Bibliografie tematiche / Isotopie Sm-Nd

Letteratura scientifica selezionata sul tema "Isotopie Sm-Nd"

Autore: Grafiati

Pubblicato: 6 luglio 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Isotopie Sm-Nd".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Articoli di riviste sul tema "Isotopie Sm-Nd":

Vezinet, Adrien, Emilie Thomassot, Yan Luo, Chiranjeeb Sarkar e D. Graham Pearson. "Diachronous Redistribution of Hf and Nd Isotopes at the Crystal Scale—Consequences for the Isotopic Evolution of a Poly-Metamorphic Crustal Terrane". Geosciences 12, n. 1 (12 gennaio 2022): 36. http://dx.doi.org/10.3390/geosciences12010036.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In metamorphic rocks, mineral species react over a range of pressure–temperature conditions that do not necessarily overlap. Mineral equilibration can occur at varied points along the metamorphic pressure–temperature (PT) path, and thus at different times. The sole or dominant use of zircon isotopic compositions to constrain the evolution of metamorphic rocks might then inadvertently skew geological interpretations towards one aspect or one moment of a rock’s history. Here, we present in-situ U–Pb/Sm–Nd isotope analyses of the apatite crystals extracted from two meta-igneous rocks exposed in the Saglek Block (North Atlantic craton, Canada), an Archean metamorphic terrane, with the aim of examining the various signatures and events that they record. The data are combined with published U–Pb/Hf/O isotope compositions of zircon extracted from the same hand-specimens. We found an offset of nearly ca. 1.5 Gyr between U-Pb ages derived from the oldest zircon cores and apatite U–Pb/Sm–Nd isotopic ages, and an offset of ca. 200 Ma between the youngest zircon metamorphic overgrowths and apatite. These differences in metamorphic ages recorded by zircon and apatite mean that the redistribution of Hf isotopes (largely hosted in zircon) and Nd isotopes (largely hosted in apatite within these rocks), were not synchronous at the hand-specimen scale (≤~0.001 m3). We propose that the diachronous redistribution of Hf and Nd isotopes and their parent isotopes was caused by the different PT conditions of growth equilibration between zircon and apatite during metamorphism. These findings document the latest metamorphic evolution of the Saglek Block, highlighting the role played by intra-crustal reworking during the late-Archean regional metamorphic event.

Soloshenko, N. G., M. V. Streletskaya, M. V. Chervyakovskaya e D. V. Kiseleva. "Implementation and experience of using methods for analyzing the isotopic composition of Sm and Nd, Rb and Sr in rock samples at the Geoanalitik Center for Collective Use". LITHOSPHERE (Russia) 24, n. 2 (7 maggio 2024): 364–75. http://dx.doi.org/10.24930/1681-9004-2024-24-2-364-375.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Research subject. AGV-2 and BHVO-2 geochemical reference materials for studying the Sm, Nd and Rb, Sr isotope systems along with various rocks and mineral samples. Materials and Methods. An analysis of the isotopic composition of Sm, Nd and Rb, Sr was carried out using Neptune Plus and Triton Plus mass spectrometers. Aim. To implement analytical techniques for the isotopic composition of Sm and Nd, Rb, and Sr in various rock and mineral samples using two types of multicollector mass spectrometers – inductively coupled plasma NeptunePlus and thermal ionization TritonPlus (Thermo-Fisher), as well as a description of the procedure of processing experimental data and the experience in using techniques at the “Geoanalitik” shared research facilities of the IGG UB RAS for the period 2015-2023. Results. The analytical techniques implemented included (1) column chromatography using various ion-exchange resins, optimised for the ratio of labour costs/quality of analytical results; (2) the measurement of isotope ratios using two types of mass spectrometers; (3) the correction of mass bias of isotope ratios and the determination of Sm and Nd, Rb, and Sr concentrations by the isotope dilution method using 149Sm+150Nd and 85Rb+84Sr spikes. Testing of the techniques was carried out using the AGV-2 and BHVO-2 geochemical reference materials; their metrological characteristics were presented. When using TritonPlus, the reproducibility (BHVO-2, n=60) of measurements of 143Nd/144Nd, 147Sm/144Nd isotope ratios and Sm and Nd concentrations are ±0.000020, ±0.0004, ±1.3 and ±0.4, respectively; indicators of correctness of determining the ratios 143Nd/144Nd and 147Sm/144Nd – 0.001 and 0.25% and concentrations of Sm and Nd – 2%; the reproducibility (BHVO-2, n=63) of measurements of 87Sr/86Sr, 87Rb/86Sr isotope ratios and concentrations (Rb and Sr) are ±0.0025%, ±1.5%, ±2%, respectively. The uncertainty of a single measurement of the 143Nd/144Nd and 87Sr/86Sr isotope ratio, represented by the standard error of the average single measurement in the sample, does not exceed 0.0025%. Conclusions: the results obtained for the geochemical reference materials are in satisfactory agreement with those provided in the GeoReM database, as well as with the certified values provided by the United States Geological Survey (USGS). The described analytical techniques are used at the “Geoanalitik” shared research facilities of the IGG UB RAS to analyse various rock and mineral samples. The work presents a number of experimental results obtained, which are subsequently used in geochronological applications.

Chervyakovskaya, M. V., e V. S. Chervyakovskiy. "Determination of Sm/Nd and Sr isotopic composition using an ICP-MS Neptune Plus equipped with an NWR 213 attachment for laser ablation". LITHOSPHERE (Russia) 21, n. 5 (31 ottobre 2021): 712–23. http://dx.doi.org/10.24930/1681-9004-2021-21-5-712-723.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Research subject. The Sm/Nd isotope system was investigated using inter-laboratory natural samples of apatite, titanite, allanite, monazite, as well as intra-laboratory samples of apatite (from carbonatites, Ilmenogorsk massif, Ural), monazite (from pegmatites of the Aduy granite massif and its framing, Middle Urals) and titanite (from calcite veins, Saranov skoye chromite deposit, Middle Urals and from alkaline pegmatite, Shpat mine, Vishnevy mountains, South Urals). The Sr isotope system was investigated using inter-laboratory natural apatite samples and intra-laboratory apatite samples (from the apatite-carbonate vein, Slyudyanogorskoe deposit, Irkutsk region and from carbonatites, Ilmenogorsk massif, Ural).Methods. The research was carried using a Neptune Plus multicollector mass spectrometer with inductively coupled plasma (ThermoFisher) equipped with an NWR 213 (ESI) laser ablation attachment, located in a room of ISO class 7 at the “Geoanalyst” Center for Collective Use (IGG Ural Branch of the Russian Academy of Sciences, Ekaterinburg). Results. The article describes methodological approaches for studying Sm/Nd and Sr isotope systems in natural phosphate and silicate minerals by inductively coupled plasma mass spectrometry with laser ablation, implemented on the equipment of the Center for Collective Use “Geoanalyst” (IGG Ural Branch of the Russian Academy of Sciences, Ekaterinburg). A comparative analysis of the obtained results with those reported in literature showed their satisfactory agreement. The developed analytical approaches were used to study apatite samples (analysis of the Sr isotope system) and those of apatite, monazite, titanite (analysis of the Sr isotope system). Conclusions. The developed approaches to the analysis of Sm/Nd and Sr isotopic systems can be recommended for investigating such minerals, as apatite, titanite, allanite, monazite (analysis of the Sm/Nd isotope system); apatite (analysis of the Sr isotope system). The achieved analysis errors allow the results to be used for interpreting various geochemical processes.

Dempsey, C. S., A. N. Halliday e I. G. Meighan. "Combined Sm-Nd and Rb-Sr isotope systematics in the Donegal granitoids and their petrogenetic implications". Geological Magazine 127, n. 1 (gennaio 1990): 75–80. http://dx.doi.org/10.1017/s0016756800014175.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

AbstractThe metaluminous to peraluminous granitoids of the Donegal batholith, northwest Ireland, were emplaced at c. 400 Ma into greenschist-amphibolite facies metasediments of the Dalradian Supergroup. Sm-Nd and Rb-Sr isotopic data are provided for eleven granitoid samples from six of the plutons and one specimen from the northeast granodiorite pluton of the Newry complex, Co. Down; the Donegal results reveal essentially similar initial Sr isotope ratios (0.7051–0.7068) but highly variable initial eNd values, −1.2 to −8.3 (and −0.5 for Newry). Certain granitoids have distinctive Nd isotopic compositions characteristic of the involvement of old, LREE-enriched continental crust in some cases or young crust and/or mantle-derived magmas in others. The Nd and Sr isotopic variations can be explained by a variety of mixing hypotheses.

Huber, Miłosz A., Stanisław Hałas, Yuri N. Neradovsky, Tamara B. Bayanova, Artem W. Mokrushin e Lesia Lata. "Stable isotope geochemistry of sulfides from intrusion in Monchegorsk, northern part of Baltic Shield". Geochronometria 43, n. 1 (1 giugno 2016): 96–101. http://dx.doi.org/10.1515/geochr-2015-0034.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Abstract The sulfide minerals from old mafic intrusion rocks from the Kola Peninsula were analyzed on stable sulfur isotopes. These samples were already dated by the Sm-Nd method. These sulfide samples were evaluated upon a geochemical composition by ICP-MS. The sulfide mineral samples were selected from the main ore-bearing rocks of the Monchetundra layered intrusion. The analyzed sulfides formed several generations of mineralization associated with primary and hydrothermal stage of formation of the deposits. Isotopic studies confirm a few consecutive stages of mineralization. These data were compared with the results of Sm-Nd dating of sulfide mineralization. The results of geochemical and geochronological studies indicate a complementarity in the context of determining the mineralization stages.

Collerson, Kenneth D., Malcolm T. McCulloch e Allan P. Nutman. "Sr and Nd isotope systematics of polymetamorphic Archean gneisses from southern West Greenland and northern Labrador". Canadian Journal of Earth Sciences 26, n. 3 (1 marzo 1989): 446–66. http://dx.doi.org/10.1139/e89-039.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Sr and Nd isotopic data for middle to late Archean polymetamorphic felsic gneisses from localities in the Nuuk area, West Greenland, are compared and contrasted with new isotopic results for early Archean Amîtsoq gneisses and with data for isotopically reworked Kiyuktok gneisses from the Saglek area, Labrador. Sr isotopic data for individual suites of felsic gneisses record the time-integrated effect of variable Rb–Sr fractionation during prograde and retrograde events as well as the effect of source inhomogeneity.Contrasting petrologic and Sr–Nd isotopic characteristics are the result of differences in level of exposure, caused partially by juxtaposition of terranes of different metamorphic character by movement on ductile shear zones and post-shearing folding deformation. Sm–Nd systematics of felsic gneisses from Nordafar, Ikerasakitsup akornga, Tinissaq, and Kangimut sammisoq – Qasigianguit define a geologically meaningless ca. 3280 Ma Nd "isochron", which is the result of mixing of samples from unrelated suites and the effect of open-system behaviour. Gneisses lying on this pseudoisochron were variably affected by ca. 2800–2900 Ma prograde granulite-facies metamorphism and structurally controlled retrogression under amphibolite- to greenschist-facies conditions.The study shows that Sr–Nd isotope systematics of geologically identifiable units may be modified by open-system behaviour during prograde and retrograde metamorphism. Isotopic data from gneiss complexes metamorphosed under granulite-facies conditions may therefore yield equivocal information concerning isochron interpretation, significance of model ages, and estimates of crustal residence time.

Nedosekova, I. L., V. A. Koroteev, T. B. Bayanova, P. A. Serov, V. I. Popova e M. V. Chervyakovskaya. "On the age of pyrochlore carbonatites from the Ilmeno-Vishnevogorsky Alkaline Complex, the Southern Urals (insights from Rb-Sr and Sm-Nd isotopic data)". LITHOSPHERE (Russia) 20, n. 4 (31 agosto 2020): 486–98. http://dx.doi.org/10.24930/1681-9004-2020-20-4-486-498.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Research subject. In this research, we carried out Sm-Nd- и Rb-Sr-dating of pyrochlore carbonatite from the Vishnevogorsky niobium deposit, Ilmeno-Vishnevogorsky Alkaline Complex, Southern Urals. IVC is located in the Ural fold region and is a carbonatite complex of the linear type. Rare metal (Nb-Zr-TR) deposits and occurrences are related to IVC. The age and the duration of IVC deposits formation remains a matter of debate. To determine the age of IVC carbonatites and related niobium ore, we measured Sm-Nd and Rb-Sr isotopic compositions and concentrations of the elements in the minerals (pyrochlore, calcite, apatite, biotite) and bulk sample of pyrochlore carbonatite. Materials and methods. The Sm and Nd isotopic compositions and concentrations were determined on a Finnigan MAT-262L (RPQ) seven-collector mass spectrometer in the static regime at the Geological Institute of the Kola Scientific Center, Apatity, Russia. The Sr and Rb isotopic compositions and concentrations were determined on thermos-ionization mass spectrometer Triton Plus (“Geoanalitik”, IGG UD RAN, Ekaterinburg, Russia). Results. Age of pyrochlore carbonatites from ore zone 140 (Vishnevogorsky deposit, IVC) defined by Sm-Nd and Rb-Sr isotopic methods. Mineral Sm-Nd-isochron (5 points) indicated age 229 ± 16 Ma, mineral Rb-Sr-isochron (5 points) showed similar age 250.5 ± 1.2 Ma. Conclusions. Results Sm-Nd и Rb-Sr dating indicate that the pyrochlore сarbonatites of ore zone 140 crystallized ≈ 250 Ma ago, at the stage of the postcollisional extension, possibly, in connection with exhumation complex, which was accompanied by decompression, partial melting of rocks, involving fluids, dissolution and precipitation of Ordovician-Silurian alkaline-carbonatitе complex. Thus, the formation of the IVC carbonatites and related Nb-ore, which began in Silurian (S), continued in Permian (P) and Triassic (T1-2) and was associated with the post-collision stage of tectonic activity in the Ural Fold Belt.

DICKIN, ALAN P. "The Chondritic Moon: a solution to the 142Nd conundrum and implications for terrestrial mantle evolution". Geological Magazine 153, n. 3 (8 gennaio 2016): 548–55. http://dx.doi.org/10.1017/s0016756815000990.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

AbstractRecent discoveries that the Earth has a supra-chondritic 142Nd signature have thrown chondritic geochemical Earth models into doubt. Several solutions have been proposed to explain this discrepancy but none has been widely accepted. This paper reviews Nd isotope data for the Moon which bridge the gap between the 142Nd signatures of chondritic meteorites and the accessible Earth. Different chondrite classes define a 142Nd–148Nd correlation line attributed to incomplete mixing of nucleosynthetic components in the solar nebula. Terrestrial standards have 142Nd signatures well above this correlation line, but the 142Nd signature of the Bulk Moon is c. 6 ppm lower than terrestrial (assuming a chondritic Sm/Nd ratio) and falls within error of enstatite chondrites. In view of the demonstrated isotopic similarity between the Earth and Moon, giant impact models require the Moon to be a sample of the early Earth. Therefore, it is inferred that the Earth–Moon system was generated from material similar to enstatite chondrites, but Earth's mantle experienced Sm/Nd fractionation very soon after the Moon-forming collision. Such fractionation processes have been attributed to subduction of early Fe-enriched crust into a deep mantle storage reservoir. Because Sm/Nd fractionation occurred when most 146Sm had already decayed, the hidden incompatible-element-enriched reservoir only became slightly depressed in its 142Nd signature, explaining why this signal has not yet been detected in ocean island basalt sources.

Carlson, Richard W., Lars E. Borg, Amy M. Gaffney e Maud Boyet. "Rb-Sr, Sm-Nd and Lu-Hf isotope systematics of the lunar Mg-suite: the age of the lunar crust and its relation to the time of Moon formation". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, n. 2024 (13 settembre 2014): 20130246. http://dx.doi.org/10.1098/rsta.2013.0246.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

New Rb-Sr, 146,147 Sm- 142,143 Nd and Lu-Hf isotopic analyses of Mg-suite lunar crustal rocks 67667, 76335, 77215 and 78238, including an internal isochron for norite 77215, were undertaken to better define the time and duration of lunar crust formation and the history of the source materials of the Mg-suite. Isochron ages determined in this study for 77215 are: Rb-Sr=4450±270 Ma, 147 Sm- 143 Nd=4283±23 Ma and Lu-Hf=4421±68 Ma. The data define an initial 146 Sm/ 144 Sm ratio of 0.00193±0.00092 corresponding to ages between 4348 and 4413 Ma depending on the half-life and initial abundance used for 146 Sm. The initial Nd and Hf isotopic compositions of all samples indicate a source region with slight enrichment in the incompatible elements in accord with previous suggestions that the Mg-suite crustal rocks contain a component of KREEP. The Sm/Nd— 142 Nd/ 144 Nd correlation shown by both ferroan anorthosite and Mg-suite rocks is coincident with the trend defined by mare and KREEP basalts, the slope of which corresponds to ages between 4.35 and 4.45 Ga. These data, along with similar ages for various early Earth differentiation events, are in accord with the model of lunar formation via giant impact into Earth at ca 4.4 Ga.

Sakhno, V. G., e L. S. Tsurikova. "Isotopic and geochemical features of the genesis of igneous complexes and ore-magmatic systems in the Chukotka sector of the Russian Arctic coast". LITHOSPHERE (Russia) 20, n. 2 (25 aprile 2020): 196–211. http://dx.doi.org/10.24930/1681-9004-2020-20-2-196-211.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Research subject. The isotopic composition (Pb-Pb, Sm-Nd, Rb-Sr, Os/Os, Hf/Hf, 3 He/4 He, etc.) of magmatic complexes and ore-magmatic systems (OMS) of two ore clusters (Kupolsky and Ilirneysky) located in the subpolar Western Chukotka was studied. These ore clusters differ from each other both in their structural position and the age of their magmatic complexes, within which the largest deposits of Au-Ag type are known. Materials and methods. The Pb-Pb, Rb-Sr, SmNd, Re-Os, Lu-Hf, 3 He/4 He, 40Ar/36Ar and sulphur isotopic systems were studied at the VSEGEI centre for isotopic studies (St. Petersburg), as well as at the Institute of Geology, Geochemistry and Ore Deposits (IGEM, Moscow) and the Laboratory of Stable Isotopes of the Far Eastern Geological Institute (FEGI, Vladivostok). Re and Os were measured using an ELEMENT-2 inductively coupled plasma single-collector mass spectrometer. Sulphur isotopic ratios were measured using a Finnigan MAT 253 isotope mass spectrometer. Results and conclusions. On the basis of the isotope-geochemical data obtained, an assumption was made that various deep sources participated in the magma generation, and the differentiated composition of late melts may reflect the melting processes of the crust upper horizons. When comparing the data on the magmatism of the Ilirneysky and Kupolsky ore clusters, a different degree of crustal rock influence on melt generation was revealed. The Kupolsky ore cluster is characterised by a large influence of mantle sources in intraplate magmatism associated with ore formation processes. This is likely to have determined a greater amount of mineralisation in the Kupolsky cluster compared to the Ilirneysky ore cluster.

Più fonti

Tesi sul tema "Isotopie Sm-Nd":

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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Le Crétacé est caractérisé par d'importants changements paléogéographiques, géodynamiques et climatiques, incluant notamment la formation de nouveaux océans dont l'Océan Atlantique équatorial, la fragmentation continue du Gondwana et des périodes à effet de serre. Tous ces changements sont potentiellement contenus dans les enregistrements sédimentaires des bassins. Le système Andes-Amazonie-Marge équatoriale est un vaste système sédimentaire dont l'évolution géodynamique et paléoenvironnementale est enregistrée dans les bassins d'avant-pays retroarc amazonien, les bassins intracratoniques brésiliens et ceux de la marge équatoriale. Dans la partie occidentale (région andine), des études récentes suggèrent que le début de l'orogenèse andine s'est produit au cours du Crétacé supérieur, mais le développement des systèmes de drainage et la source des sédiments déposés au cours du Crétacé restent encore peu connus. Le Crétacé inférieur est enregistré dans des bassins brésiliens intracratoniques et équatoriaux et témoigne des phases de rifting crustal suivant la fragmentation du Gondwana. Le bassin d'Araripe est un bon exemple de ces bassins puis qu'il contient un registre sédimentaire complet et particulièrement bien étudié. Cependant, l'origine des sédiments issus des différentes étapes tectoniques de la formation de bassin ainsi que la provenance crétacée des incursions marines l'ayant affecté restent à préciser. Cette thèse vise à proposer une reconstruction paléogéographique du système Andes-Amazonie-Marge équatoriale pendant le Crétacé et à analyser les changements géodynamiques et tectoniques qu'ont affecté. Pour ce faire, nous avons utilisé les méthodes de la provenance et en particulier la géochimie des éléments majeurs et traces, la composition isotopique en Sm et Nd, les âges U-Pb sur zircons. Les résultats obtenus ont permis d'identifier les zones sources du bassin d'Araripe pendent les phases pré, syn et post-rift et ainsi de mieux comprendre la configuration paléogéographique de la région nord-est du Brésil au début du Crétacé. Les sédiments du bassin d'Araripe proviennent principalement des terrains Paléoprotérozoïque (2,3-1,6 Ga) de la province de Borborema et des plutons granitiques du cycle Brasiliano (720-541Ma). Le bassin possède une histoire sédimentaire liée aux phases de rupture de l'Atlantique Sud et équatorial. Pendant la phase pré-rift (~152-135 Ma), le bassin faisait partie de la dépression Afro-Brésilienne et recevait des sédiments en provenance du N-NO. Lors la phase rift (~135-125Ma), il y a eu un changement de source due à rupture continentale et à la formation de l'Atlantique Sud, avec un apport de sédiments en provenance de la partie orientale de la province de Borborema. Pendant la phase post-rift (121-113 Ma), le bassin a cessé d'être alimenté par la partie orientale et les incursions marines ont dominé l'environnement de sédimentation. Enfin, au cours de la phase post-rift II (113-100 Ma) un dernier changement de sources a été observée, avec des sources au NE qui reflètent le moment final de la fragmentation du Gondwana. L'étude de la provenance des sédiments des bassins de l'Amazonie occidentale (Acre et Madre de Dios) indique que les sources sont cratoniques, provenant principalement des terrains Ventuari-Tapajos (2,0 - 1,82 Ga) et Rio Negro - Juruena (1,82 - 1,54 Ga). Ces résultats indiquent qu'un vaste réseau de drainage intracontinental ("Sanozama") qu'a émergé en réponse au soulèvement de l'Arche de Purus et des régions cratoniques du Brésil et des Guyanes pendant l'ouverture de l'océan Atlantique équatorial. L'intégration des résultats obtenue compilée avec les données de la littérature a permis de proposer quatre cartes paléogéographiques de la partie septentrionale de la plate-forme sud-américaine. Ils mettent en évidence comment les mécanismes géodynamiques liées à l'ouverture des océans atlantiques sud et équatoriaux ont contrôlé et façonné la paléogéographie de cette région
The 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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Les buts de cette thèse sont (1) de déterminer si les âges modèles en Nd obtenus sur des terrains protérozoïques migmatisés correspondent réellement à l'âge d'extraction du magma de sa source mantellique (exemple du Limpopo Belt en Afrique du Sud) et (2) de comparer les âges Sm-Nd sur grenat et les âges U-Pb sur zircon déterminés sur des éclogites (exemple du Dabieshan en Chine Centrale). La Zone Centrale du Limpopo Belt est constituée principalement d'orthogneiss et de paragneiss. Elle a subi un métamorphisme granulitique suivi par des conditions métamorphiques de décompression à 2.0 Ga (trajectoire pression et température dans le sens horaire). Nous avons effectué des analyses isotopiques en Sm-Nd et U-Pb combinées aux analyses en éléments majeurs et traces sur trois examples de migmatites formées à 2.0 Ga afin d'étudier le fractionnement chimique et isotopique qui pourrait avoir lieu au cours de la migmatisation. La fusion partielle selon la réaction de déhydratation de la biotite met en exergue des comportements différents du système isotopique Sm-Nd dans les métagreywackes et dans les métapélites. Dans le premier cas, l'équilibre chimique et l'homogénéisation isotopique en Nd n'ont pas été achevés à cause de la fusion incongruente du plagioclase et de l'influence des minéraux accessoires sur la composition chimique des liquides. Il est démontré que la monazite est préférentiellement entraînée dans les leucosomes plutôt que l'apatite, provoquant ainsi la domination de la composition chimique de la monazite sur celles des liquides. De plus, la composition isotopique en Nd non-radiogénique de ce minéral accessoire domine celle du leucosome. Ainsi, les âges modèles en Nd des leucosomes sont jusqu'à 400 Ma plus vieux que ceux obtenus sur les paléosomes. Les âges modèles en Nd obtenus sur ces roches ne peuvent donc pas être uti lisés comme âge de formation de la croûte continentale en Afrique du Sud. Dans le cas des métapelites, la fusion incongruente du plagioclase a influencé la distribution des éléments majeurs, des Larges Ion Lithophi le Element ainsi que des Rare Earth Efement entre les paléosomes et les leucosomes. L'échange isotopique -en Nd entre les différents composants migmatitiques a été pratiquement atteint, au contraire des isotopes du Pb qui ne montrent qu'une homogénéisation partielle. Cependant, deux leucosomes à grenat présentent des compositions isotopiques en Sm-Nd et U-Pb supérieures aux autres composants migmatitiques. Ceci suggère qu'en règle générale les minéraux accessoires ont été chimiquement et isotopiquement équilibrés avec les leucosomes et les paléosomes. De ce fait, les âges modèles en Nd calculés sur les paléosomes et les leucosomes représentent des âges significatifs pour la formation de la croûte continentale dans la Zone Centrale du Limpopo Belt. Le dernier exemple est un orthogneiss migmatitique qui s'est formé par ségrégation métamorphique à des conditions subsolidus. La distribution des éléments majeurs et traces est directement proportionnelle à la quantité de chaque minéraux formant les composants migmatitiques. L'échange __ _ ___ _ isotopique en Pb a été achevé comme le montre l'isochrone en Pb-Pb sur les roches -:_~~ totales à 2.0 Ga. De plus, les caractéristiques géochimiques associées à une modélisation de la distribution des REE indiquent que le système est resté clos à - -----l'échelle de la roche totale durant le processus de migmatisation .. Ainsi, la composition isotopique en Nd du protolithe a pu être déterminée grâce à l'équation de conservation de masse et peut être utilisée pour défini~ l'âge de la formation de la croûte continentale. Le terrain Métamorphique de Ultra-Haute Pression (UHPM) du Dabieshan ______ est caractérisé par la présence de coésite et de quartz pseudomorphe dans les éclogites de composition basaltique mais aussi dans les roches d'origine sédimentaire. Les Isochrones en Sm-Nd sur grenat-omphacite-roche totale des éclogites à coésite du Massif de Bixiling donnent des âges variant entre 210 ± 9 Ma et 218 ± 4 Ma, très similaires aux âges U-Pb sur zircon à 218.4 ± 1.8 Ma et 218.4 ± 2.5 Ma (Ames et al., 1995). De plus, une isochrone Sm-Nd sur grenat-disthène-roche totale d'une éclogite rétromorphosée donne un âge à 231 ± 35 Ma en accord avec un âge à 233 ± 21 Ma (intercepte bas dans le diagramme concordia). Nous avons (:lffectué des datations par les méthodes Rb-Sr et Ar-Ar sur des phengites et des biotites de l'encaissant des éclogites à coésite de Bixiling. Les âges varient entre 198 ± 4 Ma et 212 ± 2 Ma recouvrant les âges précedemment obtenus par Sm-Nd sur les éclogites à coésite. Par conséquent, les âges Sm-Nd sur grenat sont en accord avec les âges U-Pb sur zircon et montrent que les gneiss quartzo-feldspathiques ont subi un événement métamorphique à -210 Ma comme les éclogites. L'homogénéisation isotopique en Nd entre les différents minéraux semblent être atteinte à l'âge du métamorphisme.

Nowicki, G. [Verfasser]. "Kernspektroskopische Untersuchungen der Isotone ¹³⁷Nd und ¹³⁹Sm / G. Nowicki". Karlsruhe : KIT-Bibliothek, 2010. http://d-nb.info/118725276X/34.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Thorogood, 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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Anglin, Carolyn Diane Carleton University Dissertation Geology. "Sm-Nd and Sr isotopic studies of scheelite from some Superior Province gold deposits". Ottawa, 1992.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Goodwin-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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kay, 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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Thesis advisor: Christopher J. Hepburn
The 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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The Saglek-Hebron Gneiss Complex (SHC) is located in Northern Labrador within the Nain Province. It has recorded multiple magmatic events over more than 1 billion years, making it ideal to study the evolution of mantle-derived rocks through time. Here we present a 147Sm-143Nd isotopic study focussing on the different generations of mantle-derived rocks in the SHC. A total of 83 samples have been analysed, including: 1) mafic metavolcanic rocks; 2) ultramafic rocks divided into two distinct groups (a Fe-rich group enriched in incompatible elements and more depleted ultramafic rocks with lower Fe contents); 3) mafic metamorphosed dikes called the Saglek dikes; and 4) undeformed mafic dikes. Some samples exhibit evidence of post-magmatic geochemical and isotopic disturbance but only the least disturbed samples have been considered to constrain the timing of formation of the different lithologies and the isotopic composition of their mantle source. The mafic metavolcanic rocks combined with the co-genetic low-Fe ultramafic rocks yield an isochron age of 3819 ± 190 Ma (MSWD=34, n=25) with an initial εNd value of +2.3 ± 0.6. The high-Fe enriched ultramafic rocks yield a younger age of 3433 ± 220 Ma (MSWD=10.4, n=10) with an initial εNd= +1.8 ± 0.5. The two generations of mafic dikes appear to have been emplaced in the Mesoarchean and the Neoarchean. The Saglek dikes yield an isochron age of 3565 ±120 Ma (MSWD=1.17, n=10) with an initial εNd value of +1.7 ± 0.1, while the Sm-Nd isochron age for the undeformed mafic dikes is 2694 ±79 Ma (MSWD=3.2, n=21) with an initial εNd value of +1.7 ± 0.1. All generations of mantle-derived rocks yield positive initial εNd values, where only the Eoarchean rocks display an initial Nd isotopic composition similar to the depleted mantle. The Mesoarchean ultramafic rocks, Saglek dikes and Neoarchean mafic dikes display almost identical initial εNd values, despite an age difference of ~800 Ma. This could suggest the contribution of distinct mantle sources or, if all generations of mantle-derived rocks in the SHC were produced from the same mantle source, it implies that this source evolved with a nearly chondritic Sm/Nd ratio for almost the whole Archean Eon. The fact that the initial isotopic compositions of the mantle-derived rocks appear to deviate from the depleted mantle with time, could also suggest an increasing interaction with older evolved crust.

Linkermann, 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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Europe’s largest chrome deposit is hosted by the 2.44 Ga Kemi ultramafic layered intrusion. The lower half of the intrusion consists of peridotites, pyroxenites and chromitite layers while the upper half consists of websterites, gabbronorites and leucogabbros. The mafic minerals of the lower and upper parts of the intrusion are altered to serpentine, chlorite, talc, amphiboles and carbonates. However, the original mineralogy is still preserved in the middle part of the intrusion. Earlier work on the Kemi intrusion concentrated mainly on the economically important chromitite layers and suggested that these layers were formed through contamination of a single pulse of primitive magma by underlying Archaean basement crustal material. The broad variations of the major element concentrations reflect variations in the mode of the Kemi rocks. The petrology, which shows olivine- and orthopyroxene-dominated rocks in the lower portion of the intrusion to plagioclase- and clinopyroxene-dominated rocks in the upper portion, shows a gross consistency with a fractional crystallization process.The incompatible elements are relatively enriched in the lower portion of the intrusion which is not consistent with a broad fractional crystallization process. These variations suggest that the ultramafic portion of the KemiIntrusion is relatively enriched in trapped liquid compared to the mafic portion.ε2.44 Nd values ranges from +4 (consistent with depleted mantle source) to -10 (indicating a contribution from Archaean crust). The lower peridotites, pyroxenites and websterites have ε2.44 Nd values ranging between depleted mantle signatures and -2, whereas the gabbroic cumulates have ε2.44 Nd values which cover a range from around -5 to -10. Nd isotopic variation in the lower part of the profile is punctuated by distinct spikes to lower ε2.44 Nd corresponding to the chromitite horizons. Both the lower and upper portions of the Kemi Intrusion show enrichment of LREEC1 relative to HREEC1. The LREEC1 enriched values start to increase markedly from about the 1000 meter mark and continue to increase in value towards the roof of the intrusion.The main enrichment of PGE (ΣPPGE = 55 to 148 ppb) occurs approximately 90 to 160 m above the basal contact, beginning within andcontinuing above the main chromitite ore horizon. The mantle-normalized PGE abundances of the main chromitite horizon and the peridotites and pyroxenites below it show enrichment of IPGEPM (Os + Ir + Ru) relative to PPGEPM (Rh + Pd + Pt). In contrast, the overlying rocks are characterised by enrichment of PPGEPM relative to IPGEPM. These PGE-patterns suggest the influence of two distinct controlling processes above and below the main chromitite reef.The isotopic data are consistent with the initial introduction of multiple pulses of depleted mantle-derived magma crystallising olivine and pyroxene. Before the parent magma was fed into the Kemi magma chamber, it underwent crustal contamination and assimilation in a staging chamber within the lower crust. Some of these pulses were “critically crustally contaminated”, inducing chromite saturation and precipitation. The modelling also predicts minor in-situ contamination of the parent magma in the Kemi chamber with its wall and roof rocks. Above the main chromitite layer (about 160 m above the basal contact), the chromite content decreases and the PPGEPM/IPGEPM values increase which is consistent with scavenging of the IPGE into the lowermost layers and/or evolving magma compositions. Above 1000 m, the isotopic and REE data indicate a new magma pulse which has also been extensively contaminated in the staging magma chamber before emplacement into the Kemi magma chamber. The contamination in the staging magma chamber increased which is reflected in a progressively larger crustal component towards the top of the Kemi Intrusion

Schmitt, 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.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Libri sul tema "Isotopie Sm-Nd":

Survey, Ontario Geological. Geochronology Compilation Map For Ontario : Sheet 2: Southern Ontario: Grenville : Province and Environs : rb-sr, nd-sm, U-pb, and Other Isotopic Systems. S.l: s.n, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Capitoli di libri sul tema "Isotopie Sm-Nd":

Champion, David C., e David L. Huston. "Applications of Neodymium Isotopes to Ore Deposits and Metallogenic Terranes; Using Regional Isotopic Maps and the Mineral Systems Concept". In Isotopes in Economic Geology, Metallogenesis and Exploration, 123–54. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27897-6_5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

AbstractAlthough radiogenic isotopes historically have been used in ore genesis studies for age dating and as tracers, here we document the use of regional- and continental-scale Sm–Nd isotope data and derived isotopic maps to assist with metallogenic interpretation, including the identification of metallogenic terranes. For the Sm–Nd system, calculated Nd model ages, which are time independent, are of most value for small-scale isotopic maps. Typically, one- or two-stage depleted mantle model ages (TDM, T2DM) are used to infer age when the isotope characteristics of the rock were in isotopic equilibrium with a modelled (mantle) reservoir. An additional advantage is that Nd model ages provide, with a number of assumptions, an estimate of the approximate age of continental crust in a region. Regional- and continental-scale Nd model age maps, constructed from rocks such as granites, which effectively sample the middle to lower crust, therefore, provide a proxy to constrain the nature of the crust within a region. They are of increasing use in metallogenic analysis, especially when combined with a mineral systems approach, which recognizes that mineral deposits are the result of geological processes, at a scales from the ore shoot to the craton. These maps can be used empirically and/or predictively to identify and target large parts of mineral systems that may be indicative, or form part of, metallogenic terranes. Examples presented here include observed spatial relationships between mineral provinces and isotopic domains; the identification of old and/or thick cratonic blocks; determination of tectonic regimes favorable for mineralization; identification of isotopically juvenile zones that may indicate rifts or primitive arcs; recognition of crustal breaks that define metallogenic terrane boundaries or delineate fluid pathways; and, as baseline maps. Of course, any analysis of Sm–Nd and similar isotopic maps are predicated on integration with geological, geochemical and geophysical information data. In the future, research in this area should focus on the spatial and temporal evolution of the whole lithosphere at the province- to global-scales to more effectively targeting mineral exploration. This must involve integration of radiogenic isotopic data with other data, in particular, geophysical data, which has the advantage of being able to directly image the crust and lithosphere and being of a more continuous nature as compared to invariably incomplete isotopic data sets.

Waltenberg, Kathryn. "Application of the Lu–Hf Isotopic System to Ore Geology, Metallogenesis and Mineral Exploration". In Isotopes in Economic Geology, Metallogenesis and Exploration, 189–208. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-27897-6_7.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

AbstractThe Lu-Hf isotopic system, much like the Sm-Nd isotopic system, can be used to understand crustal evolution and growth. Crustal differentiation processes yield reservoirs with differing initial Lu/Hf values, and radioactive decay of 176Lu results in diverging 176Hf/177Hf between reservoirs over time. This chapter outlines the fundamentals of the Lu-Hf isotopic system, and provides several case studies outlining the utility of this system to mineral exploration and understanding formation processes of ore deposits. The current, rapid, evolution of this field of isotope science means that breadth of applications of the Lu-Hf system are increasing, especially in situations where high-precision, detailed analyses are required.

Ashwal, Lewis D., e Joseph L. Wooden. "Sm-Nd Isotopic Studies of Proterozoic Anorthosites: Systematics and Implications". In The Deep Proterozoic Crust in the North Atlantic Provinces, 61–73. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5450-2_5.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kinny, Peter D., e Roland Maas. "12. Lu-Hf and Sm-Nd isotope systems in zircon". In Zircon, a cura di John M. Hanchar e Paul W. O. Hoskin, 327–42. Berlin, Boston: De Gruyter, 2003. http://dx.doi.org/10.1515/9781501509322-015.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

McCulloch, M. T. "Sm-Nd isotopic constraints on the evolution of Precambrian crust in the Australian continent". In Proterozic Lithospheric Evolution, 115–30. Washington, D. C.: American Geophysical Union, 1987. http://dx.doi.org/10.1029/gd017p0115.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Fan, Y., T. F. Zhou, F. Yuan, M. A. Wu, M. J. Hou, G. Voicu, Q. H. Hu e Q. M. Zhang. "Sm-Nd isotope dating of fluorites from the Xiangquan thallium deposit, Anhui Province, East China". In Mineral Deposit Research: Meeting the Global Challenge, 381–83. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/3-540-27946-6_100.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Soroka, Elena I., Oksana B. Azovskova, Mikhail Yu Rovnushkin, Mikhail E. Pritchin, Irina V. Smoleva, Natalia G. Soloshenko, Maria V. Streletskaya e Maria V. Zaitceva. "Isotopic (δ13C, δ18O, Rb-Sr and Sm-Nd) Studies of Carbonates from the Vorontsovskoe Gold Deposit (Northern Urals)". In Springer Proceedings in Earth and Environmental Sciences, 245–52. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-00925-0_36.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Krymsky, R. S., B. V. Belyatsky, A. K. Rub e M. G. Rub. "The genesis of the rare-metal greisen Tigrinoe ore-deposit (Sikhote-Alin, Russia): Sm-Nd and Rb-Sr isotope constraints". In Mineral Deposits at the Beginning of the 21st Century, 433–36. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003077503-110.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ben-Tami, Abdelhay, Said Belkacim, Bouchra Baidada, Jamal El Kabouri, Mohamed Assalmi, Mohamed Bhilisse e Mohammed Bouabdellah. "Lithostratigraphy, Whole-Rock, and Sm–Nd Isotopic Data of the Ediacaran Magmatic Rocks from the Zgounder Ag–Hg Deposit (Siroua Massif, Central Anti-Atlas, Morocco)". In Advances in Science, Technology & Innovation, 167–71. Cham: Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-48758-3_38.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

"The Sm–Nd method". In Radiogenic Isotope Geology, 70–100. Cambridge University Press, 2005. http://dx.doi.org/10.1017/cbo9781139165150.005.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Atti di convegni sul tema "Isotopie Sm-Nd":

Frossard, Paul, Maud Boyet, Audrey Bouvier, Pierre Bonnand e Delphine Auclair. "Deciphering Nd and Sm Isotope Composition in Chondrites". In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.755.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Ray, Esha, Debajyoti Paul, Rajneesh Bhutani, Ramananda Chakrabarti e Shouye Yang. "Sm-Nd isotope systematics of Indian shales constrain the growth of Indian continental crust". In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.14275.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Yermakov, Y., M. Spasennykh, E. Leushina, E. Kozlova, N. Bogdanovich, A. Voropaev e Y. Kostitsyn. "Application of Sm-Nd Isotope Geochemistry for Unconventional Reservoir Characterization (On The Example of Bazhenov Formation)". In EAGE/SPE Workshop on Shale Science 2021. European Association of Geoscientists & Engineers, 2021. http://dx.doi.org/10.3997/2214-4609.202151022.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Apen, Francisco, Corey J. Wall, John Cottle, Mark D. Schmitz, Andrew R. C. Kylander-Clark e Gareth G. E. Seward. "APATITES FOR DESTRUCTION: NEW REFERENCE APATITES FOR U-PB PETROCHRONOLOGY AND SM-ND AND SR ISOTOPE GEOCHEMISTRY". In GSA Connects 2021 in Portland, Oregon. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021am-365621.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Kuper, Kathy, Christopher Kirkland, Hugo Olierook, Massimo Chiaradia e Katy Evans. "Apatite Sm-Nd and U-Pb isotopes unravel crust-mantle interactions in the Fraser Zone, Western Australia". In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.19088.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Alam, Meraj ALam, Md Naushad Naushad e Talat Ahmad Ahmad. "Geochemical and Sm-Nd Isotopic Constraints on the Petrogenesis and Tectonic Significance of Magmatism in Mahakoshal Belt, Central India". In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.32.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Marshall, Edward W., John C. Lassiter e Jaime D. Barnes. "NEW RE-OS AND SM-ND ISOTOPIC CONSTRAINTS ON THE TECTONIC SETTING OF THE 1.4 GA LAURENTIAN MAGMATIC EVENT". In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-298860.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Hammerli, Johannes, e Tony I. S. Kemp. "DECOUPLING OF LU-HF AND SM-ND ISOTOPE SYSTEMS DURING CRUSTAL MELTING: AN EXAMPLE FROM THE HIDAKA METAMORPHIC BELT, JAPAN". In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-282915.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Jabbour, Marieme, Moha Ikenne, Brian Cousens, Richard Ernst, Mustapha Souhassou, Abdelilah Benhammou e Amine Bajaddi. "A revised geodynamic significance of the Tachdamt Bleida series (Bou Azzer El Graara, central Anti-Atlas, Morocco): geochemistry and Sm-Nd isotopes". In Goldschmidt2022. France: European Association of Geochemistry, 2022. http://dx.doi.org/10.46427/gold2022.12204.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

D, Kamalakannan, e Balakrishnan S. "Mesoarchean Mafic Magmatism from Two Distinct Mantle Sources: Evidence from Sm-Nd Isotopic Studies on Metabasalts of the Gadag Greenstone Belt, Dharwar Craton, India". In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.505.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Rapporti di organizzazioni sul tema "Isotopie Sm-Nd":

Piercey, S. J., e J. L. Pilote. Nd-Hf isotope geochemistry and lithogeochemistry of the Rambler Rhyolite, Ming VMS deposit, Baie Verte Peninsula, Newfoundland: evidence for slab melting and implications for VMS localization. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328988.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

New high precision lithogeochemistry and Nd and Hf isotopic data were collected on felsic rocks of the Rambler Rhyolite formation from the Ming volcanogenic massive sulphide (VMS) deposit, Baie Verte Peninsula, Newfoundland. The Rambler Rhyolite formation consists of intermediate to felsic volcanic and volcaniclastic rocks with U-shaped primitive mantle normalized trace element patterns with negative Nb anomalies, light rare earth element-enrichment (high La/Sm), and distinctively positive Zr and Hf anomalies relative to surrounding middle rare earth elements (high Zr-Hf/Sm). The Rambler Rhyolite samples have epsilon-Ndt = -2.5 to -1.1 and epsilon-Hft = +3.6 to +6.6; depleted mantle model ages are TDM(Nd) = 1.3-1.5 Ga and TDM(Hf) = 0.9-1.1Ga. The decoupling of the Nd and Hf isotopic data is reflected in epsilon-Hft isotopic data that lies above the mantle array in epsilon-Ndt -epsilon-Hft space with positive ?epsilon-Hft values (+2.3 to +6.2). These Hf-Nd isotopic attributes, and high Zr-Hf/Sm and U-shaped trace element patterns, are consistent with these rocks having formed as slab melts, consistent with previous studies. The association of these slab melt rocks with Au-bearing VMS mineralization, and their FI-FII trace element signatures that are similar to rhyolites in Au-rich VMS deposits in other belts (e.g., Abitibi), suggests that assuming that FI-FII felsic rocks are less prospective is invalid and highlights the importance of having an integrated, full understanding of the tectono-magmatic history of a given belt before assigning whether or not it is prospective for VMS mineralization.

Berman, R. G., B. E. Taylor, W. J. Davis, M. Sanborn-Barrie e J B Whalen. Crustal architecture and evolution of the central Thelon tectonic zone, Nunavut: insights from Sm-Nd and O isotope analysis, U-Pb zircon geochronology, and targeted bedrock mapping. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/332497.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

New isotopic analyses (Sm-Nd, O, and U-Pb), targeted geological mapping, and previously published whole-rock geochemical data and high-resolution aeromagnetic surveys define ten crustal domains across the central Thelon tectonic zone. In the eastern Slave Craton, granitoid rocks in the Overby Lake domain are more isotopically evolved than in the Tinney Hills domain and include tonalite dated at 2.71 Ga. The 400 km long main leucogranite belt separates most early (ca. 2.07-1.95 Ga) Thelon tectonic zone plutonic belts from the Queen Maud Block. Oxygen isotopes support its formation via melting of a sedimentary source during peak metamorphism, which coincides with three, new 1.925-1.91 Ga leucogranite ages. Modelling of Nd-Sm isotopes indicates Neoarchean crust as basement to early Thelon tectonic zone plutonic belts. Detrital zircon geochronology suggests a 2.5 Ga basement component that is not recognized in exposed crustal domains, but is compatible with the Dharwar Craton, which can be paleomagnetically reconstructed adjacent to the Slave Craton at 2.2 Ga. Two tectonic models are discussed for the evolution of the Thelon tectonic zone in the convergent margin tectonic setting indicated by the whole-rock geochemistry and mantle-like oxygen isotopic compositions of plutonic rocks. In one model, ca. 2.1 Ga extension precedes east-dipping subduction, which leads to 1.97 Ga collision of the Slave Craton with a composite Thelon tectonic zone basement-Rae Craton, upper plate. The second model proposes a ca. 2.05 Ga Slave-microcontinent (Thelon tectonic zone basement) collision, followed by a polarity flip with west-dipping subduction, leading to ca. 1.95 Ga collision of the Rae Craton.

Roddick, J. C., R. W. Sullivan e F. O. Dudas. Precise Calibration of Tracer Compositions For Sm - Nd Isotopic Studies. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1992. http://dx.doi.org/10.4095/132926.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Peterson, T. D., S. Pehrsson, T. Skulski e H. Sandeman. Compilation of Sm-Nd isotope analyses of igneous suites, western Churchill Province. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2010. http://dx.doi.org/10.4095/285360.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Anglin, C. D. Preliminary Sm - Nd Isotopic Analyses of Scheelites From Val D'or Gold Deposits, Quebec. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1990. http://dx.doi.org/10.4095/131262.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Mitchell, R. K., O. van Breemen, W. J. Davis e R. Buenviaje. Sm-Nd isotopic data from the Canadian Shield north of 60 degrees latitude, northern Canada. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2010. http://dx.doi.org/10.4095/287188.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Theriault, R. J. Methods for Rb-Sr and Sm-Nd isotopic analyses at the geochronology laboratory, Geological Survey of Canada. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1990. http://dx.doi.org/10.4095/129062.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Thériault, R. J., e S. Tella. Sm-Nd isotopic study on mafic volcanic rocks from the Rankin Inlet and Tavani regions, District of Keewatin, Northwest Territories. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1997. http://dx.doi.org/10.4095/209092.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

van Breemen, O., S. Pehrsson e T. D. Peterson. Reconnaissance U-Pb SHRIMP geochronology and Sm-Nd isotope analyses from the Tehery-Wager Bay gneiss domain, western Churchill Province, Nunavut. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2007. http://dx.doi.org/10.4095/224019.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

van Breemen, O., J. R. Henderson, C. W. Jefferson, R. M. Johnstone e R. Stern. U-Pb age and Sm-Nd isotopic studies in Archean Hood River and Torp Lake supracrustal belts, northern Slave Province, Northwest Territories. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1994. http://dx.doi.org/10.4095/195167.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri