Academic literature on the topic 'REE geochemistry'

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Journal articles on the topic "REE geochemistry"

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Cruz, Armanda, Pedro A. Dinis, Alberto Gomes, and Paula Leite. "Influence of Sediment Cycling on the Rare-Earth Element Geochemistry of Fluvial Deposits (Caculuvar–Mucope, Cunene River Basin, Angola)." Geosciences 11, no. 9 (September 11, 2021): 384. http://dx.doi.org/10.3390/geosciences11090384.

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The rare-earth element (REE) geochemistry of sedimentary deposits has been used in provenance investigations despite the transformation that this group of elements may suffer during a depositional cycle. In the present investigation, we used the geochemistry and XRD mineralogy of a set of sand and mud fluvial deposits to evaluate the ability of REE parameters in provenance tracing, and the changes in REE geochemistry associated with weathering and sorting. The analyzed deposits were generated in a subtropical drainage basin where mafic and felsic units are evenly represented, and these crystalline rocks are covered by sedimentary successions in a wide portion of the basin. A few element ratios appear to hold robust information about primary sources (Eu/Y, Eu/Eu*, LaN/YbN, LaN/SmN, and GdN/YbN), and the provenance signal is best preserved in sand than in mud deposits. Sediment cycles, however, change the REE geochemistry, affecting mud and sand deposits differently. They are responsible for significant REE depletion through quartz dilution in sands and may promote discernible changes in REE patterns in muds (e.g., increase in Ce content and some light REE depletion relative to heavy REE).
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Gammons, Christopher H., and Scott A. Wood. "The aqueous geochemistry of REE." Chemical Geology 166, no. 1-2 (May 2000): 103–24. http://dx.doi.org/10.1016/s0009-2541(99)00186-2.

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Kalender, Leyla, and Gamze Aytimur. "REE Geochemistry of Euphrates River, Turkey." Journal of Chemistry 2016 (2016): 1–13. http://dx.doi.org/10.1155/2016/1012021.

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The study area is located on the Euphrates River at 38°41°32.48′′N–38°14′24.10′′N latitude and 39°56′4.59′′E–39°8°13.41′′E longitude. The Euphrates is the longest river in Western Asia. The lithological units observed from the bottom to the top are Permo-Triassic Keban Metamorphites, Late Cretaceous Kömürhan Ophiolites, Upper Cretaceous Elazığ Magmatic Complex, Middle Eocene Maden Complex and Kırkgeçit Formation, Upper Pliocene and Lower Eocene Seske Formation and Upper Miocene, Pliocene Karabakır and Çaybağı Formations, Palu Formation, and Holocene Euphrates River sediments. The geochemical studies show that87Sr/86Sr and143Nd/144Nd isotopic compositions in the Euphrates River bank sediments are 0.7053, 0.7048, and 0.7057 and 0.512654, 0.512836, and 0.512775, respectively. These values indicate mixing of both carbonate-rich shallow marine sediment and felsic-mafic rocks from Elazığ Magmatic Complex into the stream sediments. The positiveεNd (0)values (0.35, 3.9, and 2.7) are higher downstream in the studied sediments due to weathering of the mafic volcanic rocks. The chondrite, NAS, and UCC normalized patterns show that the REE compositions of the Euphrates River sediments are higher than chondrite composition but close to NAS and UCC. The river sediments in the tectonic zone and the weathered granodioritic rocks of the Elazığ Magmatic complex affect upstream water compositions.
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Bonev, Nikolay, Petyo Filipov, and Tanya Stoylkova. "Chemical composition of late Eocene–early Oligocene corals in reef buildups from the Thrace basin, Bulgaria–Greece: Paleoenvironmental implications." Geologica Balcanica 51, no. 1 (April 2022): 23–33. http://dx.doi.org/10.52321/geolbalc.51.1.23.

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Coral whole-rock geochemistry and in situ LA-ICP-MS analyses of coral skeletons were performed on late Eocene–early Oligocene coral reef buildups from the Eastern Rhodope–Thrace region of Bulgaria and Greece. Coral reefs are locally associated with voluminous Oligocene volcanism in the region. The reefs are subdivided into (i) eruption-associated reefs (Krumovgrad); (ii) pre-eruption reefs (Ivaylovgrad); and (iii) Metaxades-Didymotycho reefs from field relations, trace element and rare-earth element (REE) abundances. Coral assemblages are dominated by Cladocora sp., which is accompanied by Porites sp., Colpophyllia sp., Favites sp. and Leptoseris sp. Eruption-associated reefs are characterized by their higher REE content than the lower in all REE contents of pre-eruption reefs showing negative Ce anomaly, and Metaxades-Didymotycho reefs that have lower middle-heavy REE contents compared to previous groups. Trace element and REE geochemistry of the coral skeletons indicates volcanic contribution to seawater, mostly evident in the eruption associated reefs, and contribution from terrestrial input in the site of coral buildup deposition. Contribution from a different source of prior diagenetic nature, along with subsequent diagenetic modification, is inferred. The increase in REE+Y (ΣREY) from pre-eruption to eruption-associated reefs is well correlated with elevated amounts of terrigenous elements like Al and Fe.
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Wu, Chengyu, and Shunso Ishihara. "REE geochemistry of the Southern Thailand granites." Journal of Southeast Asian Earth Sciences 10, no. 1-2 (July 1994): 81–94. http://dx.doi.org/10.1016/0743-9547(94)90010-8.

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Suhua, Yu, and Wen Qizhong. "REE geochemistry of loess in Xinjiang, China." Chinese Journal of Geochemistry 11, no. 3 (July 1992): 277–87. http://dx.doi.org/10.1007/bf02842272.

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Salih, Makki Omer, Bo Wan, and David R. Lentz. "Geochemistry and petrogenesis of anorogenic REE-bearing peralkaline granitoids from Northern Sudan." Neues Jahrbuch für Mineralogie - Abhandlungen 197, no. 2 (October 22, 2021): 185–208. http://dx.doi.org/10.1127/njma/2021/0274.

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Green, T. H., and N. J. Pearson. "High-pressure, synthetic loveringite-davidite and its rare earth element geochemistry." Mineralogical Magazine 51, no. 359 (March 1987): 145–49. http://dx.doi.org/10.1180/minmag.1987.051.359.16.

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AbstractLoveringite-davidite members of the crichtonite group were synthesized at high pressure and temperature (7.5 kbar, 1000–1050 °C) from a melt of TiO2 and rare earth element (REE) enriched basaltic andesite composition. Four sets of partition coefficients for La, Srn, Ho, Lu and Sr (analogue for Eu2+) were obtained. These show that light and heavy REE are readily accommodated, but the intermediate REE are discriminated against in the loveringite—davidite structure. This confirms the previously proposed two sites (A and M) for REE substitution in the crichtonite group. Additional experiments verified the stability of REE-rich crichtonite group minerals to 20 kbar, 1300 °C and 30 kbar, 1000 °C, and indicate that this phase may be an important accessory repository for the light and heavy REE in the upper mantle.
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Bowerman, Melissa, Amy Christianson, Robert A. Creaser, and Robert W. Luth. "A petrological and geochemical study of the volcanic rocks of the Crowsnest Formation, southwestern Alberta, and of the Howell Creek suite, British Columbia." Canadian Journal of Earth Sciences 43, no. 11 (November 1, 2006): 1621–37. http://dx.doi.org/10.1139/e06-037.

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Alkaline igneous rocks of the Crowsnest Formation in southwestern Alberta and in the Howell Creek area in southeastern British Columbia have been suggested previously to be cogenetic. To test this hypothesis, samples of both suites were characterized petrographically and their major and trace element geochemistry was determined. A subset of the samples was analyzed for whole-rock Sr and Nd isotope geochemistry. The samples of the two suites are latites, trachytes, and phonolites based on the International Union of Geological Sciences (IUGS) total alkalis versus silica (TAS) diagram. Samples from both suites show similar patterns on mantle-normalized trace element diagrams, being enriched relative to mantle values but depleted in the high field-strength elements Nb, Ta, and Ti relative to the large-ion lithophile elements. The chondrite-normalized rare-earth element (REE) patterns for both suites are light REE enriched, with no Eu anomaly and flat heavy REE. The isotope geochemistry of both suites is characterized by low initial 87Sr/86Sr (SrT = 0.704 to 0.706) and low εNdT (–7 to –16). The Howell Creek samples have lower εNdT and higher SrT than do the Crowsnest samples. Based on the intra- and intersuite differences in the isotope geochemistry, we conclude that these samples are not cogenetic, but rather represent samples that have experienced similar evolutionary histories from a heterogeneous source region in the subcontinental lithospheric mantle.
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Chen, Wei, Huang Honghui, Tian Bai, and Shaoyong Jiang. "Geochemistry of Monazite within Carbonatite Related REE Deposits." Resources 6, no. 4 (September 27, 2017): 51. http://dx.doi.org/10.3390/resources6040051.

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Dissertations / Theses on the topic "REE geochemistry"

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Zhong, Shaojun. "Precipitation kinetics and partitioning of rare earth elements (REE) between calcite and seawater." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41198.

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A novel and simple "constant-addition" technique was used to study calcite precipitation kinetics and the partitioning of REE between calcite overgrowths and their parent seawater solutions under steady state conditions.
As a consequence of solute interactions in solution and at the growing mineral surface, the calcite precipitation mechanism in seawater is complex. It is dominated by the following reversible overall reaction: $ rm Ca sp{2+}+CO sbsp{3}{2-} rightleftharpoons CaCO sb3.$ A kinetic expression is proposed which describes the precipitation rate according to this reaction. A partial reaction order of 3 with respect to CO$ sb3 sp{2-}$ is obtained.
REE have a strong affinity for calcite and substitute for Ca$ sp{2+}$. REE partition coefficients in calcite overgrowths were calculated from their concentrations in the overgrowths and their parent solutions using a non-thermodynamic homogeneous model. The concentrations were determined by chelation and gradient ion chromatography (CGIC) using a revised procedure. REE partition coefficients decrease gradually with increasing REE atomic number. They are sensitive to changes in (REE): (Ca$ sp{2+}$) and the presence of O$ sb2$ in solution, but unaffected by the precipitation rate, $ rm lbrack CO sb3 sp{2-} rbrack$ or Pco$ sb2$ of the solution. The partitioning behaviour of REE is negatively correlated to the solubility of their respective carbonates and influenced by speciation, adsorption, and subsequent surface reactions (e.g., dehydration).
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Ramirez-Caro, Daniel. "Rare earth elements (REE) as geochemical clues to reconstruct hydrocarbon generation history." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/16871.

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Master of Science
Department of Geology
Matthew Totten
The REE distribution patterns and total concentrations of the organic matter of the Woodford shale reveal a potential avenue to investigate hydrocarbon maturation processes in a source rock. Ten samples of the organic matter fraction and 10 samples of the silicate-carbonate fraction of the Woodford shale from north central Oklahoma were analyzed by methods developed at KSU. Thirteen oil samples from Woodford Devonian oil and Mississippian oil samples were analyzed for REE also. REE concentration levels in an average shale range from 170 ppm to 185 ppm, and concentration levels in modern day plants occur in the ppb levels. The REE concentrations in the organic matter of the Woodford Shale samples analyzed ranged from 300 to 800 ppm. The high concentrations of the REEs in the Woodford Shale, as compared to the modern-day plants, are reflections of the transformations of buried Woodford Shale organic materials in post-depositional environmental conditions with potential contributions of exchanges of REE coming from associated sediments. The distribution patterns of REEs in the organic materials normalized to PAAS (post-Archean Australian Shale) had the following significant features: (1) all but two out of the ten samples had a La-Lu trend with HREE enrichment in general, (2) all but two samples showed Ho and Tm positive enrichments, (3) only one sample had positive Eu anomalies, (4) three samples had Ce negative anomalies, although one was with a positive Ce anomaly, (5) all but three out of ten had MREE enrichment by varied degrees. It is hypothesized that Ho and Tm positive anomalies in the organic materials of the Woodford Shale are reflections of enzymic influence related to the plant physiology. Similar arguments may be made for the Eu and the Ce anomalies in the Woodford Shale organic materials. The varied MREE enrichments are likely to have been related to some phosphate mineralization events, as the Woodford Shale is well known for having abundant presence of phosphate nodules. The trend of HREE enrichment in general for the Woodford Shale organic materials can be related to inheritance from sources with REE-complexes stabilized by interaction between the metals and carbonate ligands or carboxylate ligands or both. Therefore, a reasonable suggestion about the history of the REEs in the organic materials would be that both source and burial transformation effects of the deposited organic materials in association with the inorganic constituents had an influence on the general trend and the specific trends in the distribution patterns of the REEs. This study provides a valuable insight into the understandings of the REE landscapes in the organic fraction of the Woodford Shale in northern Oklahoma, linking these understandings to the REE analysis of an oil generated from the same source bed and comparing it to oil produced from younger Mississippian oil. The information gathered from this study may ultimately prove useful to trace the chemical history of oils generated from the Woodford Shale source beds.
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Sahlström, Fredrik. "Ore Petrography and Geochemistry of some REE-bearing Fe-oxide Assemblages from the Idkerberget Deposit, Bergslagen, Sweden." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-182875.

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The mine dumps of Kiruna-type apatite-iron oxide ore in Bergslagen, South Central Sweden, contain elevated amounts of rare earth elements (REEs). A recently started project at Uppsala University has been initiated to study these ores among others in order to document occurrences of REEs and other critical elements in the mine dumps. In this study a selection of samples from the Idkerberget deposit have been studied with respect to their geochemistry and petrography with a special focus on REE-bearing phases. In addition, their mining potential and their relationship to related ore deposits such as Blötberget, Grängesberg and Kiirunavaara have been considered. The bulk geochemistry of the ores was analyzed using ICP-ES and ICP-MS. Polished sections of the ore samples were studied using ore microscopy, SEM-EDS and WDS microprobe technique. The results indicate that the ores consist mainly of magnetite and hematite, with minor silicates, flourapatite, pyrite, chalcopyrite, monazite-(Ce), allanite-(Ce), thorium silicate, titanite and zircon. Most REEs were originally hosted in flourapatite, but metamorphic and/or hydrothermal overprinting has resulted in complex textures and neomineralisation involving exotic REE-bearing minerals such as monazite-(Ce), allanite-(Ce) and secondary flourapatite. These features have also been observed in the related ore deposits nearby. The ores are enriched in REEs by factors between 1 and 9 compared to crustal values, with LREEs being the most enriched. These enrichments are rather low compared to other REE-ores currently being mined, but the easy access to the ores could mean that mining can be profitable with the current demand of these commodities.
Varphögar av apatitjärnmalm av Kirunatyp ifrån järnmalmsbrytning i Bergslagen, Sydcentrala Sverige, innehåller förhöjda halter av sällsynta jordartsmetaller. Ett projekt vid Uppsala Universitet undersöker förekomster av sällsynta jordartsmetaller och andra kritiska element i varphögar bland annat från apatitjärnmalmer. I denna studie har prover från ett av Bergslagens apatitjärnmalmsfält, Idkerberget, undersökts geokemiskt och petrografiskt med fokus på faser som innehåller sällsynta jordartsmetaller. Deras utvinningspotential och deras relation till liknande förekomster såsom Blötberget, Grängesberg samt Kiirunavaara har också tagits i beaktning. Bulkgeokemin i proverna analyserades med ICP-EM och ICP-MS. Polerprov av malmerna undersöktes medelst optisk mikroskopi, SEM-EDS samt med WDS-mikrosondteknik. Resultaten visar att malmerna framförallt består av magnetit och hematit, med mindre mängder silikater, flourapatit, pyrit, kopparkis, monazit-(Ce), allanit-(Ce), thoriumsilikat, titanit och zirkon. Sällsynta jordartsmetaller är i huvudsak bundna i flourapatit, men metamorfa och/eller hydrotermala processer har resulterat i nybildningen av exotiska mineral såsom monazit-(Ce), allanit-(Ce), och sekundär flourapatit. Dessa egenskaper har även observerats i apatitjärnmalmer från andra platser. Proverna från Idkerberget har 1-9 gånger högre koncentration av sällsynta jordartsmetaller än jordskorpan generellt, och lätta sällsynta jordartsmetaller är de mest anrikade. Dessa halter är relativt låga jämfört med sällsynta jordartsmalmer som bryts i dagsläget, men eftersom materialet förekommer i enorma varphögar gör tillgängligheten att metallerna ändå kan utvinnas med vinst om efterfrågan på denna resurs består.
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Aiglsperger, Thomas Hans. "Mineralogy and geochemistry of the platinum group elements (PGE), rare earth elements (REE) and scandium in nickel laterites." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/396340.

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Ni laterites are considered worthy targets for critical metals (CM) exploration as rare earth elements (REE), Sc and platinum group elements (PGE) can be concentrated during weathering as a result of residual and secondary enrichment. In this investigation geochemical and mineralogical data of CM from two different nickel laterite types (i) from the Moa Bay mining area in Cuba (oxide type) and (ii) from the Falcondo mining area in the Dominican Republic (hydrous Mg silicate type) are presented. Emphasis is given on examining their potential to accumulate CM and on processes involved. Results show that CM are concentrated towards the surface in specific zones: (i) REE in clay minerals rich horizons and within zones composed of secondary Mn oxide(s) (ii) Sc within zones rich in secondary Fe and Mn bearing oxide(s) and (iii) PGE in zones with high concentrations of residual chromian spinel and secondary Fe and Mn bearing oxide(s) at upper levels of the Ni laterite profiles. Concentration factors involve (i) residual enrichment by intense weathering (ii) mobilization of CM during changing Eh and pH conditions with subsequent reprecipitation at favourable geochemical barriers (iii) interactions between biosphere and limonitic soils at highest levels of the profile (critical zone) with involved neoformation processes. Total contents of CM in both Ni laterite types are low when compared with conventional CM ore deposits but are of economic significance as CM have to be seen as cost inexpensive by-products during the Ni (+Co) production. Innovative extraction methods currently under development are believed to boost the significance of Ni laterites as future unconventional CM ore deposits. Two Ni laterite profiles from the Falcondo mining area have been compared for their platinum group element (PGE) geochemistry and mineralogy. One profile (Loma Peguera) is characterized by PGE-enriched (up to 3.5 ppm total PGE) chromitite bodies incorporated within the saprolite, whereas the second profile is chromitite-free (Loma Caribe). Total PGE contents of both profiles slightly increase from parent rocks (36 and 30 ppb, respectively) to saprolite (-50 ppb) and reach highest levels within the limonite zone (640 and 264 ppb, respectively). Chondrite-normalized PGE patterns of saprolite and limonite reveal rather flat shapes with positive peaks of Ru and Pd. Three types of platinum group minerals (PGM) were found by using an innovative hydroseparation technique: (i) primary PGM inclusions in fresh Cr-spinel (laurite and bowieite), (ii) secondary PGM (e.g., Ru-Fe-Os-Ir compounds) from weathering of preexisting PGM (e.g., serpentinization and/or laterization), and (iii) PGM precipitated after PGE mobilization within the laterite (neoformation). Results provide evidence that (i) PGM occurrence and PGE enrichment in the laterite profiles is independent of chromitite incorporation; (ii) PGE enrichment is residual on the profile scale; and (iii) PGE are mobile on a local scale leading to in situ growth of PGM within limonite, probably by bioreduction and/or electrochemical metal accretion. Free grains of PGM with delicate morphologies were discovered in limonite hosted chromitite samples (“floating chromitites”) from highest levels in the Falcondo Ni laterite deposit (Dominican Republic). Textural and chemical evidence obtained via SEM and EMP analysis points to a multistage formation: (i) primary PGM formation at magmatic stage; (ii) transformation to highly porous secondary Os-Ru PGM during serpentinization; (iii) neoformation of Ir-Fe-Ni-(Pt) mineral phases during early stages of lateritization; (iv) neoformation of Pt-(Ir) mineral phases within the critical zone of the profile resulting in nugget shaped accumulation of rounded particulates during late stages of lateritization. The observation of accumulations of most likely biogenic mediated in situ growth of Pt rich nanoparticles in supergene environments could help to explain (i) why Pt bearing nuggets are the most abundant PGM found in surface environments, (ii) why Pt nuggets from placer deposits generally surpass the grain sizes of Pt grains found in parent rocks by several orders of magnitude (few micrometers vs. several millimeters) and (iii) how anthropogenic PGE contamination may affect our biosphere. Osmium chromitite, saprolite and limonite (Falcondo mining area), suggest that serpentinization of the Loma Caribe peridotite has not significantly affected the Re-Os system in Os-rich PGM. This is noted by the fact, that primary PGM formed at magmatic stage and secondary Ru-Os-Mg- isotope characteristics from primary and secondary PGM, separated from Si PGM formed due desulphurization of primary PGM with significant incorporation of Mg silicates, have almost identical Os isotope characteristics, typical of the mantle. However, the Re-Os system can be significantly disturbed during stages of lateritization when porous secondary PGM react with Fe-rich fluids, thus forming hexaferrum and magnetite in the 187 188 interstices of secondary PGM. Here presented data indicate that more radiogenic ratios in higher levels of the weathering profile are linked to steady mobilization of PGE within secondary PGM resulting in subsequent loss of Os counterbalanced by the incorporation of Fe. Os/ Os In this investigation presented data clearly states that PGE are neither noble nor inert in surface environments, at least in those related to tropical Ni laterites from the Northern Caribbean.
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Inguaggiato, Claudio. "Geochemistry of Zr, Hf and REE in extreme water environments : hyperacid, hypersaline and lake waters in hydrothermal systems." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066007/document.

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Cette thèse de doctorat traite du comportement géochimique de Zr, Hf et Terres Rares dans des environnements aqueux extrêmes. Les études ont été effectuées dans les eaux hyper-salines long de la faille de la Mer Morte (Israël), les eaux hyper-acides dans le système volcanique hydrothermal du Nevado del Ruiz (Colombie) et les eaux riches en CO2 du système volcanique hydrothermal de l'île de Pantelleria, en comprenant le lac alcalin “Specchio di Venere”. Haute appauvrissement en Terres Rares légères a été trouvé dans les eaux acides dominées par le sulfate où on a reconnu la formation d’alunite et jarosite. Certaines eaux long de la faille de la Mer Morte montrent des enrichissements en Terres Rares intermédiaires, causés par la dissolution des minéraux évaporitiques. Les grandes variations redox et de pH observées dans ces systèmes hydrothermaux sont la cause des anomalies de Eu et Ce. Les eaux sulfates acides (1 < pH < 3.6) se caractérisent par des relations de Zr/Hf sous-condritiques et des relations condritiques de Y/Ho. Les rapports de Zr/Hf augment à l'augmentation du rapport Cl/SO4 en suggérant un comportement différent de Zr et Hf. Contrairement aux eaux acides, les relations de Y/Ho et Zr/Hf dans les eaux proches de la neutralité avec valeurs de Eh positives augmentent vers des valeurs super-condritiques, en raison de l'élimination préférentielle par les oxyhydroxydes de fer, de l'Hf et Ho que de Zr et Y. Le distribution des Terres Rares, avec les rapports de Y/Ho et Zr/Hf du “Specchio di Venere” montrent l’interaction entre les particules atmosphériques qui viennent du désert du Sahara et le lac “Specchio di Venere”, démontrent qu’ils sont de traceurs géochimiques
This thesis concerns the geochemistry of Zr, Hf and REE (Rare Earth Elements) in extreme water environments. The investigations were carried out in hypersaline waters covering a wide range of Eh values along Dead Sea Fault (Israel), in hyperacid waters circulating in Nevado del Ruiz volcano-hydrothermal system (Colombia) and in CO2-rich waters in Pantelleria volcano-hydrothermal system (Italy), including the alkaline lake “Specchio di Venere” within a calderic depression. The acidic sulphates waters characterized by the precipitation of alunite and jarosite show a strong LREE depletion. The REE in waters along Dead Sea Fault show MREE enrichments in waters with relative high Ca and SO4 concentrations due to the water interaction with MREE-enriched salt minerals. In the natural waters, changing of pH and Eh induce variations of Ce and Eu anomalies, due to the different behaviour of these elements with respect to the neighbours REE. In sulphate acidic waters, Zr/Hf ratios are very low down to 4.7, while quite constant Y/Ho ratio (close to the local rock value) indicates the lack of decoupling. Zr/Hf ratio increases as Cl/SO4 ratio increases. On the contrary, Zr/Hf and Y/Ho ratios in near-neutral pH waters with positive Eh values change from near-chondritic to super-chondritic. The precipitation of Fe-oxyhydroxides removes preferentially Hf and Ho with respect to Zr and Y. The interaction of atmospheric fallout from the nearby Sahara Desert with the water of the lake “Specchio di Venere” was recognized by the Zr, Hf and REE distribution. Zr, Hf and REE show the capability to trace the interaction process between open water bodies and atmospheric fallout
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Baldwin, Geoffrey James. "THE STRATIGRAPHY AND GEOCHEMISTRY OF THE RAPITAN IRON FORMATION, NORTHWEST TERRITORIES AND YUKON, CANADA." Thesis, Laurentian University of Sudbury, 2014. https://zone.biblio.laurentian.ca/dspace/handle/10219/2194.

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The Neoproterozoic was a time of major change in Earth’s surficial history, including a major rise in atmospheric oxygen, the first appearance of complex metazoan life, and a series of worldwide glaciations. A particular interesting element of these so called “snowball Earth” glacial deposits is the presence of iron formation, a distinctive Precambrian rock type that is largely absent from the post-Paleoproterozoic record. Despite being relatively poorly studied with respect to their geochemistry and sedimentology, Neoproterozoic iron formations are used to support many models for the record of oxygen concentrations of the Earth. The classical example of Neoproterozoic iron formation is the Rapitan iron formation of northwestern Canada. This hematite-jasper iron formation is associated with glaciogenic turbidites and diamictites. Despite being the archetype, the Rapitan iron formation has not been studied in the context of recent ideas about the Neoproterozoic. In this thesis, the stratigraphy, geochemistry, and basin architecture of the Rapitan iron formation are reassessed. Using the REE+Y and the redox-sensitive elements Mo and U, it is shown that the Rapitan iron formation was deposited in a partially restricted basin from biogenically reduced iron under variable redox conditions. Elemental Re and Mo isotopes further show that although oxic and ferruginous conditions predominated during deposition of the iron formation, a transition towards a sulfidic water column locally terminated deposition. Finally, regional stratigraphy and geochemistry show that the iron formation was preferentially deposited in deep, newly formed basins that were protected from significant siliciclastic sedimentation. These basins were delimited by inferred crustal-scale faults trending roughly perpendicular to the axis of the rift basin, and allowed significant changes in thickness and sedimentological character over short distances along strike. These factors help build an overall geotectonic regime under which Neoproterozoic iron formations were deposited: young, deep rift basins that had undergone marine incursion, and were intermittently sealed by an ice shelf, allowing for the generation of an anoxic, iron-rich water column. The absence of the Eu anomaly and the heavy Mo isotopic signature indicate that the open ocean was fully oxygenated at the time of Rapitan iron formation deposition, as opposed to ferruginous as previously suggested.
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Vanderstraeten, Aubry. "Advances in geochemical tracing of atmospheric dust in Antarctica." Doctoral thesis, Universite Libre de Bruxelles, 2020. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/312773.

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AbstractAtmospheric dust is a major component of the Earth System. The optical properties of dust and their roles in cloud nucleation processes have a major impact on Earth’s radiative budget and hydrological cycle. Dusts also take part in many biogeochemical cycles in surface waters of the oceans and on land through their capacity to supply key micronutrients (e.g. Fe, P) sustaining primary production. The aim of this thesis is to improve the understanding of dust cycle by creating new and innovative methods allowing to trace the source regions of dust and quantify their respective contributions. We developed a chromatographic method to isolate and analyze six isotopic systems (i.e. Pb, Nd, Sr, Zn, Cu, Fe) widely used to trace dust source areas. We optimized a new method for single, low-mass dust samples and, in doing so, we observed that the usual rock reference materials (RM) used to calibrate isotopic analysis were not representative of dust. In fact, there is little to no RM for dust and therefore, we set out to characterize precisely the isotopic signatures of two new dust reference materials, ATD and BCR-723. The latter two are representative of natural-like and urban-like dust that we propose now as new standards for atmospheric dust studies. We also investigated dust deposition, along a 250-km transect from the NE Antarctic coastline to the Princess Elisabeth Station area. Using dust samples collected from Sigma-2 passive samplers or isolated from snow samples, we determined the morphology, size distribution and chemical composition of the dust samples at the particle-scale using an automated Scanning Electron Microscope coupled to Energy Dispersive Spectroscopy (SEM-EDS). More than 5500 particles were analysed and the results showed that the grain-size distribution was <5 μm. We also observe difference in mineralogy at the coast compared to the inland section of our transect: dominance of quartz and aluminosilicates at the coast and of Fe-Mg silicates near the Sør Rondane. Based on this discrepancy, we interpret the ‘coastal’ dust samples to come from distal source while Fe-Mg silicate rich samples were hypothesized to originate from the nearby Sør Rondane range. To trace the source of those dust samples, we analysed their REE content and developed a whole new statistical approach to trace and quantify their source(s). The idea is to correlate systematically the REE pattern of those samples with, not only, PSA REE pattern from distal and local rocks but also with all their possible mixing combinations. To do so, we used the correlation coefficient (R), Akaike and Bayesian Information Criterion (AIC-BIC) to determine whether a dust sample traces a single or a mixture of multiple PSAs. Using this numerical method, we determined that local inputs of dust from the Sør Rondane mountains dominate the inland-most section of the 250-km transect. In contrast, coastal sampling sites (up to 50 km inland) are influenced by dust coming from Puna-Altiplano, Patagonia and Southern Africa. As such, this work presents the first unambiguous geochemical evidence that Southern African dust reach North East Antarctic coast. Finally, we also revisited the REE-dataset measured in EPICA Dome-C (EDC, Gabrielli et al. [Quaternary Science Reviews 29 (2010) 265-273]) and EPICA Dronning Maud Land (EDML, Wegner et al. [Climate of the Past 8 (2012) 135-147]) ice cores in order to reconstruct the dust provenance over the last glacial-interglacial interval. Our results showed that,during the Last Glacial Maximum (before 18 kyr BP), dust in both ice cores was predominantly coming from New-Zealand (NZ) with secondary inputs from South-Central Western Argentina (S-CWA) and Patagonia. The glacial-interglacial transition (18-11.6 kyr BP) saw the decline of NZ and S-CWA inputs and the increase of contributions from Patagonia, Southern Africa and Puna Altiplano. The Holocene (after 11.7 kyr BP) is marked by dust inputs coming from Patagonia, Southern Africa and Puna Altiplano while NZ stabilized to a secondary level and S-CWA ceased to supply dust. We demonstrated that variations and relative contributions recorded in ice cores are all related to important climatic changes in source regions having an impact on their capacity to supply dust. Our REE statistical approach provide an unprecedented way to identify and quantify the dust source regions in Antarctic ice core and in doing shed new light of those ‘iconic’ archives of Earth’s climate and atmospheric circulation.
RésuméLes particules atmosphériques (PA) sont un composant majeur du système Terre. Leurs propriétés optiques ainsi que leur rôle au sein des processus de nucléation des nuages ont des impacts majeurs sur le budget radiatif et hydrologique de la terre. Les PA interviennent aussi dans de nombreux cycles biogéochimiques à la surface des océans ou sur terre grâce à leur capacité à fournir des nutriments clés (e.g. Fe, P) soutenant la production primaire. Le but de ce doctorat est d’améliorer la compréhension du cycle des PA en créant de nouvelles méthodes innovatrices permettant de tracer leurs origines et quantifier leurs contributions. Nous avons développé une nouvelle méthode chromatographique optimisée pour les PA afin d’analyser six systèmes isotopiques (i.e. Pb, Nd, Sr, Zn, Cu, Fe) largement utilisés pour tracer l’origine des PA. Afin de combler un manque crucial en terme de matériaux de référence (MR), nous avons quantifié deux nouveaux MR de PA, ATD et BCR-723 (représentatifs des milieux naturels et urbains) et nous les proposons pour toutes les futures études géochimiques de PA. Nous avons aussi étudié les dépositions atmosphériques le long d’un ‘transect’ de 250 km depuis la côte Antarctique jusqu’à la station Belge Princesse Elisabeth. Premièrement, nous avons réalisé des analyses morphologiques et chimiques à l’échelle de la particule à l’aide d’un Microscope Electronique à Balayage à dispersion d’énergie (MEB-EDS). Les analyses ont montré une distribution granulométrique <5 μm ainsi qu’une variation de composition chimique (i.e. minéralogie) depuis la côte jusqu’aux Sør Rondane. Deuxièmement, afin de mieux identifier l’origine de ces PA, nous avons analysé les terres rares (REE) et développé dans son intégralité une nouvelle approche statistique permettant d’identifier les sources ainsi que leurs contributions relatives. Grâce à cela, nous avons déterminé que les échantillons à la côte proviennent du Puna-Altiplano, de Patagonie et du Sud de l’Afrique (SAF). C’est la première fois que des apports du SAF sont formellement identifiés en Antarctique. Finalement, nous avons revisité les data-set de REE des carottes de glace du projet EPICA (EDC et EDML) afin de reconstruire les apports de PA durant la dernière transition glacière/interglaciaire. Nos résultats ont montré que durant la dernière période glaciaire les PA proviennent principalement de Nouvelle-Zélande (NZ) avec des apports secondaires provenant de la partie Sud du centre de l’Ouest Argentin ainsi que de Patagonie. Une transition est marquée entre 18 et 11.6 ka BP jusqu’à un équilibre dès l’Holocène (après 11.7 ka BP) marqué par des apports de sources variées venant de Patagonie, SAF, Puna-Altiplano et NZ. Nous avons aussi démontré que les variations des contributions relatives de sources enregistrées dans les carottes de glaces sont toutes en relation avec des changements climatiques importants au niveau des régions sources impactant leur capacité à générer des PA. Notre approche statistique exploitant les REE apporte une méthode sans précédent pour identifier et quantifier les sources de PA des carottes de glace d’Antarctique et ouvre de nouvelles opportunités sur ces archives du climat et de la circulation atmosphérique de la Terre.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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Tourpin, Sylvie. "Perte des mémoires isotopiques (Nd, Sr, 0) et géochimiques (REE) primaires des komatiites au cours du métamorphisme : Exemple de la Finlande Orientale." Phd thesis, Université Rennes 1, 1991. http://tel.archives-ouvertes.fr/tel-00675899.

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Les komatiites ont souvent été considérées comme reflétant directement les compositions chimiques et isotopiques de leurs sources mantelliques. Cependant, l'utilisation de ces roches pour reconstituer la composition du manteau archéen apparaît abusive du fait que les komatiites montrent toutes des recristallisations métamorphiques, ce qui laisse subsister un doute profond quant à la préservation de leurs caractéristiques primaires. La possibilité d'une modification profonde des signatures isotopiques ainsi que des autres caractéristiques chimiques (incluant des éléments réputés immobiles, tels que les Terres Rares) a été démontrée à partir des coulées komatiitiques à textures spinifex de la ceinture de roches vertes de Kuhmo-Tipasjarvi (Finlande) dont l'âge est de 2.66 Ga. Ces coulées ont subi un métamorphisme dans le faciès amphibolite de bas degré, parfois accompagné de phénomènes de carbonatation et d'albitisation. Un tel métamorphisme est responsable de nombreuses anomalies dans la distribution des éléments majeurs et en traces (en particulier des Terres Rares). Les échantillons analysés définissent une "isochrone" Sm-Nd donnant un âge beaucoup plus jeune que l'âge réel de mise en place, et qui représente plutôt l'âge des recristallisations métamorphiques. Les rapports Sm-Nd des roches, la géochimie des éléments majeurs et en traces, ainsi que les rapports isotopiques de l'oxygène sont directement corrélés avec les proportions modales de minéraux secondaires. Comme l'âge du métamorphisme (Svécokarélien) est beaucoup plus récent que celui d'emplacement des coulées (900 Ma), la recristallisation a eu des conséquences profondes sur la détermination de eNd et eSr. En conclusion c'est avec énormément de prudence et de suspicion qu'il faut utiliser les méta-komatiites comme des indicateurs "fiables" des caractéristiques isotopiques du manteau archéen.
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Paquette, 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.

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Les éclogites témoignent, pour la plupart d'entre elles, de l'existence de lambeaux de paléocroûtes océaniques affectées par des conditions tectonométamorphiques très intenses. Ces roches représentent généralement les premiers épisodes de la formation des chaînes de montagne, avant les phénomènes de collision continentale. L'étude géochronologique et géochimique des éclogites est fondamentale car elle apporte d'une part de nombreuses contraintes à la géologie des massifs cristallins étudiés, et permet d'autre part de caractériser le comportement des systèmes isotopiques \ lors d'un métamorphisme de haute grade. - L'ensemble des résultats géochimiques et isotopiques montre que la maiorité des * protolithes des éclogites étudiées provenant du Massif Armoricain (Champtoceaux-Léon) et des massifs externes alpins (Aiguilles Rouges-Belledonne- Argentera) sont comparables aux basaltes de rides' médio-océaniques actuels. - L'étude géochronologique U-Pb sur zircons a révélé une large gamme d'âges de magr:natisme initial de ces métabasites. Les résultats sont divisés - en d eux groupes : les âges précambriens et les âges paléozoiques. Un modèle de faible contamination, ion géochronoches qui propose qu'une très faible contribution crustale introduise une informat logique erronnée sans perturber les caractères géochimiques des roches étudiées, permet d'interpréter la diversité des âges précambriens obtenus. Dans les deux domaines étudiés, le magmatisme océanique d'âge paléozoique a été daté en deux époques distinctes :460-500 Ma et 350-380 Ma. - Le métamorphisme éclogitique est lui -même constitué de plusieurs époques : (1) précoce : 480 Ma, (2) majeur 400-440 Ma et (3) tardif à 350-370 Ma. Ceci permet de proposer la fermeture de plusieurs domaines océaniques et une évolution non-synchrone de l'ensemble de la chaîne Hercynienne. - Dans la chaîne Alpine, les âges obtenus par U-Pb * sur zircons 286 Ma (magmatisme) pour le métagranite éclogitique du Mont Mucrone et 117 Ma (métamorphi ~ me) sur une métaquartzite éclogitique du massif de Dora-Maïra permettent de corréler les âges obtenus avec les conditions P-T du métamorphisme le système U-Pb du granite n'a pas été modifié par le métamorphisme PH-BT, au contraire l'événement HP-HT a été enregistré par les zircons d'un sédiment.
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Martin, Hervé. "Nature, origine et évolution d'un segment de croûte continentale archéenne : contraintes chimiques et isotopiques. Exemple de la Finlande orientale." Phd thesis, Université Rennes 1, 1985. http://tel.archives-ouvertes.fr/tel-00655973.

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Le but de ce mémoire est d'aborder le problème de la genèse et de l'évolution de la croate continentale. Le support de terrain ayant servi de base à cette étude est le socle de Finlande orientale dont l'histoire archéenne se déroule sur plus de 500 m.a. L'analyse a été menée en 4 étapes successives : a) une étude de terrain permet de caractériser les matériaux et d'établir leur chronologie relative. b) la radiochronologie (Rb-Sr) précise l'enchainement et la durée des événements géologiques. c) les différents aspects de la genèse de chaque unité lithologique sont envisagés à l'aide de la géochimie des éléments majeurs et en traces. d) les cootraintes géologiques, pétrographiques, géochronologiques, isotopiques et géochimiques servent à établir un modèle d'évolution géodynamique de la croOte archéenne. Parmi les principaux résultats on peut retenir : 1) que la croate continentale archaïque se différencie verticalement par recyclages successifs et acquiert progressivement des caractères modernes. 2) que si la tectonique des plaques existait bien à 1 ~ Archéen, les modalités de détail étaient différentes de celles connues de nos jours. Par exemple lors de la formation d'un rift l'évolution de celui-ci pouvait se faire soit, comme aujourd' hui par océanisation, puis subduction, soit par subsidence (sans océanisation). 3) la composition des granitoïdes formés dans les zones de convergence de plaques s'est modi fiée au cours du temps. Ceci est expliqué par le refroidissement. progressi f de la Terre; à l'Archéen les gradients géothermiques élevés permettaient la fusion de la croate océanique subductée. Aujourd'hui à l'inverse, cette croate subductée est "froide" et se déshydrate avant d'atteindre les conditions de la fusion, favorisant ainsi la fusion partielle du coin de manteau, ou de la base de la croûte continentale sus-jacents.
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Books on the topic "REE geochemistry"

1

Bove, Dana. Compositional changes induced by hydrothermal alteration at the Red Mountain alunite deposit, Lake City, Colorado. Washington, D.C: U.S. G.P.O., 1990.

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Klika, Zdeněk. Geochemistry of coal from region of the red beds bodies of the Upper Silesian Coal Basin. [Ostrava]: VŠB-Technical University Ostrava, Faculty of Mining and Geology, 1998.

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Shen, Glen T. Lead and cadmium geochemistry of corals: Reconstruction of historic perturbations in the upper ocean. Woods Hole, Mass: Woods Hole Oceanographic Institution, 1986.

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Nordstrom, Darrell Kirk. Questa baseline and pre-mining ground-water quality investigation 25. Summary of results and baseline and pre-mining ground-water geochemistry, Red River Valley, Taos County, New Mexico, 2001-2005. Reston, Va: U.S. Geological Survey, 2008.

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Lucey, Keith J. Analysis of the ground-water flow system, geochemistry, and underseepage in the vicinity of the Red Rock Dam near Pella, Iowa. Iowa City, Iowa: U.S. Dept. of the Interior, U.S. Geological Survey, 1991.

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Lucey, Keith J. Analysis of the ground-water flow system, geochemistry, and underseepage in the vicinity of the Red Rock Dam near Pella, Iowa. Iowa City, Iowa: U.S. Dept. of the Interior, U.S. Geological Survey, 1991.

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Lucey, Keith J. Analysis of the ground-water flow system, geochemistry, and underseepage in the vicinity of the Red Rock Dam near Pella, Iowa. Iowa City, Iowa: U.S. Dept. of the Interior, U.S. Geological Survey, 1991.

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Lucey, Keith J. Analysis of the ground-water flow system, geochemistry, and underseepage in the vicinity of the Red Rock Dam near Pella, Iowa. Iowa City, Iowa: U.S. Dept. of the Interior, U.S. Geological Survey, 1991.

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Nordstrom, Darrell Kirk. Questa baseline and pre-mining ground-water quality investigation: Interpretation of ground-water geochemistry in catchments other than the Straight Creek catchment, Red River Valley, Taos County, New Mexico, 2002-2003. Boulder, Colo: U.S. Geological Survey, 2005.

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Heggie, D. T. Continental margin transects: Geochemistry of sediments from the north east Australian continental margin, including the Great Barrier Reef slope, Queensland Plateau and Trough and the Osprey Embayment : AGSO project 121.11 and 121.38. Canberra: Australian Geological Survey Organisation, 1993.

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Book chapters on the topic "REE geochemistry"

1

Brookins, Douglas G. "Yttrium and the Rare Earth Elements (REE)." In Eh-pH Diagrams for Geochemistry, 122–40. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-73093-1_50.

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Antoniassi, Juliana Lívi, Daniel Uliana, Henrique Kahn, M. Manuela M. Lé Tassinari, and Carina Ulsen. "Assessment and Characterization of REE Minerals from an Alkali-Carbonatitic Complex." In Springer Geochemistry/Mineralogy, 173–86. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-13948-7_18.

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Yang, Yuangen, Congqiang Liu, Zhenli He, and Keneng Yuan. "Rare Earth Element (REE) Geochemistry During Red Soil Formation in Southern China." In The Red Soils of China, 89–100. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-1-4020-2138-1_6.

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Xueyuan, Yu. "Geochemistry of Rb, Sr and REE in Niutoushan basalts in the coastal area of Fujian Province, China." In Properties and Processes of Earth' Lower Crust, 331–38. Washington, D. C.: American Geophysical Union, 1989. http://dx.doi.org/10.1029/gm051p0331.

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Wagner, Thomas, and Jörg Erzinger. "REE geochemistry of fluid-rock interaction processes related to Alpine-type fissure vein mineralisation, Rheinisches Schiefergebirge, Germany." In Mineral Deposits at the Beginning of the 21st Century, 929–32. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003077503-236.

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Xie, Qiaoqin, Gao Qiu, Tianhu Chen, Xiaochun Xu, Xiaoyong Wang, Huayu Lu, Huifang Xu, and Junfeng Ji. "Palygorskite in the Late Miocene Red Clay Sediment from the Chinese Loess Plateau and Its Paleoclimatic Implications." In Springer Geochemistry/Mineralogy, 425–40. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-13948-7_42.

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Stoffers, P., R. Botz, and J. Scholten. "Isotope Geochemistry of Primary and Secondary Carbonate Minerals in the Shaban-Deep (Red Sea)." In Sediments and Environmental Geochemistry, 83–94. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-75097-7_5.

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Buddemeier, R. W., and J. A. Oberdorfer. "Internal Hydrology and Geochemistry of Coral Reefs and Atoll Islands: Key to Diagenetic Variations." In Reef Diagenesis, 91–111. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82812-6_6.

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Stoffers, P., and R. Botz. "Carbonate Crusts in the Red Sea: Their Composition and Isotope Geochemistry." In Facets of Modern Biogeochemistry, 242–52. Berlin, Heidelberg: Springer Berlin Heidelberg, 1990. http://dx.doi.org/10.1007/978-3-642-73978-1_20.

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Zanoni, Davide, Najeeb M. A. Rasul, Antonio Langone, and Moustafa Khorshid. "Microstructure and Geochemistry of Magmatic Dykes from the Arabian Margin, Red Sea." In Geological Setting, Palaeoenvironment and Archaeology of the Red Sea, 437–71. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99408-6_20.

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Conference papers on the topic "REE geochemistry"

1

Lee, Seung-Gu, and Young-Rok Park. "REE, Nd, Sr and Eu Isotope Geochemistry of Anorthosite at Sancheong Area, Korea." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.1443.

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Dietz, Haley, and Virginia T. McLemore. "Geochemistry of the U-Th-REE mineralized Tajo granite, Socorro County, New Mexico." In 2021 New Mexico Geological Society Annual Spring Meeting. Socorro, NM: New Mexico Geological Society, 2021. http://dx.doi.org/10.56577/sm-2021.2756.

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Riggins, Annelise M., Nelia Dunbar, Virginia McLemore, Matthew Heizler, William McIntosh, and Kwame Frempong. "Mineralogy, Geochemistry, and Chronology of the Caballo and Burro Mountains REE-Bearing Episyenites." In 2014 New Mexico Geological Society Annual Spring Meeting. Socorro, NM: New Mexico Geological Society, 2014. http://dx.doi.org/10.56577/sm-2014.269.

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Villanova-De-Benavent, Cristina, Thomas Aiglsperger, and Joaquín Proenza. "Geochemistry and mineralogy of critical metals (PGE, Co, REE, Sc) in supergene deposits." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7888.

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Oksuz, Nursel. "REE GEOCHEMISTRY, MINERALOGY AND ORIGIN OF MANGANESE IN THE ARTOVA OPHIOLITE COMPLEX, YOZGAT (TURKEY)." In SGEM2011 11th International Multidisciplinary Scientific GeoConference and EXPO. Stef92 Technology, 2011. http://dx.doi.org/10.5593/sgem2011/s01.130.

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González-Nistal, Santiago, Rodrigo Álvarez, Almudena Ordóñez, and Jorge Loredo. "Occurrence of Detrital Monazite within the Esva Watershed (NW Spain): EPMA Dating and REE Geochemistry." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.860.

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Obregón, Cynthia, Rosa Marques, Maria Isabel Prudêncio, João Carlos Waerenborgh, Bruno Vieira, Catarina Diamantino, and Edgar Carvalho. "REE GEOCHEMISTRY AND EVALUATION OF EFFECTIVENESS OF THE PASSIVE REMEDIATION SYSTEM AT LOUSAL MINE, PORTUGAL." In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.6246.

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Lu, Jue, Wei Chen, Yuancan Ying, and Shao-Yong Jiang. "Texture and Trace Element Geochemistry of Apatite in Carbonatite Related REE Deposits: Fingerprinting Magmatic-Hydrothermal Processes." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.1641.

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Yoshiya, Kazumi, Keita Itano, and Tsuyoshi Iizuka. "U-Pb chronology, REE geochemistry, and Nd isotope ratios of detrital monazites from major North and South American rivers." In Goldschmidt2022. France: European Association of Geochemistry, 2022. http://dx.doi.org/10.46427/gold2022.12006.

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Wang, Chunzeng, John F. Slack, Martin Yates, David R. Lentz, Anjana Shah, Amber H. Whittaker, and Robert Marvinney. "THE NEWLY DISCOVERED TRACHYTE-HOSTED PENNINGTON MOUNTAIN REE-NB-ZR DEPOSIT IN NORTHERN MAINE: PRELIMINARY GEOLOGY, MINERALOGY, AND GEOCHEMISTRY." In GSA Connects 2022 meeting in Denver, Colorado. Geological Society of America, 2022. http://dx.doi.org/10.1130/abs/2022am-379619.

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Reports on the topic "REE geochemistry"

1

Grunsky, E. C., P. W. B. Friske, and R. McNeil. A re-evaluation of lake sediment geochemistry from the Bancroft region of Ontario; recognizing geochemical background and sources of uranium and REE mineralization. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2014. http://dx.doi.org/10.4095/294924.

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Matte, S., M. Constantin, and R. Stevenson. Mineralogical and geochemical characterisation of the Kipawa syenite complex, Quebec: implications for rare-earth element deposits. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329212.

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The Kipawa rare-earth element (REE) deposit is located in the Parautochton zone of the Grenville Province 55 km south of the boundary with the Superior Province. The deposit is part of the Kipawa syenite complex of peralkaline syenites, gneisses, and amphibolites that are intercalated with calc-silicate rocks and marbles overlain by a peralkaline gneissic granite. The REE deposit is principally composed of eudialyte, mosandrite and britholite, and less abundant minerals such as xenotime, monazite or euxenite. The Kipawa Complex outcrops as a series of thin, folded sheet imbricates located between regional metasediments, suggesting a regional tectonic control. Several hypotheses for the origin of the complex have been suggested: crustal contamination of mantle-derived magmas, crustal melting, fluid alteration, metamorphism, and hydrothermal activity. Our objective is to characterize the mineralogical, geochemical, and isotopic composition of the Kipawa complex in order to improve our understanding of the formation and the post-formation processes, and the age of the complex. The complex has been deformed and metamorphosed with evidence of melting-recrystallization textures among REE and Zr rich magmatic and post magmatic minerals. Major and trace element geochemistry obtained by ICP-MS suggest that syenites, granites and monzonite of the complex have within-plate A2 type anorogenic signatures, and our analyses indicate a strong crustal signature based on TIMS whole rock Nd isotopes. We have analyzed zircon grains by SEM, EPMA, ICP-MS and MC-ICP-MS coupled with laser ablation (Lu-Hf). Initial isotopic results also support a strong crustal signature. Taken together, these results suggest that alkaline magmas of the Kipawa complex/deposit could have formed by partial melting of the mantle followed by strong crustal contamination or by melting of metasomatized continental crust. These processes and origins strongly differ compare to most alkaline complexes in the world. Additional TIMS and LA-MC-ICP-MS analyses are planned to investigate whether all lithologies share the same strong crustal signature.
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Manor, M. J., and S. J. Piercey. Whole-rock lithogeochemistry, Nd-Hf isotopes, and in situ zircon geochemistry of VMS-related felsic rocks, Finlayson Lake VMS district, Yukon. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328992.

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The Finlayson Lake district in southeastern Yukon is composed of a Late Paleozoic arc-backarc system that consists of metamorphosed volcanic, plutonic, and sedimentary rocks of the Yukon-Tanana and Slide Mountain terranes. These rocks host &amp;gt;40 Mt of polymetallic resources in numerous occurrences and styles of volcanogenic massive sulphide (VMS) mineralization. Geochemical and isotopic data from these rocks support previous interpretations that volcanism and plutonism occurred in arc-marginal arc (e.g., Fire Lake formation) and continental back-arc basin environments (e.g., Kudz Ze Kayah formation, Wind Lake formation, and Wolverine Lake group) where felsic magmatism formed from varying mixtures of crust- and mantle-derived material. The rocks have elevated high field strength element (HFSE) and rare earth element (REE) concentrations, and evolved to chondritic isotopic signatures, in VMS-proximal stratigraphy relative to VMS-barren assemblages. These geochemical features reflect the petrogenetic conditions that generated felsic rocks and likely played a role in the localization of VMS mineralization in the district. Preliminary in situ zircon chemistry supports these arguments with Th/U and Hf isotopic fingerprinting, where it is interpreted that the VMS-bearing lithofacies formed via crustal melting and mixing with increased juvenile, mafic magmatism; rocks that were less prospective have predominantly crustal signatures. These observations are consistent with the formation of VMS-related felsic rocks by basaltic underplating, crustal melting, and basalt-crustal melt mixing within an extensional setting. This work offers a unique perspective on magmatic petrogenesis that underscores the importance of integrating whole-rock with mineral-scale geochemistry in the characterization of VMS-related stratigraphy.
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4

Mueller, C., S. J. Piercey, M. G. Babechuk, and D. Copeland. Stratigraphy and lithogeochemistry of the Goldenville horizon and associated rocks, Baie Verte Peninsula, Newfoundland. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328990.

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The Goldenville horizon in the Baie Verte Peninsula is an important stratigraphic horizon that hosts primary (Cambrian to Ordovician) exhalative magnetite and pyrite and was a chemical trap for younger (Silurian to Devonian) orogenic gold mineralization. The horizon is overlain by basaltic flows and volcaniclastic rocks, is intercalated with variably coloured argillites and cherts, and underlain by mafic volcaniclastic rocks; the entire stratigraphy is cut by younger fine-grained mafic dykes and coarser gabbro. Lithogeochemical signatures of the Goldenville horizon allow it to be divided into high-Fe iron formation (HIF; &amp;gt;50% Fe2O3), low-Fe iron formation (LIF; 15-50% Fe2O3), and argillite with iron minerals (AIF; &amp;lt;15% Fe2O3). These variably Fe-rich rocks have Fe-Ti-Mn-Al systematics consistent with element derivation from varying mineral contributions from hydrothermal venting and ambient detrital sedimentation. Post-Archean Australian Shale (PAAS)-normalized rare earth element (REE) signatures for the HIF samples have negative Ce anomalies and patterns similar to modern hydrothermal sediment deposited under oxygenated ocean conditions. The PAAS-normalized REE signatures of LIF samples have positive Ce anomalies, similar to hydrothermal sediment deposited under anoxic to sub-oxic conditions. The paradoxical Ce behaviour is potentially explained by the Mn geochemistry of the LIF samples. The LIF have elevated MnO contents (2.0-7.5 weight %), suggesting that Mn from hydrothermal fluids was oxidized in an oxygenated water column during hydrothermal venting, Mn-oxides then scavenged Ce from seawater, and these Mn-oxides were subsequently deposited in the hydrothermal sediment. The Mn-rich LIF samples with positive Ce anomalies are intercalated with HIF with negative Ce anomalies, both regionally and on a metre scale within drill holes. Thus, the LIF positive Ce anomaly signature may record extended and particle-specific scavenging rather than sub-oxic/redox-stratified marine conditions. Collectively, results suggest that the Cambro-Ordovician Taconic seaway along the Laurentian margin may have been completely or near-completely oxygenated at the time of Goldenville horizon deposition.
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Mowbray, B., and S. J. Pehrsson. Geochemistry, petrology, and aeromagnetic mapping of the Orpheus dykes, south Rae Craton, Northwest Territories. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2019. http://dx.doi.org/10.4095/311306.

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Acosta-Góngora, P., E. Martel, and S. J. Pehrsson. Geochemistry results from the south Rae mapping project, Northwest Territories, 2015 and 2016 field seasons. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2018. http://dx.doi.org/10.4095/306501.

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7

Evans, Carol. The Geology, Geochemistry, and Alteration of Red Butte, Oregon: A Precious Metal-Bearing Paleo Hot Spring System. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.5328.

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8

Zagorevski, A., C. R. van Staal, J. H. Bédard, A. Bogatu, D. Canil, M. Coleman, M. Golding, et al. Overview of Cordilleran oceanic terranes and their significance for the tectonic evolution of the northern Cordillera. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/326053.

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Ophiolite complexes are an important component of oceanic terranes in the northern Cordillera and constitute a significant amount of juvenile crust added to the Mesozoic Laurentian continental margin during Cordilleran orogenesis. Despite their tectonic importance, few systematic studies of these complexes have been conducted. Detailed studies of the pseudostratigraphy, age, geochemistry, and structural setting of ophiolitic rocks in the northern Cordillera indicate that ophiolites formed in Permian to Middle Triassic suprasubduction zone settings and were obducted onto passive margin sequences. Re-evaluation of ophiolite complexes highlights fundamental gaps in the understanding of the tectonic framework of the northern Cordillera. The previous inclusion of ophiolite complexes into generic 'oceanic' terranes resulted in significant challenges for stratigraphic nomenclature, led to incorrect terrane definitions, and resulted in flawed tectonic reconstructions.
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Zhang, S. Geochemistry data from three oil shale intervals in unit 1, Red Head Rapids Formation (Upper Ordovician) on Southampton Island. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/288109.

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Regis, D., and M. Sanborn-Barrie. Delimiting the extent of 'Boothia terrane' crust, Nunavut: new U-Pb geochronological results. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330703.

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The Boothia Peninsula - Somerset Island region of north-central Nunavut is a frontier region (70-74°N, 94°W) long considered as part of Rae craton. Recent field mapping and acquisition of isotopic (U-Pb, Sm-Nd) data as part of the GEM-2 Boothia-Somerset project allowed this region's exposed Precambrian bedrock to be better characterized with respect to petrology and litho-geochemistry, and to be more extensively and more precisely time-calibrated. The discovery of unique, possibly exotic, basement characterized by a ca. 2.55-2.51 Ga TTG suite overlain by ca. 2.5 Ga metasedimentary rocks, cut by 2.49- 2.48 Ga plutons, are all atypical components of the Archean Rae crust. This new knowledge and the hint of similar 'Boothia terrane' crust south of Boothia Peninsula (Ryan et al., 2009), east of the Queen Maud block (Davis et al., 2014) in central Nunavut, and in northernmost Saskatchewan (Cloutier et al., 2021), raised the possibility this terrane may extend &amp;gt;1600 km across north-central Canada. During the foundational year of GEM-GeoNorth, the extent of Boothia terrane crust was explored through legacy samples collected during the 2012 GEM Frontiers' transect across mainland Nunavut. As part of this new study, field descriptions, photographic records and legacy samples were examined, and new U-Pb zircon geochronology was acquired. The new data and knowledge were used to: i) identify new components of Boothia terrane on the mainland southwest of Boothia Peninsula; ii) further distinguish this crust from that of Rae affinity; and iii) better constrain the depositional age of Sherman Group metasedimentary rocks.
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