The Mineral Deposit Research Unit's findings translate into more effective mining - and a new generation of science-savvy miners.

The continental margin off Nova Scotia (the Scotian margin) forms the northern edge of the North American Basin. The Cenozoic stratigraphy and geological history of the outer margin is not well known. This study examines aspects of the Upper Cretaceous-Cenozoic geological history of the outer Scotian margin addressing the following objectives: 1) determine the geological history of a large deep-water depocenter, 2) investigate processes that led to deep-water unconformity formation in the study area, 3) determine the role of deep-ocean circulation in margin evolution, 4) examine the effects of morphological heritage on subsequent depositional patterns. High quality 2-D and 3-D seismic reflection data along with lithostratigraphic and biostratigraphic data from hydrocarbon exploration wells provide the basis for this investigation. The seismic stratigraphy of a large deep-water depocenter along the western Scotian margin was broadly divided into four units. Unit 1 (Upper Cretaceous-Upper Eocene) is attributed to repeated, widespread erosion events interspersed with periods of hemipelagic and pelagic, carbonate-rich sedimentation. Unit 2 (Lower Oligocene-Middle Miocene) consists of a variety of seismic facies overprinted by dense, small-offset faults. Unit 3 (Middle Miocene-Upper Pliocene) is dominated by sediment drift deposition. Unit 4 (Upper Pliocene-present) is characterized by channel development and gravity flow deposition. The processes that led to regional seismic stratigraphic horizons were complex. Both large mass-wasting events and along-slope bottom currents contributed to the formation of unconformities in the study area. Most of the succession preserved in the depocenter belongs to seismic units 2 and 3. These deposits are mainly confined to the area seaward of the Abenaki carbonate bank and landward of shallow salt structures below the slope. Locally, however, modification of the slope profile through mass-wasting and bottom current processes greatly influenced subsequent depositional patterns. The Cenozoic geological evolution of the study area was strongly affected by northeast-to-southwest flowing bottom currents. The earliest indication of bottom current activity was in the Eocene. Upper Miocene and Pliocene sediment drifts represent >50% of the preserved stratigraphic section in the thickest part of the depocenter. It is clear that along-slope sedimentary processes were far more important in shaping the margin than previously understood.

A study of the Millennium and Eagle Point basement-hosted deposits was conducted to obtain a comprehensive understanding of the alteration in these two atypical uraniferous systems and to apply these findings in formulating effective exploration strategies. In addition, an investigation of the Wheeler River “apparently barren” sandstone-hosted alteration system was conducted to provide insights into the critical events needed in order to form sandstone-hosted unconformity-related deposits. At Millennium, the atypical alteration halo, wherein the inner chlorite halo is much smaller than other basement-hosted deposits, is the result of pervasive muscovite alteration of the basement rocks by Na-K-Fe basinal brines during the pre-ore stage at ca. 250°C. As alteration of the basement rocks progressed, the basinal brines acquired Ca, Fe and Mg while creating up to 20% voids in the basement rocks. Prior to the mineralizing event, the chemically modified basinal fluids formed a minor Fe-rich chamoisite halo that demarcates a redox front during the ca. 1590 Ma syn-ore stage, where uranium ore was precipitated. At Eagle Point, the atypical alteration halo, wherein dolomite and calcite alteration is more significant than other basement-hosted deposits, is the result of more intense pre-Athabasca Basin alteration. The Eagle Point deposit is also distinct by significant late remobilization of primary uraninite into secondary structures that occurred at ca. 535 Ma. At the Wheeler River “apparently barren” alteration system, the critical factor for the lack of uranium mineralization in the sandstone is the temporal relationship between the different fluids with the uranium-bearing oxidized basinal fluids present prior to the reduced chemically modified basinal fluids and reduced basement fluids. However, the possibility of a small basement-hosted uranium deposit at Wheeler River cannot be excluded because the sudoite-producing basement fluids may represent basinal brines that reacted with basement lithologies to become reducing and Mg-rich, and therefore may have precipitated uraninite during this process. The results of this study support the genetic model in which basinal fluids were likely the source of uranium deposits and that the basement fluids were unlikely significant sources of uranium in sandstone-hosted deposits. / Thesis (Ph.D, Geological Sciences & Geological Engineering) -- Queen's University, 2009-09-30 14:49:03.688

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Die 1990 stillgelegte Grube kann auf eine 750-jährige Bergbaugeschichte zurückblicken. Im vorliegenden Band werden vor allem die Ergebnisse der umfangreichen Such- und Erkundungsarbeiten der letzten Betriebsperiode zusammenfassend dargelegt. Die Rahmengesteine bilden amphibol- bis grünschieferfaziell geprägte Metamorphite proterozoischer und kambrischer Ausgangsgesteine. Die metamorphe Schichtenfolge wird unterlagert vom mittelerzgebirgischen Teilpluton, in dem vier Granittypen unterschieden werden, die petrographisch und geochemisch eine Entwicklungsreihe bilden. Die Lagerstättentektonik wird von einer diagonalen Scherflächentektonik bestimmt. Zwischen Deformation, Magmatismus, Metasomatose und Mineralisation bestehen enge genetische Beziehungen. Zeitlich lassen sich die Zinnmineralisationen nach Altersdatierungen zwischen 288 und 302 Millionen Jahren einordnen. Unter den zinnerzführenden Strukturen erlangen Ausfüllungsstrukturen (Trümerzüge, Gangzüge) die größte Bedeutung. Bei den metasomatischen Strukturen lassen sich gangförmige (Greisengänge im Exokontakt, gangartige Greisenzonen im Endokontakt), stockwerkartige (unregelmäßige Greisenkörper im Endokontakt) und lagerförmige Strukturen (Skarne) unterscheiden. Intensive pedo- und lithogeochemische Untersuchungen führten zur Berechnung von Zonalitätsreihen und zur Ableitung von Zonalitätskoeffizienten in mehreren Teillagerstätten. Die Verteilung bestimmter Spurenelemente im Kassiterit wird, abhängig vom Chemismus der zinnführenden Lösungen, vor allem durch die räumliche Position zum Granit und durch die Lithologie des Nebengesteins bestimmt. Innerhalb des gesamten variszischen Mineralisationszyklus zeigen Temperatur und Salinität der Lösungen eine relativ gleichförmige Entwicklung von höheren zu niedrigeren Werten an. Das geomechanische Verhalten des Gebirges und mögliche Auswirkungen auf die Tagesoberfläche werden entscheidend beeinflusst von den gewählten Abbauverfahren, der Lage der Abbaue in Bezug zur Erdoberfläche und der lokalen geologischen Situation. Die älteste Abbaumethode im Festgestein ist der Strossenbau. Der Firstenstoßbau kam nur in unbedeutendem Umfang zur Anwendung. In der letzten Bergbauperiode wurde der Firstenstoßbau mit Magazinierung eingeführt. Greisenkörper wurden im Teilsohlenkammerbau, die bis 40 m mächtigen Trümerzüge des Nordwestfeldes im Teilsohlenbruchbau gewonnen. Die Bemusterung der Auffahrungen geschah durch Schlitzproben, der bergmännisch nicht aufgeschlossenen Lagerstättenbereiche durch Bohrkern- oder Bohrschlammproben. Tiefbohrungen wurden mittels Sammelsplitter- und Kernproben bemustert. Mit Einstellung des Bergbaus ist im Lagerstättendistrikt Ehrenfriedersdorf bei Trümer- und Greisenerz ein Vorratsstand von 17,1 kt zu verzeichnen. Die Hauptaltlast des Erzbergbaus stellt Arsen dar. Besondere Bedeutung erlangen anthropogen bedingte As-Anomalien (Hüttenwerke, Pochwerke, Aufbereitungsrückstände).

The South Manasan ultramafic intrusion (ca. 1880 Ma) located in the Early Proterozoic Thompson Nickel Belt (TNB) contains Ni and platinum group element (PGE) mineralization hosted by disseminated sulfide. Whole-rock Ni values range from 0.3 to 1.7 wt. % and total precious metals (TPMs) range from 0 to 1.3 ppm Pt + Pd + Au and equate to tenor values (i.e., metal in 100% sulfide) of 11-39 wt. % Ni and 8-27 ppm TPMs. The South Manasan intrusion is a steeply dipping sill-like body with a boudinaged outline having a strike length of approximately 1200 m, average width of 125 m and a minimum depth extent of 1000 m. The intrusion is composed of approximately 25% fresh dunite, 50% serpentine altered dunite and 25% tectonized and carbonate altered dunite. The most intense alteration is found near the intrusion’s margin where it is in contact with metasedimentary rocks of the Pipe Formation, part of the surrounding Ospwagan Group. In fresh dunite the sulfide assemblage characterized by an intercumulate texture is dominated by pentlandite with accessory pyrite; the latter having a symplectic-like texture. The pentlandite-pyrite assemblage in the serpentinized dunite, although still characterized overall by an intercumlate-texture, has well developed platy intergrowths with chlorite and serpentine. In the most intensely modified unit (the carbonate altered dunite) the sulfide assemblage consists primarily of pyrrhotite and pentlandite. Whole-rock geochemical data (n=360), modal mineralogy and mineral chemistry obtained on representative drill core throughout the South Manasan intrusion have been used to establish a type section in order to evaluate the relative roles of primary magmatic versus secondary (i.e., serpentinization, carbonate alteration and deformation) processes. These data indicate that the primary silicate-sulfide assemblage was systematically modified during : serpentinization, carbonate alteration and deformation of the South Manasan intrusion such that a sequence of primary versus secondary events can be established. Intrusion of the original komatiitic magma and formation of the South Manasan intrusion took place at a shallow level into consolidated Ospwagan Group sediments with subsequent contamination of this melt with crustal S. This triggered sulfide saturation and generation of an immiscible sulfide melt. Calculated Ni and TPM tenor values constrain the R factor to between 500 and 2500. The early crystallization of olivine inhibited the sulfide melt from settling to the bottom of the magma column and as a consequence, the sulfides now have a primary interstitial magmatic texture. The current sulfide association dominated by pentlandite>>pyrite>chalcopyrite has a mineral paragenesis that is consistent with subsolidus re-equilibration of a primary pentlanditepyrrhotite- chalcopyrite assemblage. The subsequent processes of serpentinization, deformation and carbonate alteration resulted in modifying the primary sulfide assemblages and their textures (i.e., to platy habits), but did not greatly alter the bulk composition, in particular metal contents, except for addition of volatiles (H2O, CO2). It is concluded therefore that the enrichment of the sulfide assemblage at South Manasan in Ni and PGEs is a consequence of a primary magmatic process involving high R factor and that the effects of later overprinting processes (alteration, deformation) are not responsible for the presently observed high-tenor sulfide association.

Radiotherapy aims to sterilize cancer cells through ionization induced damages to their DNA whilst trying to reduce dose burdens to healthy tissues. This can be achieved to a certain extent by optimizing the choice of radiation to treat the patient, i.e. the types of particles and their energy based on their specific interaction patterns. In particular, the formation of complex clusters of energy deposits (EDs) increases with the linear energy transferred for a given particle. These differences cause variation in the relative biological effectiveness (RBE). The complexity of ED clusters might be related to complex forms of DNA damage, which are more difficult to repair and therefore prone to inactivate the cells. Hence, mapping of the number and complexity of ED clusters for different radiation qualities could aid to infer a surrogate measure substituting physical dose and LET as main predictors for the RBE .   In this work the spatial patterns of EDs at the nanometre scale were characterized for various energies of proton, helium, lithium and carbon ions. A track structure Monte Carlo code, LIonTrack, was developed to accurately simulate the light ion tracks in liquid water. The methods to emulate EDs at clinical dose levels in cell nucleus-sized targets for both 60Co photons and light ions were established, and applied to liquid water targets. All EDs enclosed in such targets were analyzed with a specifically developed cluster algorithm where clustering was defined by a single parameter, the maximum distance between nearest neighbour EDs. When comparing measured RBE for different radiation qualities, there are cases for which RBE do not  increase with LET but instead increase with the frequencies of high order ED clusters. A test surrogate-measure based on ED cluster frequencies correlated to parameters of experimentally determined cell survival. The tools developed in this thesis can facilitate future exploration of semi-mechanistic modelling of the RBE.

The Glacier Creek volcanogenic massive sulfide (VMS) deposit is hosted within Late Triassic, oceanic back-arc or intra-arc, rift-related, bimodal volcanic rocks (Hyd or Tats Group) of the allochthonous Alexander terrane known as the Alexander Triassic Metallogenic Belt (ATMB). The deposit presently consists of four tabular massive sulfide lenses with a resource of 4.75 Mt. at 1.84% Cu, 4.57% Zn, 0.15% Pb, 0.28 g/t Au and 29.07 g/t Ag. A deposit-scale thrust fault offsets stratigraphy along the axial surface of a deposit-scale anticline. The massive sulfide lenses are barite-rich and are divided into 6 main ore-types based on mineral assemblages. There is a large range of sphalerite compositions, with low-Fe sphalerite dominant throughout the lenses and high-Fe sphalerite at the top and bottom of the lenses in pyrrhotite-rich zones. Lenses contain anomalous Sb, Hg and Tl. Gangue minerals include barite, quartz, barian-muscovite, calcite, albite, highly subordinate chlorite and locally hyalophane and celsian. Overlying massive sulfide is a tuffaceous hydrothermal sediment with anomalous REE patterns and local hyalophane. The general footwall to all four lenses is a thick unit of coherent to volcaniclastic feldspar-phyric basalt containing extensive lateral alteration. Four alteration facies are recognized based on mineral assemblages. Mass balance calculations for the footwall indicate general gains of S, Fe, Si and K with coincident loss of Ca, Na and Mg, along with trace element gains of Tl, Sb, Hg, Ba, Zn, Cu, As and loss of Sr with increased alteration intensity. Short wavelength infrared (SWIR) spectroscopy shows a general decrease in Na, K and Al content of muscovite and increase of Fe+Mg and Ba content towards ore. Integrated petrographic, mineral, chemical and sulfur-isotope data suggest a transition during deposit formation, from high-temperature, acidic, reduced hydrothermal fluids mixing with oxidized, SO4-rich seawater, to later cooler, low fO2-fS2 conditions of formation and a lack of SO4 in seawater.

The giant Kidd Creek Mine is an Archean Cu-Zn-Ag deposit in the Abitibi Greenstone belt, located in the Superior Province of Canada and is one of the largest known base metal massive sulfide mines in the world with a tonnage of 170.7 Mt (Past production, Resource and Reserve). The massive sulfides in Mine D comprise a number of ore lenses that are interpreted to be the downplunge continuation of the Central orebody from the upper mine. These are referred to as the West, Main, and South lenses. The massive sulfides overlie a silicified rhyolitic unit at the top of a mixed assemblage of rhyolite flows, volcaniclastic sediments and ultramafic flows. The sheared nature of the fragmental units in the hanging wall of the deposit, at depth, illustrates the greater deformation that has occurred than in the upper mine. Metal zonation and the distribution of Cu stringer mineralization suggest that the West and Main lenses may be part of a single massive sulfide body (Main orebody) that has been structurally dismembered. The South Lens is a detached body, separated by late faults. The large Cu stringer zone beneath the West and Main lenses has a thickness of up to 150 metres, and is much broader and structurally remobilized in Mine D partially due to a newly identified series of vertically trending offset faults, that extends along the entire length of the massive sulfide bodies. A number of features of the North, Central and South orebodies in the upper part of the mine (e.g., Se-rich halo around Cu-rich zones) have been recognized in Mine D and provide an important framework for correlating the deep orebodies with the upper levels of the mine. Drilling below the current mine levels indicates that the massive sulfide and Cu stringer zones continue below 10,200 feet (3109 m) and highlight the remarkable continuity of the deposit downplunge with no end in sight. Two main ore suites have been recognized in the upper part of the mine and in Mine D: a low-temperature, polymetallic assemblage of Zn, Ag, Pb, Cd, Sn, Sb, As, Hg, ±Tl, ±W, and a higher-temperature suite of Cu, Co, As, Bi, Se, In, ±Ni. More than 25 different ore minerals and ore-related gangue minerals are present, including Co-As-sulfides, Cu-Sn-sulfides, Ag-minerals, and selenides. The massive ores consist mainly of pyrite, pyrrhotite, sphalerite, magnetite and chalcopyrite, together with minor galena, tetrahedrite, arsenopyrite, and native silver with a quartz and siderite gangue. Despite the high Ag content of the ores, the majority of the massive sulfides are remarkably Au poor except for a local gold zone that has been recognized in the deep mine in association with high-temperature mineralization. The trace elements in the ores exhibit strong zonation and diverse mineralogy. Spectacular albite porphyroblasts, up to 1 cm in size occur in the most Cu-rich ores of Mine D which are coincident with the peak of regional metamorphism and likely represent higher metamorphic or hydrothermal temperatures. Overall the orebodies have remained remarkably similar downplunge. However, unlike the upper part of the mine, pyrrhotite is dominantly hexagonal, only tetrahedrite was observed as the dominant sulfosalt, and magnetite occurs as both blebby porphyroblasts and as abundant intergrowths with sphalerite-chalcopyrite ores and siderite. These characteristics suggest that the deep mine has been subjected to higher metamorphic temperatures, possibly related to depth of burial, and that the original hydrothermal fluids may of had a lower H2S/CO2 and/or higher temperatures.

2008 m. krizės laikotarpiu Europos Sąjungos šalių vadovai ir institucijos suprato, kad galiojanti indėlių draudimo sistema yra nėra efektyvi, todėl būtini jos pakeitimai. Siekiant sustabdyti ES šalių-narių nepagrįstas išlaidas, skolos naštą ir bankų neatsakingumą, buvo priimta (1994) indėlių draudimo sistemos direktyva, kuri buvo dar keletą kartų atnaujinta (2009 ir 2014), tačiau reikšmingų pokyčių finansinėje rinkoje neįvyko, nes išryškėjo ekonominiai ir kultūriniai ES šalių-narių skirtumai, menkinantys indėlininkų pasitikėjimą bankais ir pačia indėlių draudimo sistema. Tyrimo objektas – indėlių draudimo direktyvos sprendimų priėmimo procesas, ES institucijų direktyvos pakeitimai bei įgyvendinimo modeliai Europos Sąjungoje. Darbo tikslas – išanalizuoti indėlių draudimo direktyvos atsiradimo priežastis, tobulinimo eigą ir procesus, kurie daro įtaką finansiniam sektoriui bei atlikus modelių analizę įvardinti į ES institucijų tarpusavio barjerus. Darbo uždaviniai: a) apibrėžti Europos indėlių draudimo sampratą ir įvertinti jos įtaką bankų sąjungai; b) ištirti indėlių draudimo direktyvos sprendimų priėmimo procesą bei ES institucijų poveikį jam; c) apžvelgti Vokietijos įtaką indėlių draudimo direktyvos sprendimų priėmimo procese; d) atlikti indėlių draudimo modelių ir politinės galimybės juos priimti Europoje analizę. Darbe naudojami skirtingi tyrimo metodai: analitinis-aprašomasis ir lyginamasis bei dokumentų ir statistikos analizė, jų pagalba ištirtas ryšys tarp ES... [toliau žr. visą tekstą] / During the crisis in 2008, EU institutions and leaders of member states understood, that existing deposit insurance system is inefficient and that it required necessary changes. In order to prevent unreasonable expenditures of EU member states, burden of debt and irresponsibility of banks, the deposit insurance system directive was adopted in 1994; it had been renewed several times in 2009 and 2014, however no significant changes on financial market had happened. The main reason for that were the emerged economic and cultural differences between EU member states, which depreciated depositor’s trust in banks and deposit insurance system itself. The object of research: the decision making process of deposit insurance directive, changes to directive by EU institutions and execution models in European Union. The objective of the study: to analyze the reasons for emergence of deposit insurance directive, improvement steps and processes, that influence the financial sector; and to name mutual barriers between EU institution after analysis of models. Tasks of the study: a) to define the concept of European deposit insurance and evaluate its influence to banking union; b) to research the decision making process of deposit insurance directive and the impact EU institutions had on it; c) to review the impact Germany had on decision making process of deposit insurance directive; d) to analyze the models of deposit insurance and political abilities to adopt them in Europe. Various... [to full text]