan niemimaalla tehty tutkimus osoittaa, että Eem-kauden (MIS 5e) meriympäristö Vienanmeren altaassa ja rannikkoalueilla vähitellen muuttui glaciolakustriseksi ympäristöksi MIS 5d:n ja MIS 5a:n välisenä aikana. Sen jälkeen Skandinavian jääkenttä (SIS) peitti Kuolan niemimaan, todennäköisimmin koko MIS:n 4 ajanjakson. SIS:n lopullinen deglasiaatio alkoi Kuolan niemimaalla kuitenkin myöhäisen Veiksel-jääkauden (MIS 2) aikana noin 16–12 ka sitten.

Multiple proxies derived from the Lake Loitsana sediment sequence (NE Finland) are employed to determine the timing of deglaciation, characterise an early Holocene proglacial lake stage and reconstruct Holocene lake development. Local-scale processes causing shifts in biological assemblages are identified and the most likely Holocene mean July air temperature (Tjul) development is assessed. The study area was deglaciated shortly prior to 10 700 cal. a BP. The sediment record reflects four local events; the presence of a glacial lake, glacial lake drainage and formation of Lake Loitsana, changes in fluvial input due to progressive wetland expansion, and gradual lake infilling. The results suggest that local events have driven changes in biological assemblages through various processes, and that biotic proxies reflect changes in environmental parameters in a highly individual manner. Furthermore, biological assemblages can themselves act as important drivers, influencing the composition of other assemblages. It is suggested that future studies should consider macrophyte abundance and food-web interactions as equally important factors when assessing changes in biological assemblages. Quantitative Tjul reconstructions based on biotic proxies display contrasting trends. While Tjul reconstructions based on pollen found in the Loitsana sequence display relatively low early Holocene values, plant macrofossil and chironomid data reflect warm summer conditions also during the early Holocene, i.e. at the peak of summer insolation. The early Holocene Tjul recorded by terrestrial pollen are affected by local factors possibly combined with a delayed response of the terrestrial ecosystem compared to the aquatic one. This study emphasises the importance of using multiple proxies in palaeoenvironmental studies and shows that local factors have a potential to drive changes in biological assemblages that can affect transfer-function based temperature reconstructions. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Epub ahead of print. Paper 2: Accepted. Paper 3: Manuscript.</p>

L'étude des interglaciaires passés qui sont des périodes chaudes avec un volume de glace réduit comme l’interglaciaire actuel, l'Holocène, est cruciale pour comprendre le climat futur. Ce travail apporte de nouvelles informations sur le climat des interglaciaires clés, les stades isotopiques marins (MIS) 11 et 31, considérés comme des analogues au réchauffement global projeté. Une analyse pollinique des sédiments du Site IODP U1385 (marge sud-ouest ibérique) a été effectuée à haute résolution, ce qui permet de comparer directement les variations de la végétation (atmosphère) avec celles de la température des eaux de surface océaniques. Nos données montrent qu’à l’échelle orbitale, la forêt du sud-ouest de l’Europe pendant le MIS 11 est principalement influencée par la précession alors que pendant le MIS 31, malgré des valeurs de précession extrêmes, le forçage dominant est l’obliquité, favorisant une végétation moins méditerranéenne et un régime climatique tempéré. De plus, la variabilité millénaire apparaît comme une caractéristique persistante mais les épisodes de refroidissement varient en intensité et durée en fonction des conditions limites qui favorisent un forçage prédominant des hautes ou basses latitudes. Enfin, nous examinons l'expression régionale de l'Holocène et de ses analogues orbitaux, les MIS 11c et 19c dans le sud-ouest de l’Europe. Ceci révèle que l'optimum Holocène se distingue par un plus fort développement forestier et donc que les MIS 11c et 19cne sont pas des analogues à l’Holocène pour notre zone d’étude. Grâce à une comparaison modèle-données, nous montrons aussi que la forêt interglaciaire dans cette région est principalement contrôlée par la précession en influençant les précipitations hivernales, facteur critique pour le développement de la forêt méditerranéenne, tandis que le CO2 joue un rôle négligeable. / The study of past interglacials, periods of reduced ice volume like our present interglacial, the Holocene, is crucial for understanding the future climate. This work provides new insights into the intensity and climate variability of key interglacials, namely Marine Isotopic Stages (MIS) 11 and 31, considered as analogues for the projected global warming. A highresolution pollen analysis at IODP Site U1385 off SW Iberia was performed, which enables adirect comparison between atmospheric-driven vegetation changes and sea surface temperature variability. At orbital time scale, this thesis shows that the dominant orbital forcing on the SW European forest was different between the interglacials of the 100-ky (MIS 11) and 41-ky (MIS31) worlds. While during MIS 11 its weak precessional forcing predominates, during MIS 31 itsextreme precession forcing is dwarfed by the prevailing influence of obliquity leading to a temperate climate regime as shown by a less Mediterranean character of the vegetation. This work also shows that millennial-scale variability was a pervasive feature and suggests that the different intensity and duration of the cooling events in SW Iberia was related to different atmospheric and oceanic configurations modulated by high or low-latitude forcing depending on the baseline climate states. Finally, this study examines the dominant forcing underlying the regional expression of the Holocene and its orbital analogues, MIS 11c and 19c, over SW Iberia using a data-model comparison approach. This comparison reveals that the Holocene optimum stands out for its higher forest development and therefore these interglacials cannot be considered as analogues for the Holocene vegetation and climate changes in Iberia. Additionally,it shows that the SW Iberian forest dynamics during these interglacials were primarily controlled by precession through its influence on winter precipitation, which is critical for the Mediterranean forest development whereas CO2 played a negligible role.