<p> In recent years, a number of qualitative calculations of various nuclear properties have been undertaken based on a "pairing-plus-quadrupole" force model. The present work involves an extension of the techniques associated with this model and is an investigation of the extent to which it can quantitatively predict properties of the low-lying levels of spherical even-even nuclei.</p> <p> As a particular application, the energies of several of the low-lying levels and the reduced transition probabilities for the first 2+ levels are calculated for the even isotopes of lead.</p> <p> These calculations show in a natural way how collective levels arise, and help to clarify the nature both of these and of the non-collective levels.</p> / Thesis / Doctor of Philosophy (PhD)

Nine basement blocks were sampled from locations spanning from Pennsylvania to Georgia in the eastern United States. These basement blocks are similar in that they have radiometric ages of approximately 1.0 billion years (with one exception), they are all at upper amphibolite to granulite grades, and are compositionally similar. Whole rock lead isotopic studies were performed on these samples in order to distinguish any possible differences in source regions that could be used to discriminate potential terranes within this 2700 km long region of the Appalachians. The lead isotopic system was used to decipher differences between these basement blocks. Traditional display of the data, in the form of ²⁰⁷Pb/²⁰⁴Pb-²⁰⁶Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb-²⁰⁶Pb/²⁰⁴Pb diagrams did not adequately bring out the similarities or differences in the data. Therefore, another method of displaying the data (e.g. Hart, 1984) was used in which the data from the Blue Ridge of Virginia was used as the reference against which all other data were compared. This method proved successful and trends were recognized. There are at least three different isotopic reservoirs within the central and southern Appalachians. There is the reservoir represented by the Blue Ridge of Virginia and six of the basement blocks that are isotopically similar (Honeybrook Upland, State Farm Gneiss, Sauratown Mountain, Tallulah Falls, Corbin Gneiss, and Pine Mountain), a second reservoir represented by the Baltimore Gneiss, and the third represented by the 1.8 billion year Carvers Gap Gneiss. The terrane that is represented by the Blue Ridge of Virginia and the six isotopically similar basement blocks is defined by ²⁰⁶Pb/²⁰⁴Pb ratios of 16.5-17.5, ²⁰⁷Pb/²⁰⁴Pb ratios of 15.4-15.5, and ²⁰⁸Pb/²⁰⁴Pb ratios of 36.0-37.0. The Baltimore Gneiss has ²⁰⁷Pb/²⁰⁴Ph ratios ranging from 15.2-15.6 and ²⁰⁸Pb/²⁰⁴Pb ratios ranging from 33.1- 38.1. These ratios although they show a broader range in values are elevated and suggest that the Baltimore Gneiss is isotopically different from the reference Blue Ridge. Carvers Gap Gneiss has ²⁰⁸Pb/²⁰⁴Pb ratios of 36.3-40.3 and ²⁰⁶Pb/²⁰⁴Pb ratios of 15.9-18.2. These ratios show that Carvers Gap Gneiss is isotopically dissimilar from the reference also. / Master of Science

Lead and strontium isotopes are two powerful tracers that can be used to identify or constrain the provenance of a wide range of archaeological materials, but these two isotopic tracers have been rarely employed to infer the sources of artifacts in the southwestern USA. This dissertation contains four studies that demonstrate how these isotopic systems can address questions about the sources of three types of archaeological materials found in this region: turquoise, lead-based glaze-paints, and metals. The analysis of 116 samples of turquoise from 17 deposits in the southwestern USA reveals that lead and strontium isotopes are robust and sensitive tracers of turquoise at multiple scales. Isotopic variation among turquoise deposits correlates with broad regional differences in the geologic and tectonic setting of the rocks and mineral deposits which host turquoise mineralization. Many turquoise deposits also have unique isotopic signatures that will enable insights into ancient patterns of turquoise acquisition at regional and local levels. To show the utility of these tracers when applied to archaeological turquoise, I use lead and strontium isotopic measurements to establish that the Silver Bell Mountains are the likely source turquoise found at the Redtail site in the Tucson Basin, Arizona, USA. This dissertation also contains new, high-precision isotopic ratios of lead ores (galena and cerrusite) from four mining districts in New Mexico, including the Cerrillos Hills. All districts studied are possible sources of lead used by Pueblo IV communities to produce glaze paints. These new measurements, made by multiple-collector ICP-MS, define the isotopic composition of the ore deposits with greater precision and accuracy than achieved in previous studies, indicating an opportunity to improve interpretations about the provenance of lead in glaze paints. Lead isotopes are also found to be useful tools for identifying lead and copper metal associated with the 1540-1542 Vázquez de Coronado expedition. Lead shot and copper crossbow boltheads from two sites with archaeological evidence for the expedition's presence were determined to share similar or identical lead isotopic ratios. I propose this specific isotopic "fingerprint" can be used to identify other artifacts belonging to the expedition in the Southwest.

No description available.

Made available in DSpace on 2014-10-09T12:32:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:11Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:32:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:11Z (GMT). No. of bitstreams: 0 / Cogumelos são espécies de fungos que têm a capacidade de reter radionuclídeos e elementos estáveis, importantes do ponto de vista tóxicológico e radiológico do meio ambiente. Estudos têm demonstrado que cogumelos podem ser utilizados como bioacumuladores na monitoração e na avaliação de contaminação e qualidade do ecossistema. No presente estudo, foram determinados os radionuclídeos 226Ra, 228Ra, 210Pb e os elementos As, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, U, Th e Zn em 24 amostras de cogumelos e de solos coletadas na região do Planalto de Poços de Caldas. O Planalto de Poços de Caldas é um exemplo de região de anomalia radioativa, apresentando cerca de 70 delas. No presente estudo, dois grupos de amostragem (do total de sete grupos) foram realizados em locais que apresentam tais anomalias. A determinação dos elementos estáveis foi realizada por Análise por Ativação com Nêutrons. As determinações de 226Ra, 228Ra e 210Pb nas amostras de cogumelos foram realizadas por separação radioquímica e suas atividades foram quantificadas em contador proporcional de fluxo gasoso Alfa e Beta Total. A determinação destes mesmos radionuclídeos nos solos foi realizada por Espectrometria Gama. A determinação dos isótopos de tório nos cogumelos foi realizada por separação radioquímica e quantificada por Espectrometria Alfa. O controle analítico de todas as metodologias utilizadas no presente trabalho foi realizado com o uso de materiais de referência certificados. Foram também analisadas amostras de cogumelos de uma região que não apresenta anomalia radioativa e os resultados comparados com os valores obtidos no Planalto de Poços de Caldas, podendo assim comprovar que cogumelos atuam como indicadores de contaminação radioativa do meio ambiente. As concentrações e atividades mais elevadas foram encontradas nas amostras coletadas nas zonas rurais do Planalto de Poços de Caldas, onde ocorrem as maiores anomalias radioativas na região. Pelos resultados obtidos, pode-se comprovar a eficiência do cogumelo como indicador de contaminação radioativa ambiental, sendo estes apropriados para avaliar os níveis de radioatividade em áreas de Materiais Radioativos de Ocorrência Natural. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

In this work, I present a multi-isotopic study (carbon, nitrogen, sulfur, strontium and lead) and Re-Os geochronology in rocks and crude oils of the Sonda de Campeche Petroleum System (SCPS). Since crude oils are complicated chemical systems easily disturbed, the Re-Os isotopic system could be affected if secondary processes perturb crude oils. Therefore, the multi stable isotopic study allows the identification of the presence and grade of these secondary processes in crude oils. The δ13C values of crude oils from the SCPS distinguish between: 1) crude oils with the fingerprint of source rocks of hydrocarbons (-28.3 to -26.7 ‰), and 2) crude oils with the fingerprint of the reservoir rocks (-25.5 to -24.9 ‰). Similarly, the δ15N values reveal that crude oils, during migration or trapping processes mimic the isotopic composition of the reservoir rocks of the Ek-Balam Formation. Furthermore, the δ34S values of crude oils from the SCPS (-8.0 to -2.5 ‰) show an absence of a thermal sulfate reduction (TSR) signature, which likely means that the use of Re-Os systematics in crude oils and rocks in the SCPS is appropriate. Strontium and lead measurements show crude oils have an isotopic composition different from rocks from the Edzna Formation but similar to rocks of the Akimpech and Ek-Balam formations, indicating that crude oils received Sr and Pb from the trapping rocks during migration or trapping processes, producing a isotopic mixing trend with rocks of these formations. Specifically, the lead isotope composition allows the identification of a source of lead never recorded before, the Guichicovi Complex. The isotopic data suggest that this Grenville Complex has been feeding with detrital material to the sedimentary rocks from Bacab, Ek-Balam and Akimpech formations in the SCPS, and in consequence contributing to the final isotopic composition of crude oils as well. Re-Os geochronology of rocks from the Edzna and Akimpech formations (152 ± 4 Ma; and 158.6 ± 5.5 Ma, respectively) provides precise ages of deposition that coincide with the ages proposed in previous studies based on the fossil record. Re-Os geochronology in crude oils yield ages with low uncertainty and moderate MSWD values, reflecting a rapid formation and migration process that occurred during evolution of the SCPS. The age of crude oils (28.3 ± 5.5 Ma) broadly agrees with petroleum generation models proposed by PEMEX.

This thesis deals with the isotopic composition of lead and 210 lead in recent galena from burning heaps after coal mining in the Lower Silesian basin. The studied sites were heaps in Radvanice, Markoušovice and Rybníček, where samples of galena, coal and burnt rocks were available. For the determination of the isotopic composition was used mass spectrometry with inductively coupled plasma (ICP - MS). Mass 210 Pb activity in galena was measured in a gamma - spectrometer Silar and the effect of radioactivity on galena crystal lattice was determined by the modified Williamson - Hall graph which was made from taken X-ray diffraction data. The values of isotope ratios in galena ranged for 207 Pb/206 Pb = 0,8402 to 0,8435 and for 208 Pb/206 Pb = 2,0663 to 2,0836. The average values of the coal were measured for 207 Pb/206 Pb = 0,8312 and 208 Pb/206 Pb = 2,0421. On the basis of these isotope ratios was found out that during the burning of coal and subsequent galena crystallization from hot gases there is no isotopic fractionation. Mass 210 Pb activity in galena ranged from 135 ± 9 Bq/g to 714 ± 22 Bq/g. Radioactivity of galena causes the developement of micro-deformation in the crystal structure. This micro-deformation is demonstrated by increased micro-strain in the crystal lattice. The level of this...

Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Bibliography : leaves 248-259. / Ph.D.

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences. / Microfiche copy available in Archives and Science. / Bibliography : leaves 48-50. / M.S.