Petrology最新文献

{"title":"Olivine from Alkali Ultramafic Rocks of the Izhmozero Pipe: Multistage Melt Evolution from Kimberlite to Melanephelinite","authors":"A. V. Kargin,&nbsp;L. V. Sazonova,&nbsp;A. A. Nosova,&nbsp;I. R. Prokopyev,&nbsp;N. M. Lebedeva,&nbsp;E. V. Yutkina,&nbsp;K. G. Erofeeva,&nbsp;E. V. Kovalchuk,&nbsp;V. O. Goryunova,&nbsp;V. D. Shcherbakov","doi":"10.1134/S0869591125700365","DOIUrl":"10.1134/S0869591125700365","url":null,"abstract":"<p>This paper reports the petrographic and geochemical characteristics of olivine from the ultramafic alkaline rocks of the Izhmozero pipe, Arkhangelsk Diamond Province, which are used to reconstruct the evolution of alkali ultramafic melts of the province from Fe–Ti-rich kimberlite to Mg–Al-rich rocks approaching melanephelinite. Based on the morphology and composition of olivine cores, three types of macrocrysts were identified: (1) <i>Ol</i>-I with the least magnesian cores (Mg# 0.904–0.913), high Ni (2856–3135 ppm) and Ti (84.2–120 ppm), moderate Ca (417–607 ppm) and Mn (829–986 ppm), V/Sc of 1.7–1.8, and diffusive transitional zones; (2) <i>Ol</i>-II with moderately magnesian cores (Mg# 0.923–0.927), high Ni (3041–3177 ppm), moderate Mn (875–1035 ppm) and Ca (557–872 ppm), low Ti (6.01–17.9 ppm), V/Sc = 1.16, and reaction zones along the core–rim boundary; and (3) <i>Ol</i>-III with highly magnesian cores (Mg# 0.935–0.948), high Ni (2692–3234 ppm), Mn (973–1451 ppm), and Ca (1461–2266 ppm), moderate Ti (39.3–70.1 ppm) and Al (175–227 ppm), and low V/Sc (0.17–0.24). Olivine macrocrysts of the <i>Ol</i>-I and <i>Ol</i>-III types have oscillatory rim zones, and outer reaction margins are characteristic of all olivine types. <i>Ol</i>-I macrocrysts are interpreted as products of interaction between a silicate–carbonate alkali-ultramafic melt (kimberlitic or aillikitic) and the lithospheric mantle at an early stage of melt ascent or as early phases crystallizing from such melts. <i>Ol</i>-II macrocrysts are rare and were derived from the depleted lithospheric mantle of the Arkhangelsk Diamond Province, but their compositions were modified by the alkali-ultramafic melts transporting them. After the formation of <i>Ol</i>-I, the ascending melt evolved toward a more magnesian composition owing to fractionation of Fe–Ti phases under changing <i>P–T–</i><span>({{f}_{{{{{text{O}}}_{2}}}}})</span> conditions. This process increased the Mg# of melt and resulted in the development of transitional zones on <i>Ol</i>-I cores owing to diffusive reequilibration and subsequent crystallization of high-Mg# <i>Ol</i>-III. After <i>Ol</i>-III formation, the melts that produced the Izhmozero rocks experienced contamination with ancient crustal material, which shifted their composition toward melanephelinite. These observations suggest that the formation of Mg–Al-rich rocks of the Izhmozero type within the Arkhangelsk Diamond Province was controlled not only by source characteristics, but also by hybridization processes at a lower crustal level.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 2","pages":"181 - 211"},"PeriodicalIF":1.1,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631733","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":"The 95th Birthday of Viktoriya Abbasovna Kononova","authors":"Editorial Board","doi":"10.1134/S0869591125700407","DOIUrl":"10.1134/S0869591125700407","url":null,"abstract":"","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 2","pages":"89 - 90"},"PeriodicalIF":1.1,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631729","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":"Alkaline Мagmatism of the Southern Siberian Craton: Stages of Formation and Mantle Sources (A Review)","authors":"A. G. Doroshkevich,&nbsp;I. A. Izbrodin,&nbsp;V. M. Savatenkov,&nbsp;A. E. Izokh,&nbsp;I. R. Prokopyev,&nbsp;A. V. Ponomarchuk,&nbsp;E. A. Zubakova,&nbsp;Ya. N. Nugumanova,&nbsp;M. N. Kruk,&nbsp;A. V. Malyutina","doi":"10.1134/S0869591125700353","DOIUrl":"10.1134/S0869591125700353","url":null,"abstract":"<div><p>A review of geochronological, geochemical, and isotopic data on the alkaline complexes and massifs of different ages (1.91–1.88 Ga, 660–630, 400–370, 310–290, 250–240 and 150–113 Ma) of the southern margin of the Siberian Craton is presented. The geochemical and isotopic characteristics of Paleoproterozoic, Late Paleozoic, and Mesozoic alkaline complexes indicate the formation of rocks from a metasomatized lithospheric mantle, which was reworked in the Late Archean–Early Proterozoic during the formation of the continental lithosphere of the Siberian Craton. The isotopic and geochemical features of the above-mentioned alkaline rocks characterize slightly different geochemical enviroment of the processes that led to the formation of the ancient lithosphere of the Siberian Craton. Isotopic characteristics of the Neoproterozoic and Triassic alkaline complexes reveal a dominant contribution of the asthenospheric component. Their magmatism was controlled by tectonic processes related to the Rodinia supercontinent breakup, which provided an influx of asthenosphere, and by plume process.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 2","pages":"91 - 109"},"PeriodicalIF":1.1,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631732","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":"Mesozoic Alkaline Syenite Porphyries of the Lamproite Series in the Gold-Bearing South Uguy Zone (Western Aldan): a Petrological Study","authors":"O. E. Karavaeva,&nbsp;A. V. Samsonov,&nbsp;K. G. Erofeeva,&nbsp;Yu. O. Larionova,&nbsp;A. V. Travin,&nbsp;L. V. Sazonova,&nbsp;E. Yu. Anikina,&nbsp;N. N. Korotaeva,&nbsp;D. A. Rylov","doi":"10.1134/S0869591125700390","DOIUrl":"10.1134/S0869591125700390","url":null,"abstract":"<div><p>The study presents petrographic, geochronological, and isotopic-geochemical data on the Mesozoic alkaline pyroxene–amphibole syenite porphyries in the Uguy graben, western Aldan Shield, East Siberia. These syenites represent the earliest (~145 Ma) and the most mafic group of alkaline magmatic rocks associated with gold mineralization in the South Uguy gold-bearing zone. The syenite porphyries show ultrapotassic, agpaitic geochemical signatures, in line with a phonolitic composition. Mafic microgranular enclaves (MMEs) within the syenite porphyries exhibit the most primitive tephryphonolite composition, thus represent remnants of early melt. Analysis of the phenocryst assemblages (clinopyroxene + amphibole + alkaline feldspar + fluorapatite) enables the reconstruction of the multi-stage evolution of the syenitic melt, spanning depths from the lower crust to a shallow magma reservoir. Based on petrographic and mineral thermobarometry data, it was established that the early phenocryst assemblages (clinopyroxene + fluorapatite + leucite?), which was in equilibrium with the MMEs, crystallized at <i>Т</i> = 1200°С and <i>Р</i> = 10–15 kbar. Two-stage numerical modeling of the system “parental magma = cumulate + residual meltˮ by a least-square mass-balance calculation established that syenitic melt likely formed through the crystal fractionation of more primitive parent melt close in composition to Early Cretaceous lamproites of the Murun massif located 100 km north of the study area. Sr-Nd isotopic composition of the syenite porphyries and lamproites indicates that the alkaline magmas originated from a metasomatized lithospheric mantle source. This source experienced two-stage enrichment in incompatible elements: in the Paleoproterozoic via intraplate and supra-subduction processes and in the Mesozoic during tectonic evolution of the Mongol-Okhotsk Orogenic Belt.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 2","pages":"162 - 180"},"PeriodicalIF":1.1,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631734","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":"Petrology of the Chik Alkaline Massif, Sangilen Highland, Tyva","authors":"N. A. Polyakov,&nbsp;A. V. Nikiforov,&nbsp;E. O. Dubinina,&nbsp;S. A. Kossova,&nbsp;A. K. Khertek,&nbsp;V. D. Abramova,&nbsp;E. A. Minervina","doi":"10.1134/S0869591125700389","DOIUrl":"10.1134/S0869591125700389","url":null,"abstract":"<p>The paper presents results of a petrological study of the Chik alkaline massif in the Sangilen Highland, Tyva: data on the chemical composition of the melteigites, ijolites, urtites, their calcite varieties, carbonatite-like silicate–carbonate rocks composing the massif, the host and contact-reaction rocks, and rock-forming minerals (clinopyroxene, nepheline, and high-Ti garnet). Data are presented on the O, C, S, and Sr isotopic composition of rocks and minerals of the massif. The data indicate a magmatic origin of the urtites, melteigites, calcite melteigite-urtites, and silicate–carbonate and garnet rocks, which have been previously thought to be metasomatic. A petrological model is proposed for the formation of the Chik massif, according to which the massif formed as a result of the assimilation of carbonate material from the host rocks by alkaline magma.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 2","pages":"136 - 161"},"PeriodicalIF":1.1,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147631737","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":"Mesoproterozoic Picrite–Picrobasalt Volcanism of the Ishimba–Tatarka Suture Zone: Petrogeochemistry, Metamorphism of the Rocks, and Rb–Sr and 147Sm–143Nd ID-TIMS Systematics","authors":"P. S. Kozlov,&nbsp;A. D. Nozhkin,&nbsp;I. I. Likhanov,&nbsp;S. V. Zinoviev,&nbsp;V. V. Reverdatto,&nbsp;Yu. L. Ronkin,&nbsp;A. A. Krylov","doi":"10.1134/S0869591125700304","DOIUrl":"10.1134/S0869591125700304","url":null,"abstract":"<div><p>The Early Mesoproterozoic (1370 Ma) age is substantiated for the picrite–picrobasaltic volcanism associated with the formation of the riftogenic Ishimba–Tatarka suture zone (paleorift) in the southwestern Siberian craton. First Rb–Sr and ¹⁴⁷Sm–¹⁴³Nd data are presented on the late Precambrian metavolcanogenic-sedimentary rocks ascribed to the Rybinsk–Panimba volcanic belt in the central part of the northern Yenisei Ridge. According to petrogeochemical composition, the protoliths of the metavolcanic rocks correspond to picrobasalts and basalts, more rarely, to picrites. The volcanogenic-sedimentary sequence in different areas rests on the same marker horizon of carbonaceous shales, which allows us to correlate the age of the Panimba volcanogenic sequence with the Korda Formation, regarding these formations at the Early Mesoproterozoic stratolevel. Geothermobarometry and analysis of features of regional metamorphism of volcanogenic-sedimentary rocks in the reference areas show uneven <i>P–T</i> conditions of transformation of the initial rocks: 4.8–4.9 kbar/527–549°C for picrobasaltic metatuffites; 5.0–5.8 kbar/543–612°C for metamafic rocks; and 3.5–4.6 kbar/522–636°C for metapelites. Based on the age (1056–996 Ma), the metamorphism is close to the Grenville tectonic epoch. The established age of picrite–picrobasalt volcanism in the Precambrian of the Yenisei Ridge correlates with the time of manifestation of trondhjemites of the Nemtikha complex and with the reference Mashak plume magmatism in the South Urals, which were formed in an intracontinental extensional geodynamic setting during the breakup of the Nuna supercontinent.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 1","pages":"38 - 60"},"PeriodicalIF":1.1,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147338664","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 Study of High-Temperature Transformations in Charoitites","authors":"A. M. Ionov,&nbsp;K. A. Gavrilicheva,&nbsp;O. I. Barkalov,&nbsp;A. N. Nekrasov,&nbsp;E. Yu. Dokuchits","doi":"10.1134/S086959112570033X","DOIUrl":"10.1134/S086959112570033X","url":null,"abstract":"<p>This paper reports the investigation of transformations occurring during heating of charoite minerals. Charoite rocks with different color characteristics (lilac, brown, and white asbestiform charoite referred to as charoite-asbestos in the Russian literature) were investigated using mass spectrometry, differential scanning calorimetry and thermogravimetry (DSC–TG), scanning electron microscopy (SEM), <i>X</i>-ray diffraction, and Raman spectroscopy. The charoites were heated up to 1200°C. During heating, dehydration and dehydroxylation of lilac, brown, and white charoites were observed in the temperature range 50–500°C. The release of H₂O and OH-groups with an endothermic effect of Δ<i>H</i> = 58 J/g was also detected in white charoite-asbestos at 720–800°C. Our study demonstrated that charoite gradually transforms to wollastonite and, then, to pseudowollastonite at temperatures above 900°C.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 1","pages":"80 - 87"},"PeriodicalIF":1.1,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147338665","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":"Esmeralda Submarine Volcano, Southern Mariana Island Arc: Geochemistry and Petrogenesis of Igneous Rocks","authors":"P. I. Fedorov,&nbsp;V. A. Rashidov,&nbsp;V. V. Ananiev","doi":"10.1134/S0869591125700316","DOIUrl":"10.1134/S0869591125700316","url":null,"abstract":"<p>The paper presents data on the mineralogy and petrochemistry of basaltoids, dacite, and gabbro dredged from Esmeralda submarine volcano, southern Mariana island arc, during Cruises 4 and 5 of the R/V <i>Vulkanolog.</i> The basaltoids and gabbros of the tholeiitic series are highly fractionated rocks, in contrast to most of the studied rocks from submarine volcanoes and basins in the southern Mariana island-arc system. The rocks contain elevated iron concentrations. The elevated Fe# is consistent with the high Fe content of the pyroxenes and plagioclase, which classes most of the dredged rocks with the association of arc ferrotholeiites. Similar to the basaltoids, the dacite sample contains both an elevated Fe content and a high Fe₂O₃ concentration in plagioclase, suggesting that the dacite may be genetically related to the dredged basaltoids. The lower concentrations of high-field strength (HFSE) and heavy rare earth (LREE) elements in the rocks than in N-MORB suggest that their parental melts were derived from a depleted mantle source at a spinel-facies depth level. The high FeO_total/MnO values and discriminant petrochemical characteristics suggest that the deep source contained pyroxenite. The enrichment of the basaltoids and gabbro in large-ion lithophile elements (LILE) and the correlations between some elemental ratios (Th/Nb, Ba/Nd, Ba/Yb, Th/Yb, etc.) indicate that the magma was generated in the presence not only of a low-temperature fluid component but also of a high-temperature magmatic melt, produced by the melting of sedimentary rocks.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 1","pages":"61 - 79"},"PeriodicalIF":1.1,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147338661","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":"Conditions of Primary Kimberlite Melt Formation by Partial Melting of Carbonated Mantle: Estimates from Experimental Data","authors":"V. K. Bulatov,&nbsp;A. V. Girnis","doi":"10.1134/S0869591125700341","DOIUrl":"10.1134/S0869591125700341","url":null,"abstract":"<p>Two experimental approaches are used to estimate the conditions of kimberlite melt generation. (1) Investigation of partial melting of carbonated ultramafic rocks. (2) Determination of the conditions of the stability of polymineralic assemblages on the kimberlite liquidus. The analysis of available experimental data and estimates of the compositions of primary kimberlite melts showed that the residual mineral assemblage during kimberlite generation included, probably, olivine, low-Ca pyroxene, and garnet. The approximation of experimental data on the compositions of melts equilibrated with such an association allowed us to calculate pressure in the melt generation zone and CO₂ content in the primary melt. Using the obtained relationships, equilibrium parameters were calculated for the supposed primary kimberlite melts, and it was argued that they could be produced by partial melting of carbonated peridotite at pressures of 40–90 kbar and temperatures of 1600–1800°C. The real temperatures could be significantly lower because of the presence of water and other volatiles. The calculations demonstrated that the primary melts contained 10–20 wt % CO₂ and were not saturated with respect to high-Ca pyroxene and magnesite. The retention of magnesite in the residue requires an increase in melt CO₂ content up to ~30 wt %, whereas the equilibrium with olivine and low-Ca pyroxene imposes high SiO₂ content (~15 wt %) and high temperature of deep melts, much above a normal cratonic geotherm.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 1","pages":"1 - 18"},"PeriodicalIF":1.1,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147338666","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":"Roots of a Collapsed Paleoproterozoic Island Arc in the Volga−Don Ocean, East Sarmatian Composite Terrane: Geochemistry, Age, and Petrogenesis","authors":"K. A. Savko,&nbsp;A. V. Samsonov,&nbsp;D. A. Goncharov,&nbsp;R. A. Terentiev,&nbsp;A. N. Larionov,&nbsp;E. Kh. Korish","doi":"10.1134/S0869591125700328","DOIUrl":"10.1134/S0869591125700328","url":null,"abstract":"<p>The Archean Varvarinsky block was distinguished in the southern Vorontsovka terrane of Eastern Sarmatia in the late 1960s. It was proved to consist of Paleoproterozoic I-type sodic diorites and granodiorites dated at 2.09 Ga. Isotopic and geochemical characteristics of its rocks (highly radiogenic Nd composition, enrichment in Cr and Ni, depletion in LILE, HFSE, and LREE, as well as low Sr/Y values) suggest their island-arc nature. The sources were aqueous melts from the mantle wedge, metasomatized by fluids during the melting of a subducted oceanic slab, followed by fractionation in intermediate chambers. The finds of the most ancient precollisional granitoid intrusions provide direct evidence that island arc structures occurred in the Volga−Don Ocean and were composed of calc-alkaline volcanics of basalt−andesite−dacite−rhyolite (BADR) composition. They are the intrusive roots of the destroyed volcanic island arcs produced during the subduction of oceanic slabs in the Volga−Don Ocean.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"34 1","pages":"19 - 37"},"PeriodicalIF":1.1,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147338663","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}