Petrology最新文献

{"title":"Subduction and Oceanic Magmatism Records in Plutonic Rocks of the Kamchatsky Mys Ophiolite, Eastern Kamchatka","authors":"B. A. Bazylev,&nbsp;M. V. Portnyagin,&nbsp;D. P. Savelyev,&nbsp;G. V. Ledneva,&nbsp;N. N. Kononkova","doi":"10.1134/S0869591123030025","DOIUrl":"10.1134/S0869591123030025","url":null,"abstract":"<p>The paper presents petrographic, mineralogical, and geochemical data on dunites, pyroxenites, peridotites, and gabbroids of the Kamchatsky Mys ophiolite. These data were acquired to distinguish cogenetic assemblages of igneous rocks, gain an insight into their geodynamic settings, and test various criteria of genetic links between the different magmatic rocks of ophiolites. The ultramafic and mafic rocks are shown to belong to two series, which differ in the compositions of the primary minerals, bulk rocks, and estimated trapped melts. The rocks of these series are found out to have been produced by geochemically different melts in different geodynamic settings, and during different episodes of mantle magmatism. The rocks of the high-Ti series (gabbro of the Olenegorsk massif, dunite and melanogabbro xenoliths in them, and vein gabbro in these xenoliths) crystallized from N-MORB melts in an oceanic spreading center. The rocks of the low-Ti series (dunite, pyroxenite, and gabbro veins in the residual spinel peridotites of the Mount Soldatskaya massif, as well as pyroxenite, peridotite, and gabbro alluvium and diluvium in the central and western parts of the peninsula) crystallized from water-rich boninite melts in relation to initial subduction magmatism. Taken into account the absence of boninite lavas from the Kamchatsky Mys ophiolite, the plutonic ultramafic rocks (including the rocks of the veins) might be the only evidence of subduction boninitic magmatism in the ophiolites. It was demonstrated that conclusions about the geodynamic settings of plutonic ultramafic and mafic rocks and recognition of cogenetic relations of these rocks with spatially associated basalts are more reliable when derived from the compositions of the trapped melts, which are estimated from their bulk geochemistry and primary mineral compositions, than when they are based on the mineral compositions only.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 3","pages":"338 - 357"},"PeriodicalIF":1.5,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5087076","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":"Magmatism in Kamchatka and the Kurile Islands","authors":"","doi":"10.1134/S0869591123030086","DOIUrl":"10.1134/S0869591123030086","url":null,"abstract":"","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 3","pages":"261 - 262"},"PeriodicalIF":1.5,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5088963","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":"Compositions of Kimberlite Melts: A Review of Melt Inclusions in Kimberlite Minerals","authors":"A. V. Golovin,&nbsp;V. S. Kamenetsky","doi":"10.1134/S0869591123020030","DOIUrl":"10.1134/S0869591123020030","url":null,"abstract":"&lt;p&gt;The paper presents a comprehensive review of currently available data on melt inclusions entrapped in minerals of kimberlites of different age and different provenance in ancient cratons. The crystallized melt inclusions represent snapshots of kimberlite melts at different stages of their evolution. All of the inclusions are completely crystallized and consist of daughter minerals and shrinkage bubbles, which sometimes contain low-density CO&lt;sub&gt;2&lt;/sub&gt;, but no aqueous fluids and quenched silicate glasses have been found so far. Although more than 60 mineral species have been identified among the daughter phases in the inclusions, all inclusions hosted in various minerals from different kimberlites have closely similar or even identical composition. The daughter minerals are various Na–K–Ca, Na–Ca, Na–Mg, K–Ca, Ca–Mg, Ca, Mg, and Na carbonates; Na–Mg and Na carbonates with additional anions Cl&lt;sup&gt;–&lt;/sup&gt;, &lt;span&gt;({text{SO}}_{4}^{{2 - }})&lt;/span&gt;, and &lt;span&gt;(text{PO}_{4}^{3 - })&lt;/span&gt;; and alkali sulfates, chlorides, phosphates, sulfides, oxides, and silicates. Alkali carbonates, sulfates, and chlorides are usually absent from among the groundmass phases of most kimberlites sampled worldwide, except the Udachnaya-East kimberlite in Siberia. However, this mineral assemblage, in association with such widespread kimberlite minerals as olivine, micas, monticellite, spinel-group minerals, perovskite, rutile, ilmenite, calcite, and dolomite, is common in the crystallized melt inclusions in all studied kimberlites. Carbonates (~30 to 85 vol %) always dominate over silicates (no more than 18 vol %) in all inclusions. All inclusions also contain variable (2 to 55 vol %.) amounts of chlorides (halite and sylvite). In cases where the abundance of carbonates is relatively low (30–50 vol %), the other major phases within inclusions are chlorides (18–55 vol %) rather than daughter silicates, as could be expected based on the traditional paradigm of the silicate composition of kimberlite melts. Published data on melt inclusions in the kimberlite minerals strongly imply that parental kimberlite melts were generated and further evolved within the Na&lt;sub&gt;2&lt;/sub&gt;O–K&lt;sub&gt;2&lt;/sub&gt;O–CaO–MgO–CO&lt;sub&gt;2&lt;/sub&gt;–Cl system, that is, they were alkali-rich carbonate/carbonate–chloride liquids. According to various estimates, SiO&lt;sub&gt;2&lt;/sub&gt; content in kimberlite melts could have varied during different stages of their evolution from a few to 19 wt %. Clearly, kimberlite bodies are altered in the crust via interaction with meteoric and/or connate waters, resulting in serpentinization of kimberlite olivine and dissolution of many bona fide magmatic minerals, such as alkali carbonates, sulfates, and chlorides. In the traditional approach to studying kimberlites, the role of such components as Na&lt;sub&gt;2&lt;/sub&gt;O, CO&lt;sub&gt;2&lt;/sub&gt;, Cl, and to a lesser extent K&lt;sub&gt;2&lt;/sub&gt;O, S, and F in the petrogenesis of kimberlite magmas and rocks have been largely underestimated, while the roles of o","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 2","pages":"143 - 178"},"PeriodicalIF":1.5,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4618789","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":"Variations in Trace Element and Isotope Composition of Neoarchean Mafic Granulites of the Southwest Siberian Craton: a Consequence of Various Mantle Sources or Crustal Contamination","authors":"O. M. Turkina","doi":"10.1134/S0869591123020066","DOIUrl":"10.1134/S0869591123020066","url":null,"abstract":"<div><p>The paper presents geochemical and isotopic characteristics of Neoarchean (2.7–2.66 Ga) mafic granulites of the Sharyzhalgay uplift in the southwestern Siberian craton. Mafic and predominant felsic granulites compose fragments of the metamorphic complex among the Neoarchean and Paleoproterozoic granitoids. The mafic granulites are characterized by the mineral association <i>Cpx + Pl ± Hbl ± Opx ± Qz</i> and include two types with different major and immobile trace element contents. The dominant rocks of the first type have a wide range of Mg# and concentrations of TiO₂ and immobile trace elements (REE, Zr, Nb), and mainly positive ε_Nd(Т) values. The first type of mafic granulites show elevated (La/Sm)_n and enrichment in Th and LREE relative to Nb, which is typical of subduction-related or crustally contaminated basalts. The absence of negative correlation between (La/Sm)_n and ε_Nd(Т) and a clear positive correlation of TiO₂ with Nb testify against the effect of crustal contamination on the composition of the mafic granulites. The magmatic protoliths of the first type of mafic granulites are suggested to form by the melting of depleted peridotites of the subcontinental lithospheric mantle modified by melts derived from basalts or terrigenous sediments of the subducting plate. Mafic granulites of the second type have a narrower range of Mg#, TiO₂ content, positive ε_Nd(Т), flat rare earth patterns and no subduction signatures, which indicates an asthenospheric depleted mantle source. Mafic granulites contaminated by the Paleoarchean crust are characterized by increased (La/Sm)_n, depletion in Nb relative to Th and LREE, and negative ε_Nd(Т) values. Post-magmatic influence of granitoids leads to the enrichment of mafic granulites in biotite and apatite, an increase in concentrations of K₂O, P₂O₅, a significant enrichment in Zr, Nb, Th, LREE, and negative ε_Nd(Т) values. The difference between mafic granulites of the first and second types is not related to crustal contamination, but is caused by melting of two types of sources: asthenospheric and subcontinental lithospheric mantle. The subcontinental lithospheric mantle of the Irkut block was isotopically depleted at the Neoarchean time (∼2.7 Ga), and its enrichment in incompatible trace elements was likely caused by felsic melts generated from the rocks of subducting plate immediately prior to mafic magmatism.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 2","pages":"204 - 222"},"PeriodicalIF":1.5,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4615613","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":"Native Iron in Siberian Traps","authors":"M. D. Tomshin,&nbsp;A. G. Kopylova,&nbsp;A. E. Vasilyeva","doi":"10.1134/S0869591123020054","DOIUrl":"10.1134/S0869591123020054","url":null,"abstract":"<p>The study of trap intrusions with a large-scale occurrence of native iron allowed us to identify general features in their composition and origin. Intrusive bodies are weakly differentiated and have similar structure and mineralogical, petrochemical and geochemical composition. Two associations of rock-forming minerals were found in all studied bodies: early deep-seated (pre-chamber) and intra-chamber. Native iron forms nodular segregations, with a subordinate amount of cohenite, troilite and magnetite–wüstite. Metallic iron can accumulate Ni, Co, Au, and PGE. Their content in metal increases by hundreds or even thousands of times compared to host silicate rock. The formation of native iron is based on the fluid-magmatic interaction between magma and reducing components of the fluid, mainly of methane–hydrogen composition. As a result, an initially homogeneous basalt liquid is dispersed into silicate and metallic components. In the course of transportation, finely dispersed iron phases form droplet-liquid segregations with a monomolecular gas layer on their surface, thus preventing enlargement of metallic droplets. In the hypabyssal chamber, magma, including metallic spherules, is degassed, and droplets are merged to form nodular segregations of native iron.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 2","pages":"223 - 236"},"PeriodicalIF":1.5,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4615614","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":"Moissanite in Rocks of the Bobruisk Basement Inlier, Belarusian Crystalline Massif, East European Craton","authors":"V. I. Levitskiy,&nbsp;I. V. Levitskiy,&nbsp;L. A. Pavlova,&nbsp;M. V. Lukashova","doi":"10.1134/S0869591123020042","DOIUrl":"10.1134/S0869591123020042","url":null,"abstract":"<p>A large range of minerals, native, intermetallic, and amorphous compounds containing K, Na, Fe, Mn, Ca, Ba, Sr, Cu, Pb, Co, Ni, Sn, Zn, Al, Ce, Nd, La, Pr, Sm, Y, Yb, Nb, Hf, W, Mo, Zr, Cr, V, Ag, Ti, Si, As, P, Bi, O, H, F, Cl, S, Se, C, B, N, and F has been identified in rocks from the Bobruisk basement inlier of the Belarusian crystalline massif in the western part of the East European craton. One of the identified phases was moissanite, which occurs as anhedral and subhedral grains up to 1.5 mm and is the 6H hexagonal polytype. One of the moissanite grains contained mineral inclusions inherent in meteorites: sinoite (Si₂N₂O), xifengite (Si₅Fe₃), and awaruite (Ni₃Fe). The moissanite and native, intermetallic, and amorphous phases associated with it occur as rare disseminated grains of various size in rocks of three rock complexes in the basement of the Bobruisk inlier. This indicates that the mineralization is overprinted. The whole set of crystalline and amorphous phases found in association with moissanite is proposed to be named <i>bobruiskites</i>. The minerals were most probably formed by an meteorite impact on rocks of the East European craton.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 2","pages":"237 - 260"},"PeriodicalIF":1.5,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4615615","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":"Highly Fractionated Granites of the Raumid Massif (S. Pamir): Oxygen Isotope and Geochemical Study","authors":"E. O. Dubinina,&nbsp;A. S. Avdeenko,&nbsp;V. N. Volkov,&nbsp;S. A. Kossova,&nbsp;E. V. Kovalchuk","doi":"10.1134/S0869591123020029","DOIUrl":"10.1134/S0869591123020029","url":null,"abstract":"<div><p>The processes of crystallization differentiation, retrograde isotopic exchange, and autometamorphism are considered with reference to the Eocene granites of the Raumid massif, which consists of eight intrusive phases and serves as an example of a “natural laboratory”. The work is based on oxygen isotope, petrographic, and geochemical study of representative samples from each intrusive phase of the massif. The isotopic and geochemical studies were carried out for all rock-forming minerals (<i>Qz</i>, <i>Pl</i>, <i>Kfs</i>, <i>Bt</i>) and their altered varieties. Based on geochemical features, the Raumid granites correspond both to A-type granites and to highly fractionated I-type granites. Our results show that the rocks of the Raumid massif are not the geochemical analog of the Eocene granitoids from the Qiangtang terrane of the Central Tibet or the Vanj complex, as it previously assumed (Chapman et al., 2018). We estimated that differentiation of felsic melts of the Raumid pluton occurred at <i>T</i> = 750–800°C, and <i>P</i> = 4.5–7.8 kbar and was mainly controlled by Pl crystallization. The melts were intruded into the hypabyssal zone in at least two stages: early (γ1–γ3) and late (γ4–γ8), although it is possible that the rocks of the γ7 and γ8 phases formed an additional separate stage. The closure temperature of the oxygen isotopic system of quartz (<i>T</i>_Qz) ranges from 420 to 610°C. The effect of the multiple intrusions of the melts on the T_Qz and apparent cooling rates is considered. The study of altered and unaltered minerals showed that autometamorphism partially overlapped with the retrograde oxygen isotope exchange in the cooling rock. The modelled δ¹⁸О values during <i>Pl</i> and <i>Kfs</i> alteration describes well the observed isotope data when the crystallization takes place at limited content of water fluid (W/M = 0.3–0.05) which could release during the Raumid’s magmas crystallization.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 2","pages":"179 - 203"},"PeriodicalIF":1.5,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4903573","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":"Late Mesozoic Carbonatite of Central Asia","authors":"A. V. Nikiforov","doi":"10.1134/S0869591123010137","DOIUrl":"10.1134/S0869591123010137","url":null,"abstract":"<div><p>Late Mesozoic carbonatites of Central Asia are developed within the Central Asian Orogenic Belt and adjacent territories of the Siberian and North China platforms. In terms of their structural position, age, geochemical characteristics, and other parameters, they differ from other carbonatite occurrences of Central Asia and are distinguished as the Late Mesozoic carbonatite province in Central Asia. The province includes separate areas of carbonatite magmatism, the geological position of which is determined by the relation with Late Mesozoic rift zones of intracontinental Asia. The carbonatites were formed within a relatively narrow time range (between 150 and 118 Ma) at the early evolution stages of these zones. The carbonatite-bearing complexes of the province are represented by subolcanic and volcanic associations of silicate rocks, carbonatites, magmatic non-silicate rocks (phosphates, sulfates, and others), as well as products of hydrothermal activity. The carbonatites are characterized by diverse composition and include calciocarbonatites, magnesiocarbonatites, and ferrocarbonatites. The silicate rocks are dominated by K–Na and K intermediate rocks. All these rocks have similar geochemical features determined by the elevated contents of LREE, Sr, Ba, and Pb, at low Nb and Ta contents. The typomorphic minerals of carbonatites of the province, in addition to carbonates, are fluorite, Ba and Sr sulfates or carbonates, LREE F-carbonates, and apatite. Unaltered carbonatites are enriched in ¹⁸О and ¹³С relative to mantle values, but in general fall within the compositional range of carbonatites around the world. Hydrothermal and supergene processes modified the mineral composition of carbonatites, which was accompanied by a change of the initial Sr, O, and C isotope composition. The Sr and Nd isotope composition of rocks of carbonatite complexes of the province in general depends on the age of the basement of a definite volcanic area. Carbonatites and associated silicate rocks have close isotope characteristics, but carbonatites usually show relative enrichment in (⁸⁷Sr) and depletion in radiogenic neodymium (¹⁴³Nd). The formation of the Late Mesozoic carbonatite province is related to the activity of mantle plumes, which controlled the Late Mesozoic magmatism in Central Asia. The plumes obviously were accompanied by fluid flows enriched in СО₂, F, and S. This caused the enrichment of lithospheric mantle in volatile components, as well as REE, Sr, Ba, and K, which were extracted by a fluid en route to the surface. Subsequent melting of metasomatized mantle produced parental melts of carbonate-bearing rock complexes.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"31 1","pages":"1 - 141"},"PeriodicalIF":1.5,"publicationDate":"2023-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4541917","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":"Aegirine-Bearing Clinopyroxenes in Granulite Xenoliths from the Udachnaya Kimberlite Pipe, Siberian Craton: Comparison of the Mössbauer and Micropobe Data","authors":"A. V. Sapegina,&nbsp;M. V. Voronin,&nbsp;A. L. Perchuk,&nbsp;O. G. Safonov","doi":"10.1134/S0869591123010083","DOIUrl":"10.1134/S0869591123010083","url":null,"abstract":"<div><p>The aegirine end-member (NaFe³⁺Si₂O₆) in clinopyroxenes resulted from incorporation of Fe³⁺ into the mineral structure. Its presence affects the accuracy of reconstruction of the <i>P-T</i> conditions in the high-grade metamorphic rocks and allows the evaluation of the redox conditions of their formation. The content of this end-member in clinopyroxenes is usually estimated using crystal chemical recalculations of microprobe analyses. However, in some publications on eclogites, the comparison of microprobe-based recalculations with Mössbauer data revealed significant difference between the measured and calculated Fe³⁺/ΣFe ratios, which can significantly affect the results of geothermometry. This paper presents the results of the Mössbauer spectroscopy measurements of clinopyroxene fractions separated from three samples of garnet–clinopyroxene granulites from the Udachnaya kimberlite pipe. The ratios Fe³⁺/ΣFe = 0.22–0.26 measured in the clinopyroxenes correspond to 6–10 mol % aegirine. These estimates are in good agreement with the values obtained for the same clinopyroxenes by the recalculation of microprobe analyses using the charge balance method. Following this conclusion, we believe that crystal chemical recalculations of microprobe analyzes of clinopyroxenes from non-eclogitic rocks make it possible to correctly estimate the Fe³⁺ content in them. Similar recalculation of microprobe analyses of clinopyroxenes in crustal xenoliths from other localities, as well as from ferrobasalts of the continental flood basalts provinces, ferrodolerite dikes, and gabbroid xenoliths (similar in bulk chemical composition to many lower–middle crustal xenoliths) revealed significant amounts of previously unaccounted aegirine (up to 13 and 4–9 mol %, respectively), which holds the potential for deciphering redox conditions in many rocks.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":"30 1","pages":"S119 - S130"},"PeriodicalIF":1.5,"publicationDate":"2023-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4828030","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":"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}