No description available.

The appearance of synthetic fertilizers on the market has increased the interest in the so-called "minor elements". Much work with water and sand cultures has proven the necessity of these elements for successful plant growth. However, the need for these elements in crop production on field soils has not been studied intensively, nor have we sufficient knowledge as to the effect of our changing fertilizer practices on the necessity for minor elements. A number of field studies to determine the necessity of boron, manganese, zinc, copper and ether minor elements, when applied singly or in combinations of two or more, have given phenomenal increases in yields under certain plant and soil conditions. Under other conditions there has been no response from their use when applied to the soil either singly or in combinations of two or more elements. It is the purpose of this study to determine under what soil conditions the need of minor elements becomes a part of our soil management problem and what part natural Chilean nitrate of soda plays in preventing and correcting this condition. Also this investigation was developed to give a comparison of yield and growth of various crops grown intensively on a number of soil types where fertilized with purified carriers of nitrogen, phosphorus and potassium and where these elements were supplied from commonly used commercial carriers. Another purpose of this study was to determine how long these soils could be cropped before minor elements would become a limiting factor in crop production as shown by yields and deficiency symptoms. / Master of Science

Neste trabalho foram avaliadas a distribuição dos elementos-traço, Ca, Fe, Cu e Zn em tecidos mamários normais e neoplásicos através da técnica de micro-fluorescência de raios X induzida por radiação síncrotron. Para tal estabelecemos uma metodologia de reconstrução espectral capaz de aferir, de maneira indireta, a composição do espectro de excitação de uma fonte de radiação síncrotron diretamente no plano da amostra. Este conhecimento é fundamental para a quantificação de elementos- traço a partir do modelo de parâmetros fundamentais, utilizado neste trabalho. Outro aspecto importante deste modelo é a composição da matriz biológica. Foram comparadas duas metodologias de preparação de amostras de tecido mamário para medidas de micro fluorescência de raios X, e suas influências sobre a matriz tecidual. A primeira metodologia utilizando amostras in natura crio- seccionadas e a segunda utilizando amostras incluídas em parafina. Os resultados mostraram que a inclusão de amostras em parafina é uma técnica viável para o estudo da distribuição de elementos- traço em tecidos mamários. Foram avaliados os aspectos histológicos da distribuição dos elementos-traço através da comparação entre os mapas de micro-fluorescência de raios X e lâminas histológicas. Os resultados mostraram que em tecidos normais, regiões glandulares possuem concentrações mais elevadas dos elementos Ca, Fe e Zn quando comparadas ao estroma conjuntivo, ao passo que o tecido tumoral apresenta maior concentração destes elementos em regiões de proliferação de células epiteliais. O elemento Cu apresenta uma distribuição mais uniforme que os demais elementos em ambos os tipos de tecido, não sendo possível distinguir tais regiões a partir de sua distribuição. Além disso, sua baixa concentração gera mapas com elevados níveis de ruído, que dificultam ou mesmo impossibilitam sua avaliação. Cores primárias foram utilizadas para avaliar a correlação espacial entre os elementos-traço. Os resultados apontam forte correlação entre os elementos Ca e Zn e uma menor correlação entre estes e o elemento Fe. O elemento Cu não mostra correlação espacial com os demais. Resultados macroscópicos mostraram correlação estatisticamente significativa entre Ca-Zn para tecidos normais, apontando para a presença regular de metaloproteinases de matriz (MMPs) nestes tecidos. Já tecidos tumorais mostraram correlação estatisticamente significativa entre os elementos Ca-Cu e Cu-Zn, apontando para a elevação do processo angiogênico e invasão tumoral / The distribution of the trace elements, Ca, Fe, Cu and Zn in normal and neoplastic mammary tissues was evaluated through the X-ray microfluorescence induced by synchrotron radiation. To this end, we created a methodology capable of indirectly measuring the composition of the excitation spectrum of a synchrotron radiation source directly in the sample plane. This knowledge is critical for the quantification of trace elements using the fundamental parameters model employed in this work. Another important aspect of this model is the composition of the biological matrix. Two sample preparation methodologies for X-ray microfluorescence measurements and their influence on the tissue matrix were compared. The first methodology used fresh samples cryo-sectioned, and the second used paraffin embedded samples. The results showed that paraffin embedded samples are feasible for the study of trace elements distribution in mammary tissues. The histological aspects of the trace element distribution were evaluated through the comparison between X-ray microfluorescence maps and histological slides. The results showed that in normal tissues, glandular regions have higher concentrations of the elements Ca, Fe and Zn than stromal tissue, whereas a higher concentration of these elements was observed in regions of proliferation of epithelial cells. Cu has a more uniform distribution than the other elements in both tissue types, and it is not possible to distinguish such regions from the Cu distribution. In addition, its low concentration generates maps with high noise levels making evaluation difficult or even impossible. Primary colors were used to evaluate the spatial correlation between trace elements. The results indicate a strong correlation between Ca and Zn and a lower correlation between these and Fe. Cu does not show spatial correlation with the others. Macroscopic results showed a statistically significant correlation between Ca- Zn for normal tissues, pointing to the regular presence of matrix metalloproteinases (MMPs) in these tissues. Tumor tissues showed a statistically significant correlation between the Ca-Cu and Cu-Zn elements, pointing to the elevation of the angiogenic process and tumor invasion

A barragem Mãe d\'Água foi construída em 1962, com o intuito de atender à demanda da Universidade Federal do Rio Grande do Sul UFRGS, mais precisamente o Instituto de Pesquisas Hidráulicas – IPH, porém, devido à falta de planejamento urbano, durante os últimos anos, vem acarretando uma diversificada série de passivos ambientais, como contaminantes orgânicos e/ou inorgânicos. Neste seguimento, o presente trabalho buscou avaliar as concentrações totais dos metais e a composição isotópica por chumbo 210 nas diferentes frações de sedimentos produzidos na bacia hidrográfica que compõe a barragem Mãe d\'Água e, assim, caracterizar a distribuição da concentração dos metais ao longo da coluna sedimentar e inferir quanto ao processo de urbanização da bacia hidrográfica caracterizando a evolução. Com referência nestas concentrações dos metais encontradas nos sedimentos, construir uma perspectiva do processo evolutivo da degradação ambiental na qual a bacia vem sendo submetida através de estudos de geocronologia (210Pb). As coletas das amostras foram realizadas em junho de 2014, sendo amostrados testemunhos sedimentares distribuídos no lago da referida barragem e o levantamento batimétrico. Para a extração dos testemunhos foi utilizado um amostrador de núcleo Piston core. Com os resultados obtidos, foramrepresentadas as concentrações dos metais Zn e Ni os quais apresentaram tendências de enriquecimento, a geocronologia datou as camadas assoreadas sendo o maior intervalo de 42 anos de deposição sedimentar, o volume do assoreamento ocupando aproximadamente 44% do volume útil do reservatório e a taxa de urbanização com tendências de crescimento e para o ano de 2014 com 88,42% da bacia urbanizada, configurando portanto uma distribuição espacial e estabelecendo correlações entre os estudos da sedimentação ao longo das últimas cinco décadas. As concentrações dos metais presentes nas amostras foram, também, comparadas com os valores de background do local para melhor visualizar o processo de enriquecimento dos sedimentos por ações antropogênicas. Foi possível concluir que com a ampliação das áreas urbanizadas, acarretou no aumentou das concentrações dos metais e no volume de sedimentos depositados no reservatório, onde a urbanização sem planejamento desta bacia é o principal fator poluidor. / The Municipality of Viamão is located in the metropolitan area of Porto Alegre, in the state of Rio Grande Sul. The Mãe d\'Água dam was built in 1962, with the purpose of meeting the demand of the Federal University of Rio Grande do Sul - UFRGS. Precisely because of the lack of urban planning during the last forty years, has led to a diversified series of environmental liabilities, such as organic and/or inorganic contaminants. The present work aimed to evaluate the total concentrations of metals and the isotopic composition per lead 210 in the different fractions of sediments produced in the watershed that make up the Mãe d\'Água dam and thus characterize the distribution of the concentration of metals along of the sedimentary column and infer about the process of urbanization of the watershed characterizing evolution. With reference to these concentrations of the metals found in the sediments, to construct a perspective of the evolutionary process of the environmental degradation in which the basin is being submitted through studies of geochronology (210Pb). Samples were collected in June 2014, and sediment deposited in the lake of the dam and bathymetric survey were sampled. A \"Piston core\" core sampler was used to extract the samples. With the results obtained, the concentrations of the metals Zn and Ni were presented, which presented enrichment tendencies, geochronology dating to the silted layers, silting volume occupying approximately 44% of the useful volume of the reservoir and the rate of urbanization with growth tendencies and for the year 2014 with 88% of the urbanized basin, thus constituting a spatial distribution and establishing correlations between sedimentation studies over the last four decades. The concentrations of the metals present in the samples were also compared with the background values of the site to better visualize the process of sediment enrichment by anthropogenic actions, where it was possible to verify that the expansion of the urbanized area increased the concentrations of the analyzed metals (Zn and Ni). It was possible to conclude that with the expansion of the urbanized areas, the increase of the concentrations of the metals and the volume of sediments deposited in the reservoir, where unplanned urbanization of this basin is the main polluting factor, resulted.

Neste trabalho foram avaliadas a distribuição dos elementos-traço, Ca, Fe, Cu e Zn em tecidos mamários normais e neoplásicos através da técnica de micro-fluorescência de raios X induzida por radiação síncrotron. Para tal estabelecemos uma metodologia de reconstrução espectral capaz de aferir, de maneira indireta, a composição do espectro de excitação de uma fonte de radiação síncrotron diretamente no plano da amostra. Este conhecimento é fundamental para a quantificação de elementos- traço a partir do modelo de parâmetros fundamentais, utilizado neste trabalho. Outro aspecto importante deste modelo é a composição da matriz biológica. Foram comparadas duas metodologias de preparação de amostras de tecido mamário para medidas de micro fluorescência de raios X, e suas influências sobre a matriz tecidual. A primeira metodologia utilizando amostras in natura crio- seccionadas e a segunda utilizando amostras incluídas em parafina. Os resultados mostraram que a inclusão de amostras em parafina é uma técnica viável para o estudo da distribuição de elementos- traço em tecidos mamários. Foram avaliados os aspectos histológicos da distribuição dos elementos-traço através da comparação entre os mapas de micro-fluorescência de raios X e lâminas histológicas. Os resultados mostraram que em tecidos normais, regiões glandulares possuem concentrações mais elevadas dos elementos Ca, Fe e Zn quando comparadas ao estroma conjuntivo, ao passo que o tecido tumoral apresenta maior concentração destes elementos em regiões de proliferação de células epiteliais. O elemento Cu apresenta uma distribuição mais uniforme que os demais elementos em ambos os tipos de tecido, não sendo possível distinguir tais regiões a partir de sua distribuição. Além disso, sua baixa concentração gera mapas com elevados níveis de ruído, que dificultam ou mesmo impossibilitam sua avaliação. Cores primárias foram utilizadas para avaliar a correlação espacial entre os elementos-traço. Os resultados apontam forte correlação entre os elementos Ca e Zn e uma menor correlação entre estes e o elemento Fe. O elemento Cu não mostra correlação espacial com os demais. Resultados macroscópicos mostraram correlação estatisticamente significativa entre Ca-Zn para tecidos normais, apontando para a presença regular de metaloproteinases de matriz (MMPs) nestes tecidos. Já tecidos tumorais mostraram correlação estatisticamente significativa entre os elementos Ca-Cu e Cu-Zn, apontando para a elevação do processo angiogênico e invasão tumoral / The distribution of the trace elements, Ca, Fe, Cu and Zn in normal and neoplastic mammary tissues was evaluated through the X-ray microfluorescence induced by synchrotron radiation. To this end, we created a methodology capable of indirectly measuring the composition of the excitation spectrum of a synchrotron radiation source directly in the sample plane. This knowledge is critical for the quantification of trace elements using the fundamental parameters model employed in this work. Another important aspect of this model is the composition of the biological matrix. Two sample preparation methodologies for X-ray microfluorescence measurements and their influence on the tissue matrix were compared. The first methodology used fresh samples cryo-sectioned, and the second used paraffin embedded samples. The results showed that paraffin embedded samples are feasible for the study of trace elements distribution in mammary tissues. The histological aspects of the trace element distribution were evaluated through the comparison between X-ray microfluorescence maps and histological slides. The results showed that in normal tissues, glandular regions have higher concentrations of the elements Ca, Fe and Zn than stromal tissue, whereas a higher concentration of these elements was observed in regions of proliferation of epithelial cells. Cu has a more uniform distribution than the other elements in both tissue types, and it is not possible to distinguish such regions from the Cu distribution. In addition, its low concentration generates maps with high noise levels making evaluation difficult or even impossible. Primary colors were used to evaluate the spatial correlation between trace elements. The results indicate a strong correlation between Ca and Zn and a lower correlation between these and Fe. Cu does not show spatial correlation with the others. Macroscopic results showed a statistically significant correlation between Ca- Zn for normal tissues, pointing to the regular presence of matrix metalloproteinases (MMPs) in these tissues. Tumor tissues showed a statistically significant correlation between the Ca-Cu and Cu-Zn elements, pointing to the elevation of the angiogenic process and tumor invasion

A cause d’une anthropisation toujours plus forte des écosystèmes, de plus en plus de menaces pèsent sur la biodiversité. Parmi celles-ci, l’exposition aux contaminants est particulièrement problématique pour les organismes vivants. Emis et utilisés dans les pays industrialisés, ces contaminants hautement persistants dans l’environnement vont gagner les régions polaires puis se bio-accumuler dans les organismes vivants au cours du temps et se bio-amplifier le long du réseau trophique. Ainsi, les oiseaux marins, longévifs et situés dans les maillons supérieurs de la chaine alimentaire, sont particulièrement exposés et vulnérables à une exposition chronique à ces contaminants. A travers une perturbation endocrinienne, ces contaminants vont pouvoir impacter certains mécanismes physiologiques et traits comportementaux, entrainant in fine des conséquences à long-terme sur la fitness des individus et populations. Ma thèse s’articule autour de trois grandes familles de contaminants : i) les composés perfluoroalkylés (PFASs), encore largement utilisés dans plusieurs secteurs industriels et agricoles et en augmentation dans l’environnement ; (ii) les composés organochlorés dits « d’héritage » (OCs), interdits depuis des années mais entrainants toujours des effets délétères sur la biodiversité et (iii) le mercure (Hg), métal lourd non-essentiel ayant une origine à la fois anthropique et naturelle. Basé sur une approche corrélative in natura, je me suis intéressé aux conséquences physiologiques et comportementales d’une exposition chronique à ces trois grandes familles de contaminants présents chez la mouette tridactyle (Rissa tridactyla) de l’Arctique Norvégien (Svalbard) au cours de son cycle reproducteur (depuis l’accouplement jusqu’à l’élevage des poussins). Spécifiquement, j’ai étudié les relations entre ces contaminants et la fertilité (morphologie et motilité des spermatozoïdes), l’expression des signaux sexuels (visuel : coloration des téguments, olfactif : signature chimique), les comportements de soins parentaux (température d’incubation et rotation de l’œuf), le vieillissement cellulaire (longueur des télomères) et la dépense énergétique (métabolisme de base). Je me suis également penché sur de potentiels mécanismes sous-jacents permettant d’expliquer ces relations. Puisque ces mécanismes physiologiques et comportementaux sont fortement impliqués dans la valeur sélective des individus, les possibles conséquences à long terme de cette exposition sur la reproduction et survie des individus sont discutées. Ce travail permet de souligner la forte toxicité de certains composés organochlorés « historiques » (en particulier les chlordanes) et d’apporter de toutes nouvelles connaissances sur la toxicité très mal connue des PFASs chez la faune sauvage. Fait important, ce travail de thèse révèle que les PFASs et les OCs pourraient agir de manière contrastée sur plusieurs mécanismes physiologiques et traits comportementaux. Spécifiquement, une forte exposition à l’oxychlordane, un métabolite du chlordane, pesticide interdit depuis des décennies, est associée à des télomères plus courts, une réduction du métabolisme de base et à une moindre capacité à incuber les œufs. A l’inverse, on observe une élongation des télomères, une augmentation du métabolisme de base et une rotation des œufs accrue chez les individus les plus exposés aux PFASs. Le Hg, au moins en ce qui concerne les paramètres étudiés, ne semble pas jouer un rôle majeur. Cette étude souligne l'importance de tenir compte de plusieurs groupes de contaminants lorsqu'on étudie les conséquences de l'exposition aux contaminants environnementaux chez la faune sauvage. / Due to increasing human activities, a growing number of threats are challenging the fate of biodiversity. Among them, environmental contamination is particularly concerning for living organisms. Used and released in industrialized countries, these highly persistent contaminants can reach remote areas such as the Arctic ecosystem and will biomagnify though food webs and bioaccumulate in organisms. Long-lived seabirds are located in the upper levels of the food chains and thus particularly exposed and sensitive to a chronic contaminants exposure. Through endocrine disruption, these contaminants can impact physiological mechanisms and behavioural traits, inducing in fine, long-term fitness consequences on individuals and populations. My thesis focuses on three groups of contaminants: (i) poly- and perfluoroalkyl substances (PFASs), still broadly used in a vast array of industrial processes and increasing in the Arctic; (ii) “legacy” organochlorine contaminants (OCs, pesticides and industrial compounds), banned from use but still well present in the Arctic and (iii) mercury (Hg), a non-essential metal coming of both natural and anthropic origins. Based on a correlative approach conducted in natura, I investigated the physiological and behavioural consequences of exposure to these contaminants during the whole breeding cycle (from pre-laying to chick-rearing period) in an Arctic seabird, the black-legged kittiwake (Rissa tridactyla) from Svalbard, Norwegian Arctic. Specifically, I examined the relationships between several PFASs, OCs, Hg and fertility (sperm morphology and motility), sexual signaling (visual: integument coloration and olfactory: chemical signature), parental care behaviors (incubation temperature and egg-turning), ageing (telomere length) and energy expenditure (basal metabolic rate). In addition, some potential underlying mechanisms were also studied to better understand the way through which contaminants can be detrimental for kittiwakes. Furthermore, since physiological mechanisms and behavioral traits investigated here are tightly involved in self maintenance and reproduction, possible effects on fitness are then discussed. This PhD work underlines the major role of certain legacy chlorinated organic compounds (e.g. chlordanes) and significantly contributes at documenting the poorly known toxicological consequences of PFASs exposure in wildlife. Importantly, this PhD shows that PFASs and OCs could impact ageing, energy expenditure and some parental care behaviors in a contrasted manner. Specifically, oxychlordane, a metabolite of a banned organochlorine pesticide was associated with decreased telomere length, lowered metabolic rate and reduced ability to incubate the eggs. Conversely, elongated telomere, increased BMR and enhanced egg rotation were observed in birds bearing the highest concentrations of PFASs. Finally, at least for the considered endpoints, Hg appears as a coming minor threat for kittiwakes. This study highlights the importance of considering several groups of contaminants when investigating the consequences of environmental contaminants exposure in wildlife.

Submitted by Kamila Costa (kamilavasconceloscosta@gmail.com) on 2015-06-23T18:23:15Z No. of bitstreams: 1 DISSERTAÇÃO-Railane I dos Santos.pdf: 1232985 bytes, checksum: d9c530851d2088931854743b4a8c3d83 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-09T14:33:32Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO-Railane I dos Santos.pdf: 1232985 bytes, checksum: d9c530851d2088931854743b4a8c3d83 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-09T14:38:42Z (GMT) No. of bitstreams: 1 DISSERTAÇÃO-Railane I dos Santos.pdf: 1232985 bytes, checksum: d9c530851d2088931854743b4a8c3d83 (MD5) / Made available in DSpace on 2015-07-09T14:38:43Z (GMT). No. of bitstreams: 1 DISSERTAÇÃO-Railane I dos Santos.pdf: 1232985 bytes, checksum: d9c530851d2088931854743b4a8c3d83 (MD5) Previous issue date: 2014-08-26 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The bottom sediments are an important compartment in assessing the intensity and form of which impact on aquatic ecosystems. In this way, the present study aimed to analyze possible changes caused by construction of the Santo Antônio hydroelectric plant in the concentrations of the metals Cr, Co, Ni, Cu, Zn and Pb in bottom sediments in the upper Madeira River and some of its main tributary. The bottom sediment samples were collected at five points in the Madeira River and in two tributaries of the right bank, Jaci Paraná rivers and Belmont, and two from the left margin, Caripunas and Jatuarana rivers, plus two Jaci Paraná river tributaries: Branco and Contra Rivers. Samples of bottom sediments were collected from July/2008 to February/2011, which corresponds to the before filling Santo Antônio hidroelectric plant reservoir period and the march/2013 to December/2011, period subsequent to the filling of the Santo.Antônio hidroelectric plant reservoir. The sediment samples were sieved in the fraction< 200 mesh (<74 mM), the extraction of chemical elements was performed by digestion with HNO3 and HCl, quantification was performed by FAAS. The metal concentrations in the before filling period of the Sto.Antôniohidroelectric plant reservoir followed the order Cr<Co<Pb<Ni<Cu<Zn and during the after filling was Cr<Co<Pb<Cu<Cu<Ni<Zn. Significant variations in concentrations between the two periods analyzed were found in the concentrations of Cu and Pb in the MD03 and MD02 collection stations in Madeira River. Multivariate statistical analyzes HCA and PCA showed similarities between Madeira River and Belmont small stream in the before filling period, and Madeira River between small streams Belmont and Jatuarana and river Jatuarana in the after filling period. / Os sedimentos de fundo constituem um compartimento importante na avaliação da intensidade e forma de impacto a qual os ecossistemas aquáticos estão submetidos. Neste sentido, o presente estudo teve como objetivo analisar possíveis alterações causadas pela construção da Usina Hidrelétrica de Santo Antônio nas concentrações dos metais Cr, Co, Ni, Cu, Zn e Pb em sedimentos de fundo no Alto Rio Madeira e em de alguns de seus principais tributários. As amostras de sedimento de fundo foram coletadas em 5 pontos no rio Madeira, em 2 tributários de sua margem direita, rio Jaci Paraná e igarapé Belmont, e 3 da margem esquerda, rios Caripunas e Jatuarana e igarapé Jatuarana, além de 2 afluentes do rio Jaci Paraná: rios Branco e Contra. As amostras de sedimentos de fundo foram coletadas de julho/2008 a fevereiro/2011, o que corresponde ao período anterior ao enchimento barragem da UHE- Santo Antônio, e de dezembro/2011 a março/2013, período posterior ao enchimento da barragem da UHE- Santo Antônio. As amostras de sedimentos foram peneiradas na fração <200 mesh (<74 μm), a extração dos elementos químicos foi realizada por digestão com HNO3 e HCl, e a quantificação foi realizada por espectrometria de absorção atômica por chama. As concentrações dos metais no rio Madeira período de pré-enchimento do reservatório da UHE-Sto. Antônio seguiram a seguinte ordem Cr<Co<Pb<Ni<Cu<Zn e no período de pós-enchimento foi Cr<Co<Pb<Cu<Ni<Zn. A maioria dos metais analisados não apresentaram diferenças significativas entre os dois períodos avaliados. Apenas Cu e Pb apresentaram diferença significativas de concentrações entre os dois períodos analisado nas estações de coleta MD03 e MD02 no rio Madeira. As análises de estatística multivariada HCA e PCA apontaram similaridades entre os pontos do rio Madeira e o igarapé Belmont no período de pré-enchimento, e com Igarapés Belmont e Jatuarana e o rio Jatuarana no período de pós-enchimento.

Previous studies have identified δ¹³C events in the Carboniferous that imply major shifts in the carbon cycle. However, inherent in this interpretation is the assumption that epicontinental seas are chemically representative of the global ocean. Our study uses stable isotope and trace element analyses of brachiopod shells to examine changes in climate and circulation of the North American epeiric sea. Formations were selected for study to provide shallow marine environments with geographic coverage of North America. These units include the Grove Church and Mattoon Formations (Illinois Basin), Glenshaw Formation (Appalachian Basin), Bird Spring Formation (Bird Spring Basin), and Oread Formation (US midcontinent). In all, 98 brachiopod shells were found to be well preserved based on screening with plane light and cathodoluminescence microscopy of thin-sections, and trace element analyses. Upper Chesterian Grove Church (Illinois Basin) samples have δ¹³C and δ¹⁸O averages of 1.1% and -3.1% respectively. These low values are interpreted as a local or regional effect caused by terrestrial runoff. Terrestrial influences are also suggested by the depositional environment: nearshore marine. Chesterian samples from the Bird Spring Formation at Arrow Canyon, Nevada average 3.7% and -1.4% for δ¹³C and δ¹⁸O respectively. The higher δ¹³C and δ¹⁸O values, compared with samples from the time equivalent Grove Church, likely reflect the freer exchange with the Panthalassa Ocean at this most western edge of North America, and best represent open-ocean conditions. Samples from the Virgilian Ames-Shumway-Plattsmouth cyclothem show a progression of δ¹³C and δ¹⁸O enrichment moving west from near the Appalachians (1.9% and -3.8%) to the Illinois Basin (3.2% and -2.4%) and finally to the US midcontinent (4.2% and -1.5%). This is interpreted as the transition from nearshore, terrestrial influence with enhanced organic matter oxidation and lower salinity to well-mixed conditions with normal salinities and potential for seafloor ventilation and upwelling. This is supported by published sediment ΣNd(t) values from the Appalachian Basin (ΣNd(t) = -9) that increase further westward (ΣNd(t) = -6) due to higher influence from the eastern Panthalassa Ocean. Mass balance calculations based on the δ¹⁸O of the brachiopod shells suggest salinities of 25 and 31 psu for the Appalachian and Illinois Basins, respectively, assuming salinities of 34.5 psu for the US midcontinent. Trace element analyses do not show a systematic east-west trend similar to stable isotopes. In both time slices, spiriferids from the intermediately-located Illinois Basin are enriched in Mg/Ca and Sr/Ca relative to those in other basins. This Mg and Sr enrichment in Illinois Basin brachiopods suggests delivery of Sr-rich fresh waters and restricted circulation in that basin.

Thesis (M.S.)--Indiana University, 2009. / Title from screen (viewed on February 2, 2010). Department of Earth Sciences, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Andrew P. Barth, Gabriel M. Filippelli, Kathy Licht. Includes vitae. Includes bibliographical references (leaves 102-110).

published_or_final_version / Botany / Master / Master of Philosophy