Ore Elements Research Articles

The Kolmozero deposit: a unique Li source in the European Arctic of Russia

Tens to hundreds of pegmatite veins can accumulate within a pegmatite field. However, only a limited number of pegmatite veins can be practically valued. Hence, there is a problem of identifying rare metal pegmatites at the stage of geological prospecting and appraisal. Geochemical indicators are most impartial, reproducible and highly informative for these purposes. The Kolmozero lithium deposit is located in the Neoarchaean metagabbro-anorthozites of the Patchemvareksky massif in the junction zone of the two major regional structures of the Archaean age, i.e. the Murmansk block and the Kolmozero-Voronya Greenstone Belt of the Kola Peninsula. It is shown that pegmatites of the Kolmozero deposit with industrially valued rare metal mineralization (Be, Ta, Nb, Li) are poor in large-ion lithophile elements (LILE) (Sr and Ba) and in high charged high field strength elements (HFSE) (REE, Th, Zr). They also have low values of fractionation indexes – Mg/Li and Zr/Hf. The defined geochemical indicators have been applied to estimate feldspar pegmatites and muscovite-feldspar pegmatites that are spatially associated with rare metal pegmatites of the Kolmozero lithium deposit. The feldspar (beryllium-bearing) and muscovite-feldspar (beryllium-niobium-tantalum) pegmatites have rare metal mineralization and, like albite-spodumene pegmatites, are rich in Li, Nb, Ta, Be and depleted by Sr, Ba, Zr, Y, REE. Contents of ore elements (Li, Nb, Ta, Be) content increases from feldspar to muscovite-feldspar and albite-spodumen pegmatites. It is accompanied by a decrease in values of fractionation indexes of Zr/Hf and Mg/Li, as well as a decrease in contents of light, medium and heavy lantanoids Zr, Ba and Sr.

New observations of Tin Mineralization Potential Vis-à-Vis Ore Petrographic, Alteration and Geochemistry in the Southeastern part of Bastar Craton, Central India

The Tin mineralizations occur around the Katekalyan area, hosted in the acid magmatic rocks. The evolution differentiating granitic magma shows residual melt enrichment where end products intruded as pegmatites into the rocks. The different kind of pegmatite occur as simple unzoned, recrystallized (granitic pegmatite), and metasomatic greisenised and albitised pegmatites which emplaced within the pre-existing rocks of metabasic intrusive, granite (KG), granite gneiss (KGG). Sometimes it also found in metasediments as mineralised and non-mineralised characters along the fractures and foliation planes trending N-S, E-W and more frequently are observed NNW-SSE trends. Cassiterite is most important Tin-ore mineral and associated with pegmatites. Some cassiterite samples exhibit colourless to brown shades zoning which indicate multi stage growth. The cassiterite samples contain significant amounts of Sn, Nb, Ta with minor W.
 The partial melting model shows that the variation 5 to 50% partial melting of bulk continental crust for KG as well as KGG rocks but bulk distribution coefficient for Sr (DSr) shows low i.e. <<10. The upper limit of partial melting of bulk crust estimates ~50 % for KG and KGG rocks are consistent with required rheological, critical melt percentage to leave the source region has decreased granite melt which were capable to mineralised tin ore elements. It is interesting to note that the SnF4 and SnCl4 probably not stable in presence of water under geologically reasonable conditions.

The variations of chemical composition and features of the distribution of rare elements in chondrites of fragments of the Chelyabinsk meteorite

Research subject. This paper reports the results of a series of experiments carried out to study the mineral and geoche mical features of 10 Chelyabinsk meteorite fragments. In addition, these fragments were analysed in terms of their chemical composition.Materials and methods. The fragments under study were represented by light-grey granular rocks of the chondrite structure having either isometric or elongated shape. Their surface was largely covered with a black-brownish fusion crust with a thickness of approximately 1 mm. The petrogenic components of the meteorite and the content of rare elements were studied using the methods of chemical silicate analysis and ICP MS respectively. All measurements were carried out using an Agilent 7700x quadrupole mass spectrometer produced by the Agilent Technologies company. The composition of sulphides and metal particles was determined by electron probe microanalysis (PCMA) usinga JXA8200 microanalyzer (Jeol, Japan).Results. The chondri and cementing matrix are found to be primarily composed of olivine and orthopyroxene. The inter-chondruli matrixis shown to consist of a pyroxene-olivine aggregate with inclusions of plagioclase, apatite, fused glass and ore minerals (tenite, kamasite, troilite, rarely pyrrhotine, pentlandite, single grains of chromite and ilmenite). The concentration of the majority of rare and ore elements in the Chelyabinsk meteorite samples is established to be close to their average values for LL-chondrite. When normalizing to coaly chondrite, the substance of the meteorite fragments and the average LL-chondrite were closest to coaly chondrite in terms of the content of siderophile elements (Mo, Ni, Cr, Co, V and Cu). At the same time, the studied meteorite fragments are shown to contain a significantly lower (nearly by one order) concentration of chalcophyle elements (Zn, Pb and Sn) with regard to С1.Conclusion. A comparison of the obtained and published analytical data (ICP MS) has allowed us to make a conclusion on the geochemical heterogeneity of different meteorite remainst hat were scattered over a wide area of the Chelyabinsk Region. The acquired evidence suggests the differentiation of meteorite substance at early stages of the formation of terrestrial planets, which is likely to have occurred due to impact processes.

Gold and other impurity elements in pyrite from the Berezovskoe deposit in the Middle Urals

Research subject. In this work, we investigated the crystals of pyrite, one of the key gold-bearing minerals, from the Berezovskoe (the Middle Urals) deposit using modern research approaches.Materials and methods. Samples for the analysis were collected from the ladder sulphide-quartz veins and related berezites in the Ilinskaya, Pervopavlovsk and Vtoropavlovsk dykes of the Berezovskoe deposit. The ores were studied using the methods of optical microscopy, X-ray microanalysis (PCMA), scanning electron microscopy (SEM) and LA-ICP-MS. The latter method was largely used to examine pyrite. Along with pyrite, the materials under study included faded ore, galena, and such rare occurring minerals as aikinite, cosalite, tetradymite and tsumoite. Results. According to the point and profile analysis, as well as grain mapping, the main impurity elements in the stu died samples are found to be Co, Ni and As. The distribution of these elements has shown a zonal character: the amounts of Co and Ni tend to increase and that of As tends to decrease towards the grain centre. In the pyrite samples, Cu, Zn and Pb occur either in the form of their sulphide micro-inclusions or as evenly distributed admixtures. The pyritic ore of later genera tions in the Pervopavlovsk dyke is established to contain gold in amounts of up to 22 g/t, with Au being zonally distributed. The goldbearing variety of pyrite is characterized by abnormally low contents of Co and Ni, as well as by an increased content of As (up to 8000 g/t). Conclusion. A common character of the distribution of main impurity elements in the pyritic ores in the studied dikes indicates similar conditions of their crystallization. The presence of late-generation pyrite with fine gold in the Pervopavlovsk dike evidences to a heterogeneous distribution of gold mineralization therein, likely due to the multistage character of the latter. This may also be an indicator of the concentration of ore columns, which fact requires further elucidation.

Content of Microelements in Brown Coals of Transbaikal Region

The coal deposits containing a complex of the major valuable microelements which have various degree of study are disclosed in Transbaikal territory. The analysis of geological material on coal deposits of Transbaikal region demonstrates great prospect for search and surveying of germanium-bearing coals in this territory. Gallium and beryllium at infrequent elements’ group is expedient to consider which are contained in local coals in the increased concentration connected among themselves. Content of these elements in coals it is caused by space exposure of coal and rare-metal deposits. The last include the production reserves of beryllium and they are a part of the Transbaikal region beryllium-bearing province in Russia. It is noted that some coal deposits of Transbaikal region have the increased content of rare-earth elements. Noble metals in the increased concentration are established in many assay of coal of various deposits that is caused by constant aurum content within the Transbaikal metallogenic province. There are data on content of valuable ore elements in coal deposits of the Transbaikal region, regularities of their placement depending on geochemical features of metallogenic provinces, conditions of accumulation and to form into various components of coals and also information about ore elements’ localization and their associations. The analysis of these data gives geological and technological characteristic to metal-bearing coals as to perspective complex of mineral raw materials. There are considered infrequent and diffuse elements, non-ferrous, noble, rare-earth and radioactive metals with concentration less than 0,1% as microelements in coals. According to the International Organization for Standardization 84 elements are detected in coals which belong to various groups of a periodic system of elements. 35-40 elements are found stably in coals of deposits of Russia in detection limits of mass analyses.

Oxidation Sulfuric Acid Autoclave Leaching of Copper Smelting Production Fine Dust

Lead, zinc, and arsenic are associated elements in copper ores. Due to deterioration of concentrate quality and involvement in recycling of secondary raw materials, these impurities are increasingly circulated in copper-smelting production, most often collected in fine dusts. Recovery of these dusts for pyrometallurgical processing leads to contamination of black copper with arsenic and lead. Results are provided for sulfuric acid autoclave leaching of OAO SUMZ dust and dust obtained after recovery melting, containing alongside copper and zinc considerable amounts of lead and arsenic. The effect of temperature and acid concentration on autoclave leaching indices is studied. Optimum dust leaching parameters are obtained: temperature 160°C, H2SO4 /(Pb+Zn+Cu) = 2.1, $$ {P}_{{\mathrm{O}}_2}=0.3\mathrm{MPa} $$ , τ = 2 h, and with these parameters the maximum degree of leaching for arsenic, copper and zinc is observed. Direct oxidizing sulfuric autoclave leaching of fine dust makes it possible to extract up to 89% copper and 92% zinc. Arsenic passes into a cake in the form of iron arsenate, which complicates subsequent processing. In order to exclude deposition of arsenic during autoclave leaching it is necessary to remove arsenic from dust where it is present in the form of oxidized compounds, and therefore it is possible to use atmospheric sulfuric acid leaching for its extraction. During two stages of atmospheric and autoclave oxidation leaching, it is possible to extract up to 93% Cu, 96% Zn, and 99% As.

Modelling ore-forming processes through a cosine similarity measure: Improved targeting of porphyry copper deposits in the Manzhouli belt, China

Recognizing distribution patterns of ore-related pathfinder elements requires an understanding of the corresponding ore-forming systems and may lead to the definition of more reliable exploration targets. Given that complex ore-forming processes in complex geological terrains can result in either enrichment or depletion of ore elements, simultaneous consideration of both processes in geochemical anomaly modelling would be advantageous for defining exploration targets. Here, we adapted the “cosine similarity measure” method for pattern recognition of ore-related geochemical anomalism to facilitate simultaneous modelling of element enrichment and depletion. We tested the performance of this new method on porphyry copper exploration data from the Manzhouli belt, China, and demonstrated that our method is highly efficient with respect to recognizing ore-related geochemical signatures and, thus, useful for “vectoring” towards porphyry copper deposits and defining more reliable geochemical exploration targets.

Thermodynamic Simulation of the Manufacture of Fe–Si–Ni–Cr Alloys

The reduction of the elements of the system containing (wt %): 40 Cr2O3, 21 FeO, 15 Al2O3, 6 SiO2, 16 MgO, 2 CaO, 0.006 P2O5 is subjected to thermodynamic simulation when the CaO content increases to a basicity of 3.15. Ferrosilicone (28% Fe, 65% Si; 7% Ni) is used as a reducer. For the simulation, the HSC Chemistry 6.12 software package developed by Outokumpu Research Oy (Finland) is used, and new thermodynamic constants for CrO and corrected constants for CaCr2O4 were introduced into its database. An increase in the reduction of chromium by 32.7% (from 64 to 95.1%) is found to occur when the slag basicity increases from 0.07 to 1.86. The rational slag basicity is 1.86–1.9. An increase in the reducer consumption from 0.5 to 1.05mred leads to an increase in the reduction of chromium by 52.4 to 95.1%. The chemical composition of the synthesized metal is (wt %) 50.4 Cr, 1.97 Si, 3.3 Ni, 0.21 Al, 0.0050 P, and Fe for balance. The simulation results can be used to calculate the reduction of the chromium ore elements using ferrosiliconickel.

Gold-Bearing Pyrrhotite Ores in East Sayan: Composition and Formation Conditions (by the Example of the Ol’ginskoe Ore Occurrence)

Abstract —We present results of study of the chemical composition, formation conditions, and genesis of gold-bearing pyrite–pyrrhotite ores widespread within the ophiolite belts in the southeast of East Sayan. The study was performed at the Ol’ginskoe ore occurrence localized in the Ol’gino gold ore zone. Sulfide mineralization zones are composed of lenticular interbeds and bodies subconfoimable with the bedding of the enclosing schist strata. The ores are carbonaceous siliceous garnet–biotite schists variably enriched in sulfide minerals, mainly pyrrhotite, with impurities of other silicate minerals: tremolite, chlorite, albite, plagioclase, diopside, and epidote. In addition, sphalerite, chalcopyrite, pyrite, and arsenopyrite are present in small amounts in the ores. The established Р–Т conditions of ore metamorphism (T = 430–540 °C, P ~ 5 kbar) correspond to the lower boundary of the epidote–amphibolite facies. Thermobarogeochemical studies of fluid inclusions in vein quartz showed close temperatures (536–340 °C) but lower pressures, 200–800 bars, which indicates that the quartz vein formation was related to a pressure drop. The predominant salts of the fluid inclusions are Fe and Mg chlorides with Na and K impurities. The geologic location, structures, textures, and mineral, geochemical, and isotope compositions of the studied sulfide ores indicate their formation in submarine deep-water environments as a result of the activity of hydrothermal systems, analogues of “black smokers”, later subjected to metamorphism. During metamorphism, primary ores underwent mineral and chemical transformations: pyrrhotitization of pyrite, appearance and coarsening of native gold particles, and redistribution of components (Mn, As, etc). The low contents of gold and some ore-forming elements (Zn, Cu, and Pb) in pyrrhotite ores testify to the removal of these elements with a metamorphogenic fluid. The removed ore-forming components might have been a source of material for later gold–sulfide–quartz deposits of the Urik–Kitoi zone in East Sayan.

In-situ observation of the interaction silicon and hematite

The reduction process of the Fe2O3 (α-hematite) by Si was investigated with in-situ transmission electron microscopy (TEM). Hematite and other iron oxides are main component of iron ore and Si is main gangue elements of iron ore. Si reduced hematite and Fe precipitated around 700°C. The electrons due to TEM(=200keV) was not necessary condition of Fe precipitation and grew until run out of Si. The residual Si reacted with precipitated Fe after a certain period of time of electron irradiation. The reaction completed very short time less than one frame of video. One of the reacted material was identified as α-FeSi2. These results indicated that the possibility of new ironmaking without CO2 emission and silicide formation.

The Olimpiadinskoe Gold Deposit (Yenisei Ridge): Temperature, Pressure, Composition of Ore-Forming Fluids, δ34S in Sulfides, 3He/4He of Fluids, Ar–Ar Age, and Duration of Formation1

Abstract —New thermobarogeochemical and isotope-geochemical data are presented, which show the intricate and long history of the formation of the unique Olimpiadinskoe gold deposit with predicted gold reserves of >1000 tons on the Yenisei Ridge. Metal-bearing oxidized water–carbon dioxide and reduced carbon dioxide–hydrocarbon fluids participated (at the same time or successively) in the formation of the deposit at 220–470 °C and 0.6–2.5 kbar. Fluids of gold-bearing mineral assemblages include CO2, hydrocarbons, and S-, N-, and halogen-containing compounds capable of transporting ore elements, including gold. Highly mobile carbon dioxide–hydrocarbon fluids were responsible for the appearance of disseminated gold mineralization in large bodies of quartz–carbonate–mica schists serving as geochemical barriers in the Olimpiadinskoe deposit. The deposit formed in the period from 817 to 660 Ma, which fits the time interval from crystallization to cooling (868–721 Ma) of the most proximal multiphase Chirimba granitoid pluton. The hydrothermal activity of the fluids that formed the Olimpiadinskoe deposit lasted at least 100–150 Myr year.

The First Discovery of Low-temperature Rhyolite Melts in Cenozoic Long-lived Bazman Volcano, East Iran; Some Problems and Discussion

The igneous rocks, some geological specifics, and also the very melt inclusions in Late Cenozoic rhyolites were studied in the long-lived Miocene (N1, ca. 20 Ma) - Late Quaternary (Q3?) Bazman volcano, eastern Iran. Unusual low temperature (ca. 690o C) silicate melt inclusions in quartz (Qtz) with a High/very High water content (from average 6.9 to 8.2 (up to 9.0 as a limit) wt% H2O) in the acid rocks were defined by independent methods for the first time. Whole-rock chemistry of the melts studied is similar to ones in subduction-related acid melts from different regions. Rhyolites studied sometimes have higher concentration of ore elements, similar to ones in even basites. Ore inheritance from economic porphyry – PCD (Cu-Au +- Mo) Paleogene (mainly Eocene - Pg2) mineralization and deposits in the region is proposed. Geological anomaly of the whole region is proposed by a complex analysis. This anomaly is maybe responsible for anomalous magmatism due to a known tomography data (since Paleocene (Pg1), as minimum), tectonics, metallogeny (including economic one), and maybe - hydrocarbons (HC, oil - gas) activity.

Geochemistry and Mineralogy of Rare Earth Elements (REE) in Bauxitic Ores of the Catalan Coastal Range, NE Spain

Karst bauxite deposits are currently investigated as a new resource for rare earth elements (REE) in order to avoid present and future supply shortfalls of these critical metals. The present work focuses on the geochemistry and mineralogy of the REE in karst bauxite deposits of the Catalan Coastal Range (CCR), NE-Spain. It is revealed that the studied bauxitic ores have a dominant breccia and local ooido-pisoidic and pelitomorphic texture. The bauxitic ores are mostly composed of kaolinite and hematite, as well as of lesser amounts of boehmite, diaspore, rutile and calcite. The mineralogy and major element composition indicate incomplete bauxitization of an argillaceous precursor material possibly derived from the erosion of the Mesozoic Ebro massif paleo-high. The studied bauxites are characterized by ∑REE (including Sc, Y) between 286 and 820 ppm (av. 483 ppm) and light REE to heavy REE (LREE/HREE) ratios up to 10.6. REE are mainly concentrated in phosphate minerals, identified as monazite-(Ce) and xenotime-(Y) of detrital origin and unidentified REE-phosphates of a possible authigenic origin. REE remobilization presumably took place under acidic conditions, whereas REE entrapment in the form of precipitation of authigenic rare earth minerals from percolating solutions was related to neutral to slightly alkaline conditions. During the bauxitization process no significant REE fractionation took place and the REE distribution pattern of the bauxitic ores was governed by the REE budget of the precursor material. Finally, adsorption as a main REE scavenging mechanism in the studied CCR bauxite deposits should not be considered, since the presented data did not reveal significant REE contents in Fe-and Mn-oxyhydroxides and clay minerals.

Thermodynamics of Arsenates, Selenites, and Sulfates in the Oxidation Zone of Sulfide Ores. XIV. Selenium Minerals in the Oxidation Zone of the Yubileynoe Massive Sulfide Deposit, the South Urals

Selenium is one of the most important minor elements in massive sulfide ores. This study focuses on selenium minerals present in the oxidation zone of the Yubeleinoe massive sulfide deposit, the South Urals, Russia: clausthalite (PbSe), tiemannite (HgSe), and naumannite (Ag2Se). These minerals are associated with goethite and siderite. Thermodynamic modeling was used to estimate the physicochemical parameters of selenide stability and the possible formation of Pb, Hg, and Ag selenites as a result of sulfide ore oxidation. The Eh–pH diagrams for the Fe–S–CO2–H2O and Fe–Se–CO2–H2O systems were calculated to estimate the physicochemical formation conditions of the Yubileinoe oxidation zone, as well as for the M–Se–Н2О and M–S–H2O (M = Hg, Pb, Ag) systems. The physicochemical parameters of clausthalite, naumannite, and tiemannite stability are consistent with these conditions. Only the formation of PbSeO3 is theoretically possible among Pb, Ag, and Hg selenites.

Geochemical Evolution and Ore-Bearing Metasomatic Rocks of the Baga-Gazryn Multiphase Massif of Rare-Metal Li–F Granites (Mongolia)

This paper considers the geochemical evolution of igneous and metasomatic rocks in the Baga-Gazryn Massif on the basis of new precision analytical data. The Baga-Gazryn rocks are characterized by enrichment in F, which is concentrated in Li–F mica, topaz, and fluorite. Along with F, zwitters and microclinites are enriched in Li, Rb, Cs, and ore elements Sn, W, Zn. High-charge elements (Zr, Hf, Nb, Ta, and Ti) and also Th and U are not very different in the Baga-Gazryn granites of various phases and metasomatic rocks.

Behavior of Sulfide Ore Elements in the Oxidation of Concentration Tailings under Cryogenic Conditions (Dalnegorsk District, Far East)

Oxidation processes in the sulfide component of the concentration located in the Dalnegorsk district were modeled in the range from–25 to 0°C. The modeling showed crystallization of the following minerals from the model solutions: hypergene Fe, Cu, Pb, Zn, Al, Mg, and Ca sulfate, arsenate, silicate, oxide, and hydroxide minerals at the tailing dumps of the Central concentrating mill and hypergene Fe, Pb, Sb, and Ca sulfate, carbonate, oxide, and hydroxide minerals at the tailing dumps of the Krasnorechensk concentrating mill. The concentrations of sulfide ore elements in the solution in the negative temperature range are much higher compared to those at positive temperatures. This takes place, because the most part of the solution passes to the solid phase (ice), and the volume of the liquid phase decreases. As a result, the hydrosphere of the district is experiencing severe anthropogenic impact from the elements of sulfide ores (S, Zn, Cu, Pb, Fe, Ag, As, and Sb) and their host rocks (Mg, K, Na, Ca, Si and Al).

Geogas prospecting for buried deposits under loess overburden: Taking Shenjiayao gold deposit as an example

The loess areas cover about 6% of China's land and they are thought to have a high likelihood of hosting valuable mineral resources. General geochemical exploration methods are restricted in this region due to the thick loess overburden. Here, we used geogas prospecting, which has been uniquely developed in China, to test its ability to delineate buried deposits at Shenjiayao gold deposit. Two different media: 5% ultrapure aqua regia and polyurethane foam, were used to sample the geogas in the soil. Based on concentrations and precision in our experiment, the polyfoam seemed to out-perform the aqua regia. To investigate how the anomalies formed, a special carrier was used to sample original substances in the geogas. Nanoscale gold-bearing particles were found both in the geogas, supporting the hypothesis that metallic nanoparticles released from orebodies and altered rocks during weathering process can be transported towards the surface. Besides the evidence of nanoparticles, correlations of elements in ores and geogas indicated the close connection between them. Therefore, our field experiment showed geogas prospecting can be effective in exploration for buried mineral resources.

Peculiarities of the distribution of rare-earth elements in the ores of some gold deposits of Eastern Transbaikalia

The distribution of rare-earth elements (REE) in ores of gold deposits of East Transbaikalia has shown that the ore-bearing magma chambers have different depths and degrees of differentiation. The greatest degree of differentiation was within the magmatic foci (Eu/Eu* — 0,29—0,32; Rb/Sr — 0,98—1,40), which are the sources of gold-quartz-arsenopyrite ores, the magmatic sources of the gold-quartz and gold-sulfide-quartz ores (Eu/Eu* — 0,53—0,72; Rb/Sr of 0,10 to 0,54) had lesser degree of differentiation. Magma chambers that are sources for the gold-quartz-arsenopyrite ores (Eu/Sm — 0,08—0,14), were at shallower depths than those for gold-quartz and gold-sulfide-quartz ores (Eu/Sm — 0,11—0,19). The formation of gold-quartz-arsenopyrite ores took place at the magma chambers, largely enriched in volatile components, it is indicated by the existence of a significant tetrad effects in REE patterns of (T1-4 - 0,80; 1,15; 1,16).

Variability in Contents of the Major Ore Components of Ferromanganese Formations in the Lakes–Seas–Oceans Series

Based on statistical methods, the available literature data were processed to analyze regularities in the distribution of five ore elements (Fe, Mn, Cu, Co, Ni) in ferromanganese nodules and crusts in an idealized lakes–seas–oceans profile. Application of the cluster analysis confirmed the regularities revealed by calculations of the mean contents of these elements and unraveled some additional features of their distribution.

Ulan-Tologoi Ta–Nb Deposit: the Role of Magmatism in the Formation of Rare Metal Mineralization

The role of magmatic differentiation is considered for the formation of the Ulan-Tologoi Ta–Nb–Zr deposit (northwestern Mongolia) related to the eponymous alkali granite pluton. Data are presented on the structure of the pluton, the composition of its rocks, and distribution of rare metal mineralization. The ores of the pluton include alkali granites with contents of ore elements exceeding the normative threshold for Ta (>100 ppm). The rare metal mineralization includes pyrochlore, columbite, zircon, bastnaesite, monazite, and thorite, which are typical of all alkali–salic rocks; however, their amount varies depending on the REE content of the rocks. The pluton was formed ~298 Ma ago under the influence of a mantle-crustal melt source.