144 research outputs found

    Lasers And Landing Sites: The Geomorphology, Stratigraphy, And Composition Of Mars

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    With each new mission to Mars, the amount of available data increases dramatically. This drastic increase in data volume requires new approaches to take advantage of the available information. The goal of the work presented here is to maximize the science return from existing and future datasets. Chapter 2 uses multiple orbital datasets to characterize Gale Crater, with a focus on the northwestern crater floor and lower mound. This work played a role in the selection of Gale Crater as the landing site for Mars Science Laboratory (MSL). It was not possible to conclusively determine the origin of the lower mound, but we interpret features on the upper mound as aeolian cross-beds. Chapters 3 and 4 investigate methods for improving the accuracy of laser-induced breakdown spectroscopy (LIBS). In Chapter 3, the accuracy of partial least squares (PLS) and two types of neural network are compared, using several pre-processing methods including automated feature selection. We find that partial least squares without averaging typically gives the best results. Chapter 3 also investigates the influence of grain size on the accuracy of analyses, showing that >20 analysis spots may be required for heterogeneous targets. In Chapter 4, we test the hypothesis that clustering the dataset before analysis leads to improved accuracy. We observe modest improvements for five k-means clusters and with iterative application of clustering and PLS. In Chapter 5, we use several methods to relate Mars Exploration Rover (MER) Panoramic camera multispectral observations to alpha particle X-ray spectrometer and MÓ§ssbauer spectrometer results. The correlation between the Gusev datasets is often poor although there is some improvement when only data from drilled spots is considered. The performance is better for the Meridiani data, but Meridiani PLS models are not generalizable to Gusev data. MSL ChemCam analyses and MastCam spectra may show higher correlations because the instruments have a similar information depth. Clustering and classification methods can be used on any dataset, and as the volume of data from planetary missions continues to increase, synthesis of multiple datasets using multivariate methods such as those in this work will become increasingly important

    Multispectral and Hyperspectral Remote Sensing Data for Mineral Exploration and Environmental Monitoring of Mined Areas

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    In recent decades, remote sensing technology has been incorporated in numerous mineral exploration projects in metallogenic provinces around the world. Multispectral and hyperspectral sensors play a significant role in affording unique data for mineral exploration and environmental hazard monitoring. This book covers the advances of remote sensing data processing algorithms in mineral exploration, and the technology can be used in monitoring and decision-making in relation to environmental mining hazard. This book presents state-of-the-art approaches on recent remote sensing and GIS-based mineral prospectivity modeling, offering excellent information to professional earth scientists, researchers, mineral exploration communities and mining companies

    Mapping Listvenite Occurrences in the Damage Zones of Northern Victoria Land, Antarctica Using ASTER Satellite Remote Sensing Data

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    Listvenites normally form during hydrothermal/metasomatic alteration of maïŹc and ultramaïŹc rocks and represent a key indicator for the occurrence of ore mineralizations in orogenic systems. Hydrothermal/metasomatic alteration mineral assemblages are one of the signiïŹcant indicators for ore mineralizations in the damage zones of major tectonic boundaries, which can be detected using multispectral satellite remote sensing data. In this research, Advanced Spaceborne Thermal Emission and ReïŹ‚ection Radiometer (ASTER) multispectral remote sensing data were used to detect listvenite occurrences and alteration mineral assemblages in the poorly exposed damage zones of the boundaries between the Wilson, Bowers and Robertson Bay terranes in Northern Victoria Land (NVL), Antarctica. Spectral information for detecting alteration mineral assemblages and listvenites were extracted at pixel and sub-pixel levels using the Principal Component Analysis (PCA)/Independent Component Analysis (ICA) fusion technique, Linear Spectral Unmixing (LSU) and Constrained Energy Minimization (CEM) algorithms. Mineralogical assemblages containing Fe 2+ , Fe 3+ , Fe-OH, Al-OH, Mg-OH and CO3 spectral absorption features were detected in the damage zones of the study area by implementing PCA/ICA fusion to visible and near infrared (VNIR) and shortwave infrared (SWIR) bands of ASTER. Silicate lithological groups were mapped and discriminated using PCA/ICA fusion to thermal infrared (TIR) bands of ASTER. Fraction images of prospective alteration minerals, including goethite, hematite, jarosite, biotite, kaolinite, muscovite, antigorite, serpentine, talc, actinolite, chlorite, epidote, calcite, dolomite and siderite and possible zones encompassing listvenite occurrences were produced using LSU and CEM algorithms to ASTER VNIR+SWIR spectral bands. Several potential zones for listvenite occurrences were identiïŹed, typically in association with maïŹc metavolcanic rocks (Glasgow Volcanics) in the Bowers Mountains.Comparison of the remote sensing results with geological investigations in the study area demonstrate invaluable implications of the remote sensing approach for mapping poorly exposed lithological units, detecting possible zones of listvenite occurrences and discriminating subpixel abundance of alteration mineral assemblages in the damage zones of the Wilson-Bowers and Bowers-Robertson Bay terrane boundaries and in intra-Bowers and Wilson terranes fault zones with high ïŹ‚uid ïŹ‚ow. The satellite remote sensing approach developed in this research is explicitly pertinent to detecting key alteration mineral indicators for prospecting hydrothermal/metasomatic ore minerals in remote and inaccessible zones situated in other orogenic systems around the world

    Caracterização e estudo comparativo de exsudaçÔes de hidrocarbonetos e plays petrolíferos em bacias terrestres das regiÔes central do Irã e sudeste do Brasil usando sensoriamento remoto espectral

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    Orientador: Carlos Roberto de Souza FilhoTese (doutorado) - Universidade Estadual de Campinas, Instituto de GeociĂȘnciasResumo: O objetivo desta pesquisa foi explorar as assinaturas de exsudaçÔes de hidrocarbonetos na superfĂ­cie usando a tecnologia de detecção remota espectral. Isso foi alcançado primeiro, realizando uma revisĂŁo abrangente das capacidades e potenciais tĂ©cnicas de detecção direta e indireta. Em seguida, a tĂ©cnica foi aplicada para investigar dois locais de teste localizados no IrĂŁ e no Brasil, conhecidos por hospedar sistemas ativos de micro-exsudaçÔes e afloramentos betuminosos, respectivamente. A primeira ĂĄrea de estudo estĂĄ localizada perto da cidade de Qom (IrĂŁ), e estĂĄ inserida no campo petrolĂ­fero Alborz, enterrado sob sedimentos datados do Oligoceno da Formação Upper Red. O segundo local estĂĄ localizado perto da cidade de Anhembi (SP), na margem oriental da bacia do ParanĂĄ, no Brasil, e inclui acumulaçÔes de betume em arenitos triĂĄssicos da Formação PirambĂłia. O trabalho na ĂĄrea de Qom integrou evidĂȘncias de (i) estudos petrogrĂĄficos e geoquĂ­micos em laboratĂłrio, (ii) investigaçÔes de afloramentos em campo, e (iii) mapeamento de anomalia em larga escala atravĂ©s de conjuntos de dados multi-espectrais ASTER e Sentinel-2. O resultado deste estudo se trata de novos indicadores mineralĂłgicos e geoquĂ­micos para a exploração de micro-exsudaçÔes e um modelo de micro-exsudaçÔes atualizado. Durante este trabalho, conseguimos desenvolver novas metodologias para anĂĄlise de dados espectroscĂłpicos. AtravĂ©s da utilização de dados simulados, indicamos que o instrumento de satĂ©lite WorldView-3 tem potencial para detecção direta de hidrocarbonetos. Na sequĂȘncia do estudo, dados reais sobre afloramentos de arenitos e Ăłleo na ĂĄrea de Anhembi foram investigados. A ĂĄrea foi fotografada novamente no chĂŁo e usando o sistema de imagem hiperespectral AisaFENIX. Seguiu-se estudos e amostragem no campo,incluindo espectroscopia de alcance fechado das amostras no laboratĂłrio usando instrumentos de imagem (ou seja, sisuCHEMA) e nĂŁo-imagem (ou seja, FieldSpec-4). O estudo demonstrou que uma abordagem espectroscĂłpica multi-escala poderia fornecer uma imagem completa das variaçÔes no conteĂșdo e composição do betume e minerais de alteração que acompanham. A assinatura de hidrocarbonetos, especialmente a centrada em 2300 nm, mostrou-se consistente e comparĂĄvel entre as escalas e capaz de estimar o teor de betume de areias de petrĂłleo em todas as escalas de imagemAbstract: The objective of this research was to explore for the signatures of seeping hydrocarbons on the surface using spectral remote sensing technology. It was achieved firstly by conducting a comprehensive review of the capacities and potentials of the technique for direct and indirect seepage detection. Next, the technique was applied to investigate two distinctive test sites located in Iran and Brazil known to retain active microseepage systems and bituminous outcrops, respectively. The first study area is located near the city of Qom in Iran, and consists of Alborz oilfield buried under Oligocene sediments of the Upper-Red Formation. The second site is located near the town of Anhembi on the eastern edge of the ParanĂĄ Basin in Brazil and includes bitumen accumulations in the Triassic sandstones of the PirambĂłia Formation. Our work in Qom area integrated evidence from (i) petrographic, spectroscopic, and geochemical studies in the laboratory, (ii) outcrop investigations in the field, and (iii) broad-scale anomaly mapping via orbital remote sensing data. The outcomes of this study was novel mineralogical and geochemical indicators for microseepage characterization and a classification scheme for the microseepage-induced alterations. Our study indicated that active microseepage systems occur in large parts of the lithofacies in Qom area, implying that the extent of the petroleum reservoir is much larger than previously thought. During this work, we also developed new methodologies for spectroscopic data analysis and processing. On the other side, by using simulated data, we indicated that WorldView-3 satellite instrument has the potential for direct hydrocarbon detection. Following this demonstration, real datasets were acquired over oil-sand outcrops of the Anhembi area. The area was further imaged on the ground and from the air by using an AisaFENIX hyperspectral imaging system. This was followed by outcrop studies and sampling in the field and close-range spectroscopy in the laboratory using both imaging (i.e. sisuCHEMA) and nonimaging instruments. The study demonstrated that a multi-scale spectroscopic approach could provide a complete picture of the variations in the content and composition of bitumen and associated alteration mineralogy. The oil signature, especially the one centered at 2300 nm, was shown to be consistent and comparable among scales, and capable of estimating the bitumen content of oil-sands at all imaging scalesDoutoradoGeologia e Recursos NaturaisDoutor em GeociĂȘncias2015/06663-7FAPES

    Value of Mineralogical Monitoring for the Mining and Minerals Industry In memory of Prof. Dr. Herbert Pöllmann

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    This Special Issue, focusing on the value of mineralogical monitoring for the mining and minerals industry, should include detailed investigations and characterizations of minerals and ores of the following fields for ore and process control: Lithium ores—determination of lithium contents by XRD methods; Copper ores and their different mineralogy; Nickel lateritic ores; Iron ores and sinter; Bauxite and bauxite overburden; Heavy mineral sands. The value of quantitative mineralogical analysis, mainly by XRD methods, combined with other techniques for the evaluation of typical metal ores and other important minerals, will be shown and demonstrated for different minerals. The different steps of mineral processing and metal contents bound to different minerals will be included. Additionally, some processing steps, mineral enrichments, and optimization of mineral determinations using XRD will be demonstrated. Statistical methods for the treatment of a large set of XRD patterns of ores and mineral concentrates, as well as their value for the characterization of mineral concentrates and ores, will be demonstrated. Determinations of metal concentrations in minerals by different methods will be included, as well as the direct prediction of process parameters from raw XRD data

    Characterizing silicate materials via Raman spectroscopy and machine learning: Implications for novel approaches to studying melt dynamics

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    Silicate melt characteristics impose dramatic influence over igneous processes that operate, or have operated on, differentiated bodies: such as the Earth and Mars. Current understanding of these melt properties, such as composition, primarily comes from investigations on their volcanic byproducts. Therefore, it is imperative to innovate on modalities capable of constraining melt information in environments where a reliance on laboratory methods is severed. Recent investigations have turned to Raman Spectroscopy and amorphous volcanics as a suitable pairing for exploring these ideas. Silicate glasses are a proxy for igneous melts; and Raman spectroscopy is a robust analytical technique capable of operating in-situ. Existing calibrations for retrieving geochemical information from such samples using their Raman data are extremely underdeveloped, with only a handful of approaches available. Here, two supervised machine learning algorithms; Partial Least Squares (PLS) and Least Absolute Shrinkage & Selection Operator (LASSO) are employed with Raman spectroscopy to quantify geochemical information in volcanic glasses and tephra, while also qualifying the underlying atomic mechanics that drive Raman signal variability. This approach establishes a foundation for future explorations into new-age modeling technologies for geoscience experiments. Chapter I’s PLS geochemical model predicted the concentrations of oxide constituents in synthetic silicate glasses (SiO2, Na2O, K2O, CaO, TiO2, Al2O3, FeOT, MgO) with increased accuracy and applicability over currently available offerings. The study presents the largest and most diverse sampling suite yet utilized to produce such models. Chapter II highlights the limitations to PLS and LASSO based strategies for constraining iron (Fe)-redox information in glasses but uncovers their ability to accurately predict glass structural parameters like polymerization (NBO/T). Chapter III yielded accurate predictions of tephra concentrations from various mixed sediment samplings using PLS and LASSO calibrations. Spectra parameterizations highlighted that tephra signatures are unique enough to be readily distinguished from more crystalline profiles using Raman spectroscopy and machine learning. PLS and LASSO technologies are shown to be suitable, yet immature, avenues for unraveling the geochemical underpinnings of the Raman collections made in this work and help set the stage for future applications to Raman data from planetary missions such as the Perseverance Rover

    Mineral identification using data-mining in hyperspectral infrared imagery

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    Les applications de l’imagerie infrarouge dans le domaine de la gĂ©ologie sont principalement des applications hyperspectrales. Elles permettent entre autre l’identification minĂ©rale, la cartographie, ainsi que l’estimation de la portĂ©e. Le plus souvent, ces acquisitions sont rĂ©alisĂ©es in-situ soit Ă  l’aide de capteurs aĂ©roportĂ©s, soit Ă  l’aide de dispositifs portatifs. La dĂ©couverte de minĂ©raux indicateurs a permis d’amĂ©liorer grandement l’exploration minĂ©rale. Ceci est en partie dĂ» Ă  l’utilisation d’instruments portatifs. Dans ce contexte le dĂ©veloppement de systĂšmes automatisĂ©s permettrait d’augmenter Ă  la fois la qualitĂ© de l’exploration et la prĂ©cision de la dĂ©tection des indicateurs. C’est dans ce cadre que s’inscrit le travail menĂ© dans ce doctorat. Le sujet consistait en l’utilisation de mĂ©thodes d’apprentissage automatique appliquĂ©es Ă  l’analyse (au traitement) d’images hyperspectrales prises dans les longueurs d’onde infrarouge. L’objectif recherchĂ© Ă©tant l’identification de grains minĂ©raux de petites tailles utilisĂ©s comme indicateurs minĂ©ral -ogiques. Une application potentielle de cette recherche serait le dĂ©veloppement d’un outil logiciel d’assistance pour l’analyse des Ă©chantillons lors de l’exploration minĂ©rale. Les expĂ©riences ont Ă©tĂ© menĂ©es en laboratoire dans la gamme relative Ă  l’infrarouge thermique (Long Wave InfraRed, LWIR) de 7.7m Ă  11.8 m. Ces essais ont permis de proposer une mĂ©thode pour calculer l’annulation du continuum. La mĂ©thode utilisĂ©e lors de ces essais utilise la factorisation matricielle non nĂ©gative (NMF). En utlisant une factorisation du premier ordre on peut dĂ©duire le rayonnement de pĂ©nĂ©tration, lequel peut ensuite ĂȘtre comparĂ© et analysĂ© par rapport Ă  d’autres mĂ©thodes plus communes. L’analyse des rĂ©sultats spectraux en comparaison avec plusieurs bibliothĂšques existantes de donnĂ©es a permis de mettre en Ă©vidence la suppression du continuum. Les expĂ©rience ayant menĂ©s Ă  ce rĂ©sultat ont Ă©tĂ© conduites en utilisant une plaque Infragold ainsi qu’un objectif macro LWIR. L’identification automatique de grains de diffĂ©rents matĂ©riaux tels que la pyrope, l’olivine et le quartz a commencĂ©. Lors d’une phase de comparaison entre des approches supervisĂ©es et non supervisĂ©es, cette derniĂšre s’est montrĂ©e plus appropriĂ© en raison du comportement indĂ©pendant par rapport Ă  l’étape d’entraĂźnement. Afin de confirmer la qualitĂ© de ces rĂ©sultats quatre expĂ©riences ont Ă©tĂ© menĂ©es. Lors d’une premiĂšre expĂ©rience deux algorithmes ont Ă©tĂ© Ă©valuĂ©s pour application de regroupements en utilisant l’approche FCC (False Colour Composite). Cet essai a permis d’observer une vitesse de convergence, jusqu’a vingt fois plus rapide, ainsi qu’une efficacitĂ© significativement accrue concernant l’identification en comparaison des rĂ©sultats de la littĂ©rature. Cependant des essais effectuĂ©s sur des donnĂ©es LWIR ont montrĂ© un manque de prĂ©diction de la surface du grain lorsque les grains Ă©taient irrĂ©guliers avec prĂ©sence d’agrĂ©gats minĂ©raux. La seconde expĂ©rience a consistĂ©, en une analyse quantitaive comparative entre deux bases de donnĂ©es de Ground Truth (GT), nommĂ©e rigid-GT et observed-GT (rigide-GT: Ă©tiquet manuel de la rĂ©gion, observĂ©e-GT:Ă©tiquetage manuel les pixels). La prĂ©cision des rĂ©sultats Ă©tait 1.5 fois meilleur lorsque l’on a utlisĂ© la base de donnĂ©es observed-GT que rigid-GT. Pour les deux derniĂšres epxĂ©rience, des donnĂ©es venant d’un MEB (Microscope Électronique Ă  Balayage) ainsi que d’un microscopie Ă  fluorescence (XRF) ont Ă©tĂ© ajoutĂ©es. Ces donnĂ©es ont permis d’introduire des informations relatives tant aux agrĂ©gats minĂ©raux qu’à la surface des grains. Les rĂ©sultats ont Ă©tĂ© comparĂ©s par des techniques d’identification automatique des minĂ©raux, utilisant ArcGIS. Cette derniĂšre a montrĂ© une performance prometteuse quand Ă  l’identification automatique et Ă  aussi Ă©tĂ© utilisĂ©e pour la GT de validation. Dans l’ensemble, les quatre mĂ©thodes de cette thĂšse reprĂ©sentent des mĂ©thodologies bĂ©nĂ©fiques pour l’identification des minĂ©raux. Ces mĂ©thodes prĂ©sentent l’avantage d’ĂȘtre non-destructives, relativement prĂ©cises et d’avoir un faible coĂ»t en temps calcul ce qui pourrait les qualifier pour ĂȘtre utilisĂ©e dans des conditions de laboratoire ou sur le terrain.The geological applications of hyperspectral infrared imagery mainly consist in mineral identification, mapping, airborne or portable instruments, and core logging. Finding the mineral indicators offer considerable benefits in terms of mineralogy and mineral exploration which usually involves application of portable instrument and core logging. Moreover, faster and more mechanized systems development increases the precision of identifying mineral indicators and avoid any possible mis-classification. Therefore, the objective of this thesis was to create a tool to using hyperspectral infrared imagery and process the data through image analysis and machine learning methods to identify small size mineral grains used as mineral indicators. This system would be applied for different circumstances to provide an assistant for geological analysis and mineralogy exploration. The experiments were conducted in laboratory conditions in the long-wave infrared (7.7ÎŒm to 11.8ÎŒm - LWIR), with a LWIR-macro lens (to improve spatial resolution), an Infragold plate, and a heating source. The process began with a method to calculate the continuum removal. The approach is the application of Non-negative Matrix Factorization (NMF) to extract Rank-1 NMF and estimate the down-welling radiance and then compare it with other conventional methods. The results indicate successful suppression of the continuum from the spectra and enable the spectra to be compared with spectral libraries. Afterwards, to have an automated system, supervised and unsupervised approaches have been tested for identification of pyrope, olivine and quartz grains. The results indicated that the unsupervised approach was more suitable due to independent behavior against training stage. Once these results obtained, two algorithms were tested to create False Color Composites (FCC) applying a clustering approach. The results of this comparison indicate significant computational efficiency (more than 20 times faster) and promising performance for mineral identification. Finally, the reliability of the automated LWIR hyperspectral infrared mineral identification has been tested and the difficulty for identification of the irregular grain’s surface along with the mineral aggregates has been verified. The results were compared to two different Ground Truth(GT) (i.e. rigid-GT and observed-GT) for quantitative calculation. Observed-GT increased the accuracy up to 1.5 times than rigid-GT. The samples were also examined by Micro X-ray Fluorescence (XRF) and Scanning Electron Microscope (SEM) in order to retrieve information for the mineral aggregates and the grain’s surface (biotite, epidote, goethite, diopside, smithsonite, tourmaline, kyanite, scheelite, pyrope, olivine, and quartz). The results of XRF imagery compared with automatic mineral identification techniques, using ArcGIS, and represented a promising performance for automatic identification and have been used for GT validation. In overall, the four methods (i.e. 1.Continuum removal methods; 2. Classification or clustering methods for mineral identification; 3. Two algorithms for clustering of mineral spectra; 4. Reliability verification) in this thesis represent beneficial methodologies to identify minerals. These methods have the advantages to be a non-destructive, relatively accurate and have low computational complexity that might be used to identify and assess mineral grains in the laboratory conditions or in the field

    Lithological and hydrothermal alteration mapping of epithermal, porphyry and tourmaline breccia districts in the Argentine Andes using ASTER imagery

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    The area of interest is located on the eastern flank of the Andean Cordillera, San Juan province, Argentina. The 3600 km2 area is characterized by Siluro-Devonian to Neogene sedimentary and igneous rocks and unconsolidated Quaternary sediments. Epithermal, porphyry-related, and magmatic-hydrothermal breccia-hosted ore deposits, common in this part of the Frontal Cordillera, are associated with various types of hydrothermal alteration assemblages. Kaolinite – alunite-rich argillic, quartz – illite-rich phyllic, epidote – chlorite – calcite-rich propylitic and silicic are the most common hydrothermal alteration assemblages in the study area. VNIR, SWIR and TIR ASTER data were used to characterize geological features on a portion of the Frontal Cordillera. Red-green-blue band combinations, band ratios, logical operations, mineral indices and principal component analysis were applied to successfully identify rock types and hydrothermal alteration zones in the study area. These techniques were used to enhance geological features to contrast different lithologies and zones with high concentrations of argillic, phyllic, propylitic alteration mineral assemblages and silicic altered rocks. Alteration minerals detected with portable short-wave infrared spectrometry in hand specimens confirmed the capability of ASTER to identify hydrothermal alteration assemblages. The results from field control areas confirmed the presence of those minerals in the areas classified by ASTER processing techniques and allowed mapping the same mineralogy where pixels had similar information. The current study proved ASTER processing techniques to be valuable mapping tools for geological reconnaissance of a large area of the Argentinean Frontal Cordillera, providing preliminary lithologic and hydrothermal alteration maps that are accurate as well as cost and time effective
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