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EN
Geological mapping and sampling of sediment-hosted copper-silver mineralization in NE Colombia identified the association of the Astronium graveolens tree (Diomate Gusanero) with the elevated presence of copper (up to 317 ppm) and silver (up to 24 ppm) in plant ash. During the dry season, when most plants lose their leaves, young Astronium graveolens seedlings growing along copper sulfide-rich showings retain their green foliage. This observation allowed authors to effectively use this plant as an exploration guide in search for copper mineralization and Astronium graveolens can be potentially considered as a geobotanical indicator plant. The observed resistance of Astronium graveolens to the presence of copper sulfides suggests that this tree could be also a potential excellent species for reforestation and reclamation of tailings and other mining waste.
EN
Chlorite-mica-quartz schist in the Gierczyn-Przecznica area in SW Poland contains polymetallic ores which were the source of tin and cobalt in the past. This mineralogical study revealed the presence of silver-bearing minerals including members of the tetrahedrite (Ag <3 apfu) and freibergite series (3 < Ag < 8 apfu), galena (0.26–1.48 wt.% Ag), and a phase with the chemical composition of Te-rich canfieldite Ag8Sn(S,Te)6. In Przecznica Sn-sulphides are represented by stannite while cobaltite is the most abundant host for cobalt, followed by Co-bearing arsenopyrite. Glaucodot, ullmannite and members of the löllingite-rammelsbergite solid-solution series (Fe,Ni,Co)As2 also contain cobalt but are scarce in the samples. An exposure in the “Psi Grzbiet” area is characterized by the presence of Ag, Ni, Sb and Te minerals accompanied by very small amounts of As-bearing phases (represented by arsenopyrite) while the mineralogical composition in the Przecznica area is characterized by an abundance of As phases and a lack of Sb minerals. Sulphur isotopes of sulphides from Przecznica are heavier than in most deposits related to the Karkonosze Granite intrusion, while their Pb isotope signature in galena suggests an Early Paleozoic pre-Variscan affinity rather than a Variscan one.
EN
The Sin Quyen deposit is characterized by a high accumulation of rare earth elements (REE). This deposit belongs to the IOCG type copper deposits (Iron Oxide Copper-Gold Deposits). In the deposit, the REE carrier minerals have been identified as follow: allanite, titanite, uraninite, monazite, apatite, chevkinite, aeschynite, bastnäsite, and epidote. In the skarn zone, contents of allanite range from single percentages to 10% in hand-size specimens. Locally, minerals of epidote subgroup which occur in large amounts in the host rocks are important. The studied allanites have concentrations of: REE (14–27 wt%), Ca (9–16 wt%), Al (8–19 wt%), Si (26–34 wt%) and Fe (12–21 wt%). Two populations of allanite are documented, the first is texturally older and probably related to the Ca-K alteration (second stage of crystallization). This population has higher REE concentration ranging from 20 to 27 wt%. The second population is texturally younger and has a lower total REE concentration ranging from 14 to 19.9 wt%, which occur mostly as a rim surrounding the older and likely arose during the K alteration with Cu-Au mineralization (third crystallization). The chemical composition indicates that the studied allanites belong to the Ce-La-ferriallanite family, with low ΣHREE and an average of 0.21 wt.%. A temperature of 355°C which was calculated using a value of δ34S isotopes is interpreted as a temperature of the second crystallization stage of allanite. In the studied deposit, excluding allanite and titanite, the other bearing REE minerals have an insignificant role in the REE balance, since they either have the total content of REE, which is often close to the WDS detection limit (rf. the epidote subgroup), or their only occur at the single points. The content of total REE in accessory uraninites is high and range from 1.311% up to 7.959% with an average value of 4.852%.
XX
Złoże Sin Quyen charakteryzuje się wysoką zawartością pierwiastków ziem rzadkich (REE). Złoże to należy do typu złóż miedzi IOCG (Iron Oxide Copper-Gold Deposits). Zidentyfikowane minerały zawierające REE to: allanit, tytanit, uraninit, monacyt, apatyt, czewkinit, aeschynit, bastnäsyt i epidotyt. W próbkach wielkości dłoni, pobranych ze strefy skarnowej, zawartości allanitu wahają się od pojedynczych do 10%. Lokalnie, minerały podrzędnej grupy epidotytu są ważne z powodu ich licznego występowania. Badane allanity zawierają: REE (14–27 wt%), Ca (9–16% wag.), Al (8–19% wag.), Si (26–34% wag.) i Fe (12–21% wag.). Udokumentowano dwie populacje allanitu, pierwsza jest teksturalnie starsza i prawdopodobnie związana z alteracją Ca-K (drugi etap krystalizacji). Ta populacja ma wyższe koncentracje REE, które są zawarte w przedziale od 20 do 27% wag. Druga populacja jest młodsza i zawiera mniejsze ilości ziem rzadkich (od 14 do 19,9% wag.). Populacja ta występuje głównie w postaci obwódek regeneracyjnych, tworząc zrosty ze starszą populacją i jest związana z alteracją potasową oraz mineralizacją Cu-Au (trzeci etap krystalizacji). Skład chemiczny wskazuje, że badane allanity należą do podgrupy Ce-La-ferriallanitu, o niskiej i średniej koncentracji ΣHREE 0,21% wag. Temperatura krystalizacji 355°C, została obliczona na podstawie wartości δ34S. Ta temperatura jest interpretowana jako temperatura drugiego etapu krystalizacji. W badanym złożu, poza allanitami i tytanitami, inne minerały REE i ich nośniki mają małe znaczenie w bilansie ich zawartości. Na przykład sumaryczna zawartość REE w podrzędnie występującym epidocie, jest na poziomie wykrywalności metody WDS, a inne minerały, takie jak uraninit, czewkinit, aeschynit, czy bastnäsyt występują zbyt rzadko, aby wpływać na bilans tych metali. W akcesorycznym uraninicie, pomierzone zawartości REE wahają się w granicach 1,31–7,96%, przy średniej zawartości 4,85%.
EN
The Kyaukse Sabe Taung copper deposit is located in the western margin of the Shan Plateau, central Myanmar. It has estimated reserves of 1.6 Mt of ore grading 3.15% Cu, with additional Ag and Au enrichment. This deposit is typically hosted by Middle Ordovician limestone of the Wunbye Formation and the mineralization is controlled by the regional structures. The ore-mineral assemblage consists of pyrite, chalcopyrite, tetrahedrite, chalcocite, covellite, bornite, native copper, malachite, azurite, cuprite, tenorite, silver amalgams and Bi-sulphosalts, members of hammarite-aikinite series. Gangue minerals are quartz, dolomite, ankerite and calcite. Silver mineralization is represented by acanthite and by silver amalgams with a high content of Hg, ranging from 2.15 to 26.68 wt.%. Silver minerals are a result of supergene alteration of Ag- and Hg-bearing tetrahedrite and could increase economic value of the deposit. Silver association is located within the lowermost part of the supergene zone in the deposit, and tracking the redox barrier position can help to identify parts of the orebody with silver enrichment. The δ34S values of chalcopyrite are +5.7 to +10.7‰ and those of tetrahedrite are +1.6 to +1.7‰.
EN
Cassiterite and base-metal mineralisation from the Gierczyn mine on the Karkonosze-Izera Massif, Poland has been studied using electron microprobe and LA-ICP-MS (Laser Ablation Inductively Coupled Plasma Mass Spectrometry) techniques in order to determine the content of indium in the ore minerals. The main carriers of this element are sphalerite (up to 433 μ/g of In), chalcopyrite (up to 117 μ/g of In) and cassiterite (up to 0.02 wt.% In). Trace element contents of sulphides, especially Ga in chalcopyrite intergrown with sphalerite in comparison with chalcopyrite without sphalerite, may indicate metamorphic re-equlibration and suggests that the ore minerals might recrystallized and underwent metamorphism in conditions of greenschist/amphibolite facies. Although the deposits in the Stara Kamienica Schist Belt are not of economic value, they can contribute to better understanding of the relations between trace element partitioning and the formation of ore minerals.
EN
New data on chemistry of Cr spinels hosted within the ultramafic massif located in SE Kosovo show variations in their primary composition, which depends on ore and rock types. Spinels form disseminated and vein type ores and accessory spinels in peridotites are characterized by lower Cr and higher Fe concentrations in comparison to spinels making up massive ores. Concentrations of these metals increase in altered spinels both in ores and peridotites. Contents ofMn and Zn tend to be higher in accessory spinels than in spinels occurring in ores. The lower Cr:Fe ratio for Cr-rich spinels in disseminated ores in relations to chromite in massive ores may have an influence on their industrial usefulness. The use of EPMA-WDS technique for detrital spinels should be considered as an effective tool for chromium deposit exploration, especially in greenfield projects, to assess an ultramafic massifpotential for hosting rich ores. Chemical analyses of spinels are recommended in planning a beneficiation process for the low-grade chromite ores, in order to obtain high quality concentrates.
EN
The main subject of research in this paper is glauconite with its useful parameters, which is the object of exploitation in the “Górka Lubartowska-Niedźwiada” deposit. The main glauconitic horizon (lower Eocene) is built by loamy fine-grained and medium greenish sands with marine fauna and fragments of amber (ca. 7 m thick). Thin lamins and pockets of silts containing phosphorites and also glauconitic sands with underlaying very thin quartz-glauconitic sands are found at the bottom of this layer. The glauconite deposit in “Górka Lubartowska-Niedźwiada” is an amount of ca. 30% by volume of the main glauconitic horizon. Glauconite of the 1M polytype (XRD) shows large granulometric and morphological differentiation (SEM-EDS). It frequently contains aggregations of euhedral or framboidal pyrite grains (RS), which is indicative of the euxinic nature of the formation environment of the rocks under study. The individual glauconite grains show distinct chemical variability, manifested in a lower share of Al2O3 and an increased content of MgO and CaO (EPMA, XRF). At the same time, a large share of K2O (above 8% by weight) allows it to be included in highly matured glauconite, thus it can be considered as a potential raw material for the production of mineral fertilizers. The association of glauconite with phosphates (SEM-EDS) and anatase inclusions in the grains of glauconite (RS) indirectly point to the contribution of the decomposing organic matter to the formation of grains of this mineral. The xylite fragments preserved in the sediment show a low degree of coalification, which is typical of soft lignite. This also shows that the transformation process was taking place under a relatively small overburden.
PL
Złoże piasków glaukonitowych „Górka Lubartowska-Niedźwiada” znajduje się na obszarze Niziny Podlaskiej (E Polska). Właściwy horyzont glaukonitowy (dolny eocen) budują silnie zailone, drobno- i średnioziarniste piaski, barwy zielonkawej, zawierające faunę morską a także okruchy bursztynu (ok. 7 m miąższości). W spągu tych osadów pojawiają się drobne laminy i soczewki zailonego, zdiagenezowanego mułku glaukonitowego z otoczakami i konkrecjami fosforytów oraz warstwa drobno- i średnioziarnistych piasków glaukonitowych, podścielona bardzo drobną laminą zwartego piaskowca kwarcowo-glaukonitowego. Badaniom poddano piaski kwarcowo-glaukonitowe, próbki piaskowca kwarcowo-glaukonitowego oraz 10 drobnych kawałków ksylitu z osadów czwartorzędowych dolnych. Glaukonit obecny w tych osadach w politypie 1M wykazuje duże zróżnicowanie granulometryczne i morfologiczne. Tworzy formy agregatowe, zazwyczaj zawierające framboidalne lub euhedralne kryształy pirytu wskazujące na euksyniczny charakter środowiska powstawania badanych skał. Glaukonit ten zawiera wyraźnie niższy udział glinu (Al2O3), natomiast podwyższony udział magnezu (MgO) i wapnia (CaO). W analizowanych ziarnach glaukonitu średni udział K2O jest wysoki, zatem można go zaliczyć do glaukonitu wysoko dojrzałego. Mimo stosunkowo wysokiej zawartości żelaza może być on potencjalnym surowcem do produkcji nawozów mineralnych. Asocjacja glaukonitu z fosforanami (SEM-EDS) oraz wrostki anatazu w ziarnach glaukonitu (RS) pośrednio wskazują na udział rozkładającej się materii organicznej w tworzeniu się ziaren tego minerału. Zachowane w osadzie fragmenty ksylitów wykazują niski stopień uwęglenia, co jest typowe dla miękkiego węgla brunatnego. Świadczy to jednocześnie, że proces przeobrażeń zachodził pod stosunkowo niedużym nadkładem.
EN
Magnetite, pyrite, pyrrhotite, chalcopyrite and sphalerite are the major minerals identified in the deposit, while ilmenite, marcasite, tennantite, cubanite, arsenopyrite, galena, allanite, chevkinite, apatite, Bi-native, bismuthinite, electrum, native gold, and tellurides are the minor ones in the Iron Oxide Copper Gold (IOCG) Sin Quyen deposit. The REEs are hosted mostly by allanite, and the minor minerals by chevkinite, monazite, apatite and uraninite. Based on chemical analyses and Raman spectroscopy, two varieties of allanite have been documented: (1) with lower total REE contents of 13-19 wt.%, and (2) with higher contents of 20-23 wt.%. Uraninite from copper-iron massive ores is inhomogeneous in both optical properties and chemical composition. The concentrations of uranium and total rare earth element oxides (REOs) in the paragenetically earlier uraninite are 84.55-85.96% and 1.9-8.0% on average, respectively, whereas in paragenetically later uraninite, the U and ΣREE2O3 concentrations are 96.2-96.7% and 1.3-2.7% on average respectively. The thorium concentration in both the early and late uraninites is very low (0.21-0.22% and 0.2 % on average). These are the highest REE concentrations as compared with the known concentrations of these elements in uraninite. Electron microprobe “chemical” dating of the uraninite yielded an age of 500 ±33 Ma (n = 35) for the paragenetically early uraninite, and an age of 73 ±15 Ma (n = 6) for the paragenetically later ones. The minerals of the older age, which is interpreted as the primary ore mineralization stage, correspond in age with a range of deposits along the East Gondwana margin. The measured δ34S of sulphide minerals from -2.78 to +8.65‰ suggests hydrothermal origin of fluid that was responsible for transportation and crystallization.
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