scholarly journals Unique Ultra-Rich Rare Metal Ores of the Tomtor Complex and Problem of Their Genesis

2019 ◽  
Vol 5 ◽  
pp. 70-88
Author(s):  
A.V. Lapin ◽  
A.V. Tolstov ◽  
I.M. Kulikova
Keyword(s):  
Mineral Composition ◽  
Rare Metal ◽  
Genetic Models ◽  
Textural Features ◽  
Weathering Crusts ◽  
Geologic Setting

Main genetic models of the formation of ultra-rich rare metal ores of the Tomtor deposit (Yakutia) are compared on the basis of their structural-textural features, mineral composition, and geologic setting: 1) reducing epigenesis of laterite weathering crusts of carbonatites and 2) redeposition of weathering products of carbonatites. It is shown that the unique features of the Tomtor deposit are explained by more complex (compared with other deposits of weathering crusts of carbonatites) evolution, which is expressed in two consecutive stages of supergenesis: laterite weathering and reducing epigenesis and their total ore-concentrating efects. The searching-forecast criteria for ores of the Tomtor type are suggested on the basis of epigenetic model of their formation.

scholarly journals Structural-lithological geological-genetic model and mineral composition of Krasnokutskaya rare-metal-titanium placer deposits (Ukraine)

2019 ◽  
pp. 540-556
Author(s):  
E. A. Ganja ◽  
A. V. Lalomov ◽  
A. V. Chefranova ◽  
A. V. Grigor’eva ◽  
L. O. Magazina
Keyword(s):  
Mineral Composition ◽  
Genetic Model ◽  
Rare Metal ◽  
Mineral Deposit ◽  
Donets Basin ◽  
The North ◽  
North Eastern ◽  
Placer Deposits ◽  
Metal Titanium

The conditions of the occurrence, structure, material composition and controlling factors of Krasnokutsky rare-metal-titanium placer deposit localized in the Miocene sediments of the North-Eastern slope of the Dnieper-Donets basin are investigated. Distinguished lithofacies complexes (alluvial-deltaic, coastal and shallow marine, aeolian) correspond to the Lower (Aquitanian), Middle (Burdigalian) and Upper (Langhian) members of Novopetrovskaya Formation of Miocene. Placer bodies are localized in the littoral marine-coastal complexes of Middle Novopetrovskaya sub-formation. Placerforming process is related to phases of stabilization of the shoreline of the regressive phase of the Sub-Paratetic basin. Main search and forecasting criteria for the identification of promising sites within the Kharkiv-Sumy placer-bearing zone are stabilization of the shoreline in the Middle Novopetrovskaya time simultaneously with development of transverse thereto alluvial-deltaic structures that supply weak mineralized sediments. Also, the deltaic ledge breaking the monotony coastal migration and playing the role of structural-sedimentary traps. The developed digital structural-lithological model of the Krasnokutskoye mineral deposit allows us to offer a set of criteria for comparative evaluation of different placer-bearing areas in order to determine the order of their development. The mineral composition of productive deposits is typical for the placers of the region and for rare-metal-titanium placers as a whole; the increased content of rutile and zircon, which rise the industrial value of placers of this zone, are associated with the influence of crystalline rocks of the Voronezh massif.

Textural features of some Bushveld norites

1952 ◽  
Vol 29 (218) ◽  
pp. 913-924 ◽  
Author(s):  
Alfred Kingsley Wells
Keyword(s):  
Phase Boundary ◽  
Mineral Composition ◽  
Detailed Examination ◽  
Laboratory Work ◽  
Textural Features ◽  
Structural Relationships ◽  
International Geological ◽  
International Geological Congress ◽  
Basic Rocks ◽  
Made In

Geophysical Laboratory work is especially applicable to quenched rocks, but does not lend itself to the solution of problems connected with the interpretation of structural relationships between the component minerals of deep-seated rocks. The detailed examination of a rock of simple mineral composition might be expected to yield a picture of the way in which phase-boundary adjustments are made in a rock crystallizing under such conditions. Some of the Bushveld basic rocks are of such a nature, and in the present paper an attempt is made to analyse and interpret the structural relationships between the two minerals bronzite and bytownite (An78-80), of which they are composed. The material studied was collected under the guidance of Dr. A. L. Hall during the International Geological Congress in 1929, supplemented by core specimens recently made available through the courtesy of an old student of the College.

Lithostructural Geological-Genetic Model and Mineral Composition of the Krasnokutsk Rare Metal–Titanium Placer Deposit (Ukraine)

2019 ◽  
Vol 54 (6) ◽  
pp. 465-479
Author(s):  
E. A. Ganzha ◽  
A. V. Lalomov ◽  
A. V. Chefranova ◽  
A. V. Grigor’eva ◽  
L. O. Magazina
Keyword(s):  
Mineral Composition ◽  
Genetic Model ◽  
Rare Metal ◽  
Placer Deposit ◽  
Metal Titanium

scholarly journals Mineralogy of Phoscorites of the Arbarastakh Complex (Republic of Sakha, Yakutia, Russia)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 556
Author(s):  
Mikhail Nikolaevich Kruk ◽  
Anna Gennadievna Doroshkevich ◽  
Ilya Romanovich Prokopyev ◽  
Ivan Aleksandrovich Izbrodin
Keyword(s):  
Mineral Composition ◽  
Siberian Craton ◽  
Chemical Compositions ◽  
Textural Features ◽  
Carbonatite Complex ◽  
Southwestern Part ◽  
Modal Composition ◽  
Accessory Minerals ◽  
Ree Mineralization ◽  
Primary Minerals

The Arbarastakh ultramafic carbonatite complex is located in the southwestern part of the Siberian Craton and contains ore-bearing carbonatites and phoscorites with Zr-Nb-REE mineralization. Based on the modal composition, textural features, and chemical compositions of minerals, the phoscorites from Arbarastakh can be subdivided into two groups: FOS 1 and FOS 2. FOS 1 contains the primary minerals olivine, magnetite with isomorphic Ti impurities, phlogopite replaced by tetraferriphlogopite along the rims, and apatite poorly enriched in REE. Baddeleyite predominates among the accessory minerals in FOS 1. Zirconolite enriched with REE and Nb and pyrochlore are found in smaller quantities. FOS 2 has a similar mineral composition but contains much less olivine, magnetite is enriched in Mg, and the phlogopite is enriched in Ba and Al. Of the accessory minerals, pyrochlore predominates and is enriched in Ta, Th, and U; baddeleyite is subordinate and enriched in Nb. Chemical and textural differences suggest that the phoscorites were formed by the sequential introduction of different portions of the melt. The melt that formed the FOS 1 was enriched in Zr and REE relative to the FOS 2 melt; the melt that formed the FOS 2 was enriched in Al, Ba, Nb, Ta, Th, U, and, to a lesser extent, Sr.

scholarly journals Koytash Deposit As A Prospective Object Of Uzbekistan For Expanding Resources Of Wollastonite, Precious Metals And Other Associated Elements

2021 ◽  
Vol 03 (01) ◽  
pp. 25-29
Author(s):  
Makhsud Ashirov ◽  
◽  
Ibragimov Rustam Kholikulovich ◽  
Jasur Rakhmatullaev ◽  
◽  
...  
Keyword(s):  
Mineral Composition ◽  
Noble Metals ◽  
Metal Sulfide ◽  
Precious Metals ◽  
Rare Metal ◽  
Metal Deposit ◽  
Rare Metal Deposit

The article discusses complex and conjugated formation of wollostonite, sulfide-rare metal and silver-base polymetallic ores of Koytash deposit. Forms recommended for co-extraction, mineral composition and elements-impurities of them have been revealed. These data on rare-metal sulfide and sulfide-polymetallic ores of Koytash skarn-rare metal deposit proves its prospects in extraction of both rare metal and noble metals, bismuth and wollastonite.

scholarly journals New data on titanium mineralization in fenitized precambrian carbonate rocks of Middle Timan bystrinskaya series

2021 ◽  
Vol 6 ◽  
pp. 38-48
Author(s):  
I. I. Golubeva ◽  
◽  
A. S. Shuisky ◽  
V. N. Filippov ◽  
E. M. Tropnikov ◽  
...  
Keyword(s):  
Mineral Composition ◽  
Carbonate Rocks ◽  
Parent Rocks ◽  
Middle Timan ◽  
Weathering Crusts ◽  
High Concentrations

Fenitized Precambrian carbonate rocks (Middle Timan) are parent rocks for bauxite — phosphate weathering crusts. Therefore, the mineral composition of fenites, characterized by rich and varied mineralization, is of great interest. Titanium minerals especially attract attention, since their high concentrations are noted in bauxite-phosphate weathering crusts. For example, in the bauxites of the Verkhne-Shchugorsk area, the amount of rutile may reach 6000—7000 g/t. Titanium mineralization is represented by titanite, rutile, anatase, and cassite.

scholarly journals Petrografie xenolitů vyvřelých hornin v neovulkanitech z lomu Bučník u obce Komňa

2019 ◽  
Vol 26 (1-2) ◽  
Author(s):  
Michaela Hašková ◽  
Kamil Kropáč
Keyword(s):  
Mineral Composition ◽  
Magma Chamber ◽  
Hydrothermal Alteration ◽  
Coarse Grained ◽  
Textural Features ◽  
Genetic Affinity ◽  
Secondary Minerals ◽  
Plutonic Rocks

Neovolcanites from the Uherský Brod area sporadically enclose cm to dm large xenoliths of plutonic rocks. This paper focuses on characterization of xenoliths from the Bučník hill which are enclosed in trachyandesites by using classic petrographic methods. Based on mineral composition and textural features of main rock-forming minerals, the studied xenoliths can be classified as fine- to coarse-grained pyroxenic-amphibolic gabbros or diorites, respectively. They consist mainly of intermediate polysynthetically twinned plagioclase (andesine to labradorite; An44–55) and yellow-brown pleochroic magnesiohastingsite to pargasite (XMg = 0.64–0.75; Si = 6.09–6.29 apfu; Ti = 0.30–0.42 apfu). Relicts of diopside (XMg = 0.70–0.80; Ti = 0.01–0.03 apfu; Na = 0.03–0.04 apfu), brown strongly pleochroic phlogopite leaflets (XMg = 0.58–0.65; Si = 5.51–5.60), apatite columns (predominantly fluorapatite; F = 0.43–0.77 apfu) and K-feldspar (Ab16–17Or82–84An00–01) grains are less frequent. Amphiboles sporadically enclose round or tabular inclusions of labradorite to bytownite (An64–72) and subhedral olivine (Fo64). Xenoliths are similarly to host trachyandesites affected by superimposed hydrothermal alteration. Secondary minerals represent acid plagioclase (An05–10), chlorites (clinochlore; XMg = 0.55–0.67; Si = 3.13–3.29 apfu), carbonates (calcite and siderite), Ti-minerals (ilmenite, rutile and titanite), sulphides (pyrite and chalcopyrite) and less frequently quartz. The genetic affinity of xenoliths and the host neovolcanites is evidenced by the similarity in mineral composition and whole-rock chemistry. Xenoliths can be interpreted either as material from deeper parts of the magma chamber, or more probably as crystal cumulates (i.e. equivalents of cumulate gabbros).

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