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

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.

2021 ◽  
Vol 29 (1) ◽  
pp. 90-107
Author(s):  
Zdeněk Dolníček ◽  
Jana Ulmanová ◽  
Karel Malý ◽  
Jaroslav Havlíček ◽  
Jiří Sejkora

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.


Author(s):  
M. M. Kostenko ◽  
P. A. Kondratenko

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.


2021 ◽  
Vol 29 (1) ◽  
pp. 6-15 ◽  
Author(s):  
Zdeněk Dolníček ◽  
Jana Ulmanová

An interesting ore mineralization containing Pb-Bi minerals, present in a thin layer parallel with schistosity of the host amphibolite, was newly recognized in the Libodřice quarry near Kolín (Kutná Hora Crystalline Complex, Czech Republic). The disseminations of ore minerals are formed especially by pyrrhotite and chalcopyrite, less pyrite and accessory galena, native bismuth, cosalite, bismuthinite and joséite-B. The equilibrium textural relationships of rock-forming silicates and main sulphides indicate that the ore assemblage underwent metamorphic recrystallization together with the host rock, however, indications of younger local re-equilibrations under changed physico-chemical conditions (especially temperature, fugacity of sulphur, fugacity of oxygen) were also observed. The presence of polysynthetic lamellae in chalcopyrite suggests for its origin/re-crystallization at temperatures above 550 °C. Sporadic cosalite, stable at temperatures below 425 °C, was probably precursor of pseudomorphs today formed by galena and native bismuth. Pseudomorphs originated at temperatures below 271 °C probably due to local decrease of sulphur fugacity caused by growth of associated pyrrhotite. The local sulphurisation of small amount of native bismuth to bismuthinite and small part of pyrrhotite to pyrite finished the process of ore evolution. The presence of elevated contents of Te, Se and Ni in the studied mineralization confirms the source of these elements in the host rock environment, which was presupposed on the basis of earlier mineralogical study of Alpine-type veins in the area of the Kutná Hora Crystalline Complex.


Author(s):  
С.Г. Парада ◽  
М.Ю. Маркин ◽  
В.В. Столяров ◽  
Х.О. Чотчаев

Проведен сопоставительный анализ документации керна буровых скважин и результатов химикоаналитических определений золота в керновых пробах из рудных интервалов золотоносных скарнов Зыгыркольской зоны. Показано, что содержания золота в рудных интервалах не зависят от типа, форм проявления, количества и состава рудных минералов. Отсутствие связи концентраций золота с сульфидами, магнетитом и гематитом подтвердилось и при исследовании пробпротолочек, составленных из хвостов 50 бороздовых проб, отобранных из рудных интервалов, в которых содержания золота по результатам химического анализа составили от 0,6 до 9,9 г/т. Результаты минералогического анализа шлихов показали крайнюю бедность их рудными минералами. В минералогических пробах руд с максимальными содержаниями золота установлены частицы самородного золота, при полном отсутствии в этих пробах сульфидов и других рудных минералов. Множественная корреляция, выполненная по массиву химикоаналитических данных, полученных по результатам кернового опробования золотоносных скарнов Зыгыркольской рудоносной зоны, показала, что золото достаточно сильно положительно коррелируется только с висмутом. Это соответствует минералогическим данным о наличии ассоциации самородного золота с самородным висмутом, установленной по результатам электронномикроскопических исследований. Установлено также отсутствие значимой корреляции золота и серебра, что может свидетельствовать о разных этапах золотой и серебряной минерализаций. Относительно сильная положительная корреляция серебра со свинцом, сурьмой, цинком, мышьяком, марганцем и оловом свидетельствует о связи этого элемента с проявлениями сульфидной минерализации, содержащими галенит, пираргирит и другие сульфоантимониты, сульфоарсениды и сульфостанаты, а также алабандин. Таким образом, установлено, что золотое оруденение в скарнах Зыгыркольской зоны является монометалльным (чисто золотым), образовавшимся раньше так называемых сопутствующих сульфидных и сульфидномагнетитовых минерализаций Тырныаузского рудного поля The correlative analysis of borehole core documentation and results of gold determination in core samples from ore intervals of gold bearing skarns of the Zygyrkol zone has been carried out. It was shown that gold contents in the ore fntervals does not depend on the type, forms of manifestation, number and composition of ore minerals. Absence of connection of gold concentration with sulphides, magnetite and hematite has been also confirmed at investigation of crush samples, composed of tails of 50 trench samples, taken from ore intervals, in which gold contents by results of chemical analysis made from 0.6 to 9,9 g/t. Results of mineralogical analysis of blacksands have shown their extreme poverty in ore minerals. In the mineralogic samples of ores with maximal gold contents there were established particles of native gold, at full absence of sulphides and other ore minerals in these samples. Plural correlation carried out on the array of chemicalanalytic data, obtained by results of core sampling of goldbearing skarns of the Zygyrkol ore bearing zone, has shown that the gold is sufficiently strong correlated only with bismuth. This corresponds to the mineralogical data about existence of association of native gold with native bismuth, established on results of electronmicroscopic research. There is established also absence of significant correlation of gold and silver, what can testify in favor of different stages of golden and silver mineralizations. Relatively strong positive correlation of silver with lead, antimonium, zinc, arsenic, maqnganese and tin, testify about link of this element with manifestations of sulphide mineralization, containing galenite, pyrargyrite and other sulphoantimonites, sulphoarsenides and sulphostannates, and also alabandite. So it has been stated that golden mineralization in skarns of the Zygyrkol zone is monometallic (pure golden), formed earlier than so called attendant sulphide and sulphidemagnetite mineralizations of the Tyrnyauz ore field


Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1002
Author(s):  
Jiří Sejkora ◽  
Martin Števko ◽  
Jaroslav Pršek ◽  
Róbert Hovorič ◽  
Emil Makovicky ◽  
...  

Unique association of sulphosalts was discovered at the Kľačianka occurrence, Nízke Tatry Mts., Slovak Republic. It is bound to thin hydrothermal veins with Sb mineralization hosted by the Variscan muscovite-biotite granodiorite and granite of Prašivá type. Ore mineralogy and crystal chemistry of ore minerals are studied here by ore microscopy, X-ray powder diffraction, electron microprobe analyses, and Raman spectroscopy. The early ore mineralization composed of pyrite and arsenopyrite is hosted in quartz gangue and is followed by abundant association of sulfosalts. Stibnite, zinkenite, robinsonite (including Cu-bearing variety), jamesonite, scainiite, dadsonite, disulfodadsonite, rouxelite, chovanite, semseyite, boulangerite, geocronite, tintinaite (with low Bi contents), tetrahedrite-(Fe), tetrahedrite-(Zn), bournonite, chalcostibite, bismuthinite, and gladite in association with sphalerite and rare galena and gold are identified here. The chlorine-rich character of the described sulphosalt association is its characteristic phenomenon. It is represented not only by the occurrence of Cl-sulphosalt and dadsonite, but increased Cl contents were detected in boulangerite, chovanite, disulfodadsonite, robinsonite, rouxelite, scainiite, or tintinaite. The presence of oxygen-containing sulphosalts, such as rouxelite, scainiite and chovanite, is also interesting. The crystallization of these rare chloro-, oxy- and oxy-chloro-sulphosalts at the Kľačianka occurrence required very specific conditions (elevated O2/S2 fugacity) and high chlorine activity in ore-forming fluids.


Mineralogia ◽  
2012 ◽  
Vol 43 (3-4) ◽  
pp. 199-212
Author(s):  
Łukasz Karwowski ◽  
Marek Markowiak

AbstractIn one small mineral vein in core from borehole 144-Ż in the Żarki-Kotowice area, almost all of the ore minerals known from related deposits in the vicinity occur. Some of the minerals in the vein described in this paper, namely, nickeline, hessite, native silver and minerals of the cobaltite-gersdorffite group, have not previously been reported from elsewhere in the Kraków-Lubliniec tectonic zone. The identified minerals are chalcopyrite, pyrite, marcasite, sphalerite, Co-rich pyrite, tennantite, tetrahedrite, bornite, galena, magnetite, hematite, cassiterite, pyrrhotite, wolframite (ferberite), scheelite, molybdenite, nickeline, minerals of the cobaltitegersdorffite group, carrollite, hessite and native silver. Moreover, native bismuth, bismuthinite, a Cu- and Ag-rich sulfosalt of Bi (cuprobismutite) and Ni-rich pyrite also occur in the vein. We suggest that, the ore mineralization from the borehole probably reflects post-magmatic hydrothermal activity related to an unseen granitic intrusion located under the Mesozoic sediments in the Żarki-Pilica area.


2013 ◽  
Vol 2 (1) ◽  
pp. 61-66
Author(s):  
Maciej Rybicki ◽  
Łukasz Karwowski ◽  
Kamila Banasik

Abstract In “Stanisław” quarry, that is located on Garby Izerskie, ore minerals-bearing calcsilicate skarns were found in 2009. The samples were studied using microscopical method of reflected light and scanning electron microscopy (SEM). Based on SEM study, the predominant ore minerals in investigated samples are chalcopyrite, pyrrhotite, bismuth telluride and native bismuth. Moreover, acanthite, native gold and native silver were also identified. Our studies are the first report of above mentioned minerals from the Garby Izerskie area.


KURVATEK ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 25-33
Author(s):  
Fatimah Fatimah

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.


Author(s):  
O. Hrinchenko ◽  
S. Bondarenko ◽  
T. Mironchuk

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.


2008 ◽  
Vol 72 (4) ◽  
pp. 953-970 ◽  
Author(s):  
T. Oberthür ◽  
T. W. Weiser

AbstractGold mineralization at the Viceroy Mine is hosted in extensional veins in steep shear zones that transect metabasalts of the Archaean Arcturus Formation. The gold mineralization is generally made up of banded or massive quartz carrying abundant coarse arsenopyrite. However, most striking is a distinct suite of Au-Bi-Te-S minerals, namely joseite-A (Bi4TeS2), joseite-B (Bi4Te2S), hedleyite (Bi7Te3), ikunolite (Bi4S3), ‘protojoseite’ (Bi3TeS), an unnamed mineral (Bi6Te2S), bismuthinite (Bi2S3), native Bi, native gold, maldonite (Au2Bi), and jonassonite (AuBi5S4). The majority of the Bi-Te-S phases is characterized by Bi/(Se+Te) ratios of >1. Accordingly, this assemblage formed at reduced conditions at relatively low fS2 and fTe2. Fluid-inclusion thermometry indicates depositional temperatures of the main stage of mineralization of up to 342°C, in the normal range of mesothermal, orogenic gold deposits worldwide. However, melting temperatures of Au-Bi-Te phases down to at least 235°C (assemblage (Au2Bi + Bi + Bi7Te3)) imply that the Au-Bi-Te phases have been present as liquids or melt droplets. Furthermore, the close association of native gold, native bismuth and other Bi-Te-S phases suggests that gold was scavenged from the hydrothermal fluids by Bi-Te-S liquids or melts. It is concluded that a liquid/melt-collecting mechanism was probably active at Viceroy Mine, where the distinct Au-Bi-Te-S assemblage either formed late as part of the main, arsenopyrite-dominated mineralization, or it represents a different mineralization event, related to rejuvenation of the shear system. In either case, some of the gold may have been extracted from pre-existing, gold-bearing arsenopyrite by Bi-Te-S melts, thus leading to an upgrade of the gold ores at Viceroy. The Au-Bi-Te-S assemblage represents an epithermal-style mineralization overprinted on an otherwise mesothermal (orogenic) gold mineralization.


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