Dissertationen zum Thema „Isotopie Sm-Nd“
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De, Assunção Rodrigues Mariana. „Analyse de la provenance sédimentaire des bassins du Crétacé du système Andes-Amazonie-marge équatoriale et des relations avec la paléogéographie et la tectonique“. Electronic Thesis or Diss., Toulouse 3, 2023. http://www.theses.fr/2023TOU30363.
Der volle Inhalt der QuelleThe Cretaceous is characterized by major paleogeographic, geodynamic, and climatic changes, including the formation of new oceans such as the equatorial Atlantic Ocean, the continued fragmentation of Gondwana, and greenhouse effect periods. All these changes are potentially contained in the sedimentary records of the basins. The Andes-Amazonia-Equatorial Margin system is a vast sedimentary system whose geodynamic and palaeoenvironmental evolution is recorded in the Amazonian retroarc foreland basins, the Brazilian intracratonic basins, and those of the equatorial margin. In the western part (Andean region), recent studies suggest that the onset of the Andean orogeny occurred during the Late Cretaceous, but the development of drainage systems and the source of sediments deposited during the Cretaceous are still poorly understood. The Lower Cretaceous is recorded in Brazilian intracratonic and equatorial basins and bears witness to crustal rifting phases following Gondwana's break-up. The Araripe Basin is a good example of these basins since it contains a complete and particularly well-studied sedimentary record. However, the origin of the sediments from the various tectonic stages of basin formation and the Cretaceous origin of the marine incursions that affected it remain to be determined. The aim of this thesis is to propose a palaeogeographic reconstruction of the Andes-Amazonia-Equatorial Margin system during the Cretaceous and to analyze the geodynamic and tectonic changes that affected it. To do this, we used provenance methods, in particular major and trace element geochemistry, Sm and Nd isotopic composition, and U-Pb ages on zircons. The results obtained have enabled us to identify the source zones of the Araripe Basin during the pre-, syn- and post-rift phases and thus to gain a better understanding of the palaeogeographic configuration of the north-eastern region of Brazil at the beginning of the Cretaceous. The sediments in the Araripe basin come mainly from the Palaeoproterozoic (2.3-1.6 Ga) terrains of the Borborema province and the granitic plutons of the Brasiliano cycle (720-541Ma). The basin has a sedimentary history linked to the South Atlantic and equatorial break-up phases. During the pre-rift phase (~152-135 Ma), the basin was part of the Afro-Brazilian depression and received sediments from the N-NW. During the rift phase (~135-125Ma), there was a change in source due to continental break-up and the formation of the South Atlantic, with an influx of sediments from the eastern part of the Borborema province. During the post-rift phase (121-113 Ma), the basin ceased to be fed by the eastern part and marine incursions dominated the sedimentation environment. Finally, during the post-rift II phase (113-100 Ma) a last change in sources was observed, with sources to the NE reflecting the final moment of the fragmentation of Gondwana. A study of the provenance of sediments from the basins of western Amazonia (Acre and Madre de Dios) indicates that the sources are cratonic, originating mainly from the Ventuari-Tapajos (2.0 - 1.82 Ga) and Rio Negro - Juruena (1.82 - 1.54 Ga) terrains. These results indicate that a vast intracontinental drainage network ('Sanozama') emerged in response to the uplift of the Purus Arch and the cratonic regions of Brazil and the Guianas during the opening of the equatorial Atlantic Ocean. The integration of the results obtained compiled with data from the literature has made it possible to propose four palaeogeographic maps of the northern part of the South American platform. They highlight how geodynamic mechanisms linked to the opening of the South Atlantic and equatorial oceans controlled and shaped the paleogeography of this region
Chavagnac, Valérie. „Behaviour of the Sm-Nd isotopie system during metamorphism : Examples from the HT-LP metamorphic terrane of the Limpopo Belt, South Africa and the UHP metamorphic terrane of Dabieshan, Central China“. Phd thesis, Université Rennes 1, 1998. http://tel.archives-ouvertes.fr/tel-00620022.
Der volle Inhalt der QuelleNowicki, G. [Verfasser]. „Kernspektroskopische Untersuchungen der Isotone ¹³⁷Nd und ¹³⁹Sm / G. Nowicki“. Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/118725276X/34.
Der volle Inhalt der QuelleThorogood, E. J. „Provenance of the pre-Devonian sediments of England and Wales : Sm-Nd isotopic evidence“. Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293429.
Der volle Inhalt der QuelleAnglin, Carolyn Diane Carleton University Dissertation Geology. „Sm-Nd and Sr isotopic studies of scheelite from some Superior Province gold deposits“. Ottawa, 1992.
Den vollen Inhalt der Quelle findenGoodwin-Bell, Jo-Anne Stafford. „A geochemical and Sm-Nd isotopic study of Cordilleran eclogites from the Yukon-Tanana terrane“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/MQ28939.pdf.
Der volle Inhalt der QuelleKay, Andrew. „Sm-Nd isotope, major element, and trace element geochemistry of the Nashoba terrane, eastern Massachusetts“. Thesis, Boston College, 2012. http://hdl.handle.net/2345/bc-ir:107672.
Der volle Inhalt der QuelleThe Nashoba terrane in eastern Massachusetts comprises Cambrian-Ordovician mafic to felsic metavolcanic rocks and interlayered sediments metamorphosed during the mid-Paleozoic and intruded by a series of dioritic to granitic plutons during the Silurian to earliest Carboniferous. This work comprises two parts discussing the Sm-Nd isotope characteristics and major and trace element geochemistry of the Nashoba terrane: the first discusses the Cambrian-Ordovician metamorphosed units, the second discusses the Silurian-Carboniferous plutons. Part I: The Nashoba terrane in eastern Massachusetts lies between rocks of Ganderian affinity to the northwest and Avalonian affinity to the southeast. Its relationship to either domain was unclear and has been investigated. Major and trace element geochemical data indicate a mix of arc, MORB, and alkaline rift related signatures consistent with an origin of the terrane as a primitive volcanic arc-backarc complex built on thinned continental crust. Newly determined Sm-Nd isotopic data clarifies the original tectonic setting. Amphibolites of the Marlboro and Nashoba Formations have high εNd values (+4 to +7.5) consistent with formation in a primitive volcanic arc with minimal interaction between arc magmas and crust. Intermediate and felsic gneisses have moderate εNd values between +1.2 and –0.75 indicating a mixture of juvenile arc magmas and an evolved (likely basement) source. Depleted mantle model ages of 1.2 to 1.6 Ga indicate a Mesoproterozoic or older age for this source. Metasedimentary rocks have negative εNd values between –6 and –8.3 indicating derivation primarily from an isotopically evolved source (or sources). The model ages of these metasedimentary rocks (1.6 to 1.8 Ga) indicate a source area of Paleoproterozoic or older age. The εNd values and model ages of the intermediate and felsic rocks and metasedimentary rocks indicates that the basement to the Nashoba terrane is Ganderian rather than Avalonian. The Nashoba terrane therefore represents a southward continuation of Ganderian arc-backarc activity as typified by the Penobscot and/or Popelogan-Victoria arc systems and the Tetagouche-Exploits backarc basin in the northern Appalachians. Part II: Between 430 and 350 Ma the Nashoba terrane experienced episodic dioritic and granitic plutonism. Previous workers have suggested a supra-subduction zone setting for this magmatism based on the calc-alkaline nature of the diorites. Previously determined major and trace element geochemical data along with newly determined Sm-Nd isotopic data indicate that a subduction zone was active beneath the Nashoba terrane during the majority of the 430 to ca. 350 Ma magmatism (and likely throughout). Trace element geochemistry indicates a strong arc component in all magmas and suggests that the various Silurian to Carboniferous plutonic rocks of the Nashoba terrane could all have been derived by modification of a slightly enriched NMORB-type source via subduction zone input and crustal contamination. Most of the rocks from this period have intermediate εNd values consistent with contamination of juvenile magmas by an evolved source. The late Proterozoic model ages for most of these rocks suggest the Ganderian basement of the Nashoba terrane as the source of evolved material. One rhyolite from the nearby Newbury Volcanic Complex (of unknown affinity) has a moderately negative εNd value consistent with derivation by partial melting of Cambrian-Ordovician metasedimentary rocks of the Nashoba terrane. This suggests that the Newbury Volcanic Complex formed as the surface expression of mid-Paleozoic Nashoba terrane plutonism. Geochemical and isotopic similarities between the plutonic rocks of the Nashoba terrane and widespread contemporary Ganderian plutonism suggest that the Nashoba terrane remained a part of Ganderia during its transit and accretion to the Laurentian margin. Significantly younger model ages in the youngest granitic rocks indicate that Avalonian crust may have underthrust the Nashoba terrane after 400 Ma and contributed to the generation of these granites
Thesis (MS) — Boston College, 2012
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Earth and Environmental Sciences
Flageole, Janick. „Sm-Nd Isotopic Composition of Mantle-Derived Rocks from the Saglek-Hebron Gneiss Complex, Northern Labrador“. Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39208.
Der volle Inhalt der QuelleLinkermann, Sean Aaron. „Emplacement of the 2.44 Ga ultramafic layered Kemi intrusion, Finland PGE, geochemical and Sm-Nd isotopic implications“. Thesis, Rhodes University, 2011. http://hdl.handle.net/10962/d1005552.
Der volle Inhalt der QuelleSchmitt, Wolfgang. „Application of the Sm-Nd Isotope System to the Late Quaternary Paleoceanography of the Yermak Plateau (Arctic Ocean)“. Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-71834.
Der volle Inhalt der QuelleKondo, Nozomi. „Major element composition of the Hadean crust: constraints from Sm-Nd isotope systematics and high-pressure melting experiments“. Kyoto University, 2018. http://hdl.handle.net/2433/232387.
Der volle Inhalt der Quelle0048
新制・課程博士
博士(人間・環境学)
甲第21186号
人博第858号
新制||人||204(附属図書館)
29||人博||858(吉田南総合図書館)
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 小木曽 哲, 教授 石川 尚人, 教授 酒井 敏, 准教授 飯塚 毅
学位規則第4条第1項該当
Farrell, Thomas. „Investigating the Tectonic Significance of Spiral Garnets from the Betic-Rif Arc of Southern Spain and Northern Morocco Using Sm-Nd Garnet Geochronology:“. Thesis, Boston College, 2019. http://hdl.handle.net/2345/bc-ir:108592.
Der volle Inhalt der QuelleSpiral garnets are well-documented metamorphic microstructures that have been observed in orogens throughout the world. The preferred orientation of spiral garnet axes has been proposed (Bell and Johnson, 1989) to record and preserve information about the timing, rate, and orientation of the tectonic-scale processes. Using the model of Be Spiral garnets are well-documented metamorphic microstructures that have been observed in orogens throughout the world. The preferred orientation of spiral garnet axes has been proposed (Bell and Johnson, 1989) to record and preserve information about the timing, rate, and orientation of the tectonic-scale processes. Using the model of Bell and Johnson (1989), Aerden et al. (2013) proposed a link between the preferred orientation of spiral garnets and changes in relative plate motion between Iberia and Africa. The goal of this thesis is to this relationship by absolutely dating, eight samples from the Betic-Rif arc with measurable spiral axis orientations were chosen for Sm-Nd garnet geochronology. Chapter one is a detailed literature review of prior work on the formation and interpretation of spiral garnets. In chapter two we present 11 bulk Sm-Nd garnet ages from eight samples, these ages range from 35.6 ± 2.8 to 13.62 ± 0.69 Ma. The results from the obtained bulk garnet ages reveal a more complex relationship between FIA orientations and plate motion that originally hypothesized in Aerden et al. (2013). Large-scale rigid block rotations that postdate garnet growth may have influenced the current orientation of FIA from the western Betic-Rif. In chapter three, zoned geochronology was conducted on a single sample from the Nevado-Filabride Complex. This study revealed spiral garnet formation occurring on a rapid timescale, just 〖0.45〗_(-0.32)^(+0.51) Myr. While other zoned garnet studies have shown similar rapid growth in subduction zone setting (Dragovic et al., 2012), this is the first such documentation of such rapid growth from a garnet hosting spiral inclusion trails in a regional metamorphic setting. We calculated strain rates considering different genetic models for the spiral inclusion trails either by garnet rotation in simple shear, or by episodic overgrowth of suborthogonal crenulation cleavages due to switching stress axes. In both cases a similar fast strain rate of ca. 10-13 s-1 was obtained, which is an order of magnitude faster than typical regional strain rates and faster than previous spiral garnet studies regardless of the method used to calculate strain-rate
Thesis (MS) — Boston College, 2019
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Earth and Environmental Sciences
BROS, REGIS. „Geochimie isotopique (sm-nd, rb-sr, k-ar, u) des argiles du bassin proterozoique de franceville et des reacteurs d'oklo (gabon)“. Université Louis Pasteur (Strasbourg) (1971-2008), 1993. http://www.theses.fr/1993STR13059.
Der volle Inhalt der QuelleWAKAKI, Shigeyuki. „Estimation of optimal isotopic compositions of Sr, Ba, Nd and Sm spikes for double spike thermal ionization mass spectrometry by error propagation simulation“. Dept. of Earth and Planetary Sciences, Nagoya University, 2012. http://hdl.handle.net/2237/20538.
Der volle Inhalt der QuelleMaruoka, Miriam Tyoka da Silva. „Is?topos de Nd na proveni?ncia de rochas e sedimentos da Bacia Potiguar, NE do Brasil“. Universidade Federal do Rio Grande do Norte, 2007. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18804.
Der volle Inhalt der QuelleNd ISOTOPES IN THE PROVENANCE OF TERRIGENOUS AND CARBONATE ROCKS AND SEDIMENTS OF THE POTIGUAR BASIN, NORTHEASTERN BRAZIL. Mesozoic and Cenozoic rocks from the Potiguar Basin, including terrigenous and carbonate sediments have been investigated to identify their isotopic signature and source areas. Additionally, this study aims to determine the provenance of terrigenous and carbonate sediments on the Brazilian Continental shelf adjacent to Potiguar Basin. The Sm-Nd isotopic signatures of the rocks yielded model ages (TDM) in the range of 2,19- 2,88 Ga, indicating archean to paleoproterozoic sources from the basement. The terrigenous sediments yielded model ages (TDM) in the range of 2,31-2,26 Ga, from 17,5 to 0 cm depth. Despite the small number of samples, limited variations of provenance ages indicates the homogenization of the sediments, probably due to the strong influence of the basement, as the main source of sediments to the shelf. The Sm-Nd isotopic signatures of the carbonate sediments yielded model ages (TDM) in the range of 2,09-2,61 Ga, indicating archean to paleoproterozoic sources from the basement. The results also indicate that the shelf sediments are mainly derived from the A?u River or other small rivers from the Setentrional Sector of Rio Grande do Norte State. The littoral drift doesn?t seem to contribute with sediments from the Oriental Sector since isotopic signatures from this sector were not detected.
An?lises isot?picas Sm-Nd em rochas mesoz?icas e cenoz?icas da Bacia Potiguar, incluindo sedimentos terr?genos e carbon?ticos que aportam do Rio Piranhas-A?u, foram realizadas objetivando a caracteriza??o de suas assinaturas isot?picas e identifica??o de suas ?reas fonte. As assinaturas isot?picas Sm-Nd das rochas apresentaram idades modelo (TDM) variando de 2,88 a 2,19 Ga, indicando fontes, principalmente, paleoproteroz?icas e arquenas do embasamento. Os sedimentos terr?genos plataformais apresentaram idades modelo (TDM) de 2,31 Ga e 2,26 Ga, coletados, respectivamente, nas profundidades de 10-17,5 cm e 0-5 cm. Apesar do n?mero pequeno de amostras, a pequena varia??o na idade indica homogeneiza??o dos sedimentos, talvez devido a forte influ?ncia do embasamento como fonte de material para a plataforma. As assinaturas isot?picas Sm-Nd dos sedimentos carbon?ticos plataformais apresentaram idades modelo (TDM) variando de 2,61 a 2,09 Ga, indicando fontes do embasamento arqueano a paleoproteroz?ico. Estes resultados indicam ainda que os sedimentos terr?genos presentes na plataforma em estudo s?o ou foram trazidos principalmente pelo rio A?u, ou outros rios menores da por??o setentrional do Rio Grande do Norte. A deriva litor?nea aparentemente n?o tem compet?ncia para arrastar sedimentos da por??o oriental para a setentrional, tendo em vista que os valores ?Nd registrados n?o s?o compat?veis com as rochas da por??o oriental.
Santos, Gustavo Macedo de Paula. „Quimioestratigrafia isotópica (C, O, Sr) e geocronologia (U-Pb, Sm-Nd) das rochas da Formação Sete Lagoas, Grupo Bambuí“. Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-10022014-110652/.
Der volle Inhalt der QuelleRecently published geochronological data has arisen questions on the Sete Lagoas Formation (SLF) depositional evolution. This unit is mainly composed by carbonate rocks with subordinated pelitic intercalations and represents the basal unit of the Bambuí Group, which overlies the glacial deposits of the Jequitaí Formation in the São Francisco Craton (SFC). This study combines isotope chemostratigraphy (C, O, Sr) and geochronology (U -Pb and Hf on detrital zircons and Sm-Nd on whole rock samples) in five sections of the SLF in the Lagoa Santa (MG) region, southern part of SFC, in order to answer such questions. Vespasiano (VS) and Ana Paula (AP) sections are composed by gray limestones and beige dolostones, with high contents of detrital sediments and poor in organic matter. The most representative \'delta\'\'POT.13C\' values obtained oscillate within a narrow range around 0%o. These data allow positioning these sections in the first depositional sequence of the SLF, above the basal Sturtian cap carbonates (~740 Ma) of this unit. Bairro da Lapinha (BL), Pedra do Baú (BAU) and Parque da Gruta da Lapinha (PGL) sections comprises dark gray to black limestones, with low detrital sediments contents and rich in organic matter. They are characterized by very positive \'delta\'\'POT.13\'C values (> 6%o) and \'87 ANTPOT.Sr\'/ \'86 ANTPOT.Sr\' ratios close to 0.7075. These sections belong to the second sequence of the SLF. Detrital zircons were retrieved from three marl samples from sections VS, AP and PGL and dated by the U-Pb method. The results indicate that the siliciclastic sediments of the SLF come from sources of long crustal residence time located in the Araçuaí-West Congo Orogen. The youngest population is 557 Ma aged and sets the maximum depositional age for the second sequence of SLF and most of the Bambuí Group. Furthermore, younger concordant zircon grains with ages of 537 ± 4 Ma and 506 ± 7 Ma for the first and second sequence, respectively, refute the hypothesis of a major sedimentation gap between the sequences, as recently proposed, and endorse an Ediacaran/Cambrian age for the SLF. If such gap does exist, it lies between the Sturtian cap carbonates and the sections with \'delta\'\'POT.13\' C around 0%o. These ages also indicate that the deposition of most of the Bambuí Group took place in a foreland basin, after the closure of the Adamastor Ocean which led to the edification of the Araçuaí Belt to the east of the SFC. The \'87 ANTPOT.Sr\'/ \'86 ANTPOT.Sr\' ratios obtained on the SLF carbonates contrast with the recently proposed Sr evolution curves, especially for the Cambrian, from where ratios higher than 0.7085 would be expected. It is possible that the SLF was deposited on a restricted eipiric sea and global correlations based on Sr isotopes are not reliable in such cases.
Hepple, Robert Alexander. „The effects of low degree alteration on Sm-Nd and U-Pb isotope systematics in Eoarchean basalts from the Doolena Gap and Warralong Greenstone belts, Pilbara Craton, Western Australia“. Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/74860/1/Robert_Hepple_Thesis.pdf.
Der volle Inhalt der QuellePaquette, Jean-Louis. „Comportement des systèmes isotopiques U-Pb et Sm-Nd dans le métamorphisme éclogitique. Chaîne Hercynienne et chaîne Alpine“. Phd thesis, Université Rennes 1, 1987. http://tel.archives-ouvertes.fr/tel-00675107.
Der volle Inhalt der QuelleSantos, Gustavo Macedo de Paula. „Quimioestratigrafia isotópica (C, O, Sr, Li, Mg) e proveniência sedimentar (U-Pb, Hf, Sm-Nd) do grupo Bambuí no sul da bacia do São Francisco“. Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-26042018-092122/.
Der volle Inhalt der QuelleThis work presents new C, O, Sr, Mg and Li isotope data and Rare Earth Element (REE) concentrations for the carbonate rocks of the Bambuí Group, in the southern São Francisco Basin. U-Pb and Hf geochronology in detrital zircon grains and whole rock Sm-Nd ages in siliciclastic rocks in the same area are also presented. The chemostratigraphic data allow subdividing the three lower units of the Bambuí Group in three Chemostratigraphic Intervals (CI), each one recording a different evolution stage of the basin. The CI-1 comprises the Sete Lagoas Formation cap carbonates that display C isotope negative excursion, very negative \'delta\'¹³C values and 87Sr/86Sr ratios increasing upwards from 0.7074 to 0.7082. This intervals marks the start of the marine transgression over the São Francisco Craton in which the basin was subject to local controls over seawater, as shown by the flat type shale normalized REE distributions and coupled facies dependent \'delta\'Li and \'delta\'26Mg values variations. The CI-2 corresponds to the middle portion of the Sete Lagoas Formation where the Cloudina sp. (550-542 Ma) occurrence was described. The carbonate rocks of this interval display \'delta\'¹³C values around 0%o, \'delta\'7Li values around 16%o, \'delta\'26Mg around -3.5%o and 87Sr/86Sr between 0.7080 and 0.7087 that are expected for the Ediacaran-Cambrian limit. During this stage, the marine transgression provided connection of the São Francisco basin to other West Gondwana basins, allowing fauna migration and isotope homogenization. In spite of the global geochemical signals observed, the intracontinental scenario kept the basin subject to local controls, as shown by the enrichment in light REE and two perfectly coupled \'delta\'7Li and \'delta\'26Mg negative excursions. The CI-3 comprises the limestones of the upper Sete Lagoas, Serra de Santa Helena and Lagoa do Jacaré formations and with very positive \'delta\'¹³C values (> +3%o) and 87Sr/86Sr ratios around 0.7075, lower than those expected for the Ediacaran-Cambrian limit. The CI-3 records the restriction of the basin in relation to the global ocean geochemical and isotope reservoir, probably by the uplift of the craton\"s marginal orogens. Such uplift caused higher denudation rates and consequent decrease in the weathering intensity of the source areas, diminishing the dissolved influx to the basin that is observed in the Mg and Li isotope systems decouplement and in cycles of Sr/Ca ratios and 26Mg decrease by carbonate precipitation removal. The weathering intensity decrease caused the dissolved influx from carbonates to be more important than the one from silicates, resulting in the drop down of the 87Sr/86Sr ratios, the appearance of the \"seawater\" REE shale normalized distributions, and sulphate supply restriction driving methanogenesis. The geochronological data show that no significant reorganization of the basin source areas occurred from the deposition of the Carrancas Formation and Moema Laminites finer facies to the Lagoa do Jacaré Formation. Although the data do not solve the age and geotectonic questions, they add another argument against the existence of an unconformity at the base of the Sete Lagoas Formation, suggesting that the glaciation of the São Francisco Basin is likely Middle to Late Ediacaran in age. If there is an unconformity, the only available absolute age suggests it is a Sturtian Glaciation (~720 Ma).
Schneider, Julie. „COMPORTEMENT DES RADIOCHRONOMETRES Rb/Sr, Ar/Ar ET Sm/Nd AU COURS DU METAMORPHISME : CAS DES ECLOGITES DE L'ARC DE BERGEN (NORVEGE)“. Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2004. http://tel.archives-ouvertes.fr/tel-00463535.
Der volle Inhalt der QuelleCanile, Fernanda Maciel. „Geologia isotópica em zircões detríticos (U-Pb, Hf e O) e em rocha total (Sm-Nd e Pb-Pb) das rochas da Bacia do Paraná em Santa Catarina“. Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-24022016-140417/.
Der volle Inhalt der QuelleU-Pb, Hf and O isotope data were obtained from detrital zircons from late Paleozoic-early Mesozoic units from Paraná Basin, southeastern Brazil, in order to constain the provenance of the sediments, as well as to contribute to the understanding of the tectonic evolution of the basin. Whole rock Sm-Nd and Pb-Pb isotopic signatures were also taken in order to help the interpretation. The studied section, White Column in Santa Catarina state, includes rocks from 11 stratigraphic units (from base to top): Rio do Sul Formation, Rio Bonito Formation (Triunfo, Paraguaçu and Siderópolis members), Palermo Formation, Irati Formation, Serra Alta Formation, Teresina Formation, and Rio do Rasto Formation (Serrinha and Morro Pelado members) and Botucatu Formation. U-Pb ages were obtained on 1941 detrital zircons and range from 242 Ma to 3400 Ma. All sedimentary units show four main detrital age groups, Neoarchean (2700-2500 Ma), mid-Paleoproterozoic (2000-1800 Ma), Grenvillian (1100-900 Ma) and Brasiliano (850-490 Ma), reflecting the importance of the Precambrian basement bordering the east side of the basin, such as Dom Feliciano, Kaoko and Namaque-Natal Belts as source areas, including the local basement that was dated at 584 Ma. The Siderópolis Member shows an important change in the source of sediments with a Permian age-peak (266 to 290 Ma). This age-peak persists towards the top of the section until the Botucatu Formation. O and Hf isotopic signatures from the detrital zircons show that a portion of the mid-Paleoproterozoic grains is probably from rocks of the presently covered basement, which was exposed until the deposition of the Rio Bonito Formation. O and Hf isotopes also show that some Grenvillian aged zircons are from Argentinian rocks, which implies a long transport distance. Isotopic signatures of part of the Permian grains also link them to sources from Argentina and Chile, and part of these grains has more rounded shapes, suggesting that they reached the basin after long distance traveling on subaquatic environment and nor only through the air (ash falls) as it is commonly accepted. Other younger age peaks (Ordovician to Carboniferous) found from Palermo Formation upsection are also linked to Argentinian and Chilean sources, showing the importance of distant sources during the filling of the basin. The Sm-Nd and Pb-Pb data on whole rocks show that the sediments from the Paraná Basin present predominance of sources with crustal origin. Osotopic signatures are similar to granitoid rocks from Santa Catarina, Ribeira Belt, Brazilian Shield, Namaqua-Natal and Kaoko Belts, as well as the Arequipa-Antofalla terranes (Andes basement) and granitoids from North Patagonia. These data corroborate the observed detrital zircon patterns thar point to both proximal and distal source areas. \'T IND.DM\' model ages older than 1.4 Ga and more negative (-10 to -15) epsilon values were observed in the lower units (Rio do Sul Formation to Paraguaçu Member), while the upper units show \'\'épsilos\' IND.Nd(0)\' values ranging from -6 to -12 and \'T IND. DM\' model ages younger than 1.5 Ga, corroborating the addition of a younger source starting from the Siderópolis Member deposition upwards, as noted by detrital zircon data (Permian age-peak).
Li, Yuting. „Investigating sediment size distributions and size-specific Sm-Nd isotopes as paleoceanographic proxy in the North Atlantic Ocean : reconstructing past deep-sea current speeds since Last Glacial Maximum“. Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/273776.
Der volle Inhalt der QuelleChavagnac, Valérie. „Behaviour of the Sm-Nd isotopic system during metamorphism : examples from HT-LP metamorphic terrane of the Limpopo Belt, South Africa and the UHP metamorphic terrane of Dabieshan, Central China“. Rennes 1, 1998. http://www.theses.fr/1998REN10101.
Der volle Inhalt der QuelleSchneider, Julie. „Comportement des radiochronomètres Rb/Sr, Ar/Ar et Sm/Nd au cours du métamorphisme : Cas des éclogites de l'arc de Bergen (Norvège)“. Phd thesis, Montpellier 2, 2004. http://tel.archives-ouvertes.fr/tel-00440768.
Der volle Inhalt der QuelleChavagnac, Valérie. „Behaviour of the Sm-Nd isotopic system during metamorphism : examples from the HT-LP metamorphic terrane of the Limpopo Belt, South Africa and the UHP metamorphic terrane of Dabieshan, Central China /“. Rennes : Géosciences, Université de Rennes I, 1999. http://catalogue.bnf.fr/ark:/12148/cb370399598.
Der volle Inhalt der QuelleCampos, Roberto Sacks de. „Petrologia, caracterização geológica, geoquímica e geocronológica do magmatismo pré, sin e pós-colisional presente no Complexo Metamórfico Brusque nas regiões de Itapema e Botuverá, Santa Catarina, Brasil“. reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/32594.
Der volle Inhalt der QuelleThis work objective the characterization of the petrology, geochemistry, geochronology and metamorphism of ortoderivate rocks that belong to Brusque Metamorphic Complex BMC) in two regions: Itapema and Botuverá, Santa Catarina, Brazil. Within these, good expositions of mafic and metaultramafic rocks occur in both regions. In Itapema, bodies of peraluminous leucogranites were also investigated. Around Botuverá were investigated diabase dikes and lamprophyres. The analysis of the conditions of generation and sources of magmatic events responsible for the development of these rocks was essential for the characterization and assessment of the significance of these tectonic units in the BMC, and it were placed during the pre-, syn-and post-collisional period of it’s evolution. The regional foliation of the complex is represented by a low angle S2 surface in Itapema region and a higher angle foliation in the region of Botuverá, folded by actuation of the D3 event. Petrography and Hb-Pl geothermometry data indicate that the main foliation of the mafic schists was generated in conditions between the transition of greenschist and lower amphibolite facies. The pre-orogenic magmatism of the Brusque Metamorphic Complex consists of lenses of mafic-ultramafic, products from the metamorphism of basalts, gabbros, related cumulate rocks and volcanogenic sediments. These rocks have a tholeiitic affinity and high contents of LREE and LILE elements. The analysis of incompatible elements ratios, the position of igneous bodies intercalated with the metasediments and the absence of oceanic crust suggest that the basalts were placed in an intra-continental plate environment, synchronous with sedimentation of the basin. The initial εNd values between -2.96 and 5.05 for the metavolcanics of Itapema and between -0.14 and -6.97 for the rocks of Botuverá indicate the involvement of Paleoproterozoic crust on the genesis of these magmas. The generally high 87Sr/86Sr values justify the involvement of crust, and the highest values found in Botuverá, highlight the greater involvement of this component in the region. Syn tectonic magmatism is represented by bodies of peraluminous leucogranite showing emplacement concordant to S2 foliation. Compositional parameters of these rocks characterized by low ratios K2O/Na2O, CaO/Na2O and LaN / YbN, low levels of Rb, Sr, Zr, Y, Yb and Lu, are consistent with magmas generated from partial melting of pelitic rocks, with limited participation of differentiation processes. In the region of Botuverá the occurrence of diabase dykes and lamprophyres cutting the regional metamorphic units indicates that its position is post-collisional. Geochemically show affinity between the tholeiitic and shonshonitic series. The distribution pattern of trace elements and the Th/Yb for Ta/Yb ratios indicate that extraction of diabase occur from an enriched mantle source, with the presence of rutile and garnet in the residue and heavily contaminated by crust. These characteristics are similar to those found in rocks post-collisional basaltic volcanic in south Brazil. The scattered values of єNd (618) in basic terms, ranging between -13.74 and +5.52 highlight the heterogeneity of mantle supply and reinforce the importance of crustal component in the generation of these rocks. A concordant age of 618 ± 8.7 Ma by U-Pb (LA-ICP-MS) zircon method were obtained, marking a early magmatic processes of post-collisional Brasiliano orogeny in the region of Botuverá.
Harper, Charles L. „On the nature of time in cosmological perspective : a comparative study of the weak and strong interaction chronometries via an analysis of high resolution ⁸⁷Rb-β-̄⁸⁷Sr, ²³⁵/²³⁸U-α-²⁰⁷/⁷⁰⁶Pb and ¹⁴²Sm-α-¹⁴³Nd isotopic age determinations of meteoritic, lunar and geological samples“. Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670359.
Der volle Inhalt der QuelleLahaye, Yann. „L'altération des komatiites“. Phd thesis, Université Rennes 1, 1995. http://tel.archives-ouvertes.fr/tel-00655890.
Der volle Inhalt der QuelleDavid, Marta Edith Velásquez. „Composição isotópica de Pb-Sr e Nd da mineralização de ouro do depósito Córrego do Sítio, Quadrilátero Ferrífero (MG): implicações na modelagem conceitual“. Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/44/44141/tde-19042007-142433/.
Der volle Inhalt der QuelleThe Quadrilátero Ferrífero is an important geotectonic unit of the São Francisco Craton that host iron and gold deposits within the vulcanosedimentary rocks of the greenstone belt Rio das Velhas. The geodynamic evolution of this greenstone includes several tectonometamorphic events. Gold deposits were formed by epithermal fluids, remobilized during the Proterozoic orogenic processes, are associated whit the banded iron formations and are sporadically disseminate in metapelitic rocks within the top of the greenstone sequence. In the ores is common the crystallization of iron sulfide minerals during diverse stages. Gold deposits have an important structural control by folds, reverse faults and strike-slip shearing zones, and are commons several hydrothermal alteration processes like sericitization, chloritization and carbonate usually related to the deformation. The Córrego do Sítio gold deposit is hosted in turbiditic siliciclastic rocks that are metamorphosed in the greenschist facies. The gold is associated with the iron sulfide arsenopyrite and pyrite, which are disseminated in metapelitic rocks and quartz-carbonate veins. The mineralization includes vary stages of crystallization, (1) pyrite and pyrrotite (2) arsenopyrite, pyrrotite and fine pyrite, (3) arsenopyrite whit pyrrotite and sulphosalts in quartz vein, and (4) pervasive pyrite. An integrated Pb, Sr e Nd, isotopic study of the Córrego do Sítio deposit allowed to identify that sources of the mineralizing fluids was the host rocks, that in the policiclic evolution the gold mineralizaton had participation events of metamorphism and hidrothermalism to age 2.2, 2.0 and 0.6 Ga. respectively the wich induced the hydrothermal circulation processes in the study area. The isotopic character of this deposit and its comparison with similar ones, suggest that the gold and its metals associated it is deposited in Córrego do Sítio to age 2.2 Ga. and that metals were derived from the banded iron formations, and remobilized by hidrothermal fluids across reverse faults. Although U-Pb (SHRIMP) and K-Ar geochronologic data were not conclusive to constrain the age of the mineralization, they provide to age ~2.7 Ga. that a good limit for the sedimentation of the host rock. It is suggest that there is a potential for gold prospection within the metapellitic rocks associated with banded iron formation of the Greenstone Rio das Velhas, and that the more relevant targets include areas with inverse and strike-slip fault.
Boulay, Sébastien. „Enregistrements sédimentaires des variations de la mousson sud-est asiatique au cours des 2 derniers millions d'années“. Phd thesis, Université Paris Sud - Paris XI, 2003. http://tel.archives-ouvertes.fr/tel-00006427.
Der volle Inhalt der QuelleFeneyrol, Julien. „Pétrologie, géochimie et genèse des gisements de tsavorite associés aux gneiss et roches calco-silicatées graphiteux de Lemshuku et Namalulu, Tanzanie“. Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0348/document.
Der volle Inhalt der QuelleTsavorite, a (V, Cr, Mn)-bearing green grossular, is hosted by graphitic gneisses or calc-silicates, often asssociated with dolomitic marbles, and belonging to the Metamorphic Neoproterozoic Mozambique Belt. Tsavorite is found either as nodules or in quartz veins (primary deposits), or in placers (secondary deposits). The mineralogical study of tsavorites suggests a new protocol to certificate their geographical origin, based on the V/Cr ratio, Mn content and delta18O. The study of the Lemshuku and Namalulu deposits in Tanzania has shown that the metamorphism of organic matter-rich and evaporites-rich sedimentary protoliths occurred at P = 7.0 ± 0.4 kbar and T = 677 ± 14°C, at 634 ± 22 Ma (U-Th-Pb dating on monazite). The metamorphic series cooled down at around 500 Ma (40Ar-39Ar dating on muscovite). Two metasomatic stages are linked to the formation of tsavorite : (i) diffusion metasomatism forming nodules at P = 5.0-7.4 kbar and T = 580-691°C; (ii) calcitic infiltration metasomatism forming quartz veins at P = 3.6-4.9 kbar and T = 505-587°C. These last have been dated in situ with Sm-Nd dating at 606 ± 36 Ma. Continental evaporites, deposited in a coastal marine sabkha with (Si, Ca)-bearing sediments, transformed into tsavorite in the case of the nodules, while the molten salts are associated with the formation of the quartz veins. The mineralisations are controlled by lithostratigraphy and structure
Romano, Antônio Wilson. „Évolution tectonique de la région nord-ouest du quadrilatère ferrifère : Minas Gerais-Brésil (Géochronologie du socle, aspects géochimiques et pétrographiques des supergroupes Rio Das Velhas et Minas)“. Nancy 1, 1989. http://www.theses.fr/1989NAN10364.
Der volle Inhalt der QuellePin, Christian. „Essai sur la chronologie et l'évolution géodynamique de la chaîne hercynienne d'Europe“. Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 1989. http://tel.archives-ouvertes.fr/tel-01001861.
Der volle Inhalt der QuelleMaas, Roland. „The application of Sm-Nd and Rb-Sr isotopic systematics to ore deposits“. Phd thesis, 1987. http://hdl.handle.net/1885/140154.
Der volle Inhalt der QuelleMkaza, Masizole. „Sm-Nd isotopic disequilibrium between minerals in Merenskycyclic units of the Bushveld Complex, South Africa“. Thesis, 2009. http://hdl.handle.net/10210/1964.
Der volle Inhalt der QuelleLau, W. K. „Geochemical and Sm-Nd isotopic composition of Palaeoproterozoic eclogite and associated rocks in the Usagaran Orogenic Belt, Tanzania“. Thesis, 2009. http://hdl.handle.net/2440/129279.
Der volle Inhalt der QuelleEclogites from the Usagaran Orogenic Belt of Tanzania have been reliably dated at 2.0 Ga and are the oldest reported subduction-related eclogites within a well-preserved orogenic belt. Based on limited geochemistry from two samples of eclogite from the Usagaran Belt, Möller et al. (1995) concluded that the protoliths were similar to MORB. This study analyzed a larger number of eclogitic samples and a suite of structurally intercalated mafic and pelitic rocks to establish the tectonic setting of the Usagaran Orogenic Belt rocks. Eclogitic rocks from the Usagaran Orogenic Belt display LILE and LREE enrichment relative to present-day MORB. Variations in εNd values from depleted mantel at 2.0 Ga supported this interpretation. The mantle-derived mafic rocks show strong Nb depletions, indicating that they are subduction-related. Enrichment of mafic rocks in LILE and LREE are likely caused by dehydration of the subducting slab with some contamination from crustally derived materials perhaps via subducted sediment. The intercalated pelites are mainly derived from the Tanzanian Craton, with a significant mafic input evidenced by high Cr & Ni values. Based on the geochemical isotopic compositions and field relationships, the eclogites, mafic rocks and pelites all formed in a subduction setting that operated around 2.0 Ga. Despite the fact that the Earth was hotter in its early history, modern plate tectonics, (i. e., subduction of cold oceanic crust into a warm mantle resulting in high-pressure low-temperature metamorphism), occurred and was recorded in the Usagaran Belt during the Palaeoproterozoic. Thus modern-style plate tectonics have operated since at least 2.0 Ga.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2009
Trestrail, J. L. „U-Pb detrital zircon, geochemical and Nd isotope constraints on sedimentary provenance of the Chewings Range Quartzite, Warumpi Province, Arunta Region, NT“. Thesis, 2010. http://hdl.handle.net/2440/106279.
Der volle Inhalt der QuelleThe Chewings Range Quartzite is a meta-sedimentary cover sequence located in the Warumpi Province of the Arunta Region. U-Pb detrital Zircon analysis of the Chewings Range Quartzite indicates a minimum depositional age of ~ 1640Ma, with the main population of zircons residing within a range of 1700 – 1800Ma. Evidence from Sm-Nd isotopic data suggests that a series of Staurolite Garnet Schists, often grouped with the Chewings Range Quartzite, has a significantly more juvenile character. This suggests that it may represent a new unit with a significantly differing provenance to that of the Chewings Range Quartzite. Combined REE, geochemistry and detrital zircon dating suggests that the Chewings Range Quartzite was derived primarily off the Arunta Region and North Australian Craton, while the Stauralite Garnet Schists holds more affinity with juvenile Musgrave Province to the south.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2010
Chaumba, Jefferson B. „The Russell Lake Allochthon, southern Appalachians structure, petrography, bulk-rock and mineral chemistry, O, H, and Sm-Nd isotope geochemistry /“. 2009. http://purl.galileo.usg.edu/uga%5Fetd/chaumba%5Fjefferson%5Fb%5F200908%5Fphd.
Der volle Inhalt der QuelleDirected by Michael Roden. For abstract see https://getd.libs.uga.edu/pdfs/chaumba%5Fjefferson%5Fb%5F200908%5Fphd.pdf. Includes bibliographical references (leaves 246-279).
Schmitt, Wolfgang [Verfasser]. „Application of the Sm-Nd isotope system to the late quaternary paleoceanography of the Yermak Plateau (Arctic Ocean) / vorgelegt von Wolfgang Schmitt“. 2007. http://d-nb.info/985282169/34.
Der volle Inhalt der QuelleGomwe, Tafadzwa Euphrasia Sharon. „A geochemical profile through the Uitkomst Complex on the farm Slaaihoek, with special reference to the platinum-group elements and Sm-Nd isotopes“. Diss., 2002. http://hdl.handle.net/2263/28469.
Der volle Inhalt der QuelleDissertation (MSc)--University of Pretoria, 2006.
Geography, Geoinformatics and Meteorology
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Higgie, D. R. „Tectonic provenance of the Palaeoproterozoic Plum Tree Volcanics: implications for the initiation of the McArthur Basin“. Thesis, 2018. http://hdl.handle.net/2440/130627.
Der volle Inhalt der QuelleThe Palaeoproterozoic (1825 ±4Ma) Plum Tree Volcanics are a bimodal suite of basalt and rhyolite lavas forming part of the fluvial conglomerate-sandstone sequence of the upper Edith River Group. They are preserved in remnants unconformably overlying the Pine Creek Orogen north of Katherine in the Edith River, Mt Callanan and Birdie Creek Basins. These sequences directly post-date the convergent deformation of the Pine Creek Orogen and mark the beginning of the extensional regime that initiated the McArthur Basin. The tectonic setting of the Plum Tree volcanism, whether divergent intraplate rift or mantle hotspot, may suggest how the formation of the McArthur Basin began and provide insight into how the Pine Creek Orogen compression ceased. In this paper, geochemical methods were used to determine the tectonic setting of the Plum Tree Volcanics. Whole rock geochemical data were collected via XRF, ICP-MS and ICP-OES. Nd-Sm and Sr isotopic data were collected via column chromatography and TIMS. Petrographic data were collected via optical petrography. Radiogenic Sr (87Sr/86Sr= ~0.708) and non-radiogenic Nd (εNd(i)= -6 to -8) isotopes suggest a crustal component in melt evolution. Modelling of melt evolution by pure fractional crystallisation presents well-fitting liquid lines of descent, suggesting a fractional crystallisation driven melt evolution. Tholeiitic basalts and trace element geochemistry suggests a mantle derived melt driven by a mantle plume and intraplate continental rifting. Modelling of AFC processes suggest a lower crust sourced assimilant. Ambiguous basalt geochemistry supports a continental rift derived melt and an oxygen fugacity of FMQ -1 suggests a primitive, reduced melt reflecting a mantle parent. Optical petrography presents a plagioclase and clinopyroxene rich mineral assemblage reflecting a mantle parent.
Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Physical Sciences, 2018
Larbi, Youcef. „Caractérisation géochimique (éléments majeurs et éléments en traces), traçage isotopique (Sm-Nd, Lu-Hf) et géochronologie (Pb-Pb, U-Pb) du groupe de Wakeham, N.E. Québec : bassin sédimentaire prétérozoïque dans la province de Grenville“. Thèse, 2003. http://constellation.uqac.ca/745/1/17773537.pdf.
Der volle Inhalt der QuelleVan, Wyck Nicholas. „Oxygen and carbon isotopic constraints on the development of eclogites, Holsn/oy, Norway and major and trace element, common Pb, Sm-Nd, and zircon geochronology constraints on petrogenesis and tectonic setting of pre- and early proterozoic rocks in Wisconsin“. 1995. http://catalog.hathitrust.org/api/volumes/oclc/32642090.html.
Der volle Inhalt der QuelleRobinson, Frank Alexander. „Geochronological and geochemical constraints on the lithospheric evolution of the Arabian shield, Saudi Arabia: understanding plutonic rock petrogenesis in an accretionary orogen“. Thesis, 2014. http://hdl.handle.net/2440/84674.
Der volle Inhalt der QuelleThesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2014