O complexo estuarino-lagunar de Cananéia-Iguape, localizado na porção sul do litoral do Estado de São Paulo, integra uma importante reserva ambiental e um ecossistema costeiro extremamente produtivo. A região abriga o canal do Valo Grande, construído há mais de 160 anos, o qual favorece a introdução água doce do rio Ribeira de Iguape diretamente no sistema estuarino contribuindo à importantes alterações biogeoquímicas como o aporte de nutrientes, metais e outros elementos pouco solúveis, que acabam tendo como destino os sedimentos. No presente trabalho foi realizada a coleta de amostras da coluna de água e de sedimentos de superfície ao longo do complexo estuarino-lagunar de Cananéia-Iguape e ambientes contíguos. Também houve a realização de perfis de sedimento na região sul do estuário, considerada mais preservada. O objetivo principal foi avaliar os processos que regem a distribuição dos Elementos Terras Raras (ETR) nos sedimentos do sistema, conhecendo as propriedades hidroquímicas do sistema, associando e comparando os ETR a outros elementos presentes em baixas concentrações, de modo natural ou resultantes de alterações de origem antrópica, utilizando padrões de fracionamento, anomalias e assinatura geoquímica de minerais que atuam na distribuição dos ETR verificando seu potencial para evidenciar a origem e interpretar níveis naturais e efeitos antrópicos aos quais o Complexo está submetido. Os resultados mostraram que as características hidroquímicas na região norte do Complexo encontram-se fortemente influenciadas pelo aporte de águas fluviais via Valo Grande e pelos processos biogeoquímicos associados a ele, enquanto a região sul apresentou-se mais conservada, mostrando equilíbrio biogeoquímico natural de sistemas estuarinos, oferecendo maior suporte à produção primária. Nos sedimentos de superfície, as concentrações elementares de Al, As, Ba, Ca, Cd, Co, Cr, Cs, Fe, Hg, Hf, P, Pb, Rb, Sb, Sc, Th, U, Zn, Zr e ETR* apresentaram distribuição bastante relacionada às características deposicionais/texturais, de forma que a maioria destes elementos tiveram maiores concentrações em regiões de baixa energia hidrodinâmica, no interior do rio Ribeira de Iguape e no mar Pequeno. Considerando como referência os valores guias de qualidade dos sedimentos canadenses (TEL e PEL), os elementos As, Cd, Pb, Cr, Hg e Zn apresentaram concentração abaixo dos valores que indicam frequente ocorrência de efeitos adversos nos organismos aquáticos (PEL), mas foi observado que em alguns locais, As, Cr, Pb e Zn superaram os valores de concentração que indicam uma baixa probabilidade de ocorrência de efeitos adversos à biota (TEL). Fatores de enriquecimento calculados com relação à crosta continental superior (FEUCC) e ao background geoquímico regional (FEBG) apontaram regiões onde ocorrem concentrações de Pb, P e Sb acima dos níveis considerados naturais, entretanto evidenciaram que os altos valores de As e Cr estariam relacionados a um enriquecimento natural dos sedimentos na região. No caso dos ETR, o FEUCC e FEBG indicaram enriquecimento na região do mar adjacente ao estuário e em estações no rio Ribeira e no Valo Grande. A aplicação de modelagem através da regressão múltipla linear mostrou que os valores, que seriam normalmente considerados anômalos, são naturais e refletem a presença de minerais pesados nestes locais. Outros elementos que parecem naturalmente enriquecidos onde há ocorrência minerais pesados são: As, Ca, Cr, Th, U, além dos elementos ditos sinalizadores, como Hf e Zr. Anomalias de Ce mostraram a possível relação com processos de oxidação de Ce+3 a Ce+4 mediada biológicamente nas zonas mais produtivas do estuário. Dos quatro perfis de sedimento obtidos na região sul do estuário, três mostraram seções com valores de FEUCC e FEBG para Pb que sugerem contribuição antrópica. Tais padrões decrescem em direção ao sul do sistema, porém praticamente não mostram variação temporal. Nenhuma concentração de Pb superou o valor de TEL nos testemunhos estudados. Zn e Hg mostraram enriquecimentos pontuais em diferentes seções do testemunho T3. Com relação aos ETR, houve novamente a observação de enriquecimento causado por minerais pesados, e os teores modelados parecem refletir níveis naturais para estes elementos nos quatro testemunhos. Tais informações podem ser utilizadas na ampliação do uso de ferramentas biogeoquímicas de avaliação e prevenção de riscos aos quais o sistema estudado está sujeito, e na tomada de decisão pelo poder público no sentido da conservação ambiental da região. / The estuary-lagoon complex of Cananéia-Iguape, in the southern portion of the coast of São Paulo state, is part of an important environmental reserve and an extremely productive coastal ecosystem. The region encloses the Valo Grande channel, built more than 160 years ago, which favors the introduction of fresh water from Ribeira de Iguape river directly into the estuarine system contributing to important biogeochemical changes in the region. Through this channel, many nutrients arrive at the estuary, as well as, metals and other slightly soluble elements, that end up as sediments. In this research, samples of the water column and surface sediments were collected in the estuary-lagoon complex of Cananéia-Iguape and contiguous environments, as well as, sediment profiles in the south of the estuary, considered to be the most conserved region. The main objective of this study was to evaluate the processes that govern the distribution of rare earth elements (REE) in the sediments of the system, associating and comparing them to other elements, both essential and toxic, using fractionation patterns, anomalies and the geochemical signature of minerals that act in the distribution of REE to evaluate the origin and interpret natural levels and the amplitude of possible anthropic effects to which the Complex is submitted. The results show that the hydrochemical characteristics in the northern region of the complex are strongly influenced by the provision of fresh water through Valo Grande channel and its resulting biogeochemical processes, while the southern region is more conserved, showing the natural biogeochemical balance of estuarine systems, offering greater support to primary production. The elemental concentrations of Al, As, Ba, Ca, Cd, Co, Cr, Cs, Fe, Hg, Hf, P, Pb, Rb, Sb, Sc, Th, U, Zn, Zr and REE* in the surface sediments, show distribution related to depositional/textural characteristics, in such a way most of these elements presented their highest concentrations in regions of recognized low hydrodynamic energy, in the Ribeira de Iguape river and Mar Pequeno region. A comparison of the values obtained for As, Cd, Pb, Cr, Hg and Zn with the Canadian sediment quality guidelines (TEL and PEL) shows that none of the evaluated elements reached concentrations indicating a frequent occurrence of negative effects on aquatic organisms (PEL), however, As, Cr, Pb and Zn have sometimes exceeded concentration values indicating a low probability of occurrence of adverse effects on biota (TEL). Enrichment factors calculated in relation to the upper continental crust (FEUCC) and the regional geochemical background (FEBG) pointed out regions where Pb, P and Sb accumulated above the levels considered natural, however have shown that the high values of As and Cr are related to a natural enrichment of the sediments in the region. For the REE, FEUCC and FEBG indicated enrichment in the sea region adjacent to the estuary and at stations in Ribeira de Iguape river and Valo Grande. Data modeling through linear multiple regression showed that the values, which would normally be considered anomalous, are natural and reflect the presence of heavy minerals at these sites. Other elements that appear to be naturally enriched where there is the indication of occurrence of such minerals are As, Ca, Cr, Th, U, in addition to the signaling elements Hf and Zr. Ce anomalies showed a possible relationship with biologically mediated Ce+3 to Ce+4 oxidation processes in the most productive areas of the estuary. Out of the four sediment profiles obtained in the southern region of the estuary, three showed sections with FEUCC and FEBG values for Pb suggesting anthropogenic contribution. Such values decrease towards the south of the system, however showed a small time variation. None of the obtained Pb values overcame the values of TEL for such sediment profiles. Zn and Hg showed one-off enrichments in different sections of T3 sediment core. Regarding REE, there was again the observation of enrichment caused by heavy minerals in one of the sediment cores, and the modeled contents seem to reflect natural levels for these elements in the four cores. Such information can be used in the expansion of the biogeochemical tools for assessment and prevention of the risks to which the studied system is subject and in the decision making by the public sector towards the environmental preservation of the region.

No presente trabalho são descritas as etapas de desenvolvimento e implantação das rotinas analíticas utilizando ICP-OES e ICP-MS para a determinação de elementos terras raras em materiais geológicos. A implantação inclui determinações comparativas de vários granitóides dos maciços ou complexos Ibiúna-Piedade, SP, e Cunhaporanga, PR, já previamente analisados por meio de ICP-MS e INAA (Universidade Kansas, em Lawrence, USA). Através de uma pequena modificação no método inicial, os limites de detecção para a análise dos ETR por ICP-OES foram melhorados para concentrações próximas à 10 vezes o condrito. Porém para a análise de ETR em materiais geológicos com valores inferiores a estes é necessária a utilização de uma técnica mais sensível como o ICP-MS. A técnica ICP-MS não é livre de problemas sendo necessárias correções de interferências moleculares e drift instrumental para a obtenção de resultados com precisão e exatidão adequados. Realizou-se a etapa de validação do método utilizando materiais de referência internacionais geológicos. A análise estatística dos resultados obtidos utilizando três métodos de abertura de amostra (ataque ácido em forno de microondas, em bombas tipo Parr e fusão alcalina) mostrou a possibilidade de utilização do ataque ácido em forno de microondas e da fusão alcalina com posterior separação cromatográfica como alternativas eficientes para a determinação de ETR apesar da baixa eficiência nas recuperações dos elementos Zr e Hf em rochas ácidas e gnáissicas equivalentes. / The steps for the development of the analytical routines leading to the determination of the rare earth elements (REE) with the use of ICP-AES and ICP-MS techniques are discussed in this contribution. The set-up of these routines was also evaluated with determinations of REE in several granitoid rocks from the Piedade-Ibiuna (SP) and Cunhaporanga (PR) complexes, and the results compared with those obtained in other laboratories (University of Kansas, Lawrence) with ICP-MS and INAA. The work previously performed for the adaptation of REE determination with ICPAES was reviewed, allowing analyses to be realized with better results for concentrations close to 10 times the chondrite value. At lower concentrations, REE analysis have to be performed with ICP-MS. The ICP-MS technique shows much better accuracy and precision than ICPAES, but presents problems of its own. Instrumental drift corrections, as well as corrections due to molecular interferences, are mandatory. Evaluation of the successfully adapted routines was realized analyzing international reference materials several times and applying statistical tests. A comparison of results with three dissolution techniques (acid attack in microwave oven, use of Parr type bombs, and alkaline fusion with borates) showed that both acid attack and alkaline fusion with later chromatographic separation are rather efficient alternatives for the determination of REE, although Zr and Hf are not fully recovered in many acid igneous and equivalent gneissic rocks.

Les interactions fluide-roche intervenant dans les systèmes hydrothermaux océaniques ont été étudiées expérimentalement en surveillant les isotopes du Mg et Sr. Les résultats suggèrent que les réactions rapides à températures moyennes pourraient expliquer en partie les divergences identifiées précédemment dans le bilan marin du Sr. De plus, la ré-dissolution de l'anhydrite dans les stades avancés peut expliquer les faibles quantités d'anhydrite trouvée dans les échantillons de basalte océanique altérés. L'évolution du δ26/24Mg dans les fluides indique que le Mg isotopiquement lourd a été incorporé préférentiellement dans les minéraux des argiles.Le fractionnement entre les terres rares et le Ca pendant la précipitation de calcite a été étudié expérimentalement. Ces données suggèrent que l'incorporation du REE3+ dans la structure de la calcite est probablement équilibrée par l'incorporation de Na+ et que les coefficients de partage déduits pour les conditions marines peuvent varier considérablement selon la composition du fluide. Enfin, l'étude de la solubilité de l'hydroxylbastnasite (REE(CO3)(OH)), conduite au cours de ce travail, indique que cette phase est moins soluble que les autres carbonates des terres rares connus. / The fluid-rock interactions occurring in hydrothermal systems at or near mid-oceanic ridges (MOR) were studied experimentally while monitoring the Mg and Sr isotopic evolution. The results suggest that fast intermediate-temperature reactions could partly explain previously identified discrepancies in the marine 87Sr/86Sr budget. Furthermore, late-stage anhydrite re-dissolution caused by fluid reduction and temperature decreases in our experiments represent a potential explanation for the low amounts of anhydrite found in altered oceanic basalt samples. The fluid δ26/24Mg indicate that isotopically heavy Mg was preferentially incorporated into the clays. Towards the interpretation of rare earth element (REE) patterns in marine calcite, the fractionation between the REEs and Ca during the precipitation of calcite was studied experimentally. These data suggest that the incorporation of REE3+ ions into the calcite structure was likely charge balanced by incorporation of Na+, and that inferred partition coefficients for marine conditions can vary substantially depending on the fluid composition. Furthermore, the solubility of hydroxylbastnasite (REE(CO3)(OH)) was determined, indicating that this phase is less soluble than other known REE carbonates.

The demand for rare earth elements (REEs) has increased over the last decade due to applications in high technology devices including those in the defense industry. The recovery of REEs from primary sources such as rare earth minerals are viable using physical separations followed by chemical processing. However, weak market values and environmental concerns have limited the viability of such operations. On the other hand, REE recovery from secondary sources such as apatite ore, bauxite waste, and waste recycling, provides an opportunity to take advantage of a resource that does not require mining costs as well as other associated costs given that these expenses are covered by the revenue generated from the production of the primary material. Coal-based materials represent a potential source for REEs which may be extracted and concentrated by the use of physical and/or chemical processes. The current study focused on developing a leaching process to extract REEs from the pre-combustion coal sources including coarse and fine refuse and low-valued material obtained from coal preparation plants. Materials collected for leaching characteristic studies were found to have average total REE concentrations in the range of 200-350 ppm on a whole sample basis. Mineralogy studies performed on Fire Clay seam coal refuse using SEM-EDS detected micro-dispersed rare earth phosphate mineral particles which are generally difficult to dissolve in strong acid solutions. On the other hand, XRD analysis results from a high REE content segment of the West Kentucky No. 13 coal seam indicated the presence of fluorapatite which is soluble in weak acid solutions. The mineral associations of REEs were studied by extracting REEs using different types of acids under various pH conditions. Differential extraction of the REEs was examined along with the associated impurity elements such as iron, aluminum, and calcium among others. The findings showed that the light REEs were primarily associated in a phosphate mineral form, whereas the heavy REEs were mostly present in an ion substitution form associated with clay minerals. Relatively high concentrations of REEs were discovered in mixed-phase particles consisting of both coal and mineral matter. By reducing the particle size, more leachable forms of REEs were liberated and recovered along with the associated mineral matter embedded in the coal structure. The type of lixiviant played an important role during the initial stage of leaching but was found to be insignificant as the system reached equilibrium. Solids concentration in the leaching medium has an important role in establishing the throughput capacity of the leaching system. Test results found that an increase in solids concentration had a significant negative effect on rare earth recovery. This finding may be explained by higher concentrations of soluble calcium-based minerals such as calcite which provided localized pH increases near and within the pores of the solids. The result was precipitation of CaSO4 within the pores which blocked access for the lixiviants. This hypothesis was supported by the findings from BET and XPS analyses which found lower pore volume in high solid concentration systems and the existence of CaSO4 on the surface of the solids. Leaching test results obtained using sulfuric acid over a range of temperatures showed that the leaching process was mainly driven by a diffusion control process. The activation energy determined for an Illinois No. 6 coal source was 14.6 kJ/mol at the beginning of the reaction and 35.9 kJ/mol for the rest of the leaching process up to 2 hours. For material collected from the Fire Clay coal seam, the apparent activation energy was 36 kJ/mol at the start of the leaching reaction and decreased to 27 kJ/mol over the remaining period of the test. The activation energy values were nearly equivalent to the upper-level values that generally define a diffusion control process and the lower values of a chemical reaction control process. The lack of clarity in defining a clear control mechanism is likely associated with the variability in associated mineralogy, various modes of occurrence of the REEs and the interfacial transfer of product through the porous structure of the coal-based particles which requires relatively high activation energy. As such, both diffusion control and chemical reaction control mechanisms are likely occurring simultaneously during the leaching process with diffusion control being more dominant.

Basalt outcrops in Curlew Valley consist of vii several flow remnants and eruptive centers situated along the valley margins. Basalt is also found in association with salic rocks that erupted in the central portion of The basalts are of probable Pliocene age and the valley. were erupted during a period of active extensional tectonics. Since their emplacement, and downfaulted. the basalts have been extensively eroded The present morphology reflects the erosional and depositional processes of prehistoric Lake Bonneville. Twelve samples were analyzed chemically for major oxides, trace elements, and rare-earth elements. The basalts form a hypersthene normative series ranging from olivine tholeiite to tholeiite. Based on chemical data, the basalts form three distinct groups. Comparison of the major oxides shows two of the groups forming a differentiation sequence separate from the third group. Trace element and rare-earth element data indicate that the three chemical groups are related to a common source but that two batches of magma probably emanated from this source. Pyrolite, spinel lherzolite, and garnet lherzolite were evaluated as hypothetical mantle materials from which a parent magma might be derived through partial melting. Based on rare-earth element profiles, garnet lherzolite appears to be the most likely source material for deriving the basalts. The trace element and rare-earth element data do not show any anomalies that would suggest contamination from crustal material. Comparison of chemical data shows that the Curlew Valley basalts are genetically similar to basalts from the Kelton and Rozel Point-Black Mountain areas, southwest and southeast of the study area, respectively. The Curlew Valley basalts are chemically similar to olivine tholeiites from the Snake River Plain and Blackfoot Reservoir areas in Idaho, but they do not show much similarity to basalts near Snowville, Utah, northeast of the study area. The Curlew Valley basalts are generally more iron rich and less alkalic than other basaltic rocks from the eastern Basin and Range Province.

Lithium and neodymium are two critical materials in our modern society, many technological solutions depend on them. Lithium is used in batteries, which are used in cars and portable electronics. Neodymium, which is a rare earth element, is mainly used in permanent magnets which are used in smartphones, hard disc drives and turbines. There are many reports regarding the availability of the metals, with different results. The available data on the reserves varies considerably, from the few sources there are. In this report, based on geological availability, forecasts are done to investigate how much the production can increase and when it will peak. The prognoses are based on historic production to which different functions, the logistic, gompertz and richards, are fitted with the least square method. The production will peak in the end of this century and in the beginning of the next century for both metals. The production of lithium does not seem to be sufficient for both producing electric and hybrid cars with only li-ion batteries along with fusion. The neodymium production will be sufficient for producing a lower percentage of direct driven wind turbines and electric cars with NiMH batteries. Lithium in seawater is sometimes considered a future source. Since the lithium concentration is low, large volumes have to be processed in order to extract a reasonable amount of lithium. Currently it is not economic to extract lithium from seawater.

Im frühen Sonnensystem fanden während der Kondensation der chemischen Elemente volatilitätskontrollierte Fraktionierungsprozesse statt. Gegenstand dieser Doktorarbeit sind Fraktionierungen refraktär-lithophiler Elemente in einzelnen Chondritkomponenten sowie zwischen Bulk-Chondriten, Achondriten und Planeten. Mittels laser ablation inductively coupled plasma mass spectrometry wurden die Gehalte der Seltenen Erden (REE) sowie von Nb, Ta, Zr und Hf analysiert. Einzelne Chondritkomponenten wurden in-situ an dem CV-Chondrit Leoville untersucht. Von den Bulk-Chondriten, Achondriten und terrestrischen Proben wurden Gesamtgesteinsproben durch Laserschmelzen unter aerodynamischer Levitation angefertigt. Die Untersuchung der verschiedenen Bestandteile des Leoville-Chondrits ergab, dass die refraktären Einschlüsse volatilitätskontrollierte fraktionierte REE group-II-Muster und subchondritische Nb/Ta-Verhältnisse aufweisen. Sie sind demzufolge aus einem residualen Gas entstanden, von dem zuvor eine ultrarefraktäre Komponente isoliert worden war. Chondren haben zumeist relativ unfraktionierte REE-Muster sowie unfraktionierte Zr/Hf- und Nb/Ta-Verhältnisse. Einige Typ-1-Chondren, die Al-reichen Chondren und die Chondritmatrix weisen jedoch fraktionierte REE-Muster auf. Dies ist ein Hinweis auf Beimengungen refraktären Materials mit REE group-II-Muster. Die Analysen an Bulk-Chondriten zeigen, dass kohlige Chondrite im Vergleich zu dem CI-Chondrit Orgueil charakteristische volatilitätskontrollierte REE-Muster (ultrarefraktär oder group-II) besitzen, was auf den Einbau refraktärer Komponenten mit fraktionierten Seltenen Erden zurückgeführt wurde. Die Mehrheit der gewöhnlichen, Rumuruti- und Enstatit-Chondrite hat dagegen relativ unfraktionierte REE-Muster. Es konnte gezeigt werden, dass sowohl gewöhnliche, Enstatit- und Rumuruti-Chondrite als auch Proben von Achondriten, Mars, Mond und Erde geringe negative Tm-Anomalien gegenüber dem CI-Chondrit Orgueil aufweisen. Die Objekte des inneren Sonnensystems wurden daher anhand ihrer relativen Gehalte an schweren Seltenen Erden (HREE) in zwei Gruppen eingeteilt: Ein kohliges und ein nichtkohliges Chondrit-Reservoir, dem auch die Achondrite, Mars, Erde und Mond angehören. Es wurde angenommen, dass die Objekte des nichtkohligen Chondrit-Reservoirs die HREE-Verhältnisse des Sonnensystems widerspiegeln; kohlige Chondrite haben dagegen variable Tm-Anomalien, welche durch den Eintrag fraktionierter refraktärer Komponenten in ihre Entstehungsregion zu erklären sind. CI-Chondrite, welche allgemein als die chemisch primitivste Chondritgruppe angesehen werden, hätten in diesem Fall eine positive Tm-Anomalie von 4,8 ± 0,9 % und stimmten somit chemisch nicht mit dem Sonnensystem überein. Durch eine Beimengung von nur 0,2 Gewichtsprozent einer refraktären Komponente mit REE group-II-Muster zu den CI-Chondriten konnte diese Tm-Anomalie erklärt werden.

Increased demand for rare earth elements (REEs) for applications in modern technologies has led to an increase in REE exploration. Several deposits are expected to begin mining within a decade, but few studies have examined the possible environmental effects created by these mines. Metal toxicity is thought to be greater in aqueous environments when metals occur as free ions rather than complexes, and the speciation can also impact the treatment technologies utilized to reduce metal concentrations. This research investigates the mineralogical source of REEs and the mechanism of REE mobility in low-temperature waters that have interacted with pilot plant tailings from the Nechalacho deposit, Northwest Territories. The Nechalacho deposit is owned by Avalon Rare Metals Inc. and located approximately 100 km east of Yellowknife. The deposit is hosted within a hydrothermally altered layered nepheline-sodalite syenite in the peralkaline Blatchford Lake complex. The main REE ore minerals are zircon, fergusonite, allanite, monazite, bastnäsite, and synchisite-parasite. Characterization of the tailings using mineral liberation analyzer (MLA) show that the ore minerals are fine grained and well liberated. Bastnäsite and synchisite-parasite are the only potentially soluble ore minerals at low temperature and near-neutral pH. Shake flask experiments were designed to simulate the interaction of tailings with three different leach waters to identify soluble phases and mobile elements. Decanted solutions from the shake flasks were filtered to 0.45µm and 0.01µm. Speciation modelling of the 0.01µm filtrate suggests that carbonate ligands will form the dominant complexes with the REEs, and <2% occur as free metal ions. Higher proportions of LREEs (1-6%) occur as free metal ions than HREEs (<1%) and LREEs occur in higher concentrations (2 to 8 times greater) than the HREE. REEs were found in the colloidal fraction ([REEcolloid] = [REE0.45µm] – [REE0.01µm]). Ionic strength is the dominant control on distribution of REEs between colloidal and dissolved fraction. Colloids captured on filters from ultrafiltration analyzed using scanning electron microscopy and synchrotron microanalysis show REEs are hosted in colloidal rare earth minerals (e.g. zircon) and also show colloidal humic acid, Fe-oxides and Mn-oxides. Speciation modeling shows that REE sorption to these phases is probable. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-05-28 11:06:41.351

The geological province of the Mount Painter in the North Flinders Ranges (South Australia) is well-known for its uranium mineralisation, and uraniferous granites. The presence in the nearby Cenozoic sediments of the Lake Frome basin of uranium mineralisations (Beverley deposit) and the recent discovery of the Four Mile deposit has triggered the interest of explorers. Based on extensive laser-ablation inductively-coupled-plasma-mass-spectrometry (LA-ICPMS) U-Pb geochronological data and mineralogy of U-Th-bearing minerals, rock geochemistry and petrography, we present a global study on the mobility of U, Th and REE in the Mount Painter Domain, including a detailed reconstitution of the Beverley deposit genesis. Seven significant stages of U-Th-REE mobility are recognised: 1. The possible presence U-enriched ~1600 Ma lower crust under the MPD 2. Intrusion of two A-type Mesoproterozoic granites suites (~1575, and ~1560 Ma respectively) with high HFSE contents and crustal origin; the porphyritic biotite K-rich highly-enriched Yerila granite belongs to the youngest suite and hosts magmatic allanite-(Ce), potassic-hastingsite, ilmenite, fergusonite-(Y), chevkinite, molybdenite, zircon, uranothorite, uraninite and titanite and fluorite 3. Late-magmatic or post-magmatic metasomatism in the same granites; evidenced by F-rich annite, zircon, Y-bearing Al-F-titanite (< 6 kbar, >400°C), Y-rich fluorapatite, synchysite-(Ce) and fluorite. Early ilmenite, molybdenite, allanite-(Ce) and oligoclase reacted with an alkaline oxidising F-rich melt or fluid. The latemagmatic to post-magmatic metasomatism is also recorded at the intrusion contact in regional rocks, forming allanite-, magnetite-, uranothorite-, zircon- (1501 ± 6 Ma), and uraninite-bearing calcsilicate skarns. The spreading of zircon ages in the Yerila granite (~1565 to ~1521) relates to the mixing of magmatic and metasomatic crystals. 4. the MPD was subject to the Delamerian orogeny and related metamorphism (amphibolite facies); most Mesoproterozoic granitic assemblages present signs of recrystallisation or stress; recrystallisation of monazite-(Ce) and xenotime-(Y) during Paleozoic (Cambrian) (490-495 Ma). U-Th-rich minerals also bear Delamerian ages (polycrase-(Y), euxenite-(Y), davidite-(La) and uraninite). 5. Anatexis of local basement during Ordovician and generation of peraluminous granite (British Empire granite) with low Th/U. The granite is enriched in U and Y. We provide the first robust ages on it: 456 ± 9 and 459 ± 9 Ma on zircon, 453.3 ± 4.6 on xenotime-(Y). 6. Very active hydrothermal/pegmatitic uranium remobilisation along active faults; brannerite-quartz veins formation (367 ± 13 Ma), further signs of remobilisation or hydrothermal event during Permian (284 ± 25 Ma in thorite) and around the Mt Gee (~290 Ma radiogenic gain in davidite) which agrees with the previous data (paleomagnetic ages of 250-300 Ma). 7. Cenozoic supergene uranium remobilisation in MPD and migration of U-rich oxidised groundwaters into the Lake Frome. The uranium is precipitated in the sandy formation of the lake and in the top layer of the underlying organic-matter-rich clays and silts. The micro-environment of reduction efficiently trap U but also REE, fingerprinting the REE-rich MPD granite source. Coffinite and carnotite give concordant Pliocene ages (6.7 to 3.4 Ma). Provenance studies on the sands hosting the Beverley mineralisations suggest a reworking of Early Cretaceous glacial or glacio-lacustrine sediments originally sourced in Eastern Australia (Lachlan Fold Belt). The youngest recorded zircon (130 Ma) doesn’t constrain the sediment age but refines the provenance region (New England Orogen). / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1370301 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009

The geological province of the Mount Painter in the North Flinders Ranges (South Australia) is well-known for its uranium mineralisation, and uraniferous granites. The presence in the nearby Cenozoic sediments of the Lake Frome basin of uranium mineralisations (Beverley deposit) and the recent discovery of the Four Mile deposit has triggered the interest of explorers. Based on extensive laser-ablation inductively-coupled-plasma-mass-spectrometry (LA-ICPMS) U-Pb geochronological data and mineralogy of U-Th-bearing minerals, rock geochemistry and petrography, we present a global study on the mobility of U, Th and REE in the Mount Painter Domain, including a detailed reconstitution of the Beverley deposit genesis. Seven significant stages of U-Th-REE mobility are recognised: 1. The possible presence U-enriched ~1600 Ma lower crust under the MPD 2. Intrusion of two A-type Mesoproterozoic granites suites (~1575, and ~1560 Ma respectively) with high HFSE contents and crustal origin; the porphyritic biotite K-rich highly-enriched Yerila granite belongs to the youngest suite and hosts magmatic allanite-(Ce), potassic-hastingsite, ilmenite, fergusonite-(Y), chevkinite, molybdenite, zircon, uranothorite, uraninite and titanite and fluorite 3. Late-magmatic or post-magmatic metasomatism in the same granites; evidenced by F-rich annite, zircon, Y-bearing Al-F-titanite (< 6 kbar, >400°C), Y-rich fluorapatite, synchysite-(Ce) and fluorite. Early ilmenite, molybdenite, allanite-(Ce) and oligoclase reacted with an alkaline oxidising F-rich melt or fluid. The latemagmatic to post-magmatic metasomatism is also recorded at the intrusion contact in regional rocks, forming allanite-, magnetite-, uranothorite-, zircon- (1501 ± 6 Ma), and uraninite-bearing calcsilicate skarns. The spreading of zircon ages in the Yerila granite (~1565 to ~1521) relates to the mixing of magmatic and metasomatic crystals. 4. the MPD was subject to the Delamerian orogeny and related metamorphism (amphibolite facies); most Mesoproterozoic granitic assemblages present signs of recrystallisation or stress; recrystallisation of monazite-(Ce) and xenotime-(Y) during Paleozoic (Cambrian) (490-495 Ma). U-Th-rich minerals also bear Delamerian ages (polycrase-(Y), euxenite-(Y), davidite-(La) and uraninite). 5. Anatexis of local basement during Ordovician and generation of peraluminous granite (British Empire granite) with low Th/U. The granite is enriched in U and Y. We provide the first robust ages on it: 456 ± 9 and 459 ± 9 Ma on zircon, 453.3 ± 4.6 on xenotime-(Y). 6. Very active hydrothermal/pegmatitic uranium remobilisation along active faults; brannerite-quartz veins formation (367 ± 13 Ma), further signs of remobilisation or hydrothermal event during Permian (284 ± 25 Ma in thorite) and around the Mt Gee (~290 Ma radiogenic gain in davidite) which agrees with the previous data (paleomagnetic ages of 250-300 Ma). 7. Cenozoic supergene uranium remobilisation in MPD and migration of U-rich oxidised groundwaters into the Lake Frome. The uranium is precipitated in the sandy formation of the lake and in the top layer of the underlying organic-matter-rich clays and silts. The micro-environment of reduction efficiently trap U but also REE, fingerprinting the REE-rich MPD granite source. Coffinite and carnotite give concordant Pliocene ages (6.7 to 3.4 Ma). Provenance studies on the sands hosting the Beverley mineralisations suggest a reworking of Early Cretaceous glacial or glacio-lacustrine sediments originally sourced in Eastern Australia (Lachlan Fold Belt). The youngest recorded zircon (130 Ma) doesn’t constrain the sediment age but refines the provenance region (New England Orogen). / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1370301 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009