Mineralization of the Zechstein Lower Anhydrite in the Fore-Sudetic Monocline

2018 ◽  
Vol 472 (472) ◽  
pp. 135-154 ◽  
Author(s):  
Sławomir Oszczepalski ◽  
Andrzej Chmielewski
Keyword(s):  
Partial Replacement ◽  
Bottom Part ◽  
Metal Concentrations ◽  
Sulphide Minerals ◽  
Significant Variability ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Intense Activity ◽  
Mineralizing Fluids ◽  
Copper Sulphides

The paper presents the characteristics of ore mineralization of the Lower Anhydrite in the Fore-Sudetic Monocline. Both reduced and oxidized (Rote Fäule) rocks have been investigated. Reduced anhydrites are characterized by significant variability of metal concentrations and sulphide minerals. The most intensely mineralized anhydrites occur above the oxidized bottom part of the Lower Anhydrite. Mineralization in this part is dominated by copper sulphides (chalcocite, digenite, covellite, bornite and chalcopyrite) which are accompanied by galena and sphalerite. Further away from the oxidized zone, zinc and lead sulphides predominate over copper sulphides, and pyrite mineralization is also observed. Complex intergrowths and replacement textures of sulphides, as well as intergrowths of the ore minerals with sulphates and carbonates are considered to have formed after lithification of the enclosing sediments, and indicate that the original associations of sulphides were overprinted by superimposed later mineralization. Oxidized anhydrites generally have no significant concentrations of metals like Cu, Pb and Zn. The relict mineralization there is represented by remnants of tiny grains of copper sulphides (mainly covellite, digenite and chalcocite) and pyrite, profoundly altered as a result of their partial replacement by hematite. This mineralization present in the oxidized anhydrites indicates that hematite emplacement overlapped deposition of the original sulphides and extended oxidation up into the Lower Anhydrite. Position of the reduced and oxidized areas of anhydrites enriched in metals indicates centres of the most intense activity of the ascending mineralizing fluids.

scholarly journals PEMODELAN BAWAH PERMUKAAN MANIFESTASI MINERAL DENGAN METODE GEOMAGNETIK DAERAH PACITAN JAWA TIMUR

KURVATEK ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 25-33
Author(s):  
Fatimah Fatimah
Keyword(s):  
Image Data ◽  
Geological Structure ◽  
Magnetic Data ◽  
Magnetic Intensity ◽  
Magmatic Arc ◽  
The North ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Extensional Structure ◽  
Anomaly Map

Tulakan Subdistrict, Pacitan Regency, East Java Province. This area is part of the Southern Mountain Zone of East Java, which is the Sunda-Banda magmatic arc of Oligo-Miocene age, where there are alterations and indications of valuable ore minerals. Field magnetic data is taken in an area of 1 x 1 km, with the looping method on the grid trajectory within 200 x 100 m. Then, magnetic data correction and data processing were carried out with Oasis Montaj. From the magnetic anomaly map, the value of high magnetic intensity in the southern part is fresh (intrusive) andesit-dasitic rock as host rock which causes alteration, in the middle has a low magnetic intensity value which is in the direction of the relatively NE-SW river direction, whereas in the north with high intensity is fresh andesite lava. From the image data, it can be seen that the straightness pattern of the geological structure which is dominated by the extensional structure with the direction of NE-SW and E-W is the main trap of epithermal veins carrying ore mineralization mainly Cu, Pb in the study area.

scholarly journals GRANITOIDS, RARE-METAL PEGMATITES AND Ta-Nb MINERALIZATION OF SHPOLIANO-TASHLYK ORE AREA (INGUL MEGABLOCK, UKRAINIAN SHIELD)

2018 ◽  
pp. 24-29
Author(s):  
O. Hrinchenko ◽  
S. Bondarenko ◽  
T. Mironchuk
Keyword(s):  
Rare Metal ◽  
Ukrainian Shield ◽  
Wide Range ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Isomorphic Series ◽  
Single Complex ◽  
Complex Features ◽  
First Time ◽  
Range Of Values

Composition of granites, genetically associated pegmatites and superimposed metasomatites distributed within Shpoliano-Tashlyk ore area (Ingul megablock) is considered. It is established, that on the basis of similarity in their petrographic and petrochemical features granitoids of the area can be related to single complex. Features of ore mineralization are defined by both composition of granitoids (Sgranites) after which rare-metal pegmatites are formed and intensity of superimposed metasomatic alterations. Main minerals-concentrators of Ta and Nb mineralization in granitic pegmatites and metasomatites are represented by minerals of three isomorphic series – columbite-tantalite (Fe,Mn)(Nb,Ta,Ti)2O6, ilmenorutile-struverite (Ti,Nb,Ta)O2 and pyrochlore-microlite (Ca,Na)2Ta2O6(O,B,OH,F). Depending on geological setting such ore minerals as tapiolite, ixiolite, cassiterite, uraninite, nigerite, gahnite are commonly found in association with these minerals. Chemical composion of tantalo-niobates sampled from ore-bearing pegmatites and metasomatites is investigated by microprobe analysis. Most minerals of columbite-tantalite series are characterized by distinct and rhythmic internal zonality and contrasting mosaic structure which are related to considerable heterogeneities of their chemical composition. Within one aggregate mineral phases with wide range of values – from 9,80 to 71,0 % for Ta2O5 and from 10,6 to 70,1 % for Nb2O5 – are established. Among minerals ferruginous varieties which composition relates to Fe-columbite-tantalites (Nb2O5/Ta2O5 = 1–1,2; FeO/MnO = 2,5–6) prevail. Columbite-tantalites are characterised by high contents of admixture elements present (%): TiO2 – to 5,88; WO3 – to 3,70; SnO2 – to 9,20; Sc2O3 – to 5,40. Scandium ores occur as scandium-rich minerals that are mostly confined to the minerals of columbite-tantalite series found in Polohivka ore field. On the Ukrainian Shield high contents of Sc2O3 in tantalo-niobates are established for the first time. Minerals of ilmenorutile-struverite series do not quantitatively yield to minerals of columbite-tantalite series. For minerals of this series Nb2O5/Ta2O5 ratio varies in the range of 0,6-1,4. Among characteristic admixture-elements are prevailed (%): SnO2 – to 3,1, V2O5 – to 5,05; FeO – to 11,51, Cr2O3 – to 1,20. Minerals of pyrochlore-microlite series are of subordinate importance. For the first time by results of U-Pb dating of columbite-tantalites from Mostove ore manifestation (Shpoliano-Tashlyk area) the age of Ta-Nb mineralization is established to be about 1965 ± 25 million years.

scholarly journals Minerály kontaminovaných granitových pegmatitů z lomu Pohled u Havlíčkova Brodu (moldanubikum), část II: prvky a sulfidy

2021 ◽  
Vol 29 (1) ◽  
pp. 90-107
Author(s):  
Zdeněk Dolníček ◽  
Jana Ulmanová ◽  
Karel Malý ◽  
Jaroslav Havlíček ◽  
Jiří Sejkora
Keyword(s):  
Raman Spectrum ◽  
Metamorphic Rocks ◽  
Mineral Association ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Mineralogical Study ◽  
Native Bismuth ◽  
Polymetallic Ore ◽  
Hydrothermal Veins ◽  
Cobalt And Nickel

In the Pohled quarry near Havlíčkův Brod town (central part of Czech Republic), texturally and mineralogically simple contaminated anatectic pegmatites form dikes or irregular bodies cementing breccia of host metamorphic rocks (paragneisses, amphibolites) belonging to the Monotonous (Ostrong) Group of the Moldanubicum of the Bohemian Massif. They exhibit signs of intense hydrothermal overprint and also the presence of abundant disseminations, nests and veinlets of ore minerals. A detailed mineralogical study revealed the presence of an extraordinary rich ore assemblage (20 species in total, including one unnamed phase). The oldest minerals are sphalerite (rich in Fe), löllingite, Fe-Co-Ni sulphoarsenides (cobaltite, glaucodot, arsenopyrite, gersdorffite), pyrrhotite, galena and chalcopyrite, in later portion accompanied by inclusions of Bi-minerals (native bismuth, bismuthinite, joséite-A, joséite-B, ikunolite and a Pb-Bi sulphosalt). The composition of the Pb-Bi sulphosalt is equal to Ag,Fe-substituted eclarite; its identity was confirmed also by Raman spectrum. Pyrite is very abundant phase, present probably in several generations. The Fe-Co-Ni thiospinels disseminated in younger chlorite, and represented by siegenite, violarite, grimmite and an unnamed NiFe2S4 phase, are the youngest ore minerals. The mineral association as well as chemical composition of most ore minerals are well comparable to those of local polymetallic ore veins and Alpine-type veins, which give evidence for identical origin of all these ore mineralizations. The formation of pegmatite-hosted ore assemblage was long-lasting multiphase process, which took place at temperatures between ca. 350 and <120 °C during changing fugacities of sulphur, tellurium and oxygen. A distinct enrichment in cobalt and nickel of ore mineralization hosted by pegmatites (in comparison with hydrothermal veins) is explained in terms of pronounced interactions of fluids with amphibolites and serpentinites.

Accessory and Ore Mineralization of Schists from the Basement of the Yamal Peninsula (Zapadno-Yarotinsky Area, Western Siberia)

2021 ◽  
pp. 49-55
Author(s):  
Yuriy V. Erokhin ◽  
Kirill S. Ivanov ◽  
Anatoliy V. Zakharov ◽  
Vera V. Khiller
Keyword(s):  
Western Siberia ◽  
The Arctic ◽  
Yamal Peninsula ◽  
Metamorphic Rocks ◽  
The West ◽  
Temperature Range ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Native Silver ◽  
The Yamal Peninsula

The results of studying the mineralogy of metamorphic schists from the Pre-Jurassic base of the Arctic part of the West Siberian plate are presented. The accessory and ore mineralization of schists from the Zapadno-Yarotinsky license area located in the southern part of the Yamal Peninsula is studied. The schists was uncovered by the Zapadno-Yarotinskaya No. 300 well at a depth of 2762 m. Above the section, the metamorphic rocks are overlain by a young Meso-Cenozoic cover. The schists are mainly composed of quartz, plagioclase (albite), carbonates (dolomite and siderite), mica (muscovite) and chlorite (donbassite). The discovered accessory and ore minerals in the metamorphic schists of the Zapadno-Yarotinsky area can be divided into two groups. The first group includes minerals that were formed during the metamorphism of schists, or were preserved as detrital matter. These minerals include zircon, fluorapatite, and rutile as the most stable compounds. The remaining mineralization (pyrite, sphalerite, chalcopyrite, cubanite, galena, cobaltite, barite, xenotime-(Y), goyazite, synchysite-(Nd), native silver and copper) is clearly secondary and was formed as a result of superimposed metasomatic processes. Judging from the described mineralogy, the schists underwent changes as a result of superimposed propyllitization. The temperature range of this process is determined by the formation of cubanite in association with chalcopyrite at a temperature of 200-210 оС.

MASSIVE COPPER SULPHIDE MINERALIZATION IN DOLOMITES FROM THE LUBIN MINE (FORE-SUDETIC MONOCLINE)

2017 ◽  
pp. 29-48 ◽  
Author(s):  
Piotr Król ◽  
Zbigniew Sawłowicz
Keyword(s):  
Cross Sections ◽  
Copper Sulphide ◽  
Copper Deposits ◽  
Sulphide Mineralization ◽  
Ore Mineralization ◽  
First Time ◽  
Mineralizing Fluids ◽  
Scanning Electron

Massive ore mineralization in dolomites is described for the first time from the Fore-Sudetic copper deposits. Three cross-sections from the Lubin Mine were studied using polarized optical (PLM) and scanning electron (SEM-EDS) microscopy, also cathodoluminescence (CL) and XRD. Massive mineralization, composed mainly of chalcocite with calcite admixture, occurs in dolomites as horizontal pseudovein, locally underlain by clay-carbonate breccia and shale. Underlying dolomites were partly calcitized (dedolomitized). Various calcite generations are characterized in detail. A model of the formation of massive mineralization is proposed. Mesotectonic intralayer movements caused the cracking of dolomite layers and the formation of breccia. Calcitization led to both dedolomitization and the partial infilling of cracks. Mineralizing fluids infilled the cracks completely, partly replacing calcite and adjacent rocks.

scholarly journals STRUCTURAL AND MORPHOLOGICAL FEATURES OF VERBA MOLYBDENUM ORE MINERALIZATION

2018 ◽  
pp. 15-19
Author(s):  
M. M. Kostenko ◽  
P. A. Kondratenko
Keyword(s):  
Internal Structure ◽  
Complex Structure ◽  
Morphological Features ◽  
Ukrainian Shield ◽  
Granite Massif ◽  
South Eastern ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Mineralized Zone ◽  
Native Bismuth

The article shows the Verba ore mineralization of molybdenum (Volyn Block of the Ukrainian Shield) is associated with small granite intrusions. They are located in the south-eastern exocontact zone of the Ustynivka granite massif of the Paleoproterozoic Chisinau complex. The Verba minera­lization is a linear-coarse mineralized zone of the complex structure. This is confirmed by the development in its rocks of frequent, non-orientated veins of quartz, fluorite-quartz and carbonate-quartz compositions and numerous cracks. They have molybdenite and concomitant mineralization, as well as the wide spreading of molybdenite inclusions directly in the granites. A number of differently oriented faults and of small fracturing local zones, cataclasite, millonitized and breccias represents the internal structure of the mineralized zone. The characteristic of molybdenite the leading ore minerals is shown. It is morphologically represented by a closely connected scattered inclusions, rarely veined inclusions, and associated ore minerals: cassiterite, bismuth, native bismuth, emlectocytes, galena, sphalerite, chalcopyrite, pyrite, ilmenite, magnetite and titanomagnetite.

scholarly journals Selenium-Rich Ag–Au Mineralization at the Kremnica Au–Ag Epithermal Deposit, Slovak Republic

Minerals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 572 ◽  
Author(s):  
Martin Števko ◽  
Jiří Sejkora ◽  
Zdeněk Dolníček ◽  
Pavel Škácha
Keyword(s):  
Base Metal ◽  
Slovak Republic ◽  
Epithermal Deposit ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Ore Mineralogy ◽  
Chemical Trends ◽  
New Phase ◽  
Epithermal Au ◽  
Ore District

Selenium-rich Au–Ag mineralization has been discovered in the Kremnica ore district, central Slovakia. The mineralization is hosted by a single quartz–dolomite vein hosted by Neogene propyllitized andesites of the Kremnica stratovolcano. Ore mineralogy and crystal chemistry of individual ore minerals have been studied here. The early base-metal ore mineralization composed of pyrite, sphalerite, and chalcopyrite lacks selenium, whereas the superimposed Au–Ag paragenesis is Se-enriched. The Au–Ag alloys, uytenbogaardtite, minerals of the galena–clausthalite series, acanthite–naumannite series, diaphorite, miargyrite, pyrargyrite–proustite, polybasite group, minerals of the tetrahedrite group and andorite branch (andorite IV, andorite VI, Ag-excess fizélyite), freieslebenite, and rare Pb–Sb sulphosalts (scaiinite, robinsonite, plagionite) have been identified here. Besides selenides, the most Se-enriched phases are miargyrite, proustite–pyrargyrite, and polybasite–pearceite, whose Se contents are among the highest reported worldwide. In addition, one new phase has been found, corresponding to a Se-analogue of pearceite containing 2.08–3.54 apfu Se. The style of mineralization, paragenetic situation, and chemical trends observed in individual minerals are comparable to those of Au–Ag low-sulphidation epithermal Au–Ag mineralizations of the Kremnica and neighboring Štiavnica and Hodruša-Hámre ore districts. However, the pronounced enrichment in selenium is a specific feature of the studied vein only.

On genesis of massive sulfide polymetallic ore deposits of Rudny Altai

2021 ◽  
pp. 3-16
Author(s):  
B. DIYACHKOV ◽  
M. MIZERNAYA ◽  
A. PYATKOVA ◽  
A. BISATOVA ◽  
A. MIROSHNIKOVA ◽  
...  
Keyword(s):  
Precious Metals ◽  
Massive Sulfide ◽  
Ore Deposits ◽  
Vertical Range ◽  
Long Duration ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
High Concentrations ◽  
Individual Grains ◽  
Polymetallic Ore

Many geologists assign most of large- and medium-sized massive sulfide polymetallic ore deposits of Eastern Kazakhstan to the VMS type. These ore deposits formed in the Devonian, under conditions of rifting and active basalt-andesite-rhyolite volcanism. Ore bodies of these deposits are noted to be clearly confined to formations of several geochronologic levels (D1e to D3fm). Hydrothermal-sedimentary syngenetic and hydrothermal-metasomatic ores are distinguished. High concentrations of base metals in the ores (above 10 % sum metals) and their rather simple mineral composition (chalcopyrite, pyrite, galena, and sphalerite) are a characteristic feature of all the massive sulfide polymetallic ore deposits of Rudny Altai. The ores are noted to be multicomponental, with elevated contents of the admixtures of precious metals and rare elements (Cd, Se, Bi, Te, Ta, W, etc.). Mineralogical investigations of the ores have demonstrated an intricate relationships of the major ore minerals (chalcopyrite, pyrite, sphalerite, galena) that exhibit several generations and different geochemical specialization. Minerals of Au, Ag, Te, Bi, and other elements are encountered as individual grains or microscopic inclusions and stringers in minerals of Cu, Pb, and Zn. A significant vertical range of the ore mineralization (more than 100 m), the complexity and long duration of the ore-forming processes, the clearly defined confinement of the ore mineralization to certain geochronologic levels, – all these allow us to suppose a possibility of discovery of new ore lodes or individual ore deposits within the already known ore fields of the Kazakhstan segment of Rudny Altai

Mineralogická charakteristika hydrotermální mineralizace ze starých těžebních pozůstatků v oblasti Mladoňov - Nový Malín (silezikum)

2020 ◽  
Vol 28 (2) ◽  
pp. 261-275
Author(s):  
Zdeněk Dolníček ◽  
Miroslav Nepejchal ◽  
Vlastimil Flášar ◽  
Jana Ulmanová
Keyword(s):  
Electron Microprobe ◽  
Bohemian Massif ◽  
Native Gold ◽  
Native Copper ◽  
Ore Minerals ◽  
Ore Mineralization ◽  
Area North ◽  
Native Bismuth

In the area north of Mladoňov, which is built by phyllites and quartzites of the Vrbno Group and granite-derived phyllonites of the Desná Group (Silesicum, northern part of the Bohemian Massif), there were found two types of hydrothermal ore mineralization in vein material sampled from remnants of old mining/prospection. The Cu(-Bi-Au) mineralization hosted by quartz gangue was found at the locality Husarčina šachta. A main ore mineral is chalcopyrite, which contains inclusions of pyrite, native bismuth, bismuthinite, a phase close to bismite, and native gold with fineness of 717 - 818. Baryte, recorded in part of collected samples, probably represents a significantly younger hypogene mineralization. Supergene minerals include malachite, azurite, a phase close to chrysocolla, bornite, Cu-sulphides, tenorite, native copper, limonite and probably also cuprite. A quartz-pyrite-pyrrhotite mineralization with accessory arsenopyrite and xenotime-(Y) and supergene limonite and baryte was recorded at localities Husarčina šachta and Kopka. Sporadically, Fe-sulphides contain elevated contents of Au (measurable by means of an electron microprobe), probably due to submicroscopic inclusions of native gold. Gold could be leached from wall rocks by ore fluids and/or remobilized from older mineralization to the younger one. The presence of traces of Cr, Co and Ni in some ore minerals implies for wider circulation of parent fluids involving probably also basic or ultrabasic rocks.

scholarly journals Indium Mineralization in the Volcanic Dome-Hosted Ánimas–Chocaya–Siete Suyos Polymetallic Deposit, Potosí, Bolivia

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 604 ◽  
Author(s):  
Torró ◽  
Cazorla ◽  
Melgarejo ◽  
Camprubí ◽  
Tarrés ◽  
...  
Keyword(s):  
Electron Probe ◽  
The Other ◽  
Ore Mineralization ◽  
Coupled Substitution ◽  
Stage 1 ◽  
Low Sulfidation ◽  
Petrographic Study ◽  
Mineralizing Fluids ◽  
Volcanic Dome

A volcanic dome complex of Miocene age hosts the In-bearing Ánimas–Chocaya–Siete Suyos district in SW Bolivia. Ore mineralization occurs as banded and massive infillings in sub-vertical, NE-SW striking veins. In this article, a detailed petrographic study is combined with in situ mineral geochemistry determinations in ore from the Arturo, Chorro and Diez veins in the Siete Suyos mine, the Ánimas, Burton, Colorada, and Rosario veins in the Ánimas mine and the Nueva vein in the Chocaya mine. A three-stage paragenetic sequence is roughly determined for all of them, and includes (1) an early low-sulfidation stage that is dominated by cassiterite, pyrrhotite, arsenopyrite, and high-Fe sphalerite (FeS > 21 mol. %); (2) a second intermediate-sulfidation stage dominated by pyrite + marcasite ± intermediate product, sphalerite (FeS < 21 mol. %), stannite, and local famatinite; and, (3) a late intermediate-sulfidation stage dominated by galena and Ag-Pb-Sn sulfosalts. Electron-probe microanalyses reveal high indium enrichment in stage-2 sphalerite (up to 9.66 wt.% In) and stannite (up to 4.11 wt.% In), and a moderate enrichment in rare wurtzite (up to 1.61 wt.% In), stage-1 sphalerite (0.35 wt.% In), cassiterite (up to 0.25 wt.% In2O3), and ramdohrite (up to 0.24 wt.% In). Therefore, the main indium mineralization in the district can be associated to the second, intermediate-sulfidation stage, chiefly in those veins in which sphalerite and stannite are more abundant. Atomic concentrations of In and Cu in sphalerite yield a positive correlation at Cu/In = 1 that agrees with a (Cu+ + In3+) 2Zn2+ coupled substitution. The availability of Cu in the mineralizing fluids during the crystallization of sphalerite is, in consequence, essential for the incorporation of indium in its crystal lattice and would control the distribution of indium enrichment at different scales. The highest concentrations of indium in sphalerite, which is found in the Diez vein in the Siete Suyos mine, occur in crustiform bands of sphalerite with local “chalcopyrite disease” texture, which has not been observed in the other studied veins. In stannite, the atomic concentrations of In are negatively correlated with those of Cu and Sn at Cu + In = 2 and Sn + In = 1. Thus, atomic proportions and correlations suggest the contextualization of the main indium mineralization in the sphalerite–stannite–roquesite pseudoternary system.

Sign in / Sign up

Export Citation Format

Share Document