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

O problema de rejeitos radioativos é uma preocupação de âmbito mundial, uma vez que não há, ainda, um local definido para a construção de um repositório para rejeitos radioativos de alto nível. Uma das etapas preliminares para a escolha do local mais apropriado é o estudo geológico associado a estudos experimentais de adsorção das espécies químicas envolvidas nos processo. Neste trabalho foi utilizado uma amostra de rocha basáltica, da região sul da Formação Serra Geral, coletada em Frederico Westphalen (RS), que servirá como candidata à rocha hospedeira para locação de rejeitos radioativos. Foram realizados dois experimentos, a saber: "Batch Test" e percolação, ambos sob pressão atmosférica, à temperatura ambiente de 25°C, com a finalidade de estudar a capacidade de sorção dos elementos terras raras - ETR. Os ETR são utilizados neste trabalho em função de sua analogia com os actinídeos, visando a investigar o comportamento geoquímico e a especiações dos mesmos em águas naturais, buscando a possibilidade de armazenamento geológico de rejeitos radioativos, uma vez que a adsorção dos ETR depende de variáveis do ambiente como pH, força iônica, temperatura e presença de ligantes, como carbonatos e constituintes de superfícies dos minerais. Foi realizado experimento de percolação dos ETR, a 100ppb, no basalto (com granulometria 80 mesh) em soluções com força iônica I= 0,025 M e I=0,5 M de NaCl. O pH foi controlado em uma faixa de 5,6 a 7,6 com adição de HNO3. As concentrações foram analisadas por ICP-MS. O "Batch Test" é uma eficiente forma de se obter isotermas de sorção/dessorção, além de valores da razão entre as distribuições sólido/solução e estimar a solubilidade. O experimento de percolação, foi realizado sob pH controlado em torno de 6, e permitiu verificar a "preferência" dos ETR pesados em relação aos ETR leves. / The problem of radioactive wastes is a concern of world-wide scope, a time that does not still have a defined local for the construction of a repository for radioactive wastes of high level. One of the preliminary stages for the choice of the place more appropriate is the geologic study associated to the experimental studies of adsorprtion of the involved chemical species in the process. In this work, a sample of basaltic rock was used, of the South Region of the Formation Serra Geral, collected in Frederico Westphalen Town (RS), that it will be probably a candidate to the rock hostess for location of radioactive wastes. Two experiments have been carried out through, namely: "Test Batch" and Percolating, both under atmospheric pressure, at the ambient temperature of 25°C, with the purpose to study the capacity of sorption of the rare earth elements - REE. The REE are used in this work in function of its analogy with the actinídes, aiming at to investigate the chemistry behavior and the speciations of the same in natural waters, searching the possibility of geologic storage of radioactive wastes, a time that the adsorption of the REE depends on variables of the environment as pH, ionic strengh, temperature and presence of ligants, as carbonates and constituent of surfaces of minerals. Experiment of percolating of the REE was carried through, 100ppb, in the basalt (with 80 mesh) in solutions with ionic strengh I= 0,025 M and I=0,5 M of NaCl. pH was controlled in a range of 5,6 the 7,6 with HNO3 addition. The concentrations were analyzed by ICP-MS. The "Batch Test" is an efficient form of studing sorption/dessorption isotherms, beyond values of the reason between the distributions solid/solution and estimation of the solubility. The percolating experiment, was carried through under pH controlled around 6, and allowed to verify the behaviour of heavy REE in comparison with the light REE.

Os pegmatitos estudados estão associados à fácies albita granito do granito Madeira, a qual corresponde ao depósito de Sn-Nb-Ta (F, ETR, U, Th) Madeira, na mina Pitinga (AM) e estão associados a falhas de orientação N320/60SW. Estas rochas contêm minerais poucos comuns como gagarinita (NaCaYF6), genthelvita (Zn4Be3(SiO4)3S) e polilitionita (KLi2AlSi4O10(F, OH)2), além de grandes quantidades de criolita (Na3AlF6). Com base na composição química e mineralógica, estes pegmatitos foram classificados em três tipos: PEG ANF (teores médios de K e Na, com alta concentração de anfibólios), PEG POL (rico em K e com alta concentração de polilitionita) e PEG CRIO (rico em Na e com alta concentração de criolita). Estes pegmatitos contêm altos teores de ETR (especialmente ETRP) e Y, que estão concentrados principalmente na xenotima e na gagarinita. Estes elementos também ocorrem em elevados teores na grande parte dos demais minerais analisados. Também se destacam as concentrações anômalas de F, muito superiores às detectadas nos pegmatitos de outras localidades, e que promoveram o enriquecimento em Li, Na, K, Rb e Cs. A similaridade na composição química do AGN com os pegmatitos indica que eles possuem a mesma fonte. / The pegmatites studied are associated with the albite granite facies of the Madeira granite, which corresponds to the Sn-Nb-Ta (F, ETR, U, Th) Madeira deposit at the Pitinga mine (AM). They are associated with N320/60SW orientation faults. These rocks contain few common minerals such as gagarinite (NaCaYF6), genthelvite (Zn4Be3(SiO4)3S) and polylithionite (KLi2AlSi4O10(F,OH)2), as well as large amounts of cryolite (Na3AlF6). Based on the chemical and mineralogical composition, these pegmatites were classified into three groups: PEG ANF (medium K and Na, with high concentration of amphiboles), PEG POL (K rich and with high polylithionite concentration) and PEG CRIO (rich in Na and with high concentration of cryolite). These pegmatites contain high levels of REE (especially HREE) and Y, which are mainly concentrated in xenotime and gagarinite. These elements also occur at high levels in most of the other minerals analyzed. Anomalous concentrations of F, much higher than those detected in pegmatites from other localities, were also highlighted, and promoted enrichment in Li, Na, K, Rb and Cs. The similarity in the chemical composition of AGN with pegmatites indicates that they have the same source.

O problema de rejeitos radioativos é uma preocupação de âmbito mundial, uma vez que não há, ainda, um local definido para a construção de um repositório para rejeitos radioativos de alto nível. Uma das etapas preliminares para a escolha do local mais apropriado é o estudo geológico associado a estudos experimentais de adsorção das espécies químicas envolvidas nos processo. Neste trabalho foi utilizado uma amostra de rocha basáltica, da região sul da Formação Serra Geral, coletada em Frederico Westphalen (RS), que servirá como candidata à rocha hospedeira para locação de rejeitos radioativos. Foram realizados dois experimentos, a saber: "Batch Test" e percolação, ambos sob pressão atmosférica, à temperatura ambiente de 25°C, com a finalidade de estudar a capacidade de sorção dos elementos terras raras - ETR. Os ETR são utilizados neste trabalho em função de sua analogia com os actinídeos, visando a investigar o comportamento geoquímico e a especiações dos mesmos em águas naturais, buscando a possibilidade de armazenamento geológico de rejeitos radioativos, uma vez que a adsorção dos ETR depende de variáveis do ambiente como pH, força iônica, temperatura e presença de ligantes, como carbonatos e constituintes de superfícies dos minerais. Foi realizado experimento de percolação dos ETR, a 100ppb, no basalto (com granulometria 80 mesh) em soluções com força iônica I= 0,025 M e I=0,5 M de NaCl. O pH foi controlado em uma faixa de 5,6 a 7,6 com adição de HNO3. As concentrações foram analisadas por ICP-MS. O "Batch Test" é uma eficiente forma de se obter isotermas de sorção/dessorção, além de valores da razão entre as distribuições sólido/solução e estimar a solubilidade. O experimento de percolação, foi realizado sob pH controlado em torno de 6, e permitiu verificar a "preferência" dos ETR pesados em relação aos ETR leves. / The problem of radioactive wastes is a concern of world-wide scope, a time that does not still have a defined local for the construction of a repository for radioactive wastes of high level. One of the preliminary stages for the choice of the place more appropriate is the geologic study associated to the experimental studies of adsorprtion of the involved chemical species in the process. In this work, a sample of basaltic rock was used, of the South Region of the Formation Serra Geral, collected in Frederico Westphalen Town (RS), that it will be probably a candidate to the rock hostess for location of radioactive wastes. Two experiments have been carried out through, namely: "Test Batch" and Percolating, both under atmospheric pressure, at the ambient temperature of 25°C, with the purpose to study the capacity of sorption of the rare earth elements - REE. The REE are used in this work in function of its analogy with the actinídes, aiming at to investigate the chemistry behavior and the speciations of the same in natural waters, searching the possibility of geologic storage of radioactive wastes, a time that the adsorption of the REE depends on variables of the environment as pH, ionic strengh, temperature and presence of ligants, as carbonates and constituent of surfaces of minerals. Experiment of percolating of the REE was carried through, 100ppb, in the basalt (with 80 mesh) in solutions with ionic strengh I= 0,025 M and I=0,5 M of NaCl. pH was controlled in a range of 5,6 the 7,6 with HNO3 addition. The concentrations were analyzed by ICP-MS. The "Batch Test" is an efficient form of studing sorption/dessorption isotherms, beyond values of the reason between the distributions solid/solution and estimation of the solubility. The percolating experiment, was carried through under pH controlled around 6, and allowed to verify the behaviour of heavy REE in comparison with the light REE.

Master of Science / Geology / Matthew E. Brueseke / Previous K-Ar dating and petrography (Obradovich, 1978) have identified Pilot Knob as an ~3.4 (±0.06) Ma alkaline intrusive body. Bulk rock geochemistry obtained via XRF from four samples of Pilot Knob verifies the transitionally alkaline composition of the body, and new REE data also show enriched La, Ce, and Nd concentrations, consistent with rare earth element (REE) enrichment. Given the increased demand for REEs over the past ~30 years and China accounting for > 90% of global REE production (Kynicky, et al. 2012), it is important to evaluate new domestic REE sources. This includes those associated with alkaline intrusive complexes, because they are demonstrated to host high REE concentrations (Verplanck and Van Gosen, 2011). Such alkaline igneous occurrences show complex mineralization and consist of many minerals containing substitutional REEs (Mariano and Mariano, 2012). This study evaluates the petrogenesis and mineralogy of Pilot Knob (and a secondary field site, Wildcat Hill) and determines whether the intrusive body is consistent with an economically viable REE deposit. Additionally, given its geographic location and Pliocene faulting and magmatism (e.g., predating the earliest volcanism at Yellowstone), Pilot Knob may represent one of the earliest structural manifestations of the “arrival” of the Yellowstone hotspot at its current location under the North American lithosphere or magmatism associated with lithospheric extension to the south at the Leucite Hills, WY. Inspection of satellite imagery, which has been verified with field data, shows that other intrusive igneous bodies (e.g. - Wildcat Hill) exist, along an apparent normal fault zone along strike with a major extensionally related fault zone documented ~10 km northwest of Pilot Knob. Clinopyroxene geobarometry, coupled with Nd isotope data (εNd[subscript 3.5Ma] = -21.9), indicates that Pilot Knob formed via a multi-stage development history that initiated with melting of ancient lithospheric mantle, where crystallization occurred at a variety of depths. As an alkaline intrusive complex, Pilot Knob has been identified, based on mineral and chemical compositions, as a kersantite, and has been found to contain approximately 600 ppm total light-rare earth element ore lode with ~150 ppm Nd, ~175 ppm La, and ~338 ppm Ce enrichment. Apatite was found to be the primary REE-bearing mineral via petrography and electron microprobe analyses. Based on current technology and processing methods, REE concentrations were not found to be significant enough to denote an economically viable REE ore deposit at Pilot Knob.

O excessivo processo de urbanização da Região Metropolitana de São Paulo resultou na perda das características naturais dos seus cursos d\'água ocasionando profundas alterações nos regimes de vazão e de qualidade. O objetivo desse estudo foi avaliar a concentração de metais tóxicos, os semi-metais As, Sb e Se e os elementos terras raras, presentes em amostras de sedimento superficiais coletadas nos Reservatórios Billings, Guarapiranga e Rio Grande. Os elementos Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Se e Zn foram determinados pela técnica de Espectrometria de Emissão Ótica com Plasma Indutivamente Acoplado (ICP OES). Alguns elementos maiores, traço e elementos terras raras (Ce, Eu, La, Lu, Nd, Sm, Tb e Yb) foram determinados pela técnica de Análise por Ativação Neutrônica Instrumental (INAA). A concentração de Hg total foi determinada pela técnica Espectrometria de Absorção Atômica com Geração de Vapor Frio (CVAAS). A validação das metodologias foi realizada por meio da análise de materiais de referência certificados. Para avaliar as possíveis fontes de contaminação antrópicas foram utilizadas as ferramentas de fator de enriquecimento (FE) e o índice de geoacumulação (IGeo). Os resultados obtidos pelas técnicas foram comparados com os valores orientadores TEL e PEL estabelecidos pelo CCME (Canadian Council of Ministers of the Environment) e adotados pela CETESB. Todos os pontos analisados apresentaram valores > TEL para todos os metais e dois pontos da represa Billings (BILL02100 e 02030), valores > PEL para As, Cr, Cu, Hg, Ni, Pb e Zn, provavelmente em decorrência do recebimento das águas do Rio Pinheiros e das bacias de drenagem do ribeirão Cocaia e Bororé. Os valores de FE e IGeo calculados apontaram possíveis contaminações antrópicas para Sb e Se para os elementos determinados por ICP OES e de As, Cr, Sb e Zn, por INAA. O reservatório Billings apresentou, em geral, as maiores concentrações para os elementos analisados, indicando uma má qualidade de seus sedimentos. Este estudo confirma a necessidade de um monitoramento frequente da qualidade do sedimento nos reservatórios estudados como procedimento indispensável para avaliação periódica da qualidade das bacias, considerando sua importância no fornecimento de água para a Região Metropolitana de São Paulo. / The excessive urbanization process of the São Paulo Metropolitan Region resulted in the loss of the natural characteristics of its watercourses causing serious changes in flow and quality regimes. The objective of this study was evaluate the concentration of toxic metals, semi metals As, Sb and Se, and rare earth elements present in surface sediment samples collected at the Billings, Guarapiranga and Rio Grande Reservoirs. The Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Se and Zn elements were analyzed using Optical Emission Spectrometry With Inductively Coupled Plasma (ICP OES). Some major, trace and rare earth elements (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) were analyzed by the Instrumental Neutron Activation Analysis (INAA) technique. The total Hg concentration was determined by Cold Vapor Atomic Absorption Spectrometry technique (CVAAS). The validation of the methodologies was performed by means of the certified reference material analyses. To assess the sources of anthropogenic contamination, the enrichment factor (EF) and the geoacumulation index (IGeo) were calculated. The results obtained for both techniques were compared with TEL and PEL oriented values established by CCME (Canadian Council of Ministers of the Environment) and adopted by CETESB (Environmental Company of the Sao Paulo State). All sampling points showed concentration values for toxic metals >TEL and 2 points at Billings Reservoir (BILL02030 and 02100), values > PEL for As, Cr, Cu, Hg, Ni, Pb and Zn, probably due to the entrance of the Pinheiros River waters and drainage basins of the Cocaia and Bororé streams. The calculated EF and IGeo values indicated possible anthropogenic contamination for Sb and Se for the elements determined by ICP OES and As, Cr, Sb and Zn, obtained by INAA. The Billings reservoir presented, in general, the highest concentrations for the analyzed elements, indicating a poor quality of its sediments. This study confirms the need of a frequent monitoring of the sediment quality in the studied reservoirs as an indispensable procedure for periodic evaluation of the basin quality, considering its importance in the water supply for the Metropolitan Region of São Paulo.