Petrology最新文献

{"title":"Heterogeneous Metamorphism in Metabasites of the Kem-Ludy Islands, Belomorian Mobile Belt","authors":"A. L. Perchuk,&nbsp;V. M. Grigorieva,&nbsp;V. M. Kozlovsky,&nbsp;N. G. Zinovieva,&nbsp;A. B. Ermolinskiy","doi":"10.1134/S0869591125700262","DOIUrl":"10.1134/S0869591125700262","url":null,"abstract":"<p>The Kem-Ludy Islands is an understudied fragment of the Early Precambrian Belomorian eclogite province. This study presents detailed petrological analyses on four mafic rocks in a sheared gneiss matrix: eclogite, quartz–clinopyroxene–plagioclase–amphibole–garnet granofels, garnet amphibolite, and quartz-bearing gabbronorite. These rocks exhibit varying degrees of metamorphic transformations, mineral assemblages, and mineral chemistry. Epidote inclusions corresponding to an early metamorphic episode were identified in the garnet cores from the eclogite, granofels, and garnet amphibolite. Peak eclogite facies conditions reconstructed using mineral geothermobarometry yielded <i>T</i> ~ 670°C and <i>P</i>_min ~ 1.3 GPa. The granofels retains indirect evidence of the eclogite stage, while the garnet amphibolite and quartz-bearing gabbronorite completely lack such signatures. Amphibolite-facies metamorphism significantly varies among the rock, primarily due to differential fluid influence. Reconstruction of <i>P−T</i> conditions for the amphibolite stage, done for each rock using mineral geothermobarometry, phase equilibrium modeling (PerpleX), and multiequilibrium thermobarometry (TWQ), yields values of <i>T</i> = 610–730°C and <i>P</i> = 0.4–0.8 GPa. For the eclogite, a <i>P–T</i> path of near-isothermal (~670°C) decompression from ~1.3 to 0.6 GPa was established from two metamorphic stages. This <i>P−T</i> path is similar to those previously determined for some eclogites and metaultramafic rocks from the tectonic mélange in the Gridino area differs from the evolution for eclogites from the Salma and Kuru-Vaara localities.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"630 - 658"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Erratum to: Trace Element Behavior during Shock Transformation of Zircon to Reidite","authors":"A. A. Shiryaev,&nbsp;A. N. Zhukov,&nbsp;V. V. Yakushev,&nbsp;A. A. Averin,&nbsp;V. O. Yapaskurt,&nbsp;A. Yu. Borisova,&nbsp;A. Yu. Bychkov,&nbsp;O. G. Safonov,&nbsp;I. V. Lomonosov","doi":"10.1134/S0869591125560012","DOIUrl":"10.1134/S0869591125560012","url":null,"abstract":"","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"733 - 733"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0869591125560012.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Graphite as an Internal Source of CО2 During Crustal Anatexis: Experimental Study on Melting of Graphite-Bearing Garnet–Two Mica Schist at 500 MPa and 900°C","authors":"O. G. Safonov,&nbsp;L. I. Khodorevskaya,&nbsp;A. V. Spivak,&nbsp;S. A. Kosova,&nbsp;A. A. Viryus,&nbsp;V. O. Yapaskurt,&nbsp;M. V. Voronin","doi":"10.1134/S0869591125700286","DOIUrl":"10.1134/S0869591125700286","url":null,"abstract":"<p>In addition to CO₂ coming from external mantle sources, CO₂ generated by the transformation of carbonaceous material of the protolith (internal sources) is actively involved in the processes of high-grade metamorphism in the crust<i>.</i> The paper presents results of experiments at 500 MPa and 900°C on the partial melting of plagioclase-free garnet–two mica (+ quartz, apatite, ilmenite) schist containing 0, 4.2, 10.1, 14.6, and 18.6 wt % graphite. The melting of graphite-free rock results in peraluminous melts corresponding to alkali-calcic ultrapotassic granites. As the graphite content is increased, the A/CNK and A/NK indices decrease, the MALI index of the melts increases, and their compositions shift toward alkalic granites. The estimated content of H₂O + CO₂ in the melts decreases with an increase in the graphite content in the starting system. The peritectic phases are hercynite–magnetite spinel, orthoamphibole (gedrite), sillimanite, and potassium feldspar. The decrease in the Fe³⁺/ΣFe ratio in Fe–Mg minerals with an increase in the graphite content in the starting mixtures suggests more reducing conditions. This conclusion is confirmed by the log<i>f</i>O₂ values calculated from the equilibrium of spinel, sillimanite, and quartz in the experimental products, which range from ~NNO + 0.5 for experiments in the absence of graphite to lower than ~NNO − 1.5 for experiments in the presence of more than 14 wt % graphite. The interaction of Fe₂O₃ and, possibly, H₂O, released as a result of peritectic melting reactions of the initial schist minerals (primarily micas) with graphite facilitates the formation of CO₂. Modeling of phase relations showed that, along with oxygen fugacity, water activity could be an additional factor influencing phase compositions in the presence of graphite. The Raman spectroscopy of the quenched melts and bubbles in them demonstrates that CO₂ is not only the predominant component of the free fluid phase accompanying the melts but is also partially dissolved in the melt as molecular CO₂ and <span>({text{CO}}_{3}^{{2 - }})</span> complexes with alkali and alkali-earth cations. Experiments demonstrate that under conditions of high-grade metamorphism, graphite-bearing metapelites can serve as an effective internal source for CO₂ accompanying granite melts during anatexis.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"678 - 709"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mineralogical and Geochemical Features, Structure, and Stages of Formation of the Rogomu Concentrically Zoned Massif (Lapland-Belomorian Belt, Kola Peninsula)","authors":"A. Y. Barkov,&nbsp;R. F. Martin,&nbsp;L. P. Barkova,&nbsp;S. A. Silyanov,&nbsp;B. M. Lobastov","doi":"10.1134/S0869591125700237","DOIUrl":"10.1134/S0869591125700237","url":null,"abstract":"<div><p>The Rogomu massif, located in a marginal part of the central Lapland–Belomorian Belt (LBB), has a concentrically zoned structure. It is composed of a core of ultramafic rocks consisting of a peridotite core zone (PCZ) and a closely associated apopyroxenitic zone (APZ) enclosed in an apogabbroic zone (AGZ). The massif crystallized under hypabyssal conditions in the general sequence PCZ → APZ → AGZ. At the initial stage, the paragenetic association of olivine (<i>Fo</i>_87–81) and chromian members of the spinel group crystallized and accumulated in the inner and highest-temperature zone of the magma reservoir. During the formation of the PCZ, the interstitial fluid had an elevated Cl concentration, which is usually characteristic of the lower ultramafic zones of layered intrusions. The PCZ rocks are of harzburgite type, similar to bodies of the Serpentinite Belt (SB). The average chondrite-normalized REE distribution patterns in PCZ rocks are similar to those of the Chapesvara, Khanlauta and Lotmavara massifs in the SB. These are characterized by the extremely low HREE contents, which reflects their more primitive composition with respect to the LBB massifs. The presence of complete and continuous compositional series of the spinel-group minerals and plagioclase is attributed to the unstable conditions of crystallization due to the hypabyssal setting. The Rogomu massif, especially the AGZ, recrystallized at conditions of the epidote-amphibolite and amphibolite facies. Mineralogical features of the AGZ rocks show evidence of a limited mobility of high field-strength elements (REE, Y, Th, U) in the metamorphic fluids during regional recrystallization. The REE contents progressively accumulated and formed aggregates of epidote–clinozoisite grains of the higher-REE second generation. The REE (up to 12 wt % oxides in total), dominantly cerium, substitute for Ca in zoned grains of epidote–clinozoisite, which also contain zones enriched in Cr and Cl. The following scheme of coupled substitution is suggested: (REE³⁺ + <span>(square )</span>) + Cl^– → 2Ca²⁺ + O^2–. Thorium and uranium accumulated jointly in H₂O-bearing fluids to cause the repeated crystallization of submicrometric grains of thorite. These precipitated episodically on the facets of rim-to-core growth-zoned chamosite–clinochlore at a temperature ≤770–880°C. Our observations suggest the possibility of ore zones of unconventional (REE, Y, Th, U) mineralization in the differentiated mafic-ultramafic massifs in the Lapland–Belomorian Belt and other regions.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"581 - 603"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volatiles During the Crystallization of Olivine from Meimechites of the Guli Pluton, Maimecha-Kotui Province: Pyrolysis-Free Gas Chromatography–Mass Spectrometry Data","authors":"L. I. Panina,&nbsp;E. Yu. Rokosova,&nbsp;A. T. Isakova,&nbsp;V. V. Sharygin,&nbsp;A. A. Tomilenko,&nbsp;T. A. Bul’bak","doi":"10.1134/S0869591125700250","DOIUrl":"10.1134/S0869591125700250","url":null,"abstract":"<div><p>The volatile content of syngenetic melt and fluid inclusions in olivine phenocrysts (<i>Fo</i>_92–89) from meimechites of the Guli alkaline-ultrabasic carbonatite pluton was studied using gas chromatography–mass spectrometry (GC–MS). The melt inclusions in olivine were fine-crystallized. According to scanning electron microscope study, daughter phases in them were represented by diopside, phlogopite, ilmenite, Ti-bearing magnetite, titanite, nepheline, sodalite, and xenogenic chromite. According to Raman spectrometry, the fluid inclusions were low-density and contained magnesite and water. During heating experiments, after melting of the last transparent daughter phase in melt inclusions at about 1300°C, the volume of the gas phase coexisting with the melt varied from 1/4 to 2/3 of the inclusion volume, indicating its heterogeneous trapping, i.e. heterogeneity of mineral-forming environment. During olivine crystallization, the volatiles were predominantly represented by hydrocarbons (83.0 rel. %), nitrogenated (7.2 rel. %) and sulfonated (3.4 rel. %) compounds, as well as H₂O (5.9 rel. %) and CO₂ (0.3 rel. %). The hydrocarbons and sulfonated compounds include the relatively high amount of halogenated compounds (4.0 rel. %). The species diversity of the volatile components amounted 201 chemical compounds. The hydrocarbons were dominated by oxygenated components (74.5 rel. %), which include 34.0 rel. % alcohols and 9.9 rel. % ethers, 11.4 rel. % aldehydes, 6.8 rel. % ketones, and 12.2 rel. % carboxylic acids. Aliphatic and cyclic hydrocarbons accounted for only 4.6 and 3.7 rel. %, respectively. Olivine crystallized at relatively reducing conditions at H/(H + O) = 0.87. The comparison of the obtained data with data on olivine from olivinites of the Krestovskaya intrusion showed that meimechites cannot be the parental magma for olivinites of alkaline-ultrabasic carbonatite massifs.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"618 - 629"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphorus Zoning in Cumulus Olivine: A History from the Start to the End of Solidification","authors":"S. N. Sobolev,&nbsp;V. O. Yapaskurt,&nbsp;V. G. Batanova,&nbsp;A. V. Sobolev,&nbsp;A. A. Ariskin,&nbsp;I. V. Pshenitsyn,&nbsp;G. S. Nikolaev","doi":"10.1134/S0869591125700298","DOIUrl":"10.1134/S0869591125700298","url":null,"abstract":"<p>This paper presents data on the distribution of phosphorus and other elements (Ti, Al, Cr, Ni, Ca, Fe, Mg) in olivine crystals in meso- and adcumulates from the Yoko-Dovyren and Monchegorsk layered intrusions, including dunites, troctolites, anorthosites, and olivine-bearing chromitites. Olivine was found to contain skeletal and oscillatory cores, which could be formed (1) in the upper boundary layer of the magma chamber, (2) due to local mixing of magmas with different temperatures during magma emplacement process, and (3) at the boundary between the cumulate pile and the main magma volume of the chamber. Specific boundaries between olivine grains cutting the compositional zoning of one of the contacting crystals were observed. They were interpreted as indicators of pressure solution, which is one of mechanisms of compaction of original cumulate pile. Olivine grains from dunites of the Yoko-Dovyren massif and Mt. Travyanaya of the Monchegorsk massif, which demonstrate a lognormal crystal size distribution (CSD), often display signatures of resorption and subsequent overgrowth of small olivine crystals. The examination of phosphorus zoning of olivine confirmed an experimentally based conclusion that the lognormal CSD could be produced due to more extensive dissolution of smallest grains. In the case of the Yoko-Dovyren massif, this dissolution was attributed to the reaction of nonequilibrium intercumulus melt with the original cumulate crystals, whereas the overgrowth of the olivine grains occurred during further cooling. In the case of Mt. Travyanaya (Monchepluton), the dissolution was probably related to the peritectic reaction of olivine with melt producing orthopyroxene, and the additional growth of the olivine rim was caused by the inverse reaction caused by the diminishing the pyroxene stability field during magma ascent and decompression. In all types of the examined cumulates, except for chromitites, widespread relicts of intercumulus pores filled with phosphorus-rich olivine were discovered. These pores were suggested to form near the lower solidification front, when the compaction of the evolving cumulate pile was stopped. The enrichment of the pore olivine in phosphorus may indicate an increase in the degree of supersaturation/supercooling of the porous melt with respect to olivine accompanied by an increase in the olivine growth rate at the late stages of solidification.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"710 - 732"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Studies of Basaltic Melt Contamination by Sedimentary Rocks","authors":"A. V. Kostyuk,&nbsp;N. S. Gorbachev,&nbsp;M. P. Novikov,&nbsp;A. N. Nekrasov","doi":"10.1134/S0869591125700249","DOIUrl":"10.1134/S0869591125700249","url":null,"abstract":"<div><p>The results of experimental study of basaltic melt interaction with different types of sedimentary rocks of the platform shield of the Norilsk region are presented. To study the contamination of basaltic melt with host rocks, the following rocks were used in the experiments: Mokulaev basalt, sandy mudstone, pyrite-bearing sandstone with carbonaceous matter, bituminous dolomite, and marl–anhydrite rock. The experiments were carried out at the Korzhinskii Institute of Experimental Mineralogy of the Russian Academy of Sciences (IEM RAS) in a high-temperature furnace at 1 atm, 1250°C. The phase and chemical composition of the coexisting mineral associations and melts were studied, and geochemical and isotopic data on the starting and experimental products were given. It was found that the contamination of basaltic melt with sulfur- and carbon-bearing rocks of the platform cover of the Norilsk region can lead to silicate–sulfide liquid immiscibility, differentiation, and high ore potential of the trap magma. Results of experimental studies can be used to develop criteria for prospecting and forecasting of sulfide magmatic deposits.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"604 - 617"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solubility of Pyrochlore-Supergroup Minerals in Supercritical Aqueous Fluoride Solutions","authors":"A. F. Redkin,&nbsp;N. P. Kotova,&nbsp;Yu. B. Shapovalov,&nbsp;N. N. Akinfiev","doi":"10.1134/S0869591125700274","DOIUrl":"10.1134/S0869591125700274","url":null,"abstract":"<p>Experimental data on the solubility of niobium and tantalum oxides and oxyfluorides in fluoride solutions were reviewed. Experimental solubility data for pyrochlore (CaNa)Nb₂O₆F and microlite (CaNa)Ta₂O₆F were used to calculate their thermodynamic properties at 300–800°C. The thermodynamic properties of albite, andalusite, muscovite, paragonite, and pyrophyllite were refined in the temperature range 300–550°C. The influence of solution composition and aluminosilicate mineral association on the solubility of pyrochlore and microlite in the supercritical region of physicochemical parameters was modeled by thermodynamic calculations. The calculations showed that the solubility of the minerals is very low, and niobium and tantalum cannot be removed by metamorphosed solutions. Mechanisms were proposed for HF accumulation, which could play an important role in niobium and tantalum dissolution, as well as recrystallization and replacement of ore mineral phases over limited distances.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 6","pages":"659 - 677"},"PeriodicalIF":1.1,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145659292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Investigation of Cation Exchange Equilibria of the Gallium Feldspar Solid Solution (K, Rb)GaSi3O8 with KCl–RbCl–H2O Fluids at 550°C and 1.5 kbar with Applications to the Description of the Properties of Solid Solutions with the Feldspar Structure","authors":"A. R. Kotelnikov,&nbsp;N. I. Suk,&nbsp;Z. A. Kotelnikova,&nbsp;G. M. Akhmedzhanova,&nbsp;N. A. Drozhzhina","doi":"10.1134/S0869591125700183","DOIUrl":"10.1134/S0869591125700183","url":null,"abstract":"<p>Feldspars of the KGaSi₃O₈–RbGaSi₃O₈ series were synthesized at 550°C and 1.5 kbar, and their exchange reactions with 1 M KCl + 1 M RbCl solution were investigated. Using the experimental data, Margules parameters were calculated for the description of the excess mixing energies of the (K,Rb)GaSi₃O₈ solid solution: <i>W</i>^<i>G</i>1 = <i>W</i>^<i>G</i>2 = 4.46 ± 0.11 kJ/mol. We refined the unit-cell parameters of the solid solutions; the excess mixing volume is described by the Margules model: <i>W</i>^<i>V</i>1 = 2.647 ± 0.05 and <i>W</i>^<i>V</i>2 = –0.883 ± 0.04 cm³/mol. The results were compared with feldspars studied previously. Empirical relations were proposed for the calculation of the energy Margules model and unit-cell volumes for various minerals with the feldspar structure.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 5","pages":"437 - 453"},"PeriodicalIF":1.1,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trace-Elements Partitioning between Phases in the System P2O5–CaO–Na2O ± (SiO2 + Al2O3)–F–H2O–CO2 at 500 MPa","authors":"I. T. Rass,&nbsp;A. G. Polozov,&nbsp;K. I. Shmulovich","doi":"10.1134/S0869591125700146","DOIUrl":"10.1134/S0869591125700146","url":null,"abstract":"&lt;p&gt;The distribution of Ti, Zr, Nb, La, Sm, Yb, and Y was experimentally studied between phosphate−carbonate melts, silicate-bearing melts (with the addition of silicate to the starting mixtures) and minerals: apatite Ca&lt;sub&gt;5&lt;/sub&gt;(PO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;F, fluorite CaF&lt;sub&gt;2&lt;/sub&gt;, and nacaphite (Na&lt;sub&gt;2&lt;/sub&gt;Ca(PO&lt;sub&gt;4&lt;/sub&gt;)F). Four series of experimental runs were carried out in an internally heated gas pressure vessels (IHPV) at a pressure of 500 MPa, using four types of starting mixtures: (1) Ca&lt;sub&gt;5&lt;/sub&gt;(PO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;F) + CaCO&lt;sub&gt;3&lt;/sub&gt; + Na&lt;sub&gt;2&lt;/sub&gt;CO&lt;sub&gt;3&lt;/sub&gt; ± NaAlSiO&lt;sub&gt;4&lt;/sub&gt; at 1100–750°C; (2) Ca&lt;sub&gt;5&lt;/sub&gt;(PO&lt;sub&gt;4&lt;/sub&gt;)&lt;sub&gt;3&lt;/sub&gt;F + CaCO&lt;sub&gt;3&lt;/sub&gt; + NaF ± NaAlSiO&lt;sub&gt;4&lt;/sub&gt; at 950°C; (3) NaPO&lt;sub&gt;3&lt;/sub&gt; + CaCO&lt;sub&gt;3&lt;/sub&gt; + CaF&lt;sub&gt;2&lt;/sub&gt; + NaF ± NaAlSiO&lt;sub&gt;4&lt;/sub&gt; at 900°C; and (4) NaPO&lt;sub&gt;3&lt;/sub&gt; + CaCO&lt;sub&gt;3&lt;/sub&gt; + NaF ± NaAlSiO&lt;sub&gt;4&lt;/sub&gt; at 900°C with variable proportions of P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;, CaO, Na&lt;sub&gt;2&lt;/sub&gt;O, and SiO&lt;sub&gt;2&lt;/sub&gt;. H&lt;sub&gt;2&lt;/sub&gt;O (~5 mL), H&lt;sub&gt;2&lt;/sub&gt;C&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; (~1.5 mg), and a 3-mg mixture of trace-element oxides were added in equal mass proportions to all starting compositions. The experimental products were analyzed by electron probe microanalysis. Depending on the CaO and P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; proportion&lt;sub&gt;,&lt;/sub&gt; the silicate-free starting mixtures in three former series yielded two types of quenched melts: (i) calcite-rich melt with 20 mol % Na&lt;sub&gt;2&lt;/sub&gt;O at a lower P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; content and (ii) sodic carbonate−phosphate melt with a low CaO concentration at higher P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; content and with up to 20 wt % CaO. The solubility of ZrO&lt;sub&gt;2&lt;/sub&gt;, TiO&lt;sub&gt;2&lt;/sub&gt;, and Nb&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; in the calcite-rich quenched melts at 750°C is low and limited by the crystallization of Zr, Ti, and Nb oxides. At 950°C, these oxides did not form, and the concentrations of ZrO&lt;sub&gt;2&lt;/sub&gt;, TiO&lt;sub&gt;2&lt;/sub&gt;, and Nb&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; increased in the melts with increasing P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt;/(P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; + CaO) ratio. REE concentrations (in wt %) in the apatite and coexisting Ca-rich carbonate melt increased with increasing P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; content from 0.2 to 0.9 for La&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, from 0.25 to 0.75 for Sm&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, from 0.2 to 0.6 for Yb&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, and from 0.2 to 0.4 for Y&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, reaching 0.5 in a single run. In the runs of series IV, the nepheline-bearing starting mixtures yielded two immiscible melts: (1) SiO&lt;sub&gt;2&lt;/sub&gt;-free sodic phosphate-rich melt with apatite and nepheline in run IV-7 and (2) aluminosilicate melt. Run IV-8 produced two immiscible melts, sodic−phosphate and silicate, with a P&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; content in the silicate melt no higher than 25 wt %. Concentrations of TiO&lt;sub&gt;2&lt;/sub&gt;, ZrO&lt;sub&gt;2&lt;/sub&gt;, and Nb&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; are much higher in the phosphate-rich melt ","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"33 5","pages":"470 - 488"},"PeriodicalIF":1.1,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145204609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}