Дисертації з теми "Carbonatiite"
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Church, Abigail Ann. "The petrology of the Kerimasi carbonatite volcano and the carbonatites of Oldoinyo Lengai with a review of other occurrences of extrusive carbonatites." Thesis, University College London (University of London), 1996. http://discovery.ucl.ac.uk/1349623/.
Повний текст джерелаAnzolin, Henrique de Maman. "Multigerações de apatitas no carbonatito Três Estradas, sul do Brasil : significado físico-químico e implicações para a qualidade do minério fosfático." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/184646.
Повний текст джерелаRecent discoveries of carbonatite bodies in the state of Rio Grande do Sul created interest about the economic potential of these rocks. Associated with the granulitic complex Santa Maria Chico, the Três Estradas carbonatite presents a high content of apatite, making it a target to the implementation of an adventure for the production of phosphate, an important mineral for the production of inputs for the agricultural industry. In this project, this mineral was examined, as well as the weathering profile occurring in these rocks. A detailed study of the occurrence of this mineral associated with this carbonatite body was elaborated and revealed the presence of different generations of apatite along the weathering profile, evidencing processes of partial dissolution, chemical substitutions and precipitation. Once confirmed the existence of apatite of different generations, the study was directed to characterizing the populations and the geochemical environment associated with each one. Among the methods applied were the chemical analysis of the samples by x-ray fluorescence spectroscopy, electronic microprobe, Fourier-Transform infrared spectroscopy and micro Raman spectroscopy, the mineralogic analysis by x-ray diffraction, and the petrographic and textural analysis by optic microscopy complemented by scanning electron microscope. With the results obtained it was possible to comprehend the variations in the chemical composition of the apatite from the carbonatite and in the weathering profile of these rocks, allowing the identification of different types of occurrence and its chemical characteristics, as well as speculate about the supergenic condition that favored the formation of late generations of the mineral, what elevates considerably the phosphate concentration.
Luciano, Rejane Lima [UNESP]. "Petrografia e geoquímica das rochas metacarbonatíticas do Complexo Angico dos Dias, divisa Bahia/Piauí, Brasil." Universidade Estadual Paulista (UNESP), 2016. http://hdl.handle.net/11449/138310.
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Este trabalho verificou que as rochas metacarbonatíticas do Complexo Metacarbonatítico de Angico dos Dias (CMCAD), constituídas principalmente por calcita, apatita, olivina, flogopita e magnetita dispõem-se em dois conjuntos: um localizado na mina de fosfato da Galvani (corpo principal, Campo Alegre de Lourdes-BA) e o outro na Fazenda Pimenteira (Caracol-PI). Variação no conteúdo de apatita, minerais ferro-magnesianos e magnetita configura um acamadamento cumulático e permite individualizar cinco fácies petrográficas (contatos graduais). Além disso, exibem manto intempérico, que resulta no minério de fosfato residual (apatitito). Registram pelo menos três fases deformacionais marcadas por estruturas primárias (acamamento reliquiar - S0) que devido aos processos de transposição (D1) da foliação S1 e da deformação D2 associada às zonas de cavalgamento (S2) se mantêm de forma escassa nas áreas menos deformadas. D2 evolui para um bandamento tectônico vertical (S3) nas zonas de cisalhamento (D3). Dados isotópicos indicam que as rochas metacarbonatíticas, datadas em 2.011±6Ma (U-PB em badeleíta e zircão), originaram-se de uma fonte mantélica enriquecida e que o enriquecimento em 18O é reflexo do reequilíbrio durante o metamorfismo/ hidrotermalismo relacionado ao Evento Brasiliano. Dados petrográficos e de química mineral apontam: que a olivina altera para serpentina, tremolita, antofilita e magnetita; que é comum a exsolução de dolomita em calcitas e de ilmenita em magnetitas e; que os carbonatitos foram parcialmente silicificados. As demais rochas do CMCAD, milonitizadas e metamorfizadas em fácies anfibolito alto (mesopertitas), exibem processo de potassificação (fenitização), metassienito e metassienogranito, além de processos de sericitização, saussuritização e epidotização dos plagioclásios. O evento metassomático/hidrotermal (fácies xisto verde médio a alto) tem caráter regional e atinge além das rochas do CMCAD as rochas do Complexo Sobradinho-Remanso. Dados geoquímicos classificam as rochas metacarbonatíticas principalmente como calciocarbonatitos. Aquelas intensamente hidrotermalizadas são classificadas como ferrocarbonatitos e magnesiocarbonatitos. Indicam filiação magmática comum para todos os cinco litofácies, associada a processos de diferenciação magmática por segregação mineral.
This study found that the metacarbonatite rocks of the Angico dos Dias Metacarbonatite Complex (CMCAD), consisting mainly of calcite, apatite, olivine, phlogopite and magnetite are arranged in two sets: one located at the phosphate mine Galvani (main body, Campo Alegre de Lourdes-BA) and the other at the Farm Pimenteira (Caracol-PI). Variation in the content of apatite, iron-magnesium minerals and magnetite sets up a cumulatic layering and allows individualize five petrographic facies (gradual contacts). Furthermore, exhibit weathering mantle, which results in the residual phosphate ore (apatite-rock). Register at least three deformational phases marked by primary structures (layering reliquiar - S0) that due to the transposition process (D1) of the foliation S1 and D2 deformation associated with thrust zones (S2) remain scantily the least deformed areas. D2 evolves into a tectonic vertical banding (S3) in the shear zones (D3). Isotopic data indicate that metacarbonatite rocks, dated at 2,011 ± 6Ma (U-PB in baddeleyite and zircon), originated from a mantle source enriched and the enrichment in 18O reflects the rebalancing during metamorphism/hydrothermalism related the Brasiliano Event. Petrography and mineral chemistry data point: the olivine changes to serpentine, tremolite, anthophyllite and magnetite; which it is common to exsolution of dolomite in calcite and ilmenite in magnetite and; that carbonatites were partially silicified. The other rocks CMCAD, mylonite and metamorphosed to amphibolite facies high (perthites) exhibit potassification process (fenitization), metasyenite and metasyenogranite, and sericitization, saussuritization and epidotization processes of plagioclase. The metasomatic/hydrothermal event (medium to high greenschist facies) has regional character and reaches beyond CMCAD rocks the rocks of Sobradinho-Remanso Complex. Geochemical data classify metacarbonatite rocks mainly as calcium carbonatites. Those intensely hydrothermalized are classified as iron metacarbonatites and magnesium carbonatites. Indicate common magmatic membership for all five lithofacies, associated with magmatic differentiation processes for mineral segregation.
Cerva-Alves, Tiara. "Geologia dos carbonatitos ediacaranos de Caçapava do Sul, Rio Grande do Sul, Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/157570.
Повний текст джерелаThe integrated evaluation of soil geochemistry, aerogammaspectrometry (eTh), geological and structural mapping associated with description of boreholes and outcrops of Caçapava do Sul region, southernmost Brazil, led to the discovery of two carbonatite bodies. They are located near to the east and southeast of Caçapava Granite, intruding the Passo Feio Complex. The system is composed by early alvikite pink-colored rock followed by late white beforsite dikes in deformed tabular units concordant with the host rock schistosity and folds. Petrographic and scanning electron microscopy show that the alvikites are dominantly by calcite with subordinate apatite, magnetite, ilmenite, biotite, baddeleyite, zircon, rutile, pyrochlore-like and rare earth element minerals. Beforsites have the same minor and accessory minerals of the alvikites. U-Pb zircon geochronology via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was performed on a beforsite sample, yielding a 603.2 ± 4.5 Ma crystallization age, in an Ediacaran post-collisional environment with transpressive tectonism and volcanic activity market by initial shoshonitic characteristics.
Mäder, Urs Karl. "The Aley carbonatite complex." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26006.
Повний текст джерелаScience, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
Djeddi, Asma. "Pétrogenèse des carbonatites et magmas alcalins protérozoïques d’Ihouhaouene : terrane de l’In Ouzzal, Hoggar occidental, Algérie." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG022/document.
Повний текст джерелаThe In Ouzzal Archaean craton represents a succession of intrusive and metamorphic events since Eburnean, and an important marker of geodynamic processes through geological time. The Ihouhaouene area located in the N-W of In Ouzzal terrane in Algeria is unique by the presence of Proterozoic carbonatite intrusions associated with silica-saturated alkaline rocks. These intracontinental carbonatites are among the oldest and exceptional because of their diversity and the presence of unusual rare earth minerals. Carbonatites are pegmatitic or brecciated with fragments of syenite. They are calciocarbonatites with calcite (> 50 vol.%), apatite, clinopyroxene and wollastonite and are associated with red or white syenites in massive outcrops. Syenites are composed of alternating light levels of red alkaline feldspar or wollastonite associated with white feldspar and dark levels of apatite and clinopyroxene. Carbonatites and syenites form a cogenetic suite characterized by an increase in silica and decrease in calcium and CO2 content. The carbonatites have silica content ranging from 5 to 35 wt.%, 28 to 53 wt.% CaO, and 11 to 36 wt.% CO2. Syenites have high K2O (12 wt.%) and low Na2O content (1 wt.%). Carbonatites and syenites have high incompatible element concentrations with high REE content (7000*chondrites and 1000*chondrites, respectively) and high U, Pb, Sr and Th content. Trace elements (eg. Rare Earths, Nb-Ta, Zr-Hf) in magmatic minerals (apatite-pyroxene) of carbonatites and syenites reveal complex magmatic processes at the origin of these rocks involving several stages of fractional crystallization and immiscibility from a CO2-rich melilititic magma. Silica-rich carbonatites and white syenites are characterized by high Nb/Ta, Y/Zr and Rb/Sr ratios, typical of carbonate-rich magmas by immiscibility. The red syenites have characteristics of immiscible differentiated silicate melt. Silica-poor carbonatite minerals have variable subchondritic Nb/Ta (<10) indicating crystallization from highly evolved liquids and the presence of late carbonatitic magmas. Apatites, in particular, record various magmatic and supergene processes. They present, in some rocks, redistribution and enrichment in rare earth elements, which are characterized by exsolutions of britholite in silica-rich carbonatites and monazite-quartz-calcite inclusions in silica-poor carbonatites. These minerals reflect local sub-solidus re-equilibration with late-magmatic fluids rich in Cl-Th-REE for the exsolution of britholite and S-Ca-P-CO2 for monazite inclusions. The apatite and zircon present in these alkaline and carbonatite rocks, allow determination of the syn-metamorphic crystallization age of the Ihouahouene magmatic complex at 2100 Ma and confirm the pan-African age of its exhumation. The petrological, geochemical and geochronological study of Ihouhaouene carbonatites and syenites highlights the magmatic origin of these rocks and constrains the fluid-rock interactions at sub-solidus conditions leading to REE-enrichment. The carbonatites and syenites result from a low partial melting rate of a CO2-rich Precambrian mantle. Several fractional crystallization and immiscibility stages allowed the genesis of these hybrid magmas, trapped along large shear-zones during the Archean/Eburnean transition period in the In Ouzzal terrane, characterized by extensive deformation in ultra-high-temperature granulitic environment
Rahman, Aklaqur. "Alnö Carbonatite: A Future Moneymaker?" Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-328062.
Повний текст джерелаKarbonatit är en ovanlig bergart som innehåller minst 50 procent karbonater, därav namnet. De hittas ofta i samband med alkaliska silikat-bergarter, vilket innebär att de innehåller till stor del natriumoxid och kaliumoxid samt kisel, och är viktiga för att kunna förstå processer i manteln. Karbonatiter är kända för att vara innehållsrika på sällsynta jordartsmetaller, även kända som REE, jämfört med andra magmatiska bergarter. Alnökomplexet ligger i den norra delen av Alnön, nordost om Sundsvall och är ett av världens största alkaliska och karbonatit-ringkomplex, med en radie på 2,5 km. Dess ursprung i jordens inre är okänt men det tros vara ett resultat av en mantelplym, smältor från manteln som stiger mot ytan, och åldersdatering via absoluta dateringsmetoder tyder på att karbonatiterna är nästan 600 Ma. Stora mängder karbonatiter har hittats i Alnökomplexet och syftet med detta arbete är att bedöma om Alnökomplexet potentiellt kan bli gynnsam som källa för prospektering av sällsynta jordartsmetaller, ur ekonomisk synpunkt. Detta utfördes genom att analysera prover från Alnökomplexet samt studera data från Magnus Anderssons arbete om Alnökomplexet. Proverna analyserades med hjälp av en mikroprob som fotograferade apatiten, vita kristaller i ett mörkgrå matrix, då apatit indikerar på hög sannolikhet för REE-förekomst. Sedan redigerades dessa bilder med Photoshop och Paint, där andra kristaller redigerades bort så att det enda som var kvar var de vit-gråa utåtstickande kristallerna mot ett kalcitrikt matrix. Med ett annat program som heter ImageJ beräknades arean av dessa kristaller samt procenten av arean som apatiterna utgör i tunnslipen. Detta gav en viss uppskattning på hur stor mängd REE som kan förekomma i Alnökarbonatiter. Resultatet jämfördes med data från Magnus Andersson som har gjort en 3D- undersökning av karbonatiter under Alnö-komplexet. Apatiten utgjorde en area på 13 % och mängden REE var inte tillräckligt stor mängd relativ marknadspriserna samt utvinningskostnader för att räknas som vinstgivande.
Mollex, Gaëlle. "Architecture de la plomberie du volcan carbonatitique Oldoinyo Lengai : nouvelles contraintes sur la source, les transferts hydrothermaux, et la différenciation magmatique dans la chambre active." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0123/document.
Повний текст джерелаThe uniqueness of Oldoinyo Lengai to emit natrocarbonatite lavas makes this volcano a natural laboratory to study the genesis of these magmas. New helium isotopic data permit to assert that the signature of the fumaroles has been constant since 1988 despite the radical morphological change of the summit crater after the last sub-Plinian eruption in 2007-2008. The alternation of the effusive and explosive eruptions does not cause major modifications in the hydrothermal system architecture, which is inferred to be deeply rooted. Cognate xenoliths that were emitted during the eruption in 2007-2008 represent a unique opportunity to document the igneous processes occurring within the active magma chamber. The comparison between the noble gas (helium) isotopic compositions of the active magma chamber and those of the other silicate volcanoes of the Arusha region indicates that both types of magmatism have similar sources, identified as being a typical sub-continental lithospheric mantle, which was previously metasomatized by asthenospheric fluids. Moreover, these isotopic signatures confirm that no crustal contamination has occurred during the magma ascent from the mantle to the surface. Detailed petrographic descriptions coupled to a thermo-barometric approach, and to the determination of volatile solubility models for a phonolite composition, allow us to identify the melt evolution at magma chamber conditions and the storage parameters. These results indicate that the magma injected in 2007 has a phonolitic composition and contains a high amount of volatiles (3.2 wt.% H2O and 1.4 wt.% CO2) as well as a temperature around 1060° C. This magma subsequently evolved in the crustal magma chamber located at 11.5 ± 3.5 km depth until reaching a nephelinite composition and a temperature of 880°C. During the differentiation in the magma chamber, the silicate magma is enriched in calcium, sodium, magnesium and iron, whereas the content of silicate, potassium and aluminum decreases. Our results support previous studies related to this eruption, and are similar to the historical products emitted during the whole volcano history, permitting the suggestion that no major modification in the plumbing system has occurred during the Oldoinyo Lengai evolution. The trace elements (REE, LILE and HFSE) measured in the minerals and melt inclusions reveal a concentration reaching 100 to 1000 times the primitive mantle composition. A preliminary experimental study based on the recharge melt composition (phonolite) and identified magma chamber conditions (P, T) permits to reproduce the immiscibility between silicate and carbonatite liquids, key processes at the origin of the Oldoinyo Lengai carbonatites. The continuation of this experimental study will lead to a better comprehension of the carbonatite genesis, thus improving our understanding of the processes that are responsible for the enrichment in trace elements
Broom-Fendley, Sam Louis. "Targeting heavy rare earth elements in carbonatite complexes." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/18490.
Повний текст джерелаNorton, Gillian Elizabeth. "The physical properties of carbonatite and silicate magmas." Thesis, Lancaster University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316563.
Повний текст джерелаSharpe, Joanna Carleton University Dissertation Geology. "Geochemistry of the Cargill Carbonatite Complex, Kapuskasing, Ontario." Ottawa, 1987.
Знайти повний текст джерелаMoore, Meghan. "Carbonatite-related rare-earth mineralization in the Bear Lodge alkaline complex, Wyoming: Paragenesis, geochemical and isotopic characteristics." ElSevier, 2014. http://hdl.handle.net/1993/23991.
Повний текст джерелаBrod, José Affonso. "Petrology and geochemistry of the Tapira alkaline complex, Minas Gerais State, Brazil." Thesis, Durham University, 1999. http://etheses.dur.ac.uk/4971/.
Повний текст джерелаSalo, A. (Aleksi). "Geology of the Jaakonlampi area in the Siilinjärvi carbonatite complex." Bachelor's thesis, University of Oulu, 2016. http://urn.fi/URN:NBN:fi:oulu-201604091452.
Повний текст джерелаMcMahon, Sorcha Ciara. "New insights into deep mantle melts: the carbonatite-melilitite connection." Thesis, University of Bristol, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680375.
Повний текст джерелаPollock, Stephen John Carleton University Dissertation Geology. "The isotopic geochemistry of the Prairie Lake carbonatite complex, Ontario." Ottawa, 1987.
Знайти повний текст джерелаMorisset, Natalie Carleton University Dissertation Geology. "Stableisotope and radioisotope geochemistry of the Panda Hill carbonatite, Tanzania." Ottawa, 1992.
Знайти повний текст джерелаPreci, Lorenzo. "Concrezioni Carbonatiche Metano-derivate nella valle del Secchia." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
Знайти повний текст джерелаMungall, James E. "Geochemistry of carbonatite and alkali pyroxenite, Bancroft Terrane, Grenville Province, Ontario." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59521.
Повний текст джерелаBédard, L. Paul. "Pétrographie et géochimie du stock de Dolodau : syénite et carbonatite associée /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1988. http://theses.uqac.ca.
Повний текст джерелаRoopnarain, Sherissa. "Petrogenesis of Carbonatites in the Alnö Complex, Central Sweden." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-215436.
Повний текст джерелаHodgson, Neil Andrew. "Carbonatites and associated rocks from the Cape Verde Islands." Thesis, University of Leicester, 1985. http://hdl.handle.net/2381/35041.
Повний текст джерелаChmyz, Luanna. "Géochronologie et pétrogenèse du complexe ultramafique-alcalin carbonatitique de Jacupiranga (BR)." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT080/document.
Повний текст джерелаThe Jacupiranga Complex (Cajati, SP) is one of several Meso-Cenozoic alkaline units intrusive along the Parana Basin margins, in the Central-Southeastern part of the South American Platform. This unit comprises a large variety of lithotypes: dunites, whehrlites, clinopyroxenites, rocks from the ijolite series, diorites, syenites, manzonites, phonolites, lamprophyres, and carbonatites. While carbonatites have been extensively investigated over the last decades, as they host an important phosphate ore deposit, little attention has been paid to the silicate rocks. The current study presents new geochronological, mineralogical, geochemical, and isotopic data on the Jacupiranga Complex, in order to better understand the origin and evolution of the unit. 40Ar/39Ar ages for different lithotypes range from 133.7±0.5 Ma to 131.9±0.5 Ma, while monzonite zircon analyzed by SHRIMP yields a U-Pb concordia age of 134.9±0.65 Ma, indicating that the Jacupiranga emplacement was contemporaneous with the extrusion of the tholeiites of the Paraná Magmatic Province. There seems to be no obvious age progression for clinopyroxenites, diorites, or lamprophyres, although the monzonite yield both 40Ar/39Ar and U-Pb ages older than those of the other rocks. Geochemical compositions of the silicate rocks are used to evaluate two main magma-evolution trends for that unit: (1) a strongly silica-undersaturated series, probably related to nephelinite melts and (2) a mildly silica-undersaturated series related to basanite melts. Lamprophyre dikes within the complex are considered as good representatives of the basanite parental magma. Compositions of the calculated melts in equilibrium with diopside cores from clinopyroxenites are quite similar to those of the lamprophyres, suggesting that at least a part of the clinopyroxenites is related to the basanite series. Meladiorite and monzonite show petrographic features and geochemical and isotope compositions (87Sr/86Sri: 0.705979-0.706086 and 143Nd/144Ndi: 0.511945-0.512089) suggestive of crustal assimilation, although it may be relegated to a local process and to some basanite batches. Carbonatites yield isotopic ratios (Nd and Pb) and trace elements composition (e.g. Ba/La, Nb/Ta) that preclude a link by liquid immiscibility with the silicate rocks. Two scenarios are envisaged: a primary magma of carbonatite composition originated by direct partial melting of the mantle or an origin by immiscibility from a hypothetical silicate magma currently unknown in the complex. Nd-Sr-Pb-Hf isotopic data indicate an important contribution of the subcontinental lithospheric mantle (SCLM) in the genesis of those rocks. Lamprophyres and calculated melts in equilibrium with clinopyroxene show relatively high CaO/Al2O3 and La/Zr ratios and low Ti/Eu, indicating a lithospheric mantle metasomatized by CO2-rich fluids and vein-plus-wall-rock melting mechanisms. Compositional variations among those liquids are attributed to the mixing between metasomatic veins partial melt and peridotite partial melt, besides as well as to the differences in the clinopyroxene/garnet ratios on in the mantle. ΔεHf variations suggest a slightly higher role of the wall-rock peridotite as a source component for the nephelinites, whereas the basanite parental magma is mainly related to the wehrlite veins, although both are enriched magmas. Depletion in Nb-Yb, enrichment of LREE relative to HREE, and enrichment in Cs, Rb and Sr in the lamprophyres suggest that the metasomatic reactions in the mantle source were caused by slab-derived fluids. TDM model ages indicate the heterogeneous nature of the mantle source and are coherent with the values generally obtained for the alkaline occurrences from the Central-Southeastern part of the South-American Platform
Palmer, David A. S. "Geology and Geochemistry of the Amba Dongar carbonatite-hosted fluorite deposit, India." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68237.
Повний текст джерелаThe hydrothermal history of the complex is extensive, consisting of two main systems, the first resulted in large amounts of fenitization, causing extensive K and Na metasomatism of the surrounding sandstones and the second, dealt with here, was responsible for the silicification of large amounts of the calcitite and the deposition of economic quantities of fluorite.
The deposit consists of veins and vug fillings of blue, purple, white, yellow and colorless fluorite. The main ore zone, which is currently under production, and most other showings, are found near the carbonatite-sandstone contact.
Chemical analyses and mass balance calculations show that the fluids responsible for silicification removed significant quantities of Ca from the rock while adding large amounts of Si, Al and F. Alteration associated with fluorite deposition involved the removal of Al from the rock and the addition of large quantities of F and Si.
Fluid inclusions in fluorite point to a low temperature-low salinity ore fluid, which decreased in temperature and salinity with evolution. Crushing experiments performed on fluid inclusions in both fluorite and quartz reveal the presence of ${ approx0.08}$ m of dissolved CO$ sb2$ in solution while analyses of leachates and decrepitate residues from fluid inclusions show significant concentrations of Ca, Al, Na, Cl and S in their fluids. (Abstract shortened by UMI.)
Dalsin, Mallory Linda. "The mineralogy, geochemistry and geochronology of the Wicheeda Carbonatite Complex, British Columbia." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45393.
Повний текст джерелаTing, Wupao. "A fluid and solid inclusion study of the Sukulu carbonatite complex, Uganda." Thesis, Kingston University, 1994. http://eprints.kingston.ac.uk/20577/.
Повний текст джерелаOnuonga, Isaac Oriechi. "Geochemistry and mineralization of Buru and Kuge volcanic carbonatite centres, Western Kenya." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/15470.
Повний текст джерелаLee, Mi Jung. "Minéralogie, pétrologie et géochimie de l'association Phoscorite-Carbonatite du complexe alcalin de Sokli, Finlande." Saint-Etienne, EMSE, 2002. http://www.theses.fr/2002EMSE0020.
Повний текст джерелаThe Sokli complex (67°57'N, 29°05'E) is located in the north-eastern Finih Lapland, and belongs to the Paleozoic (380-360 Ma) Kola Alkaline Province (KAP). The complex comprises two main units organized as concentric zones. The outer zone is composed of alkaline silicate rocks intruded by numerous veins of carbonatites and largely transformed by the related fluids ; the inner zone is dominantly composed of carbonatites and subordinate phoscorites. Based on mineral assemblages, mineral compositions, and bulk chemical compositions, the Sokli phoscorites and carbonatites are classified in five stages of intrusion. In the early stages, phoscorites and calcite carbonatites are intimately associated with each other (P1-C1, P2-C2 and P3-C3 phoscorite-carbonatite pairs) ; in the later stages, the intrusive material is mostly dolomitic (D4 and D5 dolomite carbonatites) and lacks associated phoscorite. The latest stage rocks occur along a fracture zone in the centre of the 'magmatic core'
Baghdadi, Bashar. "Géochimie analytique et prospection : application aux roches mantelliques de type péridotitique." Paris 6, 2013. http://www.theses.fr/2013PA066235.
Повний текст джерелаAngrites are a group of rare achondrites with particular mineralogy. They are the oldest igneous rocks in the solar system (~4. 564 Ga). Their petrogenesis is poorly understood, their unusual petrography put up their origin in the heart of a great debate. The presence of metal and reaction microstructures in some samples of this group deserve to be studied carefully what has not been done yet. The thermodynamic modeling would recognize the conditions of their formation. We carried out petrogeochemical and mineralogical analysis on some angrites of the peridotitic type and on some terrestrial rocks (carbonated enclaves) of Tell Thennoun/Syria. The results allow us to constrain the P-T conditions necessary for the existence of the parental magmatism of angrites and to verify the extent to which data on terrestrial peridotites are consistent with these results. The expertise of geochemical analysis and their applications to the field of mineral exploration is one of the objectives of this thesis, the study of carbonated rocks of Tell Thennoun is an example of the latter. We conclude that the angrites parent body is a large planetoid with a metamorphic evolution and the associated magmatism is typical of early evolution of planets. About the carbonated rocks of Tell Thennoun, it seems that they represent rocks of sedimentary origin, rather than magmatic ones, which have been recycled in the Syrian rift volcanism and show a low economic interest
Bui, Andrea. "Studio della decarbonatazione durante l'interazione tra rocce carbonatiche e magma." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16264/.
Повний текст джерелаFrejd, Julia. "Magnetic Mineralogy of Nb-bearing Carbonatites from Oldoinyo Dili (Tanzania)." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-445837.
Повний текст джерелаNiob (Nb) och sällsynta jordartsmetaller (REE’s) har på senare år fått stor uppmärksamhet för sin betydelse för den moderna tekniska industrin, och specifikt för den förhöjda hållbarhet som de bidrar med. Den huvudsakliga källan till Nb och REE’s på jorden är karbonatiter och associerade alkalisilikater. Denna rapport undersöker de magnetiska egenskaperna för karbonatit-komplexet Oldoinyo Dili i norra Tanzania. Forskare har tidigare anat att det finns en koppling mellan Fe-bärande mineralogi och bildandet av Nb-mineraliseringar vid Oldoinyo Dili. Denna hypotes undersöks vidare i denna rapport genom att kombinera detaljerade petrografiska observationer med nya mätningar av magnetisk susceptibilitet. Syftet är att undersöka om det finns någon korrelation mellan förekomst av Nb-mineraliseringar och de typer av järnmineral som finns vid Oldoinyo Dili. Baserat på de genomförda magnetiska susceptibilitets-mätningarna så finns det åtminstone två olika sorters järnmineral i de undersökta proverna. De karaktäriseras av olika magnetiska trender vid upphettning/nedkylning och även av sina olika Curietemperaturer (Tc). Kombinerat med petrografiska observationer uttolkas att dessa mineral är magnetit (Fe2O4) med Tc ~580°C, samt en mineral som troligen är en solid solution av ilmenit (FeTiO3) och hematit (Fe2O3) med Tc ~300°C. Det går inte att senågon tydlig koppling mellan förekommande opaka mineral och det totala Nb-innehållet i karbonatiterna med säkerhet enbart utifrån petrografin och de genomförda magnetiska mätningarna. Resultaten av denna rapport utgör ett bra första steg mot att förstå relationen mellan Nb-mineraliseringar och den magnetiska mineralogin för Oldoinyo Dili, men mer detaljerade analyser av mineralkemin är nödvändigt för att till fullo förstå de komplexa förhållanden som råder vid bildning av dessa.
Bizzarro, Martin. "Major element and isotope geochemistry (Sr, Nd and Hf) of mantle derived peridotites, carbonatites and kimberlites from Canada and Greeland; insights into mantle dynamics." Thèse, Chicoutimi : Montréal : Université du Québec à Chicoutimi ; Université du Québec à Montréal, 2003. http://theses.uqac.ca.
Повний текст джерелаBibliogr.: f. 105-109. Document électronique également accessible en format PDF. CaQCU
Niegisch, Max, Andreas Kamradt, and Gregor Borg. "The upper zone of the Storkwitz Carbonatite: Geochemical and mineralogical characterization of the REE-mineralisation in the upper zone of the Storkwitz Carbonatite Complex from drill core SES-1/2012." Sächsisches Landesamt für Umwelt, Landwirtschaft und Geologie, 2020. https://slub.qucosa.de/id/qucosa%3A71506.
Повний текст джерелаThe Storkwitz-Carbonatite is a Late Cretaceous intrusive complex, which is well-explored by a relatively large number of exploration bore holes both from the 1970ies, 1980ies and from one more recent bore hole, SES-1/2012. The carbonatite complex hosts a (currently) marginally economic mineralisation of rare earth elements (REE) and niobium, which is technically still difficult to recover. The upper part of the carbonatitic body is located some 100-120 m below the Pre-Cenozoic land surface, which in turn is overlain by approximately 100 m of glacial, fluvio-glacial, and fluviatile sediments. The aim of this study was to characterize the mineralisation in the upper part of the intrusion geochemically and mineralogically and to try to identify indications of a supergene overprint on the late magmatic to hydrothermal mineralisation. Fresh drill core samples from the exploration bore hole SES-1/2012 have revealed that the mineralisation is associated with a carbonatitic igneous breccia body and also with several alvikite veins. The breccia body is very heterogeneous, displays a variety of matrix colours and also a range of matrix-to-clast ratios.
Fournier, Antoine. "Magmatic and hydrothermal controls of LREE mineralization of the St.-Honoré carbonatite, Québec." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68174.
Повний текст джерелаThe carbonatite comprises concentric lenses which evolved from calcitite through dolomitite, to a brecciated core of ferrocarbonatite which hosts REE mineralization, mainly as REE flurocarbonates and monazite. This mineralization forms part of the breccia cement, and is associated with hematite, chlorite, ferroan dolomite, minor thorite, ilmenorutile and pyrite.
Apatite-phlogopite geothermometer yielded magmatic temperatures between 1150 and 800$ sp circ$C for the complex, and for the REE Zone, the temperatures range between 380 and 346$ sp circ$C, and are interpreted to reflect subsolidus conditions. An independent chlorite geothermometer yielded similar temperatures (364 to 321$ sp circ$C) for the REE Zone breccia cement.
A model is proposed in which REE concentration in the magma was initially buffered by the crystallization of pyrochlore and apatite, and was subsequently allowed to build up when these phases stopped crystallizing in the most evolved ferrocarbonatite. Saturation of this magma with water, late in its crystallization history, led to the separation of an acidic aqueous phase into which the REE were partitioned as fluorocomplexes. Fluid overpressure produced hydrobrecciation which led to adiabatic expansion of the fluid and rapid cooling. The precipitation of REE minerals was caused by a combination of the drop in temperature and an increase in pH due to the interaction of the fluid with the dolomite.
Alves, Paula Regina. "The carbonatite-hosted apatite deposit of Jacupiranga, SE Brazil: styles of mineralization, ore characterization and association with mineral processing." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2008. http://scholarsmine.mst.edu/thesis/pdf/prayb4_09007dcc804f7bd9.pdf.
Повний текст джерелаVita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 9, 2008) Includes bibliographical references (p. 131-139).
Sage, R. P. "Alkali rock complexes - carbonatites of Northern Ontario and their economic potential." Ottawa, 1986.
Знайти повний текст джерелаChudy, Thomas Christof. "The petrogenesis of the Ta-bearing Fir carbonatite system, east-central British Columbia, Canada." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45749.
Повний текст джерелаCarmody, L. "Geochemical characteristics of carbonatite-related volcanism and sub-volcanic metasomatism at Oldoinyo Lengai, Tanzania." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1348540/.
Повний текст джерелаPrud'homme, Nathalie. "Caractérisation pétrographique et géochimique de la carbonatite et de la syénite de la mine Lac Shortt /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1990. http://theses.uqac.ca.
Повний текст джерела"Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en sciences de la terre" CaQCU Document électronique également accessible en format PDF. CaQCU
Hode, Vuorinen Jaana. "The Alnö alkaline and carbonatitic complex, east central Sweden - a petrogenetic study." Doctoral thesis, Stockholm University, Department of Geology and Geochemistry, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-546.
Повний текст джерелаThe Alnö complex on the central Swedish east coast is composed of a main composite intrusion (the main intrusion) and four smaller satellite intrusions (Söråker, Sälskär, Långharsholmen and Båräng) distributed around the main intrusion on Alnö Island and on the mainland north of the island. The major rock types exposed within the complex are melilitolite, pyroxenite, ijolite series (melteigite-ijolite-urtite), nepheline syenite, carbonatite and alnöite dykes. Melilitolite is only exposed within the Söråker intrusion. The intrusive sequence is melilitolite → pyroxenite → ijolite series → nepheline syenite → carbonatite → alnöite.
Mineralogical, whole rock geochemical and radiogenic isotope (Nd-Sr-Pb) studies of exposed rocks from the Alnö alkaline complex, east central Sweden, were performed in order to investigate the genetic relationships between the diverse rock-types, and to evaluate the contributions from mantle and crustal components in the genesis of the complex. Most analysed samples fall within the depleted quadrant in a eNd-eSr diagram, similar to carbonatites and alkaline silicate rocks from other complexes, indicating derivation of parental magma(s) from a source that had experienced time-integrated depletion in LIL elements. Contamination by local crust is indicated by Sr and Pb isotope data, but is geographically restricted to samples collected from the outer parts of the main intrusion and from satellite intrusions. This localized contamination is attributed to selective hydrothermal element leaching of surrounding bedrock during fenitization. Nd- and Sr-isotope data separates the carbonatites into two groups (group I and II), each related to a specific set of silicate rock types. The overlap of group II carbonatites with ijolite and nepheline syenite could indicate a common origin through liquid immiscibility but this hypothesis cannot be confirmed by trace element data because initial concentrations are obscured by fractionation processes. Interestingly, results from AFC-modelling suggest that production of ijolite residual magma requires addition of a small volume (2.4 %) of carbonatite component to the parental magma, whereas formation of nepheline syenite residuals requires removal of an almost equal amount of carbonatite (1.5 %) to yield a statistically significant result. AFC-modelling further suggests that the various silicate rock types exposed within the complex are related to the same parental olivine-melilitite magma through crystal fractionation of olivine, melilite, clinopyroxene, nepheline, Ti-andradite and minor phases. These results agree with compositional trends exhibited by clinopyroxene and Ti-andradite from the silicate rocks of the main intrusion, which suggests co-genesis of pyroxenite, ijolite series rocks and nepheline syenite. Production of ijolite-like residual liquids can be achieved by <40% fractionation whereas production of nepheline syenite residuals requires >80% fractionation.
An investigation of the origin of silicate minerals in carbonatites suggest that most silicate minerals observed in the carbonatites on Alnö Island are derived from surrounding wall-rock and/or produced through corrosive interaction between carbonatite liquid and assimilated phases. This leads to ambiguities when addressing the possible genetic link between carbonatites and associated silicate rocks as occurrences of identical “liquidus” phases in inferred immiscible liquids may not actually be such.
Hode, Vuorinen Jaana. "The Alnö alkaline and carbonatitic complex, east central Sweden : a petrogenetic study /." Stockholm : Department of Geology and Geochemistry, Stockholm University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-546.
Повний текст джерелаYa'acoby, Avee. "The petrology and petrogenesis of the Ren carbonatite sill and fenites, southeastern British Columbia, Canada." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46653.
Повний текст джерелаSubasinghe, Nalaka Deepal. "Formation of secondary phosphates by weathering of apatite rich carbonatite : an example from Sri Lanka." Thesis, University of Reading, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270305.
Повний текст джерелаMarageni, Manoka. "The geochemistry and petrogenesis of the Saltpeterkop carbonatite complex near Sutherland, Northern Cape, South Africa." Master's thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/29818.
Повний текст джерелаRiley, Teal Richard. "Quaternary volcanism of the Rockeskyll Complex, West Eifel, Germany and the carbonatite-nephelinite-phonolite association." Thesis, University of Bristol, 1994. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260870.
Повний текст джерелаNabyl, Zineb. "Caractérisation expérimentale du comportement des métaux rares au cours de la différenciation des carbonatites et des magmas alcalins." Thesis, Orléans, 2020. http://www.theses.fr/2020ORLE3048.
Повний текст джерелаCarbonatites and alkaline magmatic rocks occur in intraplate context and constitute a small fraction of the earth magmatism. Those magmas are particularly enriched in volatiles (carbon dioxide, halogens, water) and also in rare metals (REE, Hf, Zr, Ta, Nb). The associated deposits are often affected by hydrothermal and supergen processes which erase any relation to the magmatic processes at the origin of these magmas (immiscibility, differentiation, fractional crystallization) and responsible of the rare metal and volatile enrichments.High pressure and high temperature experiments have been performed to characterize the behavior of rare metals during both magma differentiation. These experiments simulate the immiscibility between carbonate and alkaline silica-undersaturated melts, during the crystallization of the magma.The optimum of carbonate melt REE enrichments across alkaline magma differentiation course is identified : carbonate melts immiscible with highly differentiated and polymerised silicate melts of phonolitic/phono-trachytic compositions are the REE richest. A modelling of carbonate melts REE enrichment based on the silicate melt composition is suggested, to identify the REE potential of carbonatites which may be immiscible with an alkaline magmatic rock, or to identify at which differentiation stage the immiscibility has occurred. Moreover, the silicate melt degree of differentiation and polymerisation has also an impact on crystal rare metal enrichments : crystals which coexist with highly differentiated and polymerized silicate melts are highly enriched in rare metals. This implies that silicate melts become depleted in REE across the differentiation compare to crystals and carbonate melts
Sumida, Viktor Yuri Doná. "Investigação geofísica (magnetometria) no carbonatito da Fazenda Varela, Domo de Lages, SC." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/44/44137/tde-26042018-090729/.
Повний текст джерелаThe present study aimed to investigate the Carbonatito Fazenda Varela, through the application of a geophysic method, magnetometry, which presents as a stand out investigation of alkaline intrusions. The results from magnetic survey that was held in Carbonatito Fazenda Varela, located in Alkaline District of Lages, Santa Catarina, reveal a strong magnetic signature, with highlight to three anomalies in the studied region: one of them has a strong remanent magnetization, whereas the other two have normal polarization, therefore, presents a weak remanent component. From the data collected through the survey, 3D models were obtained by inversion, which allowed to evaluate the extent, geometry and the contrasts of susceptibilities of the carbonatites with the sedimentary rocks of the Guatá Group, belonging to the Rio Bonito Formation. However, the presence of the remanent magnetization in one of the bodies produced inaccurate results in the inversion of the residual magnetic field. Thus, two techniques, the Vertical Integral of the Analytical Signal and the Analytical Signal of the Vertical Integral, were applied to attenuate or minimize its influence. The results of 3D models of susceptibility distribution indicated three anomalies with lengths of 70m, 15m, 80m, and depths of 90m, 50m, 115m, respectively, being presented and evaluated here.
Martin, Alexis. "Modélisation de saumures carbonatées et caractérisation hydrogéologique de la mine Niobec, Saint-Honore, Québec : /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1993. http://theses.uqac.ca.
Повний текст джерелаNgwenya, Bryne Tendelo. "Magmatic and post-magmatic geochemistry of phosphorus and rare earth elements in carbonatites." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306803.
Повний текст джерелаBurger, Erasmus Petrus. "An Investigation of the carbonatites of the Kaapvaal Craton and their tectonic context." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/43297.
Повний текст джерелаDissertation (MSc)--University of Pretoria, 2013.
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Geology
MSc
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