scholarly journals Ta-Nb mineralization in rare-metal pegmatite from north-western frame of Lypniazhka granite-migmatite structure

2020 ◽  
Vol 41 ◽  
pp. 32-41
Author(s):  
S.I. Kurуlo ◽  
◽  
N.M. Lуzhachenko ◽  
S.M. Bondarenko ◽  
V.O. Syomka ◽  
...  
Keyword(s):  
Hydrothermal Alteration ◽  
Hydrothermal Fluid ◽  
Rare Metal ◽  
Mineral Assemblages ◽  
Lower Volume ◽  
Alkaline Feldspar ◽  
First Time ◽  
North Western ◽  
Rare Metal Pegmatite ◽  
Oscillatory Zonality

The three type of rare-metal pegmatites are know in Stankuvatske ore field (Ingul megablock, the Ukraianian Shield), such as: Li-bearing, Bi-As-U and Ta-Nb pegmatites. For the first time Ta-Nb mineralisation from Ta-Nb bearing albite-K-Feldspar rare metal pegmatite have been described. Investigated pegmatite is located on the Norh-West frame of the Lypnazky granitemigmatite massive among hosted amphibolites. Rare-metal pegmatite doesn’t have obvious zonality and consist of alkaline feldspar, biotite, muscovite, dark to black colour quartz, blue-greenish apatite, nigerite, gachnite, tourmaline, monazite. The primary ferrocolumbite and Nb-rutile-II have undergone strong hydrothermal alteration. Thus primary rutile-II decomposed with formation of skeletal intergrowths of secondary cassiterite and rutile-III with a much lower volume of Nb and Ta under the influence of hydrothermal fluid. Primary homogenous Nb-rutile-I (Nb2O5+Ta2O5 from 33,5 to 42,9 wt.%) exsolved a fine trellis-like pattern and lamellar of Nb-pure rutile-III, cassiterite and Mn-rich ilmenite. The Nb-rutile-II is occurred in tabular grains with unclear internal zonation. Primary ferrcolumbite breakdown to Ti-ixiolite and Nb-rutile-III. Primary oscillatory zonality is transformed into irregularly patchy and veinlety. Recrystallized ferrotantalite is secondary and uncommon mineral. Ferrocolumbite contains 2.93 to 4.74 wt.%TiO2, and titanian ixiolite 7,33-10,76 wt.%. The (Ti,Nb)>Ta mineral assemblages, and compositional trend of columbite with very low Ta/(Ta+Nb) and Mn/ (Mn+Fe) imply a general low level of fractionation in comparison with typical beryl-columbite rare-metal pegmatites.

scholarly journals Rare-Metal Pegmatite Deposits of the Kalba Region, Eastern Kazakhstan: Age, Composition and Petrogenetic Implications

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1017
Author(s):  
Sergey V. Khromykh ◽  
Tatiana A. Oitseva ◽  
Pavel D. Kotler ◽  
Boris A. D’yachkov ◽  
Sergey Z. Smirnov ◽  
...  
Keyword(s):  
Phase 1 ◽  
Rare Metal ◽  
Rare Metals ◽  
Geochronological Data ◽  
Age Composition ◽  
Deep Faults ◽  
Mineral Assemblages ◽  
Rare Metal Pegmatite ◽  
Ore District ◽  
Eastern Kazakhstan

The paper presents new geological, mineralogical, and isotope geochronological data for rare-metal pegmatites in the Kalba granitic batholith (Eastern Kazakhstan). Mineralization is especially abundant in the Central-Kalba ore district, where pegmatite bodies occur at the top of large granite plutons and at intersections of deep faults. The pegmatites contain several successive mineral assemblages from barren quartz-microcline and quartz-microcline-albite to Li-Cs-Ta-Nb-Be-Sn-bearing cleavelandite-lepidolite-spodumene. Ar-Ar muscovite and lepidolite ages bracket the metallogenic event between 291 and 286 Ma. The pegmatite mineral deposits formed synchronously with the emplacement of the phase 1 Kalba granites during the evolution of hydrous silicate rare-metal magmas that are produced by the differentiation of granite magma at large sources with possible inputs of F and rare metals with fluids.

scholarly journals Mineralogical Tracers of Gold and Rare-Metal Mineralization in Eastern Kazakhstan

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 253
Author(s):  
Boris A. D’yachkov ◽  
Ainel Y. Bissatova ◽  
Marina A. Mizernaya ◽  
Sergey V. Khromykh ◽  
Tatiana A. Oitseva ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Mineral Resources ◽  
Metallurgical Industry ◽  
Rare Metal ◽  
Rare Metals ◽  
Mineral Assemblages ◽  
Rare Metal Mineralization ◽  
Rare Metal Pegmatite ◽  
Eastern Kazakhstan ◽  
Gold Bearing

Replenishment of mineral resources, especially gold and rare metals, is critical for progress in the mining and metallurgical industry of Eastern Kazakhstan. To substantiate the scientific background for mineral exploration, we study microinclusions in minerals from gold and rare-metal fields, as well as trace-element patterns in ores and their hosts that may mark gold and rare-metal mineralization. The revealed compositions of gold-bearing sulfide ores and a number of typical minerals (magnetite, goethite, arsenopyrite, antimonite, gold and silver) and elements (Fe, Mn, Cu, Pb, Zn, As, and Sb) can serve as exploration guides. The analyzed samples contain rare micrometer lead (alamosite, kentrolite, melanotekite, cotunnite) and nickel (bunsenite, trevorite, gersdorffite) phases and accessory cassiterite, wolframite, scheelite, and microlite. The ores bear native gold (with Ag and Pt impurities) amenable to concentration by gravity and flotation methods. Multistage rare-metal pegmatite mineralization can be predicted from the presence of mineral assemblages including cleavelandite, muscovite, lepidolite, spodumene, pollucite, tantalite, microlite, etc. and such elements as Ta, Nb, Be, Li, Cs, and Sn. Pegmatite veins bear diverse Ta minerals (columbite, tantalite-columbite, manganotantalite, ixiolite, and microlite) that accumulated rare metals late during the evolution of the pegmatite magmatic system. The discovered mineralogical and geochemical criteria are useful for exploration purposes.

Detection of slip surface in earth slide based on mineral assemblages -An example of hydrothermal alteration zone landslide in East Hokkaido Japan-

2014 ◽  
Vol 51 (3) ◽  
pp. 106-112
Author(s):  
Hiroyuki MAEDA ◽  
Masanori KOHNO ◽  
Yoshihiko SEKISHITA ◽  
Satoshi UEMATSU ◽  
Hiroshi NAYA
Keyword(s):  
Hydrothermal Alteration ◽  
Slip Surface ◽  
Alteration Zone ◽  
Mineral Assemblages

The first finding of a Greek amphora in Poland

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sylwester Czopek ◽  
Katarzyna Trybała-Zawiślak ◽  
Joanna Trąbska ◽  
Barbara Trybalska ◽  
Joanna Adamik-Proksa ◽  
...  
Keyword(s):  
Trace Elements ◽  
Forest Steppe ◽  
Iron Compounds ◽  
Fine Grained ◽  
Tof Sims ◽  
First Finding ◽  
High Calcium ◽  
The University ◽  
First Time ◽  
North Western

Abstract In 2017, an expedition of the Institute of Archeology of the University of Rzeszów (Poland) carried out excavations on a hillfort belonging to the Scythian cultural circle (its forest-steppe variant) in Chotyniec, in south-eastern Poland. The hillfort is the central and most important point of a large settlement cluster, which is the furthest north-western enclave of this cultural circle. In an excavated cult object – the so-called ‘zolnik’ – we made an interesting discovery. Here we show this unique finding for the first time: a Greek wine amphora, from the beginning of the sixth century BC. We were able to explore and reconstruct it almost entirely. Amphora is the only artefact of this type found in the present Polish borders. The amphora was subjected to archaeometric research with the use of PLM, SEM/EDS, TXRF and ToF SIMS. The massive fabric was made of high calcium clay enriched in quartz and volcanic lithoclasts. The lack of chromium and nickel among trace elements makes the vessel different from the amphoras from the Eastern Meditteranean analysed so far, suggesting a specific workshop. Red painting was executed with very fine grained iron compounds predominantly based on aluminosilicates, enriched in phosphorus. Obviously, since it is associated with the presence of Scythians in Eastern Europe, it simultaneously delimits (geography-wise) the borders of Greek influence.

scholarly journals Geodynamics and Oil and Gas Potential of the Yenisei-Khatanga Basin (Polar Siberia)

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 510 ◽  
Author(s):  
Valery Vernikovsky ◽  
Georgy Shemin ◽  
Evgeny Deev ◽  
Dmitry Metelkin ◽  
Nikolay Matushkin ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Oil And Gas ◽  
Foreland Basin ◽  
Gas Reservoirs ◽  
The North ◽  
Western Arctic ◽  
Folded Structures ◽  
Gas Potential ◽  
First Time ◽  
North Western

The geodynamic development of the north–western (Arctic) margin of the Siberian craton is comprehensively analyzed for the first time based on our database as well as on the analysis of published material, from Precambrian-Paleozoic and Mesozoic folded structures to the formation of the Mesozoic-Cenozoic Yenisei-Khatanga sedimentary basin. We identify the main stages of the region’s tectonic evolution related to collision and accretion processes, mainly subduction and rifting. It is demonstrated that the prototype of the Yenisei-Khatanga basin was a wide late Paleozoic foreland basin that extended from Southern Taimyr to the Tunguska syneclise and deepened towards Taimyr. The formation of the Yenisei-Khatanga basin, as well as of the West-Siberian basin, was due to continental rifting in the Permian-Triassic. The study describes the main oil and gas generating deposits of the basin, which are mainly Jurassic and Lower Cretaceous mudstones. It is shown that the Lower Cretaceous deposits contain 90% of known hydrocarbon reserves. These are mostly stacked reservoirs with gas, gas condensate and condensate with rims. The study also presents data on oil and gas reservoirs, plays and seals in the Triassic, Jurassic and Cretaceous complexes.

scholarly journals New records of lichens and allied fungi from the Leningrad Region, Russia. VII

2016 ◽  
Vol 53 ◽  
pp. 25 ◽  
Author(s):  
Dmitry E. Himelbrant ◽  
Irina S. Stepanchikova ◽  
Jurga Motiejūnaitė ◽  
Ludmila V. Gagarina ◽  
Alexandra V. Dyomina
Keyword(s):  
New Records ◽  
European Russia ◽  
Leningrad Region ◽  
Lichenicolous Fungi ◽  
The North ◽  
Western European ◽  
First Time ◽  
North Western

Fourteen species of lichens, fifteen lichenicolous fungi and one saprobic fungus are reported for the first time for St. Petersburg, Western or Eastern Leningrad Region. The lichen Lecidella meiococca and the lichenicolous fungus Tremella phaeophysciae are reported as new to Russia, the lichen Lecania sambucina and the lichenicolous fungus Endococcus tricolorans are new for the European Russia, the lichens Buellia arborea, Chaenotheca cinerea, Bellemerea sanguinea, resinicolous calicioid fungus Chaenothecopsis mediarossica and lichenicolous fungi Arthonia molendoi, Lichenochora obscuroides, Pronectria leptaleae, Sphaerellothecium cladoniae are new for the North-Western European Russia. The most interesting records are briefly discussed. 

scholarly journals Petrogenetic and Compositional Features of Rare Metal Pan-African Post-Collisional Pegmatites of Southwestern Nigeria; A Status Review

2018 ◽  
Vol 7 (2) ◽  
pp. 166-187
Author(s):  
Abiola Oyebamiji ◽  
Adeniyi JohnPaul Adewumi ◽  
Tehseen Zafar ◽  
Adegbola Odebunmi ◽  
Philips Falae ◽  
...  
Keyword(s):  
Mineral Chemistry ◽  
Rare Metal ◽  
Border Zone ◽  
Chemical Compositions ◽  
Molten Material ◽  
Southwestern Nigeria ◽  
Pan African ◽  
Opening And Closing ◽  
High Degree ◽  
Rare Metal Pegmatite

Abstract This research reviews the geology, petrogenesis, compositional trends and geochronology of the rare-metal pegmatite of southwestern Nigeria. The source of these pegmatites is still presently debated which have been explained as either product of highly fractionated molten material or anatexis of the local crust. However, published works of past authors have been compiled to give a detailed understanding of the formation of the mineral deposits. The basement complex of southwestern Nigeria comprises of Precambrian rocks of amphibolite, the hornblende gneiss and the granite gneisses which were formed as a result of the opening and closing of the ensialic basin with significant, extensive subduction during the Pan-African orogeny. The pegmatites in this region have shown internal zoning and a high degree of evolution from the border zone to the core zone during the crystallization and solidification of the felsic granite to pegmatite melt. The rare-metal pegmatites have distinct chemical compositions and mineralogy, containing quartz, biotite, muscovite, microcline, garnet with localized tourmaline, tantalite and columbite. These pegmatites vary significantly by their bulk-rock and mineral chemistry which indicates a more peraluminous attribute and enrichments of lithophile elements of Rb, Cs, Ta and Ba. Previous K/Ar isotopic ages (502.8±13.0 Ma and 514.5±13.2 Ma) suggest that the pegmatites are related to the post-collisional phase of intensive metasomatism. Adopted from previous studies, a five-stage conceptual model of evolution which is widely accepted have been proposed for the origin of the pegmatites.

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.

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