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1
Santaguida, Frank Carleton University Dissertation Earth Sciences. "The Paragenetic relationships of epidote-quartz hydrothermal alteration within the Noranda Volcanic Complex, Quebec". Ottawa, 1999.
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Pang, Kwan-Nang. "Origin of the permian panzhihua layered gabbroic intrusion and the hosted Fe-Ti-V oxide deposit, Sichuan Province, SW China". Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B39634000.
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Hulley, Vierah. "Reactions between country rock xenoliths and the magma of Uitkomst Complex, with implications for the origin of the sulphide mineralisation". Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-05282008-101011.
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Bowman, Ryan Lee. "CLAY MINERAL TRANSFORMATIONS IN ACIDIC ENVIRONMENTS: FINDING AN EARTHEN ANALOGUE TO THE SURFACE OF MARS". OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2608.
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Once similarities between Earth and other terrestrial bodies were discovered, determining the conditions that contributed to the evolution of surface processes on these planets, particularly Mars, is of great interest. More importantly, such research and exploration can provide proof of previous existent life within these near-surface environments. As the past environmental conditions at Mars’ surface are mostly unknown, studies of comparable environments on Earth have been crucial toward deciphering the overall geological understanding of Mars. As the discovery of past conditions on Mars become more absolute, researchers can search for more constrained bio-signatures of life that may have been present. Using the geological similarities between Earth and Mars, analogues can be used to compare the conditions on Mars and Earth and how they evolved over time, further providing more precise understanding of our own environment as it relates to the future. In this study, acid mine drainage (AMD) systems, which are one of the most acidic environments on Earth, were compared to the surface of Mars as a potential analogue to the past conditions of the planet when such acid-impacted environments were widespread at the surface of the planet.
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Adlakha, Erin Elizabeth. "The Paragenesis and Chemical Variation of Alteration Minerals Associated with Basement Rocks of the P2 Fault and the McArthur River Uranium Deposit, Athabasca Basin, Northern Saskatchewan, Canada". Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34926.
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The P2 reverse fault in the metasedimentary basement rocks of the eastern Athabasca Basin is the main structural control of the world-class McArthur River uranium deposit. The earliest preserved assemblage along the fault is oxy-dravite, rutile, quartz, pyrite and graphite. This assemblage formed at temperatures of up to 890 °C, during regional metamorphism or a thermal event at ~1.75 Ga. The exhumation and surface exposure of the rocks was accompanied by paleo-weathering, and the deposition of the Athabasca sandstones. Diagenetic fluids of the sandstones altered the basement rocks to form Sr-Ca-SO42- rich aluminum phosphate sulfate (APS) minerals + hematite ± kaolin. The onset of hydrothermal activity along the basement and the P2 fault is recorded by local anatase at 1569 ± 31 Ma. Uraniferous fluid formed an assemblage of sudoite illite, magnesio-foitite and LREE+P rich APS minerals (rims earlier diagenetic-type APS minerals) along the entire P2 fault. Magnesio-foitite exhibits a high X-site vacancy (0.70 – 0.85 apfu) and contains high Al in its Y-site (0.70 – 1.12 apfu), suggesting that magnesio-foitite likely replaced kaolin. The REE pattern of magnesio-foitite is similar to that of uraninite (CeN
6
Gill, Benjamin Charles. "High-resolution sulfur isotope records of the Paleozoic and a detailed geochemical study of the late Cambrian SPICE event utilizing sulfur isotope stratigraphy, metal chemistry and numerial modeling". Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=78&did=1871861801&SrchMode=1&sid=1&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270232379&clientId=48051.
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ZHANG, JING. "INTERACTION OF METHANOGENS WITH CLAY MINERALS, ORGANIC MATTER, AND METALS". Miami University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=miami1389881682.
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El, Kazzaz Yahia Abbas Hamed Abdalla. "Tectonics and mineralization of Wadi Allaqi, south Eastern Desert, Egypt". Thesis, University of Bedfordshire, 1995. http://hdl.handle.net/10547/606076.
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Neoproterozoic volcanic, sedimentary and volcano-sedimentary rocks of central Wadi Allaqi were deformed and metamorphosed to greenschist facies during the Pan-African orogeny. Three major, geochemically and lithostratigraphically distinct, tectonic-stratigraphy Successions with an intermediate tectonically-emplaced unit of ophiolitic rocks (Gebel Taylor Wedge), which have been metamorphosed to blueschists facies prior to emplacement, are recognised. The tectonic pile has been intruded by four granitic plutons and basic igneous sills, which were emplaced at various stages in the tectonic history. A series of large-scale thrust duplexes with a few major nappe-like folds and shear-zones, the most conspicuous of which is the Allaqi Shear-zone, structurally dominate the area. A complex polyphase structural history has been deduced consisting of earlier ductile and late more brittle deformation phases and this has been related to the regional metamorphic development. A gold mineralized quartz vein system was emplaced syn-tectonically along the first deformation (D1) shear-zones. Data from structures, petrography, fluid inclusions and stable isotopes of oxygen and hydrogen tend to support a metamorphic provenance for the auriferous fluids. The petrological, geochemical and structural evidence strongly support a back-arc basin environment for the sedimentary development of central Wadi Allaqi before the Pan-African Orogeny. A single Wilson Cycle is proposed for the evolution of the area, in which following an extensional phase, during which the marginal elements of the ancient Mozambique Ocean (in the sense of Dalziel 1991) were developed. Back-arc sedimentary rocks and volcaniclastic rocks were metamorphosed and transported as a thrust-duplex system northward over the Nile Craton and any associated marginal sedimentary sequence.
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Hicks, Judith Anne. "Gahnite and its formation in the context of regional metamorphism and mineralization in the Namaqualand metamorphic complex". Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/22024.
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Bibliography: pages 150-158.Gahnite (ZnAl₂O₄) is commonly associated with sulphide mineralization in metamorphosed massive sulphide deposits, and also occurs in marbles, pegmatites and quartz veins. Its formation has been attributed to the breakdown of Zn-staurolite or desulphidation of sphalerite during metamorphism. The stability of zinc-rich spinels under a wide range of metamorphic conditions in a variety of lithologies results in its persistence in rocks where many other prograde, high temperature minerals and sulphides have been altered. Thfs has resulted in various investigations into its use in exploration and potential for determining metamorphic parameters. With the interest in finding new ore bodies and in determining the metamorphic history and mineralogy in Namaqualand, some gahnite-bearing localities have been investigated in this study.
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La, Cruz Nikita Latesha. "Schreibersite: Synthesis, Characterization and Corrosion and Possible Implications for Origin of Life". Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5724.
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We present study of the synthesis and reactions of an analog of the meteoritic mineral schreibersite with formula (Fe,Ni)3P, believed to be a prebiotic source of reactive phosphorus that may have prompted the formation of phosphorylated biomolecules near the time of the origin of life (Pasek and Lauretta, 2005). The mineral was synthesized by mixing stoichiometric proportions of elemental iron, nickel and phosphorus and heating in a tube furnace at 820°C for approximately 235 hours under argon or under vacuum, a modification of the method of Skála and Drábek (2002). The mineral was characterized using X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), micro-raman spectroscopy and electron microprobe analysis (EMPA). Characterization indicates that both schreibersite, with approximate formula Fe2NiP and the mineral nickel-phosphide, FeNi2P were synthesized.
In addition to characterization of the solid product, the reactions of the synthetic schreibersite were investigated to determine the similarity between these and prior work done with Fe3P. Synthetic schreibersite was corroded in several solutions: seawater and sulfidic water under both oxic and anoxic conditions. After corrosion, the solutions were analyzed using phosphorus nuclear magnetic resonance spectroscopy (31P NMR) and high performance liquid chromatography attached to an inductively coupled plasma mass spectrometer (HPLC-ICP-MS) to determine phosphorus speciation as well as concentrations of phosphorus present in solution. As expected from previous studies, the NMR and HPLC-ICP-MS results indicated the presence of orthophosphate, phosphite, pyrophosphate and hypophosphate in the corrosion solutions (Pasek and Lauretta, 2005). The HPLC-ICP-MS results indicate that the extent of corrosion of the mineral—measured by the concentration of phosphorus released—depends on the ionic strength of the solution, as well as the presence or absence of the chelating agent. Finally, we report the successful phosphorylation of a potentially prebiotic molecule—choline—using synthesized schreibersite.
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Kelley, Daniel F. "Toward an Integrated Model of the Crust in the Icelandic Rift Zones". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1244046067.
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Elferink, Lisa. "The cenozoic stratigraphy and associated heavy mineral palaeo-placer deposit on Geelwal Karoo : West Coast, South Africa". Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/21452.
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ENGLISH ABSTRACT: The farm Geelwal Karoo is situated some 16km north of the Olifants River mouth on the West Coast of
South Africa and hosts fluvial, marine and aeolian deposits of post-Gondwana age. The oldest basal fluvial
succession, unconformably overlies Proterozoic and Palaeozoic basement rocks and is in turn capped by
aeolianite and littoral packages representing two transgressive cycles.
The fluvial channel clay succession is deposited in shallow bedrock-incised channels, has a wedge-shape
and is deposited parallel to the present coastline. The flow direction is along the coast and the northwardtapering,
angular, poorly sorted basal vein-quartz lag indicates a northward palaeo-flow direction. Less than
1% total heavy minerals (THM) is found in the matrix of these gravel units and the heavy mineral suite is
distinguished by zircon, pseudorutile and kyanite. The channel clay unit is dominated by an upper, mediumgrained
quartzose sand and kaolin clay facies, which shows advanced post-depositional weathering. The
fluvial unit is correlated with the channel clay unit of Hondeklip Bay and a Cretaceous age is proposed for the
initial channel incision.
The two shallow marine successions have been correlated with the Late Miocene, Early Pleistocene, +30m
and +50m packages respectively. These marine sediments were first described by John Pether (1994) in
the Hondeklip Bay area and were named according to their transgressive maxima. They are transgressive
successions arranged en echelon down the coastal bedrock gradient, from oldest and highest to youngest.
The offshore environment of the +50m package consists of fine silty sand, which is moderately sorted. The
mineral assemblage is dominated by quartz and the average THM is 18%. The inshore environment is
distinguished by a single poorly sorted basal cobble lag which shows an overall fining upward succession.
The beachface environment is composed of medium to fine-grained sand, which is moderate to well-sorted.
Mineral diversity is greatest in the inshore and beachface environments and the average THM for these two
units is greater than 35%. The +30m package has been extensively eroded due to its lower erosion and
outcrops were sporadic along the coast. The +30m offshore sediments are recognised by fine sediments
with high concentrations of glauconite and organic matter. The inshore environment is distinguished by
numerous poorly sorted pebble lags with fining upward successions. Both the inshore and beachface units
have higher feldspar concentrations than the corresponding +50m units. The average THM for these two
units is less than 3%.
The aeolianite unit, which comprises several distinct units, extends over the entire length of the study area
and is characterized by calcrete and red bed horizons. Colour variations in the otherwise homogeneous unit
are due to heavy mineral enrichment and/or different degrees of in situ weathering and cementation. The
unit is composed exclusively of fine- to medium-grained sand and the THM concentration averages 9%.
This unit is composed of more than one generation of aeolian sand and forms part of an aeolian transport
corridor which transported sand from the beach to the interior. The oldest unit has been equated with the
Upper Miocene Prospect Hill Formation, whereas the more recent yellow dune sand is equated with the
Pleistocene Springfontyn Formation. At Geelwal Karoo, only the heavy sand placer in the +50m package was deemed to be of any economic
significance. The average THM of this placer was calculated to be 40% and some 150 thousand tons of Tibearing
material can be expected from this succession. This relatively small volume of heavy minerals and
extensive cementation however, make this placer a less attractive prospect than the neighbouring Namakwa
Sands operation.AFRIKAANSE OPSOMMING: Die plaas Geelwal Karoo is ongeveer 16km noord van die Olifantsriviermond aan die Weskus van Suid- Afrika geleë en het voorkomste van fluviale, marine en eoliese afsettings van post-Gondwana ouderdom. Die oudste eenheid, ‘n basale fluviale eenheid, oorlê Proterosoiëse en Paleosoiëse plaaslike vloer gesteentes wat op hulle beurt weer bedek word deur eoliese en littorale eenhede verteenwoordigene ven twee transgressiewe siklusse. Die fluviale kanaalklei-opeenvolging, afgeset in vlak ingesnyde rotsbedding-kanale, is wigvormig en is afgeset parallel aan die huidige kuslyn in ‘n alluviale waaier-afsetting. Die vloeirigting was langs die kus en die noorwaards toespitsende, hoekige, swak gesorteerde basale aar-kwarts bodemgruis dui op ‘n noordwaards palaeo-vloeirigting. Minder as 1% totale swaarminerale (TSM) is gevind in die tussenmassa van hierdie gruis-eenhede en die swaarmineraal reeks word onderskei deur sirkoon, pseudo-rutiel en kianiet. Die kanaalklei eenheid word oorheers deur ‘n boonste, medium-korrelrige kwarts-bevattende sand en kaolien kleifasies was dui op gevorderde verwering na afsetting. Die fluviale eenheid word gekorreleer met die kleikanaal en ‘n Kryt-ouderdom word voorgestel vir die aanvanklike insnyding van die kanaal. Die twee vlak marine opeenvolgings word gekorreleer met die Laat Mioseen, vroeg Pleistoseen, naamlik die +30m en +50m eenhede onderskeidelik. Die aflandige omgewing van die +50m eenhied bestaan uit matiggesorteerde, fyn slikkerige sand. Die mineraalversameling word oorheers deur kwarts en die gemiddelde TSM is 18%. Die subgetysone word onderskei deur ‘n enkele swak-gesorteerde gruislaag en is oorwegende opwaarts fynerwordend. Die strandomgewing is goed verteenwordige en bestaan uit matig tot goedgesorteerde medium- tot fynkorrelrige sand. Die grootste mineraal-diversiteit kom voor in die subgety- en strandomgewings en die gemiddelde TSM vir hierdie eenhede is hoër as 35%. As gevolg van algemene erosie kom die +30m eenheid sporadies voor. Die aflandige omgeving is herken deur fyn kleierige of slikkerige sedimente met hoe konsentrasies gloukoniet en organiese materiaal. Die subgetysone omgewing is gekenmerk deur verskeie gruislae wat almal opwaarts fynwordend is. Altwee die subgety- en strandomgewings het hoer feldspar konsentrasies as die +50m eenhede. Die gemiddelde THM vir hierdie enhede is minder as 3%. Die eolitiese eenheid, bestaan uit verskeie duidelik-onderskeibare eenhede, beslaan die totale lengte van die studiegebied en word kenmerk deur uitgebreide kalkreet en rooi-laag horisonne. Kleurverskille in die andersins homogene eenheid kan verklaar word in terme van lae swaarmineraal konsentrasies en/of as gevolg wan verskillende grade van in situ verwering en sementering. Die eenheid bestaan uitsluitlik uit fyntot medium-korrelrige sand en het ‘n gemiddelde TSM konsentrasie van 9%. Die eenheid bestaan uit meer as een generasie eoliese sand en maak deel uit van ‘n eoliese vervoersisteem wat sand vanaf die strand na die binneland vervoer het. Die oudste sande in hierdie eenheid is gekorreleer met die Laat Mioseen Prospect Hill Formasie terwyl die meer onlangse geelduin sand vergelyk word met die Pleistoseen Springbokfontein Formasie. By Geelwal Karoo is slegs die +50m eenhede beskou as economies van belang. Die gemiddelde TSM van hierdie swaarmineraal-ertsligaam is bereken op 40% met ‘n verwagte 150 duisend ton Ti-draende material van die opeenvolging. Die relatiewe klein volume swaarminerale en uitgebreide sementering het tot gevolg dat dit ‘n minder aanloklike proposisie is as die aanliggende Namakwa Sands aanleg.
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Brennan, Michael Brendan. "The genesis of ilmenite-rich heavy mineral deposits in the Bothaville/Delmas area, and an economic analysis of titanium, with particular reference to the Dwarsfontein deposit, Delmas district". Thesis, Rhodes University, 1991. http://hdl.handle.net/10962/d1005561.
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A number of ilmenite-rich heavy mineral deposits occur along the northern margin of the intracratonic Karoo basin, and are hosted by the fluvio-deltaic Middle Ecca Group. Coastal reworking of delta front sands within a regressive, microtidal shoreline may be considered as a depositional model for the development of the heavy mineral deposits. An economic analysis of titanium suggests long term positive demand, and sustained high prices for this commodity. An evaluation of the Dwarsfontein ilmenite-rich heavy mineral deposit, using available data, indicates how important it is for deposits of this type to be situated close to an upgrading plant or export harbour.
14
Lafrance, Benoît. "Reconstruction d'un environnement de sulfures massifs volcanogènes déformé : exemple archéen de Normétal, Abitibi /". Thèse, Chicoutimi : [Montréal : Université du Québec à Chicoutimi ; Université du Québec à Montréal], 2003. http://theses.uqac.ca.
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Thèse (D.Ress.Min.) -- Université du Québec à Chicoutimi, programme extensionné à l'Université du Québec à Montréal, 2003.Bibliogr.: f. 267-278. Document électronique également accessible en format PDF. CaQCU
15
Jaisi, Deb Prasad. "Fe(III) reduction in clay minerals and its application to technetium immobilization". Oxford, Ohio : Miami University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1179946951.
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Dinis, Sauro Leonel Pereira. "Garimpeiros e exploração artesanal de pequena escala de ouro". Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/29728.
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Este trabalho foi realizado com o intuito de enquadrar a atividade do garimpo em termos históricos, geológicos, económicos e sociais e todas as questões inerentes ao tema.
O objetivo principal passa pela apresentação de uma síntese das perspetivas que o garimpo e a exploração artesanal de pequena escala de ouro apresentam quer a nível mundial, quer no caso específico de Portugal, que se apresenta como um verdadeiro desafio a esta atividade, explorando um pouco do que foi historicamente o garimpo em Portugal e como se desenvolveu noutros países, de forma que ainda hoje é uma atividade de grande importância para as principais economias mundiais.
Também procura responder aos desafios dos garimpeiros a nível de regulamentação da atividade e a realidade do garimpo ilegal, face às regulamentações impostas e aos sistemas criados, assim como, quais as metas futuras e condicionantes que fazem desta atividade um verdadeiro desafio para os garimpeiros; Artisanal gold miners and small-scale gold mining
Abstract:
This work was carried out with the intention of framing the mining activity in historical, geological, economic and social terms and all the issues inherent to the theme.
The main objective is to present a synthesis of the perspectives that gold mining and small-scale artisanal exploration present both worldwide and in the specific case of Portugal, which presents itself as a real challenge to this activity, exploring a little of what mining was historically in Portugal and how it developed in other countries, so that today it is still an activity of great importance for the main world economies.
It also seeks to respond to the miners challenges in terms of activity regulation and the reality of illegal mining, in view of the regulations imposed and the systems created, as well as what are the future and conditioning goals that make this activity a real challenge for miners
17
Jones, Marilyn Gail 1963. "Clay mineralogy and petrology of the Lower Cretaceous fine-grained clastic rocks, southeastern Arizona". Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/558100.
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Sinuka, Sikhulule. "Heavy mineral characterization and provenance interpretation of the Ecca Group of geological formations in Eastern Cape Province, South Africa". Thesis, University of Fort Hare, 2016. http://hdl.handle.net/10353/2911.
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The aim of the research focuses on characterizing heavy mineral assemblages and interpretation of the provenance of the Ecca Group of in the Eastern Cape Province, South Africa. In South Africa, the Ecca Group outcrops extensively in the Main Karoo Basin. Mudstone, siltstone, sandstone, minor conglomerate and coal are the major constituent lithologies within the group. For descriptive purposes, the Ecca is categorized into three different geographical areas: the southern area, the western and northwestern area and the northeastern area. Six of the sixteen geological formations, namely the Prince Albert, Whitehill, Collingham, Ripon, Fort Brown, Waterford and Koonap Formations are present in the study area and are best exposed in road cuttings. For purposes of comparison, the underlying Witteberg Group, the Dwyka (which has Formation status here), and the overlying Koonap Formation of the Beaufort Group, are included in the study. This study is motivated by the relatively little information that is available on the heavy minerals of the Ecca Group, and that research of this nature had not been undertaken in the study area before. Another contributing motivation was to determine whether heavy mineral assemblages could be used to identify formations of the Ecca Group and for correlating between different localities in accordance with studies done elsewhere. Additionally, diagnostic heavy mineral assemblages could aid with stratigraphic selection of future boreholes in the Ecca Group. Heavy minerals are natural provenance tracers because of their stable nature and hydrodynamic behaviour. They are both non-opaque and opaque, with apatite, epidote, garnet, rutile, staurolite, tourmaline and zircon being good examples of non-opaque grains while ilmenite and magnetite are the most common opaques. Heavies are either derived from stable minor accessory minerals or from abundant but unstable mafic components of the host rock. They are very useful in interpreting the provenance due to the fact that some minerals are diagnostic of certain source rocks. However, sediments are exposed to several factors (conditions) such as weathering, erosion, breakage due to abrasion, mixing and recycling during transportation from the source to the depositional area. This implies that there are parameters other than the parent lithology that determine their final composition.
19
Mitchell, Scott Christian. "An Improved MUSIC Model for Gibbsite". Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd831.pdf.
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Sukova, Tatjana. "Dynamic models of non-metallic mineral deposits and their use during the development of a deposit". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110307_144647-47446.
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The targets of the research were the gravel and sand deposits of different genetic type, as well as promising areas in the area of Lithuania. The present work defines the principle applied for construction of dynamical models of non-metal mineral deposits. The possibilities of automated analysis and evaluation of mineral deposit prospecting data have explored; the methodology for automation of mineral deposit use design solutions has created and introduced into a computer software; the possibilities of automation for calculation of production (mining) volumes according to the surveyor measurements have explored; the possibilities of automation for recording and controlling the production (mining) have explored in the dissertation. The modelling is done in 3D space enabling to see 3D perspective images of a pit from any point selected and prognosticate the course of excavation works.Tyrimų objektais buvo pasirinkti įvairių genetinių tipų žvyro ir smėlio telkiniai bei prognoziniai plotai išsidėstę Lietuvos teritorijoje. Disertacijoje yra apibrėžtas nerūdinių naudingųjų iškasenų telkinių dinaminių modelių sudarymo principas; išnagrinėtos naudingųjų iškasenų telkinių žvalgybos duomenų automatizuotos analizės ir vertinimo galimybės; sukurta naudingųjų iškasenų telkinių naudojimo projektinių sprendinių automatizavimo metodika ir įdiegta į programinę įrangą; išnagrinėtos kasybos apimčių pagal markšeiderinius apmatavimus apskaičiavimo automatizavimo galimybės; išnagrinėtos kasybos proceso apskaitos ir kontrolės automatizavimo galimybės. Modeliavimas atliekamas trimatėje erdvėje, kas sudaro galimybę matyti trimačius perspektyvinius karjero vaizdus iš bet kokio pasirinkto taško ir numatyti naudingųjų iškasenų telkinių kasybos darbų eigą.
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Sukova, Tatjana. "Nerūdinių naudingųjų iškasenų telkinių dinaminių modelių sudarymas ir jų panaudojimas telkinio eksploatavimo eigoje". Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110307_144708-04521.
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Tyrimų objektais buvo pasirinkti įvairių genetinių tipų žvyro ir smėlio telkiniai bei prognoziniai plotai išsidėstę Lietuvos teritorijoje. Disertacijoje yra apibrėžtas nerūdinių naudingųjų iškasenų telkinių dinaminių modelių sudarymo principas; išnagrinėtos naudingųjų iškasenų telkinių žvalgybos duomenų automatizuotos analizės ir vertinimo galimybės; sukurta naudingųjų iškasenų telkinių naudojimo projektinių sprendinių automatizavimo metodika ir įdiegta į programinę įrangą; išnagrinėtos kasybos apimčių pagal markšeiderinius apmatavimus apskaičiavimo automatizavimo galimybės; išnagrinėtos kasybos proceso apskaitos ir kontrolės automatizavimo galimybės. Modeliavimas atliekamas trimatėje erdvėje, kas sudaro galimybę matyti trimačius perspektyvinius karjero vaizdus iš bet kokio pasirinkto taško ir numatyti naudingųjų iškasenų telkinių kasybos darbų eigą.The targets of the research were the gravel and sand deposits of different genetic type, as well as promising areas in the area of Lithuania. The present work defines the principle applied for construction of dynamical models of non-metal mineral deposits. The possibilities of automated analysis and evaluation of mineral deposit prospecting data have explored; the methodology for automation of mineral deposit use design solutions has created and introduced into a computer software; the possibilities of automation for calculation of production (mining) volumes according to the surveyor measurements have explored; the possibilities of automation for recording and controlling the production (mining) have explored in the dissertation. The modelling is done in 3D space enabling to see 3D perspective images of a pit from any point selected and prognosticate the course of excavation works.
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Liu, Pingping, i 刘平平. "Petrogenesis of the Baima Fe-Ti-(V) oxide-bearing layered intrusion in the Emeishan large igneous province, SW China". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/207172.
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Volpato, Juliano 1984. "Relação entre geoquímica e minerais (Magnetita, Hematita, Pirita e Vivianita) em sedimentos estuarinos contaminados, Santos (SP)". [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/286644.
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Orientador: Wanilson Luiz SilvaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências
Made available in DSpace on 2018-08-27T06:38:54Z (GMT). No. of bitstreams: 1 Volpato_Juliano_M.pdf: 8591527 bytes, checksum: 58b14d8c8d308419f349e7d957c88674 (MD5) Previous issue date: 2015
Resumo: A existência de sedimentos altamente enriquecidos principalmente por Fe e P, provenientes das indústrias siderúrgica e de fertilizantes localizadas próximas ao estuário do rio Morrão, um dos principais receptores de efluentes industriais do Sistema Estuarino de Santos-Cubatão (São Paulo Brasil), juntamente com as condições físico-químicos do meio, constitui elementos especiais para avaliar se as condições formadoras de minerais como magnetita, hematita, pirita e vivianita podem ser influenciadas por contribuições químicas antrópicas. Este trabalho analisou as condições de formação desses minerais nos sedimentos superficiais do estuário do rio Morrão, na sua relação com a geoquímica dos sedimentos, condições físico-químicas, texturas sedimentares e conteúdo de matéria orgânica. A coleta de sedimentos de superfície consistiu em uma malha amostral de 10 x 10 m, em três transectos paralelos que cruzaram perpendicularmente o canal do rio Morrão. Os resultados mostraram que os sedimentos do rio Morrão encontram-se enriquecidos em diversos elementos químicos dentre os quais Fe, P, elementos terras raras (ETR) e vários metais-traço. O ambiente sedimentar do rio Morrão mostrou-se favorável à autigênese e coexistência de minerais como hematita, magnetita, pirita e vivianita. As fases minerais hematita e magnetita ocorrem amplamente no ambiente, já as fases minerais pirita e vivianita têm sua distribuição mais restrita. Os locais mais favoráveis à ocorrência de pirita e vivianita foram áreas de menor energia de fluxo, tais como planícies de intermaré lamosa, onde há altos teores de enxofre, ferro, fósforo, matéria orgânica e sedimentos finos
Abstract: The presence of sediments highly enriched by contaminant elements, mainly Fe and P, derived from a steel plant and fertilizer industries located near the Morrão River Estuary, the most anthropogenically influenced estuary of the Santos-Cubatão Estuarine System (São Paulo, Brazil), together with the environment physic-chemical conditions constitute special elements to evaluate if the forming conditions of mineral such as magnetite, hematite, pyrite and vivianite can be influenced by the anthropogenic input into the environment. This work studied the forming conditions of these minerals in the superficial sediments of the Morrão River Estuary in its relation with sediment geochemistry, physicochemical conditions, sedimentary texture, and organic matter content. The sample collection comprised a 10 by 10 meters grid composed of three parallel transects crossing perpendicularly the Morrão River channel. The results showed the sediments of Morrão River Estuary are enriched by several chemical elements among which Fe, P, REE and multiple trace elements. The sedimentary environment of the Morrão River showed to be propitious to the authigenesis and coexistence minerals such as hematite, magnetite, pyrite, and vivianite. Magnetite and hematite broadly occur in the environment, and pyrite and vivianite have restrict distribution. Moreover, the places more favorable to the pyrite and vivianite occurrence are areas with low water flux action, such as the intertidal mudflats, where concentrations of S, Fe, P, organic matter, and fine sediments are high
Mestrado
Geologia e Recursos Naturais
Mestre em Geociências
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彭君能 i Kwan-Nang Pang. "Origin of the permian panzhihua layered gabbroic intrusion and the hosted Fe-Ti-V oxide deposit, Sichuan Province, SW China". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B39634000.
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Cymes, Brittany Allison. "Catalytic Properties of Novel Microporous Minerals". Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1587730697926361.
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Ravi, Kommajosyula Subramanya. "Mineralogy, geochemistry, and dispersal of opaque oxides on the continental shelf of the Cascadia margin". PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/4363.
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Opaque oxide minerals (ilmenite, chromite, and magnetite) in sands from the Oregon continental shelf have been studied to establish the provenance, dispersal, and grade of potential shelf placer deposits. The study area extends southward from offshore of the Columbia River in northern Oregon to the Klamath River in northern California.
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Olivier, Wernich Corné. "The geology of the Witteberg group, Cape supergroup, with specific focus on the Perdepoort member as a potential silica source". Thesis, Nelson Mandela Metropolitan University, 2010. http://hdl.handle.net/10948/1386.
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Selected outcrops of the Upper Devonian to Lower Carboniferous, Witteberg Group, Cape Supergroup were mineralogically and structurally analyzed. The study area is located approximately 30km northwest of Kirkwood and 10km south of Darlington Dam, Eastern Cape, South Africa. Strata predominantly consist of arenaceous Witpoort Formation, which includes the Perdepoort, and Rooirand Members. The Perdepoort Member is a thinly bedded quartzite also known as the "white streak". The Rooirand Member quartzite is a highly iron stained red-brown quartzite. The dark-grey, pyritic rich shales of the Kweekvlei Formation overlie the Witpoort Formation in the southern half of the study site. These shales are highly deformed and display closely spaced thrust faults and close folds. The study area encapsulates a range of folding from tight to open folds. Faulting consists of low angle north verging thrust fault, south verging back thrusts, south and north dipping normal faults, and strike-slip faults. Closely spaced, fore-land verging thrusts faults predominate over hinterland verging back thrusts. Normal faulting post-dates thrust faulting and utilized weaknesses in axial planar cleavage and in certain instances existing thrust fault planes. Strike-slip faulting post-dates thrusting and has in places reactivated pre-existing thrust fault planes. Macro scale folding includes overturned synclines and large anticlines which have been eroded, exposing older strata. Fold axes plunge at low to moderate angles west-southwest. This correlates with tension gashes which indicate north westward directed forces. Eastward directed forces are confirmed by the presence of tension gashes and strike-slip movement. The local geology displays north westward directed compression followed by strike-slip movement. Normal faulting post-dates all other structures and is associated with the Mesozoic break-up of Gondwana. The Perdepoort Member was sampled along strike, at different outcrop latitudes. Seven samples were selected for scanning electron microscope analysis. Samples are composed almost entirely of quartz; accessories include, biotite, muscovite, sericite, baryte, and apatite. Epigenetic hematite is present along cracks within certain samples Epigenetic hematite occur along cracks with oxides and phosphates in the form of rutile, apatite and monazite present in a number of samples. When compared to other silica extraction operations the Perdepoort Member appears viable for explotation. However, for the solar cell industry the purity of this horizon is clearly far below that required for industy.
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Turner, Roxie Jessica. "Provenance and Depositional History of Late Pleistocene New Jersey Shelf Sediments". Digital Archive @ GSU, 2005. http://digitalarchive.gsu.edu/geosciences_theses/2.
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Pleistocene New Jersey shelf sedimentology is strongly influenced by glacially driven sea level changes. A combination of regressive shoreline processes, subaerial exposure, fluvial downcutting, and deposition and reworking during transgression has influenced the NJ shelf sediment composition. Sediment provenance and transport history may be determined on a shelf environment through analysis of grain size distribution, heavy mineral content, magnetic mineral concentrations, and isotopic dating methods. A combination of surface grab and stratigraphic samples were analyzed within the study area. Relatively high percentages of heavy minerals were found in the 2 phi and 3 phi size fractions and hornblende grains provided K-Ar age values indicating two groups of sediment sources. The first source is Grenville with apparent ages above 900 Ma deposited during marine OIS 1. The second source is a mixed assemblage of Grenvillian and Paleozoic sources deposited during marine OIS 3, with apparent ages of approximately 850 ± 20 Ma.
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Yang, Shenghong, i 杨胜洪. "The permian Pobei mafic-ultramafic intrusion (NE Tarim, NW China) and associated sulfide mineralization". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45874219.
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Antibus, Joanne Vinopal. "A Petrographic, Geochemical and Isotopic(Sr, O, H and C) Investigation of Alteration Minerals in Volcaniclastic Rocks at Minna Bluff, Antarctica: Petrogenesis and Implications for Paleoenvironmental Conditions". Bowling Green State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1339771052.
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Murphy, Daniel M. K. "Regolith expression of hydrothermal alteration : a study of the Groundrush and Vera Nancy gold deposits of Northern Australia". University of Western Australia. School of Earth and Environment, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0186.
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[Truncated abstract] Mineralogical and geochemical characteristics were identified for regolith overlying two Australian Au deposits that discriminate mineralized and associated hydrothermally-altered rock from weathered rock that was not hydrothermally-altered. Mineralization was lithologically controlled within a previously unrecognized diorite dyke at the lower Proterozoic mesozonal Groundrush deposit, Tanami region, Northern Territory. Although hydrothermal alteration effects within the dyke were subtle and obliterated by weathering, Ti/Zr ratios clearly discriminated the diorite dyke from visually indistinguishable but generally unmineralized dolerite. In contrast, the Carboniferous Vera Nancy low-sulphidation epithermal Au deposit, located in the Drummond Basin, northeast Queensland, comprises structurally-controlled quartz veins within a relatively chemically homogenous suite of andesitic lavas and subvolcanic intrusions. A zoned hydrothermal alteration system in the hangingwall of the main vein grades from a proximal silica-pyrite alteration zone through an argillic zone into regionally extensive propylitic 'background'. Deep chemical weathering has destroyed the minerals diagnostic of the different alteration zones in bedrock to leave a kaolinitic regolith overlying all alteration zones. However, the silica-pyrite alteration zone is identified in regolith by retention of the anomalous concentrations of Au, As, Sb and Mo present in bedrock, and mineralogical characteristics, determined from X-ray diffraction investigations, discriminated weathered argillic from propylitic alteration zones. ... Metasomatic reactions, including weathering reactions, are typically difficult to specify, as some reactants and products may be removed by fluids, and thus evidence for their involvement is absent from the observed assemblages. In addition, the range of possible reactions even for relatively simple systems is such that identifying the real reaction may be intractable without additional information. Linear algebra provides an approach to this problem. If minerals and aqueous phases are represented as columns in a matrix with elements as rows, any vectors in the null space of this matrix (if it is greater than 0-dimensional) provide coefficients to balance reactions between the phases. The 'Gale' vectors for a set of phase are the row vectors of any basis for this null space. The relationships between phases are clarified through examination of these vectors in d-dimensional Gale vector space, where d is the dimension of the null space. The hyperplane normal to any vector in Gale vector space separates the space into reactant and product half-spaces. The geometric relationships between the Gale phase vectors describe all the possible reactions. Because changes to parameters (e.g. volume, mass, density) can be determined for each possible reaction, Gale analysis can be used to identify reactions consistent with these constraints. Gale analysis of weathering at the Vera deposit indicated that all the possible weathering reactions producing kaolinite, goethite and quartz from illite, pyrite and siderite resulted in minor reductions in volume and mass only, whereas acid-neutral weathering of propylitic rocks exhibited greater mass losses, consistent with observation and geochemical interpretation.
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Vlack, Yvette A. "A Diffuse Spectral Reflectance Library of Clay Minerals and Clay Mixtures within the VIS/NIR Bands". Kent State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=kent1227006436.
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Gao, Jianfeng, i 高剑峰. "Petrogenesis of permian sulfide-bearing mafic-ultramafic intrusions insoutheast Chinese Altay and east Tianshan, NW China". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49617801.
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The Central Asia Orogenic Belt is one of the largest accretionary orogenic belts in the world. In this belt, many sulfide‐bearing mafic‐ultramafic intrusions occur along faults, including the Kalatongke complex in southeast Chinese Altay and the Huangshandong intrusion in east Tianshan.
The Kalatongke complex is a composite body including ~308Ma dioritic intrusion and 287Ma sulfide‐bearing mafic intrusion. The dioritic intrusion consists of biotite‐hornblende gabbro, diorite and quartz diorite. This intrusion was formed from a mixture of an evolved mantle‐derived magma and a crust‐derived adakitic magma combined with fractional crystallization of clinopyroxene, amphibole and plagioclase. The mafic intrusion is dominantly made up of norite in which sulfide ores, including disseminated, massive Ni‐Cu and massive Cu‐rich ores, are hosted. This intrusion was formed from two different pulses of basaltic magmas that had different magma evolution histories. The early magma pulse reached sulfide‐saturation due to minor crustal contamination and a small amount of sulfide (<0.03%) was removed before the emplacement. The evolved magmas then entered a shallow magma chamber and assimilated crustal materials to attain sulfide‐saturation again. Sulfide liquids segregated from the magma to form massive Ni‐Cu and massive Cu‐rich ores through further fractionation and residual silicate melts formed norites. A second pulse of magma underwent removal of <0.02% sulfides with stronger crustal contamination, and re‐attained S‐saturation during the emplacement and became a phenocryst‐laden magma. This magma then intruded the earlier formed massive sulfide ores and norites, forming the disseminated sulfide ores.
The Permian Huangshandong mafic‐ultramafic intrusion hosts the largest magmatic sulfide deposit in east Tianshan. It consists of a layered unit of lherzolite, gabbro and diorite and a massive unit of olivine gabbronorite and gabbronorite. Both units formed from siliceous high magnesium basaltic (SHMB) magmas derived from a hydrous, depleted mantle source. The two units of the Huangshandong intrusion formed from magmas that have undergone different processes through the evolution of the magma plumbing system. The early magma pulse gained sulfur‐saturation before the emplacement and small amounts of sulfide (<0.03%) were removed to result in a PGE‐depleted, high‐Mg magma. This magma achieved sulfide‐saturation again in a staging magma chamber through crustal contamination and fractional crystallization of olivine and Cr‐spinel (an AFC process) to form the layered unit. A second magma pulse underwent fractionation of more olivine +/‐ Cr‐spinel but less sulfide (<0.003%) removal before the emplacement and became evolved, PEG‐undepleted and low‐Mg before the injection into the magma chamber. Mixing of the two magmas triggered sulfide‐saturation to form sulfide ores with variable PGE, Ni and Cu compositions.
The study suggests that SHMB‐like magmatism, produced by melting of depleted and hydrous mantle source, may be an important feature of orogenic belts. Mafic‐ultramafic intrusions formed from SHMB‐like magmas may host economic sulfide deposits, particularly sulfide Ni‐Cu sulfide deposits.published_or_final_version
Earth Sciences
Doctoral
Doctor of Philosophy
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Nawasreh, Mohammed Khair Assa'd. "Investigations of Jordanian industrial minerals". Thesis, Cardiff University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365618.
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McCreath, Jamie Alan. "Petrology and petrogenesis of the Motzfeldt Ta-mineralisation, Gardar Province, South Greenland". Thesis, St Andrews, 2009. http://hdl.handle.net/10023/845.
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Westerlund, Kalle. "A geochemical study of diamonds, diamond inclusion minerals and other mantle minerals from the Klipspringer kimberlites, South Africa". Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/4230.
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Summary in English.Bibliography: leaves 157-171.
The Klipspringer kimberlites occur in the north-eastern part of the Kaapvaal craton which is poorly represented in kimberlite and mantle studies. The kimberlites have been dated at 148+-4 Ma and the current study presents the geochemical characteristics of their diamonds, diamond inclusion and mantle macrocrysts/bimineralic nodules. The Klipspringer lithosphere is dominated by eclogite and Iherzolite with harzburgite and dunite present to a lesser extent.
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Kranidiotis, Prokopis. "Geology, geochemistry and hydrothermal alteration at the Phelps Dodge massive sulfide deposit, Matagami, Québec". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66033.
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Kotler, Julia Michelle. "Biosignature storage in sulfate minerals- synthetic and natural investigations of the jarosite group minerals". The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-08062009-143516/.
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The discovery of jarosite on Mars in 2004 generated increased interest in the properties of the mineral related to the search for life on other planets. Several studies indicate that the formation of jarosite can be linked to biological activity on Earth and biomolecules such as amino acids have been found associated with terrestrial jarosite samples. A series of natural and synthetic investigations using different jarosite end-members has been conducted and is presented in this dissertation to investigate the possibility that jarosite can store biosignatures. Natural samples were analyzed by x-ray diffraction, elemental carbon analysis and laser-desorption Fourier transform mass spectrometry (LD-FTMS) and were found to contain the amino acid glycine. Synthetic experiments were conducted in which the different end-members were synthesized in the presence of glycine as well as the amino acid alanine and the amino acid breakdown product methylamine. These samples were analyzed by x-ray diffraction, neutron diffraction, LD-FTMS and thermogravimetric analysis (TGA) techniques. Results of these experiments show that the detection of the biosignature and the effect that biomolecule has on the jarosite minerals is dependent on the end-member and indicate that the jarosite minerals are an excellent target for detecting potential signs of past life on other planets.
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Bambi, Aurora Cuaiela Joao Mateus. "Metalogenia de las carbonatitas en dominios plutónicos, subvolcánicos y volcánicos: Tchivira, Bonga y Catanda, Angola". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/396375.
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Se han seleccionado tres carbonatitas de la estructura tectónica de Lucapa en Angola representativas de diferentes niveles de emplazamiento de los magmas: plutónico (Tchivira), subvolcánico (Bonga) y volcánico (Catanda).
Los objetivos del trabajo son los siguientes:
1) Establecer la secuencia de procesos que se dan en carbonatitas plutónicas, subvolcánicas y volcánicas;
2) establecer la distribución y el comportamiento de los elementos raros en cada uno de estos procesos.
La metodología incluye cartografía geológica de los afloramientos, muestreo según la misma o en algunos casos según columnas estratigráficas, estudio de las asociaciones minerales mediante microscopia óptica de luz transmitida/ reflejada, raman, microscopia electrónica cona analizador de energías de rayos X, difracción de polvo de rayos X, microsonda electrónica, análisis multielemental de elementos mayores y trazas y REE con ICP-MS, análisis microtermométrico de inclusiones fluidas, análisis de isótopos estables de
C y O en carbonatos.
Las carbonatitas se asocian con complejos alcalinos subsaturados de baja agpaicidad, aunque los elementos raros se concentran exclusivamente en las carbonatitas y, en menor medida, en aillikitas.
En las carbonatitas plutónicas e hipoabisales se registran tres estadios de cristalización principales, que controlan la cristalización y composición de los minerales de elementos raros:
a) estadio de cristalización magmático, con alta actividad de F en el magma y que produce la cristalización de
fluornatropirocloro; las tierras raras se concentran en fluorapatito y, en menor medida, en carbonatos primarios.
b) estadio de desgasificación y pérdida de álcalis que produce la fenitización del encajante, con precipitación de kenocalciopirocloro pobre en Na y en F. En el encaj ante pueden desarrollarse mineralizaciones similares.
c) estadio tardío, en que fluidos hidrotermales de origen meteórico procedentes de las rocas encajantes invaden la carbonatita. Se desestabilizan los carbonatos primarios, formándose ankeritización,dolomitización, fluoritización y silicificación de las carbonatitas primarias, a la vez que precipitan varias generaciones de pirocloro rico en Ba, Sr, Pb y Ta y, finalmente, rutilo rico en Nb. Las REE se concentran principalmente en carbonatos, principalmente en los del grupo de la synchisita, pero pueden estar en forma de silicatos de REE.
Por otra parte, durante los procesos supergénicos el pirocloro puede ser parcialmente desestabilizado y el niobio puede reconcentrarse en la estructura de minerales supergénicos de neoformación, como la goethita rica en Nb. Los elementos de las tierras raras pueden precipitar en forma de fosfatos secundarios de REE, como la rabdofana. En estas condiciones puede producirse la separación de Ce4+ del resto de REE. El contenido de F y Na del pirocloro primario disminuye proresivamente desde las carbonatitas plutónicas a las volcánicas, a la vez que el pirocloro se enriquece en Th, U y REE en la posición A y Ta y Zr en la posición B. En un mismo nivel estructural, las mayores concentraciones de pirocloro se dan donde se haya producido desvolatilización de la carbonatita. El
Nb, las REE y, en general, los elementos raros, tienen una muy alta movilidad en los fluidos carbonatíticos en condiciones hidrotermales, e incluso en las condiciones supergénicas.Three carbonatites from the Lucapa tectonic structure were selected for study, as representative of different levels of magma emplacement: plutonic (Tchivira), subvolcanic (Bonga) and volcanic (Catanda). The objectives of this research are the next two: 1) To establish the sequence of processes that occur in plutonic, subvolcanic and volcanic carbonatites. 2) To establish the distribution and the behavior of the rare elements in each of these processes. The methodology includes geological mapping of the outcrops, representative sampling following the above defined geological units (in some cases, along estratigraphic profiles), study of the mineral associations by transmitted/ reflected optical microscopy on thin/ polished section, Raman microprobe, scanning electron microscopy with energy dispersive analyses, X-ray powder diffraction, electron microprobe analyses, multielemental analyses of major and trace elements and REE with ICP-MS, microthermometry of fluid inclusions, C and 0 stable isotope analyses in carbonates. Carbonatites are associated with undersaturated alkaline complexes with low agpaicity, but the arre elements are concentrated ain the carbonatites and, in lesser extent, in aillikites. Three main stages of crystallization are found in the plutonic and hypabissal carbonatites. These stages control the crystallization and distribution of the minerals of rare elements: a) Stage of magmatic crystallization, whit a high F fugacity in the carbonatite magma; fluornatropyrochlore is extensively produced in this stage. Rare earth elements are concentrated in fluorapatite and, in lesser extension, in the primary carbonates. b) Stage of devolatilization and loss of alkalis. In this stage is produced the fenitization of host rocks, with precipitation of Na- and F-poor keno-calciopyrochlore. Similar enrichments can be found in the host rock. c) Late stage, when hydrothermal fluids of meteoric origin, invade the carbonatite coming from the host rocks. The primary carbonates become unstable, and the primary carbonatites are replaced by ankeritization,dolomitization, fluoritization and silicification processes, and new generations of Ba-, Sr-, Pb- and Ta-rich pyrochlore are produced, in many cases as replacements of the early formed pyrochlores. Finally, Nb-rich rutile is formed. REE are reconcentrated mainly in carbonates, commonly as members of the synchysite group, but REE silicates may also be formed. Moreover, pyrochlore may be unstable during the supergene processes and Nb may be reconcentrated in the structure of supergene minerals of neoformation, as Nb-rich goethite. The REE can precipitate as secondary phosphates, as rhabdophane. Ce4+ may fractionate from the other REE under these conditions. F and Na contents in the primary pyrochlore progressively decrease from the plutonic carbonatites towards the volcanic carbonatites. Conversely, an opposite trend is observed in the case of Th, U and REE in the A position, and in the case of Ta and Zr in the B position. The highest pyrochlore concentrations, for a given structural level, are found where carbonatite suffered a loss of volatiles. Nb, REE and, in general, the rare elements, have a very high mobility in the hydrothermal carbonatite fluids, and may also be mobile under supergene conditions.
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Soltanian, Mohamad Reza. "RELATING REACTIVE TRANSPORT TO HIERARCHICAL AND MULTISCALE SEDIMENTARY ARCHITECTURE". Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1428521270.
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Andersson, Stefan. "Malmmikroskopering - en studie av sulfidmineral från Långbantrakten, Bergslagen, Sverige". Thesis, Uppsala universitet, Berggrundsgeologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-169481.
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De sulfidgruvor belägna i Långbantrakten som studien behandlar ligger i den västra delen av Bergslagen utanför Filipstad i Värmlands län. Opaka mineral (malm) från två mindre mineraliseringar, Näset och Getberget, har studerats med malmmikroskop och mikrosond för att beskriva mineralogin i området. Båda områdena domineras av olika (Cu-Fe-Pb-Zn)-sulfider, i Näset av kopparkis (CuFeS2), blyglans (PbS) och zinkblände ((Zn,Fe)S) och i Getberget av blyglans, zinkblände, kubanit (CuFe2S3) och magnetkis (Fe1-xS). I Näset finns en del mindre frekventa mineral, två olika faser av Co-pentlandit (en nickelrik och en utan nickel), gedigen Sb och Bi, (Ni-Co)-sulfid, breithauptit (NiSb) och magnetkis. Kubanit är även ett viktigt mineral som speglar mineraliseringens bildning. I Getberget finns liknande mindre frekventa mineral, kopparkis, nickelrik Co-pentlandit, gedigen Bi och Sb, silverglans (Ag2S), breithauptit och magnetit (Fe3O4). En sen utfällning av kubanit har skett i båda områdena och visar att mineraliseringarna har genomgått en liknande bildning och det stämmer även in på mineralogin, som även den är likartad.The small sulphide mines, Näset and Getberget that have been investigated are located just outside the main mineralization of Långban, near the city of Filipstad in Värmland County. Opaque minerals have been studied in reflected light microscopy and with an electron microprobe analysis to describe the mineralogy. Both areas are dominated by various (Cu-Fe-Pb-Zn)-sulphides, Näset with chalcopyrite (CuFeS2), galena (PbS) and sphalerite ((Zn,Fe)S) and Getberget with, galena, sphalerite, cubanite (CuFe2S3) and pyrrhotite (Fe1-xS). The sulphides are also accompanied by various accessory minerals, in Näset by two different phases of Co-pentlandite (on rich in nickel and one without), native Sb and Bi, a (Ni-Co)-sulphide, breithauptite (NiSb) and pyrrhotite. Cubanite is also a very important mineral that reflects the formation of the mineralization. In Getberget there are similar accessory minerals, chalcopyrite, nickel rich Co-pentlandite, native Bi and Sb, acanthite (Ag2S), breithauptite and magnetite (Fe3O4). A late precipitation of cubanite has occurred in both areas, suggesting that the mineralizations has been formed in similar conditions. This also holds true when comparing the mineralogy, which also is similar.
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Clegg, Francis. "Thermo-analytical and spectroscopic characterisation of pore lining minerals in reservoir rocks". Thesis, Sheffield Hallam University, 1998. http://shura.shu.ac.uk/19479/.
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Two methods have been developed for the characterisation of sandstone and carbonate based hydrocarbon reservoir rocks. Particular emphasis has been directed towards determining the surface mineralogy in order to understand the flow of fluids through rocks. The first method employs Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) to distinguish the constituent minerals of a reservoir rock using characteristic bands in their vibrational spectra. Spectra collected from reservoir rocks that have undergone various sample preparations have shown that the spectra are weighted to the surface mineralogy. Spectra that are specific to the surface mineralogy have been obtained by sedimentation and ultrasonication techniques. The feasibility of applying partial least squares (PLS) modelling to DRIFTS spectra of reservoir rocks for quantitative analysis has been discussed. Application of PLS modelling to mixtures of powdered mineral standards has shown that it is possible to estimate the mineral constituents. The second method uses organic molecules as chemical probes to elucidate the surface mineralogy of reservoir rocks. Clay mineral standards which have been exposed to certain chemical probes and subsequently heated show desorption profiles (monitored by thermogravimetric analysis (TGA)) that are characteristic for each mineral. The most suitable chemical probe studied so far is Dimethylformamide (DMF). The desorption profiles of DMF from Mg, Ca, Na and K exchanged montmorillonites are characteristic for each of the clays. Characteristic desorption maxima are observed at 420, 330, 220, 190°C, respectively. The desorption of DMF from Mg-SWy-2 within a powdered mixture of mineral standards can only be detected at the 5% level using TGA, whereas using infrared or mass spectrometry 2% can easily be detected with considerable scope for detecting smaller levels. Extensive studies using Variable Temperature-DRIFTS and Variable Temperature x-ray diffraction on the complexes formed between both DMF and N-Methylformamide (NMF), and, Mg, Ca, Na and K-montmorillonites have shown that molecules retained at higher temperatures are located in the interlayer space and are associated with exchangeable cations via their carbonyl groups. Two layers of DMF and NMF are present in the interlayers at low temperatures which reduces to one upon heating to 50-170°C. NMF is found to be present in hydrogen-bonded clusters.
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Todd, Emma Claire. "Surface oxidation of sulphide minerals : nanomineralogy and electronic structure from x-ray spectroscopy". Thesis, University of Bristol, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274619.
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Coffin, Ethan S. "Biochar Mediated Microbial Reduction of FE(III) in Clay Minerals: Role of Biochra as Redbox Buffer". Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1626089600925363.
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Childe, Fiona. "Uranium-lead geochronology of metamorphic accessory minerals south of the Grenville Front, western Québec, Canada". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61060.
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U-Pb ages were determined on single grains of monazite and xenotime as well as small populations of rutile from amphibolite to granulite facies metasediments of the Quebec Gneiss Segment of the Grenville Province in an area extending 45 to 135 km south of the Grenville Front in La Verendrye Park, Quebec. Recent geochronological studies include Pb-isotope ratios of metamorphic minerals corresponding to ages of 2.5 to 2.65 Ga and U-Pb monazite ages to 2649 to 2655 Ma, which define a lower discordia intercept of approximately 1.01 Ga. Recent thermobarometric studies indicate the presence of two metamorphic episodes in the region.Monazite and xenotime grains obtained from high grade metasediments at five locations between 45 and 70 km southeast of the Grenville Front yielded $ sp{207}$Pb/$ sp{206}$Pb ages of 999 $ pm$ 5 Ma to 1021 $ pm$ 2 Ma. Monazite from the norther part of this terrane also defined an upper intercept age of 2596 $ pm$ 3 Ma.
The southernmost sample location, 135 km south of the Grenville Front, yielded both monazite and rutile. Monazite gave an age of 1072 $ pm$ 2 Ma. Small populations of rutile yielded an age of 916 $ pm$ 2 Ma. (Abstract shortened by UMI.)
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Zuo, Hongyan. "Coupled Transformation of Humic Substances and Redox Cycling Iron in Clay Minerals & Environmental Implications". Miami University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=miami1595579176346292.
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Harris, D. J. "Atomistic simulation of the structure and dynamics of grain boundaries in mantle forming minerals". Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362193.
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Dydak, Sara M. "The Hydraulic Sorting of Light and Heavy Minerals, Heavy-Mineral Concentrations, and Grain Size". W&M ScholarWorks, 1991. https://scholarworks.wm.edu/etd/1539617625.
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Shad, Farhad Ali. "Spectroscopic Identification and Characterization of Gemstone Minerals". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-450827.
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Since last few years, many artificial and modified gemstones are available whose origins are questionable and even an experienced gemmology expert may be unable to differentiate between these artificial gemstones. Raman spectroscopy is considered to be an effective method to differentiate natural and artificial gemstones as it involves a very simple sample preparation, is non-destructive in nature, and is sensitive, precise, and accurate. In the present study, Raman spectroscopy was employed to identify different gemstones available in the mineralogical collection at the Department of Earth Sciences, Uppsala University. Both precious and semiprecious gemstones like quartz, diamond, beryl, corundum, topaz and tourmaline were evaluated with the usage of a portable Raman spectrometer. The major objective of the present study was to characterize these gemstones and to identify their origin, whether these are natural or synthetic materials, by analysing and comparing Raman spectra. Shifts in dominant peak positions and widths(FWHM) for natural and synthetic samples were extracted in the course of fitting procedures and then compared with the RRUFF database. The variations of these parameters, studied both within the same variety of a gemstone, as well as in between different gemstone varieties, were found to be revealing in several ways. For example, it provided information about the internal residual stresses in quartz crystals, and about the instrumental effects on the spectra. Quartz samples of different colors, shapes, and origins (natural/synthetic) were analyzed. It was found that, within the resolution of this study, it would be difficult to differentiate between synthetic and natural non-metamorphic quartz. A higher resolution study, combined with a chemical analysis by electron microprobe, could possibly facilitate such differentiation. On the other hand, a highly-stressed metamorphic environment leaves an imprint in the crystal structure of quartz, which can be recognized by the Raman technique. For beryl varieties of gemstones, the results suggest that the synthetic crystals display slightly lower values of Raman shifts and smaller values of FWHMs as compared to their natura lcounterparts. This could possibly be used as a criterion for distinguishing between these two categories of beryl gemstones. The agreement between Raman spectra of green tourmalines and those of elbaite from the database was very good, justifying the elbaite identification. The strong correlation of peak positions and FWHMs of studied synthetic diamonds reveals that pressure-temperature and chemistry conditions of synthesis leave a distinct imprint on the crystal structure of diamond, thus making Raman spectroscopy a useful technique for investigating the origin of diamonds, for example detecting their laboratory-specific origin.
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Magdic, Matthew James. "Assessment of Soil Properties in Proximity to Abandoned Oil Wells usingRemote Sensing and Clay X-ray Analysis, Wood County, Ohio". Bowling Green State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1462537679.
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