Petrology最新文献

{"title":"Petrogenesis and Metallogeny of Intrusive Aplite Dyke from the Malanjkhand Pluton, Central India","authors":"Dinesh Pandit","doi":"10.1134/S086959112301006X","DOIUrl":"10.1134/S086959112301006X","url":null,"abstract":"<p>The relationships between textural variations and structural trends of the aplite dyke enclosed in the Malanjkhand pluton were investigated in this study. The estimated zircon saturation temperature (747–835°C) and pressure of crystallization (2.5–6.1 kbar) suggested that the aplite dyke was emplaced in the lower-middle level in the continental crust. Water solubility calculations indicated that the aplite dyke originated from the silicic magma under water undersaturated conditions. Primitive mantle normalized spider diagram showed enrichment of large-ion lithophile elements (LILEs) and depletion of high field strength elements (HFSEs). The aplite dyke displayed LREE-enriched and MREE-depleted patterns, with significant positive Eu-anomaly in the REE patterns. This observation alluded the accumulation of plagioclase crystals before the crystallization of felsic magma in the reduced environment. The presence of the positive Eu-anomaly signified that the pre-existing granitic source at the lower-middle level of the crust generated aplitic magma owing to partial melting above the felsic source rock. Trace element discrimination diagrams presented evidence for possible extensional tectonic settings coupled with felsic magmatic episodes and granitic plutonic activity in a continental rift environment, thus favoring the emplacement of the aplite dyke. Th/U ratios in the aplite dyke implied that the melt fractionation in the magma chamber and the post-magmatic hydrothermal processes exerted negligible effect on the crystallization evolution of the aplitic magma. The aplite dyke pointed to a single pulse of silicic magmatism and a continuous process of injection, thus reflecting subtle variations in the physical conditions of the formation of the host Malanjkhand pluton.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S140 - S156"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4830821","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":"Condensate in Impact Glass Samples from the Lonar Crater, India","authors":"T. A. Gornostaeva,&nbsp;A. V. Mokhov,&nbsp;A. P. Rybchuk,&nbsp;P. M. Kartashov","doi":"10.1134/S0869591123010046","DOIUrl":"10.1134/S0869591123010046","url":null,"abstract":"<p>Polycomponent condensate glasses found in nature provide an insight into condensation mechanisms, which are still understood inadequately poorly. Condensate glasses found in the impactites of the Lonar crater contain nanosized inclusions of metallic Fe, Cr, Cu, Zn, Ag, In, Te, Au, Pt, and Bi, along with Fe, Cu, and Zn sulfides. This combination may be indicative either of a brief condensation window for the almost simultaneous condensation of components with so different fugacity or of a possible mechanism of cluster condensation, provided that the condensation temperatures of such clusters are close.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S131 - S139"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5130070","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":"Crystallization Parameters, Genesis of Melts, and Sources of Magmas of the Late Cenozoic Udokan Volcanic Plateau, Central Asia","authors":"V. V. Yarmolyuk,&nbsp;V. M. Savatenkov,&nbsp;A. M. Kozlovsky,&nbsp;F. M. Stupak,&nbsp;M. V. Kuznetsov,&nbsp;L. V. Shpakovich","doi":"10.1134/S0869591123010101","DOIUrl":"10.1134/S0869591123010101","url":null,"abstract":"<p>Similar to the other areas of the Late Cenozoic volcanic province of Central Asia, the Udokan volcanic plateau (UVP) was formed in the time span between the Middle Miocene and the Pleistocene. Its rocks are highly alkaline and vary from alkaline picrobasalts and basanites to alkaline trachytes. The compositional variations of the rocks were controlled by two differentiation trends, which corresponded to different generation conditions of the parental magmas. The rocks with low SiO₂ contents (&lt;45 wt %) were formed by melts of low degrees of melting, whose melts were derived under elevated pressures and temperatures. The formation of the rocks with 45–61 wt % SiO₂ was associated with the differentiation of basalt melts, which were derived at shallower depths and at lower temperatures. The geochemical characteristics of the UVP basaltoids make them similar to OIB-type basalts. They are also close in Sr, Nd, and Pb isotopic composition, corresponding to the parameters of the moderately depleted mantle, which is close to the composition of oceanic basalt sources corresponding to the mantle of deep mantle plumes. The corresponding mantle component is present in the sources of other volcanic regions of the Late Cenozoic intraplate volcanic province in Central Asia, which indicates that the material of a lower mantle plume was involved in the formation of these regions.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S1 - S24"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4834275","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":"Ti and Cr in High-Pressure Mica: Experimental Study and Application to the Mantle Assemblages","authors":"A. A. Bendeliani,&nbsp;A. V. Bobrov,&nbsp;L. Bindi,&nbsp;N. N. Eremin","doi":"10.1134/S0869591123010113","DOIUrl":"10.1134/S0869591123010113","url":null,"abstract":"<p>Experiments aimed at the synthesis of Cr- and Ti-bearing phlogopite in the silicate-carbonate systems peridotite—K₂CO₃ + H₂O and basalt—K₂CO₃ + H₂O at 7 GPa and 900–1200°С were carried out. It is shown that the crystallization of titanium-bearing phlogopite requires subducted crustal material at mantle depths. However, the mantle peridotite should predominate over basalt for Ti-phlogopite crystallization; otherwise, dioctahedral mica (aluminoceladonite) with (Mg + Fe)/^VIAl &gt; 1 is formed via the scheme 2^VIAl = ^VITi⁴⁺ + ^VI(Mg + Fe). The competitive behavior of Ti and Cr upon incorporation into phlogopite is considered. It is shown that the presence of &gt;1.3 wt % TiO₂ introduces a limitation on the high concentrations of Cr₂O₃ via the scheme ^VI(Mg²⁺) + ^IV(Si⁴⁺) = ^VI(Cr³⁺) + ^IV(Al³⁺). This can explain the compositional patterns of phlogopite from inclusions in natural diamonds, in which the Ti content is much higher than that of Cr. The results obtained support the original idea that the composition of phlogopite may be applied to distinguish the paragenetic associations of diamond.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S157 - S173"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4829485","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 Monticellite-bearing Rocks of the Krestovskaya Intrusion: Genesis according to Melt Inclusion Study","authors":"L. I. Panina,&nbsp;A. T. Isakova,&nbsp;E. Yu. Rokosova","doi":"10.1134/S0869591123010071","DOIUrl":"10.1134/S0869591123010071","url":null,"abstract":"<div><p>The investigation of monticellitolites and olivine–monticellite rocks from the Krestovskaya Intrusion shows that the major minerals (olivine and monticellite) have higher MgO content than the same minerals in olivinites and kugdites of the intrusion. In the studied rocks olivine contains 90–93 mol % <i>Fo</i> and monticellite has 41.6–42.3 mol % <i>Fo,</i> whereas olivine and monticellite in olivinites and kugdites contain 86–87 and 37.2–41.2 mol % <i>Fo</i>, respectively. Melt inclusion study in minerals of monticellite rocks demonstrates that the monticellite rocks of the Krestovskaya Intrusion were formed by mixing of volatile-rich melts of different composition: K-rich high-iron low-alumina kamafugitic melt and Na-rich high-magnesium high-alumina picritic melt. Minerals crystallized at high temperatures in the following sequence: perovskite I (1250–1230°C) → perovskite II (≥1200°C) ↔ olivine (&gt;1200°C) → monticellite (&gt;1150°C). Perovskite I in monticellite rocks, as well as olivine in olivinites, crystallized from K-rich high-iron (Mg# = MgO/(MgO + FeO) = 0.37), low-alumina kamafugitic melt. During crystallization of late perovskite II in the monticellite rocks, the melt became more enriched in MgO (Mg# = 0.41) and richer in Na₂O and Al₂O₃, which is intermediate in composition between kamafugite and alkali picrite. Olivine in the monticellite rocks crystallized from melts similar in composition to melilitite, having a K-rich composition with Mg# = 0.39, whereas monticellite formed from a heterogeneous high-Mg Si-undersaturated melt, which is highly enriched with volatile components (including H₂O) and salts. The crystallization of minerals was accompanied by subsequent accumulation of volatile components in mixing melts, silicate–carbonate liquid immiscibility under 1250–1190°C, and polyphase carbonate–salt immiscibility under below 1190°C. In the latter event, the exsolved carbonate melt began to split into simpler immiscible fractions: alkali–sulfate–carbonate, alkali–phosphate–carbonate, and calcio–carbonate.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S101 - S118"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4834277","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":"Staurolite in Metabasites: P–T–X Parameters and the Ratios of Major Components as Criteria of Staurolite Stability","authors":"E. B. Borisova,&nbsp;Sh. K. Baltybaev,&nbsp;J. A. D. Connolly","doi":"10.1134/S0869591123010034","DOIUrl":"10.1134/S0869591123010034","url":null,"abstract":"<p>Fe–Mg staurolite is a typical and widespread mineral of medium-temperature high-alumina metapelites, whereas magnesian staurolite is only relatively rarely found in metamorphosed mafic rocks (metabasites). The most significant factors controlling staurolite stability in metabasites were identified by thermodynamic modeling and analysis of the common features of the mineral-forming processes. In contrast to staurolite in low- and medium-pressure metapelites, staurolite in metabasites is stable at medium- and high-pressure metamorphism. An increase in the proportion of carbon dioxide in the water–carbon dioxide fluid shifts the staurolite-forming mineral reactions to lower temperatures and higher pressures. Al, Fe, Mg, and Ca are the major components of rocks that are critically important for the formation of magnesian staurolite in these rocks, and the contents and ratios of these components are of crucial importance for the stability of staurolite in metabasites. To understand the processes forming the mineral in metabasites, it is instrumental to subdivide metabasites into subgroups of predominantly magnesian, ferruginous–magnesian, and ferruginous protoliths. With regard to this subdivision, three petrochemical modules are proposed in the form of ratios of major components: MgO/CaO, CaO/FM, and Al₂O₃/FM, based on which it is possible to predict the stability of staurolite in mafic rocks at appropriate <i>P–T</i> parameters of metamorphism.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S53 - S71"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4829855","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":"Grenville and Valhalla Tectonic Events at the Western Margin of the Siberian Craton: Evidence from Rocks of the Garevka Complex, Northern Yenisei Range, Russia","authors":"I. I. Likhanov","doi":"10.1134/S0869591123010058","DOIUrl":"10.1134/S0869591123010058","url":null,"abstract":"<p>Understanding the tectonic evolution of the Yenisei Range offers important clues not only for the tectonic evolution of orogenic belts at margins of ancient cratons but also for solving the problem of the incorporation of the Siberian craton into the Rodinia supercontinent. Results of mineralogical−petrological, geochemical, and isotope–geochemical studies provide an insight into the petrogenesis, geotectonic settings, thermodynamic parameters of formation, and the ages of the metamorphism and protoliths for the contrastingly compositionally different rocks of the Garevka metamorphic complex. The paper discusses the possible models for the origin of the rock complexes and the geodynamic settings in which they were formed. The western margin of the Siberian craton was determined to have been affected by two pulses of Neoproterozoic endogenic activity, which were related to the origin of the Rodinia supercontinent (930–900 and 880–845 Ma), and which correlated with Grenville and post-Grenville processes responsible for Valhalla folding. The regional geodynamic history is correlated with the coeval sequence and similar style of tectono−thermal events in the peripheries of the large Precambrian cratons Laurentia and Baltica, which is consistent with the proposed Neoproterozoic paleogeographic reconstructions of close spatiotemporal relationships between these cratons and their incorporation into Rodinia configuration.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S72 - S100"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4830802","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":"Carbonation of Serpentinites of the Mid-Atlantic Ridge: 1. Geochemical Trends and Mineral Assemblages","authors":"S. A. Silantyev,&nbsp;E. A. Krasnova,&nbsp;D. D. Badyukov,&nbsp;A. V. Zhilkina,&nbsp;T. G. Kuzmina,&nbsp;A. S. Gryaznova,&nbsp;V. D. Shcherbakov","doi":"10.1134/S0869591123010095","DOIUrl":"10.1134/S0869591123010095","url":null,"abstract":"<div><p>Abyssal peridotite outcrops compose vast areas of the ocean floor in the Atlantic, Indian, and Arctic Oceans, where they are an indispensable part of the oceanic crust section formed in the slow-spreading oceanic ridges (Mid-Atlantic Ridge, Southwest Indian Ridge, and Gakkel Ridge). The final stage in the evolution of abyssal peridotites in the oceanic crust is their carbonation, which they experience on the ocean floor surface or near it. The main goal of this study was to reconstruct the geochemical trends accompanying the carbonation of abyssal peridotites using MAR ultramafic rocks as an example and to identify the main factors that determine their geochemical and mineralogical differences. The composition variations of rock-forming minerals and their characteristic assemblages indicate that the initial stages of carbonation of abyssal peridotites occurred in crustal conditions simultaneously with the serpentinization of these rocks. The final stage in the crustal evolution of the abyssal peridotites is their exhumation on the ocean floor where they were brought up along the detachment faults. On the ocean floor, the abyssal peridotites in close association with gabbro form oceanic core complexes, and the degree of their carbonation sharply increases with time of their exposure on the ocean floor. The presented data made it possible to qualitatively reconstruct the sequence of events that determined the mineralogical and geochemical features of carbonatized abyssal peridotites of the MAR.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S25 - S52"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5130083","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 Great Dyke of the Kola Peninsula as a Marker of an Archean Cratonization in the Northern Fennoscandian Shield","authors":"A. V. Stepanova,&nbsp;A. V. Samsonov,&nbsp;E. B. Salnikova,&nbsp;S. V. Egorova,&nbsp;Yu. O. Larionova,&nbsp;A. A. Arzamastsev,&nbsp;A. N. Larionov,&nbsp;M. A. Sukhanova,&nbsp;R. V. Veselovskiy","doi":"10.1134/S086959112206008X","DOIUrl":"10.1134/S086959112206008X","url":null,"abstract":"<div><p>The results of geochronological and petrological studies of the largest mafic dyke in the northern part of the Fennoscandian Shield, called the Great Dyke of the Kola Peninsula (GDK), are presented. According to U-Pb D-TIMS baddeleyite dating, the GDK crystallization age is 2680 ± 6 Ma. The age of host granites is 2.75–2.72 Ga (U-Pb, zircon, SHRIMP-II). The dyke has a simple internal structure with no signs of multistage melt injection. It comprises equigranular and plagioclase-porphyritic dolerites and gabbro that are amphibolitized to varying degrees. All rocks are low-Mg (Mg# less than 0.37) with low concentrations of Cr and Ni, and were derived through differentiation of more primitive melts. The analysis of geochemical and Sr-Nd isotopic data suggests that GDK melts could be formed by mixing of two types of mantle melts: depleted asthenospheric melt and enriched melt formed via melting of a lithospheric mantle. The weakly fractionated HREE patterns indicate that primary GDK melts originated at shallow (&lt;60 km) depths outside the garnet stability field. The generation and injection of melts of the Neoarchean GDK occurred immediately after large-scale granitic magmatism and main crustal growth event in the Murmansk Craton and marked the cratonization of the continental lithosphere in the northeastern part of the Fennoscandian Shield.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 6","pages":"591 - 609"},"PeriodicalIF":1.5,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4624539","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":"А History of Coronitic Metagabbronorites in the Belomorian Province, Fennoscandian Shield: U-Pb (CA-ID-TIMS) Dating of Zircon–Baddeleyite Aggregates","authors":"E. B. Salnikova,&nbsp;A. V. Stepanova,&nbsp;P. Ya. Azimov,&nbsp;M. A. Sukhanova,&nbsp;A. B. Kotov,&nbsp;S. V. Egorova,&nbsp;Yu. V. Plotkina,&nbsp;E. V. Tolmacheva,&nbsp;A. V. Kervinen,&nbsp;N. V. Rodionov,&nbsp;V. S. Stepanov","doi":"10.1134/S0869591122060066","DOIUrl":"10.1134/S0869591122060066","url":null,"abstract":"<div><p>The estimation of crystallization and metamorphic reworking ages of mafic rocks in the polycyclic Precambrian areas is a difficult problem. Magmatic baddeleyite can be partially or completely replaced by polycrystalline zircon within a wide range of temperature and pressures, from greenschist to granulite facies. Evaluation of the age of each phase of the zircon–baddeleyite aggregates can provide information on both the age of the magmatic crystallization and metamorphism. U-Th-Pb (SHRIMP-II) and U-Pb (ID-TIMS) geochronological studies were carried out for single baddeleyite grains and zircon–baddeleyite aggregates from gabbronorites (“drusites”) of the Ambarnsky massif (Belomorian Province, Fennoscandian Shield). The petrological studies indicate the simultaneous growth of coronas at the olivine–plagioclase boundary and zircon rims around baddeleyite. U-Pb (ID-TIMS) dating of single baddeleyite grains yielded 2411 ± 6 Ma crystallization age of gabbronorites of the Ambarnsky massif. U-Pb (ID-TIMS) dating coupled with the discrete chemical abrasion give an age of 1911 ± 35 Ma for metamorphic zircon rims. The obtained results indicate that coronitic textures in the gabbronorites were formed 500 million years later than the magmatic crystallization of rocks as a result of the granulite-facies metamorphism that was probably related to the Lapland-Kola orogeny.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 6","pages":"567 - 590"},"PeriodicalIF":1.5,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4628653","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}