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 Mineralogy of Dolomite Carbonatites of Sevathur Complex, Tamil Nadu, India

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 355
Author(s):  
Maria Rampilova ◽  
Anna Doroshkevich ◽  
Shrinivas Viladkar ◽  
Elizaveta Zubakova
Keyword(s):  
Tamil Nadu ◽  
Minor Amount ◽  
Carbonatite Complex ◽  
Accessory Minerals ◽  
Main Mass ◽  
Fault Systems ◽  
Hydrothermal Processes ◽  
Lree Enrichment ◽  
Primary Minerals

The main mass of the Sevathur carbonatite complex (Tamil Nadu, India) consists of dolomite carbonatite with a small number of ankerite carbonatite dikes. Calcite carbonatite occurs in a very minor amount as thin veins within the dolomite carbonatite. The age (207Pb/204Pb) of the Sevathur carbonatites is 801 ± 11 Ma, they are emplaced within the Precambrian granulite terrains along NE–SW trending fault systems. Minor minerals in dolomite carbonatite are fluorapatite, phlogopite (with a kinoshitalite component), amphibole and magnetite. Pyrochlore (rich in UO2), monazite-Ce, and barite are accessory minerals. Dolomite carbonatite at the Sevathur complex contains norsethite, calcioburbankite, and benstonite as inclusions in primary calcite and are interpreted as primary minerals. They are indicative of Na, Sr, Mg, Ba, and LREE enrichment in their parental carbonatitic magma. Norsethite, calcioburbankite, and benstonite have not been previously known at Sevathur. The hydrothermal processes at the Sevathur carbonatites lead to alteration of pyrochlore into hydropyrochlore, and Ba-enrichment. Also, it leads to formation of monazite-(Ce) and barite-II.

scholarly journals Petrogenesis of Ultramafic Lamprophyres from the Terina Complex (Chadobets Upland, Russia): Mineralogy and Melt Inclusion Composition

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 419 ◽  
Author(s):  
Ilya Prokopyev ◽  
Anastasiya Starikova ◽  
Anna Doroshkevich ◽  
Yazgul Nugumanova ◽  
Vladislav Potapov
Keyword(s):  
Mineral Composition ◽  
Fractional Crystallization ◽  
Fluid Inclusions ◽  
Siberian Craton ◽  
Melt Inclusions ◽  
Melt Inclusion ◽  
Inclusion Composition ◽  
Accessory Minerals ◽  
Secondary Minerals ◽  
Peridotite Mantle

The mineral composition and melt inclusions of ultramafic lamprophyres of the Terina complex were investigated. The rocks identified were aillikites, mela-aillikites, and damtjernites, and they were originally composed of olivine macrocrysts and phenocrysts, as well as phlogopite phenocrysts in carbonate groundmass, containing phlogopite, clinopyroxene and feldspars. Minor and accessory minerals were fluorapatite, ilmenite, rutile, titanite, and sulphides. Secondary minerals identified were quartz, calcite, dolomite, serpentine, chlorite, rutile, barite, synchysite-(Ce), and monazite-(Ce). Phlogopite, calcite, clinopyroxene, Ca-amphibole, fluorapatite, magnetite, and ilmenite occurred as daughter-phases in melt inclusions. The melt inclusions also contained Fe–Ni sulphides, synchysite-(Ce) and, probably, anhydrite. The olivine macrocrysts included orthopyroxene and ilmenite, and the olivine phenocrysts included Cr-spinel and Ti-magnetite inclusions. Crystal-fluid inclusions in fluorapatite from damtjernites contain calcite, clinopyroxene, dolomite, and barite. The data that were obtained confirm that the ultramafic lamprophyres of the Terina complex crystallized from peridotite mantle-derived carbonated melts and they have not undergone significant fractional crystallization. The investigated rocks are considered to be representative of melts that are derived from carbonate-rich mantle beneath the Siberian craton.

Phosphorus minerals in tonstein; coal seam 405 at Sośnica-Makoszowy coal mine, Upper Silesia, southern Poland

2013 ◽  
Vol 63 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Magdalena Kokowska-Pawłowska ◽  
Jacek Nowak
Keyword(s):  
Trace Elements ◽  
Coal Seam ◽  
Mineral Composition ◽  
Coal Mine ◽  
Chemical Compositions ◽  
Coal Basin ◽  
Upper Silesia ◽  
Southern Poland ◽  
Basin Area

Abstract Kokowska-Pawłowska, M. and Nowak, J. 2013. Phosphorus minerals in tonstein; coal seam 405 at Sośnica- Makoszowy coal mine, Upper Silesia, southern Poland. Acta Geologica Polonica, 63 (2), 271-281. Warszawa. The paper presents results of research on tonstein, which constitutes an interburden in coal seam 405 at the Sośnica- Makoszowy coal mine, Makoszowy field (mining level 600 m), Upper Silesia, southern Poland. The mineral and chemical compositions of the tonstein differ from the typical compositions described earlier for tonsteins from Upper Silesia Coal Basin area. Additionally, minerals present in the tonsteins include kaolinite, quartz, kaolinitised biotite and feldspars. The presence of the phosphatic minerals apatite and goyazite has been recognized. The presence of gorceixite and crandallite is also possible. The contents of CaO (5.66 wt%) and P2O5 (6.2 wt%) are remarkably high. Analysis of selected trace elements demonstrated high contents of Sr (4937 ppm) and Ba (4300 ppm), related to the phosphatic minerals. On the basis of mineral composition the tonstein has been identified as a crystalline tonstein, transitional to a multiplied one.

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 REE-bearing minerals in the Rapakavi Grante, Southern Finland

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Thair Al-Ani
Keyword(s):  
Solid Solution ◽  
Electron Probe ◽  
Granitic Magma ◽  
Accessory Mineral ◽  
Hydrothermal Solutions ◽  
Rapakivi Granite ◽  
Solid Solution Series ◽  
Ree Mineralization ◽  
Geochemical Studies ◽  
Primary Minerals

AbstractThe studied rock samples belong to the classic 1615–1645 Ma Wiborg Rapakivi granite terrane of southeastern Finland. Geochemical studies show that the rapakivi granites and associated rocks form metaluminous to peraluminous A-type granites and plot in the "within plate granites (WPG)" field on the tectonic discriminate diagrams from the Onkamaa, Suomenniemi and Luumäki. The rapakivi granite displays enrichment of light over heavy REE (LREE/HREE = 2-34) and usually negative Eu anomalies (Eu/Eu* = 0.01 - 1.4). Enrichment in REE in some studied samples is confined to highly fractionated portions of the Rapakivi granite. Fractional crystallization of the evolving fluorite-rich peraluminous granitic magma was accompanied, particularly at later stages by fluid fractionation, which plays an important role in the genesis of the REE-mineralization. The studied rapakivi granites host REE-minerals including monazite-(Ce), allanite (Ce), bastnäsite (Ce), xenotime, thorite and REE-bearing mineral apatite. Monazite and allanite are the most important REE carriers in the studied granites and these minerals are strongly enriched in the LREE.Monazites are hosted in apatite, quartz, plagioclase, K-feldspar, and biotite. Grain size of monazite is variable ranging from 50 to >100 μm.Monazite contains 48-68 wt% REE2O3, 24.3-29.3 wt% P2O5 and low Th<1.5 wt%ThO2. The Y, REE, U, Th-bearing minerals are not commonly associated with the primary minerals except for Th-bearing minerals, which occur as silicates (e.g. thorite, ThSiO4); and/or replace other elements in the structure of some accessory mineral, especially xenotime, brabantite, zircon, and apatite. Electron probe microanalysis (EPMA) provides an indication of solid solution series between thorite-xenotimezircon, which are related to hydrothermal solutions enriched in REE, Y, P, U, F, and Zr.

The occurrence of niobian zirconolite, pyrochlore and baddeleyite in the Kovdor carbonatite complex, Kola Peninsula, Russia

1996 ◽  
Vol 60 (401) ◽  
pp. 639-646 ◽  
Author(s):  
C. Terry Williams
Keyword(s):  
Kola Peninsula ◽  
Incompatible Element ◽  
Fluid Composition ◽  
Carbonatite Complex ◽  
Compositional Zoning ◽  
Accessory Minerals ◽  
Element Ratios ◽  
Backscattered Electron ◽  
Oxide Minerals ◽  
High Concentrations

AbstractThe compositions and textural relationships of the oxide minerals zirconolite, pyrochlore and baddeleyite are described. These occur as accessory minerals, often intergrown with each other, from a phoscorite rock associated with the Kovdor carbonatite complex. Both the zirconolite and baddeleyite have relatively high concentrations of Nb and Ta; the pyrochlore is rich in U and Ta. Backscattered electron images, coupled with detailed microprobe analyses, reveal complex compositional zoning in zirconolite and pyrochlore which reflect changes in the fluid composition during growth of these minerals. A comparison is made of incompatible element ratios Zr/Hf, Nb/Ta and Th/U between the three accessory minerals.

scholarly journals Magmatic-Hydrothermal Processes Associated with Rare Earth Element Enrichment in the Kangankunde Carbonatite Complex, Malawi

Minerals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 442 ◽  
Author(s):  
Frances Chikanda ◽  
Tsubasa Otake ◽  
Yoko Ohtomo ◽  
Akane Ito ◽  
Takaomi D. Yokoyama ◽  
...  
Keyword(s):  
Rare Earth ◽  
Geochemical Data ◽  
Carbonatite Complex ◽  
Compositional Zoning ◽  
Ree Mineralization ◽  
Hydrothermal Processes ◽  
Magmatic Stage ◽  
Isotope Study ◽  
Late Magmatic Stage ◽  
Element Enrichment

Carbonatites undergo various magmatic-hydrothermal processes during their evolution that are important for the enrichment of rare earth elements (REE). This geochemical, petrographic, and multi-isotope study on the Kangankunde carbonatite, the largest light REE resource in the Chilwa Alkaline Province in Malawi, clarifies the critical stages of REE mineralization in this deposit. The δ56Fe values of most of the carbonatite lies within the magmatic field despite variations in the proportions of monazite, ankerite, and ferroan dolomite. Exsolution of a hydrothermal fluid from the carbonatite melts is evident based on the higher δ56Fe of the fenites, as well as the textural and compositional zoning in monazite. Field and petrographic observations, combined with geochemical data (REE patterns, and Fe, C, and O isotopes), suggest that the key stage of REE mineralization in the Kangankunde carbonatite was the late magmatic stage with an influence of carbothermal fluids i.e. magmatic–hydrothermal stage, when large (~200 µm), well-developed monazite crystals grew. The C and O isotope compositions of the carbonatite suggest a post-magmatic alteration by hydrothermal fluids, probably after the main REE mineralization stage, as the alteration occurs throughout the carbonatite but particularly in the dark carbonatites.

Mineralogical and chemical characterization of some vermiculites from the Mozambique Belt of Tanzania for agricultural use

Clay Minerals ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 1-17 ◽  
Author(s):  
E. M. M. Marwa ◽  
S. Hillier ◽  
C. M. Rice ◽  
A. A. Meharg
Keyword(s):  
Inductively Coupled Plasma ◽  
Crop Production ◽  
Chemical Characterization ◽  
Chemical Compositions ◽  
Accessory Minerals ◽  
X Ray ◽  
Mozambique Belt ◽  
Agricultural Use ◽  
Soil Conditioners

AbstractVermiculite minerals are locally available in the Mozambique Belt of Tanzania but are not currently commercially exploited. In part this may be due to lack of any precise characterization. This study was carried out as a first step to assess the suitability of these vermiculites for crop production by characterization of their mineralogical and chemical compositions. X-ray diffraction and scanning electron microscopy combined with an energy-dispersive X-ray system were used to establish the mineralogy. Electron microprobe analysis and inductively coupled plasma-mass spectrometry were used to study the chemical compositions and to identify any possible issues related to chemical composition that might affect their use if applied as soil conditioners. The samples were characterized as vermiculites and hydrobiotites with a wide variety of accessory minerals. Accessory minerals that might be of some concern are galena, fibrous amphiboles and sepiolite. The total levels of Ni in all vermiculites, and Cr in some, were also found to be high relative to common European standards and this might limit their potential as soil conditioners. It is clear that a field assessment of the bioavailability of various elements would be necessary before decisions relating to potential agricultural use could be made.

Experiment and Thermodynamic Analysis on Mineral Formation of Cement Clinker Cogeneration from Coal in Pulverized Coal Combustion Boiler

2011 ◽  
Vol 354-355 ◽  
pp. 240-245 ◽  
Author(s):  
You Zhou Jiao ◽  
Zheng Lun Shi
Keyword(s):  
Mineral Composition ◽  
Direct Synthesis ◽  
Test Stand ◽  
Cement Clinker ◽  
Chemical Compositions ◽  
Synthesis Reaction ◽  
Mineral Formation ◽  
Formation Reaction ◽  
Synthetic Reaction ◽  
Computational Analyses

Take Changguang high-sulfur coal as experimental coal type; carry out the experiment of mineral formation rule of co-generation cement clicker on two-section multiphase reaction test stand and conduct XRD, SEM and EDS analyses on the mineral composition of the obtained co-generation clicker sample. It can be found from the experimental results that the mineral composition of co-generation clinker presents great difference with the temperature change in the furnace on the test stand; when the temperature in the furnace reaches to 1,330°C, the main mineral species in co-generation clinker sample are 2CaO•SiO2, Q phase and 3CaO•3Al2O3•CaSO4with excellent hydration activity. Conducted thermodynamic calculation on the mineral formation reaction probably occurring in the chemical compositions of Q-phase cement clinker co-generated from Changguang coal. It is shown in the findings of computational analyses that, according to the chemical composition of clinker, the direct synthesis reaction of 2CaO•Al2O3•SiO2firstly occurs, followed by the direct synthesis reaction of 2CaO•SiO2, the next is the indirect synthesis reaction of Q-phase mineral, and the last is the indirect synthetic reaction of 3CaO•3Al2O3•CaSO4; the final main mineral compositions of co-generation clinker should be 2CaO•SiO2, Q phase and 3CaO•3Al2O3•CaSO4. The conclusion of thermodynamic analyses on co-generation clicker mineral formation reaction basically conforms to the mineral composition in experiment of Changguang coal co-generating Q-phase cement clinker.

scholarly journals The Effects of Calcination on Mineral Composition and Physical Properties of Limestones and Oyster Shells Derived from Different Sources

2021 ◽  
Vol 11 (4) ◽  
pp. 578-586
Author(s):  
Khalil . ◽  
Ridho Kurniawan Rusli ◽  
Andri .
Keyword(s):  
Physical Properties ◽  
Mineral Composition ◽  
Fine Particles ◽  
Oyster Shell ◽  
Angle Of Repose ◽  
Chemical Compositions ◽  
Mineral Concentration ◽  
Tapped Density ◽  
Different Sources ◽  
Decomposition Properties

Limestones and oyster shells are normally used in raw or roasted meal form in the livestock diet. Calcination is intended to improve the mineral concentration and physical characteristics of limestones and oyster shells which vary based on different chemical compositions, textures, and impurities of their types and habitats. The present research aimed to study the effects of calcination on mineral composition and the physical properties of limestones and oyster derived from various sources. Limestone samples from three local limestone mining and oyster shell samples from three shellfish species were calcined by burning at a temperature of 800-1000°C. The calcined products were analyzed for mineral content (Ca, P, Mg, Cu, Zn, and Mn), physical properties (bulk density, tapped density, specific density, and angle of repose), and particle size. Results indicated that calcination had no significant effect on Ca and P concentrations but reduced micro mineral concentration. Limestones had a higher Mg concentration than that of oyster shells, and calcination increased Mg concentration. Calcined oyster shells had higher densities, percentages of fine particles, and lower angles of response. The results suggested that the type of limestones and oyster shells could determine their thermal decomposition properties.

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