Petrology最新文献

{"title":"Metasomatized Xenoliths of Mantle Eclogites and Garnet Pyroxenites from the V. Grib Kimberlite, Arkhangelsk Province","authors":"N. M. Lebedeva,&nbsp;A. A. Nosova,&nbsp;L. V. Sazonova,&nbsp;Y. O. Larionova","doi":"10.1134/S0869591122050046","DOIUrl":"10.1134/S0869591122050046","url":null,"abstract":"<div><p>We investigated mantle eclogite and garnet pyroxenite xenoliths from the V. Grib kimberlite located in the Arkhangelsk diamond province. The eclogites in the lithospheric mantle beneath the Arkhangelsk province were strongly modified by metasomatic processes, which totally obliterated the primary features of protolith. Detailed studies of the xenoliths allowed us to distinguish the following metasomatic events: (1) early mantle metasomatism and (2) interaction with kimberlite melt. During the multiple early mantle metasomatism, primary clinopyroxene and garnet were replaced by metasomatic clinopyroxene, garnet, amphibole, calcite, and phlogopite under the influence of carbonated ultramafic melts. The impact of kimberlite melt caused the dissolution and recrystallisation of solid-phase inclusions and formation of melt pockets consisting of serpentine, chlorite, carbonate, spinel, perovskite, amphibole, recrystallized garnet, and clinopyroxene. En route to the surface in kimberlite melt, the xenoliths were disintegrated and primary garnet and clinopyroxene were metasomatized with increasing Ti and Cr contents, up to formation of high-Cr megacrysts. The garnet pyroxenites are represented by high-Ca, low-Mg and low-Ca, high-Mg types. It is shown that the high-Ca, low-Mg garnet pyroxenites can be the final products of the eclogite xenolith metasomatism by carbonated ultramafic melts. The low-Ca, high-Mg pyroxenites were derived through the interaction of a partial eclogite melt with depleted peridotites.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4283588","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":"Composition and Isotope Parameters of Metabasalts and Gabbroids of the Onot Granite–Greenstone Block, Southwestern Siberian Platform, as Indicators of Lithospheric Mantle Evolution from the Archean to Paleoproterozoic","authors":"O. M. Turkina,&nbsp;A. E. Izokh,&nbsp;A. V. Lavrenchuk,&nbsp;Ya. Yu. Shelepov","doi":"10.1134/S0869591122040063","DOIUrl":"10.1134/S0869591122040063","url":null,"abstract":"<p>The paper summarizes major and trace-element compositions and Sm–Nd isotope data on metabasites (amphibolites) and gabbroids of the Onot granite–greenstone block in the Sharyzhalgai basement uplift, southwestern Siberian craton. The Onot block consists of tectonically combined nappes of the Paleoarchean tonalite–trondhjemite–granodiorite (TTG) complex and the metasedimentary-volcanic complex of the greenstone belt (GB). The Mezoarchean (∼2.88 Ga) metabasalts of the greenstone belt and Paleoproterozoic (∼1.86 Ga) gabbronorites and vein gabbros were formed at rifting and postcollisional extension, respectively. The Archean metabasites of the greenstone belt and enclaves in the TTG complex compositionally correspond to low-Ti tholeiitic basalts and basaltic andesites. The basaltic rocks are characterized by flat REE patterns [(La/Sm)_n = 0.9–1.9], depletion in Nb relative to Th and La (Nb/Nb* = 0.4–1.1), and a wide range of mostly positive ε_Nd(T) values (from +5.2 to –1.0). The enrichment of the basaltic andesite in incompatible elements, its Eu minimum, and negative ε_Nd(T) values resulted from contamination by Paleoarchean TTG gneisses, that form the basement of GB. The Paleoproterozoic gabbronorites have high Mg# and extremely low concentrations of Ti and incompatible elements. The rocks are characterized by low (Nb/Y)_PМ (0.8–1.0), negative ε_Nd(T) values (from 0 to –1.4), and weak enrichment in Th and LREE relative to Nb. The vein gabbros have low (La/Sm)_n, positive ε_Nd(T) values of +2.8 and +0.3, and a negative Nb anomaly (Nb/Nb* = 0.3–0.4). The trace element-composition of the amphibolites, gabbronorites, and gabbros and the results of geochemical modeling indicate that the parental melts were derived mainly from weakly depleted mantle sources. The Nd isotope composition of the Paleoproterozoic gabbroids resulted from the evolution of the heterogeneous Archean lithospheric mantle. Variations in the isotope and trace-element composition of the amphibolites reflect the initially depleted nature of the Mezoarchean mantle and its metasomatic alteration by fluids/melts, which occurred before its melting at ∼2.88 Ga. The geochemical and Nd isotopic characteristics of gabbronorites and gabbros indicate that the lithospheric mantle had become progressively more heterogeneous by the Paleoproterozoic due to preceding Archean processes. The variable depletion of both the Archean and the Paleoproterozoic mafic rocks in Nb relative to Th and La may be explained by mantle metasomatism and does not reflect the geodynamic settings of the mafic magmatism.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4283576","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":"Pauzhetka Caldera (South Kamchatka): Еxploring Temporal Evolution and Origin of Voluminous Silicic Magmatism","authors":"V. O. Davydova,&nbsp;I. N. Bindeman,&nbsp;M. D. Shchekleina,&nbsp;S. N. Rychagov","doi":"10.1134/S0869591122050022","DOIUrl":"10.1134/S0869591122050022","url":null,"abstract":"<div><p>The Pauzhetka Caldera (27 × 18 km) was formed in the South Kamchatka during the Golygin Ignimbrite eruption (420–440 ka), the largest known eruption in the region in the past 1 Myr. The eruption was preceded by the 3 Ma-old mafic and intermediate volcanism. After the caldera-forming eruption, a variety of products, from basalt to rhyolite, were ejected within the caldera. For understanding the origin of voluminous silicic magmatism in thin mafic South Kamchatka crust, we used geochemical and isotope data. Our research has characterized the major and trace element composition of Golygin ignimbrite, intra-caldera hydrothermally altered deposits, pre-caldera (Mt. Orlinoe Krylo, Mt. Klyuchevskaya) and post-caldera (Kambalny Ridge, Chernye Skaly) eruptive centers. The Sr–Nd isotope composition of the Golygin ignimbrite and some eruptive post-caldera products was investigated. The isotope variations indicate that parental magmas for all rocks of the Pauzhetka area were obtained from a weakly evolved source derived through fluid-assisted melting of a subducted slab. Geochemical data support that the formation of most magmas of the Pauzhetka caldera was mainly controlled by fractional crystallization in the lower to middle crust. MELTS-modelling agrees with geochemical data. The fractional crystallization of Kambalny basalt with 2 wt % H₂O at 6 kbar provides the best fit to the observed composition of the Golygin dacite.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4277323","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":"Evolution of the Magmatic Sources of the Eastern Mongolian Volcanic Area: Evidence from Geochemical and Sr–Nd–Pb Isotope Data","authors":"M. V. Kuznetsov,&nbsp;V. M. Savatenkov,&nbsp;L. V. Shpakovich,&nbsp;V. V. Yarmolyuk,&nbsp;A. M. Kozlovsky","doi":"10.1134/S0869591122050034","DOIUrl":"10.1134/S0869591122050034","url":null,"abstract":"<p>The Eastern Mongolian Volcanic Area (EMVA) is part of the Late Mesozoic–Early Cenozoic volcanic and plutonic belt in Northeastern Asia. The EMVA evolved in three stages, with volcanic rocks of different composition produced during each of the stages and with the parental melts of the rocks derived from different sources and formed by different mechanisms. The rocks of the Early Cretaceous stage (135–100 Ma), which form the volcanic flow complex of the EMVA, are predominantly differentiated alkali basaltoids. Data on isotopic features of these rocks, particularly their Pb isotope composition, allowed us to identify the nature of their sources: peridotites of the Continental Metasomatized Lithospheric Mantle (CMLM) and lower continental crustal eclogitic rocks. The alkali basaltoids of the extrusive complex of the Uldza-gol volcanic field were formed during the next evolution stage of the EMVA at 104–90 Ma. According to their geochemical and isotope features, the melts of these rocks were derived from the same sources as those of the volcanics of the previous Early Cretaceous stage, except only that eclogite material played a more significant role in forming of the Uldza-gol basaltoid melts. During the concluding stage of the EMVA evolution in the Late Cretaceous–Early Cenozoic (87–51 Ma), OIB-like rocks of the basanite–trachybasalt association were formed in the Central Gobi in the southwestern flank of the EMVA. Asthenospheric and recycled pyroxenite components, together with not so much CMLM peridotites, were involved in forming of these rocks. The various sources of the EMVA volcanic rocks reflect two mechanisms of their formation. In the Early to Late Cretaceous, magmatism was triggered by the ascent of the asthenospheric mantle and delamination of the lithospheric mantle, whereas the Early Cenozoic magmatism was induced by the activity of a mantle plume.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4277361","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 Formation of Layered Intrusions of the Monchegorsk Magmatic Cluster","authors":"V. S. Semenov,&nbsp;O. V. Kazanov,&nbsp;S. I. Korneev,&nbsp;E. B. Salnikova,&nbsp;S. V. Semenov","doi":"10.1134/S0869591122030079","DOIUrl":"10.1134/S0869591122030079","url":null,"abstract":"<div><p>The paper presents geochronological data and results of petrological modeling of the Monchegorsk and Monchetundra layered massifs. The U-Pb ID-TIMS zircon dating of norite from the marginal zone of Mt. Nittis yielded 2506 ± 7 Ma, which coincides with previous data on similar rocks from other areas. Based on the comparison of sections of the Monchegorsk and Kivakka massifs, the pre-erosion thickness of the Monchegorsk massif is estimated as 3700 m. Calculations using rocks of the marginal zone of the Monchegorsk intrusion at a pressure of 6.5–5.5 kbar showed that the melt in equilibrium with <i>Ol</i> contained SiO₂ ≤ 55 wt %, TiO₂ ≤ 0.50 wt %, and MgO ≤14 wt %. The temperature of the primary magma could be equal to 1390°C. At a lower pressure (below 6.5 kbar), the obtained melt becomes more siliceous. In the Monchegorsk intrusion, the composition of intratelluric olivine according to this model could vary within 88–92 mol % <i>Fo</i>. The content of intratelluric olivine in the melt, depending on pressure, could vary from 11 to 24 vol %. Magmas that formed the Monchegorsk intrusion and the layered series of the Monchetundra intrusion (hole 742) were derived from different sources.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4933704","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 the Solubility of Fluorides in Fluid-Saturated Potassic Syenite Melt","authors":"O. E. Pliusnina,&nbsp;V. Yu. Chevychelov,&nbsp;A. V. Samsonov,&nbsp;A. A. Viryus","doi":"10.1134/S086959112204004X","DOIUrl":"10.1134/S086959112204004X","url":null,"abstract":"<p>The paper presents experimental results on the solubility of fluorides in fluid-saturated melt of alkaline ultrapotassic syenite-porphyry from the Gross gold ore deposit in southern Yakutia at <i>T</i> = 600–800°C, <i>P</i> = 150–260 MPa. The experiments were carried out to confirm the assumption of high solubility of fluorine in ultrapotassic syenite melt, which could contribute to the formation of specific and low-viscosity melts that were emplaced in the form of a syenite porphyry sill. The solid products after the experiments contained aluminosilicate glass, potassium feldspar, fluorite, quartz, and two fluoride phases differing in composition (potassium and aluminum fluoride and potassium and magnesium fluoride). The experimental results led us to determine a high maximum solubility of fluorine in the melt: up to 4.2–4.6 wt %, with the maximum F content found in the lowest temperature melt at 625°C. The solidus and liquidus temperatures of the syenite melt were estimated at 600–625 and 650–800°C, respectively. The aqueous fluoride fluid coexisting in equilibrium with the melt was determined to be alkaline. Potassium feldspar was the first to crystallize from the melt in the experiments, which is consistent with what is observed in samples of the naturally occurring rocks.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4934838","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: Experimental Study of the Crystallization Conditions of Ongonites of the Ary-Bulak Massif (Eastern Transbaikalia)","authors":"Ya. O. Alferyeva,&nbsp;V. Yu. Chevychelov,&nbsp;A. S. Novikova","doi":"10.1134/S0869591122330013","DOIUrl":"10.1134/S0869591122330013","url":null,"abstract":"","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4938792","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":"Riphean–Vendian–Cambrian Magmatism of the Mankhambo Block (Subpolar Urals): Geochemical Typification, Correction of Geodynamic Concepts, and the Role of Plume–Lithosphere Interaction","authors":"V. V. Kholodnov,&nbsp;G. Yu. Shardakova,&nbsp;V. A. Dushin,&nbsp;A. V. Korovko,&nbsp;E. S. Shagalov","doi":"10.1134/S0869591122040038","DOIUrl":"10.1134/S0869591122040038","url":null,"abstract":"<div><p>The geochemical typification of magmatic rocks of the Mankhambo block (southern part of the Lyapinsky anticlinorium), which is confined to the junction zone of the Ural orogen with the Timanide–Cadomide belt relics, was performed based on the generalization of abundant isotope-geochemical data, application of modified discriminant diagrams, and analysis of Y/Nb ratio. The magmatic rocks mark two stages of the geodynamic evolution of this structure. The first stage (RF_2–3) is characterized by the tholeiitic magmatism (subvolcanic basic rocks of the Shchokuryinsky and Moroinsky complexes). According to composition and source type (Y/Nb = 3–5, E-MORB), these rocks can be correlated with riftogenic plume-related series of the East European passive margin. Magmatism of the second stage (650–500 Ma) was related to the evolution of divergent transform continental margin. This stage involved the subsequent formation of calc-alkaline magmatic series (653–608 Ma) (Sys’insky and Parnuksky complexes) and bimodal basalt–rhyolite association (569–554 Ma) (Sablegorsky and Laptopaisky complexes), which vary from tholeiitic to calc-alkaline rocks. High values of the Y/Nb ratio (5–8) in the basic rocks of the Sablegorsky complex suggest that their generation was related with intensification of transform movements, when plume-related basic magma (E-MORB-type source) interacted with more depleted slab-derived component. The rhyolites of the Sablegorsky complex mark the incipient generation of the A-type rhyolite–granite association (Y/Nb = 0.2–1), which was continued (522–490 Ma) by the granites of the Mankhambo and Ilya-Iz massifs. Their genesis may be related to the differentiation of magmas from two possible sources. A-granites with Y/Nb = 2.0 (phase I of the Mankhambo massif) were generated from E-MORB-type source. Granites of phase II (Y/Nb = 0.2–1) were derived from heterogeneous sources with the participation of OIB-type component. In general, the rocks of the Vendian–Cambrian stage, in comparison with older rocks, are characterized by the highest degree of plume-lithosphere interaction, with contribution of subduction-modified lithospheric mantle. The role of crustal contamination increases from the rhyolites of the Sablegorsky and Laptopaisky complexes to the granites of the Mankhambo massif. The presence of relict zircons and the “crustal” Sr and Hf isotope signatures indicate the contribution of ancient crustal material in their protolith. The genesis of the rhyolite–granite association may be associated with the emplacement of the “Mankhambo” plume. The plume role in the magma generation of rocks of the Mankhambo block increases with decreasing age.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4938779","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":"Age, Composition, and Tectonic Setting of the Formation of Late Neoproterozoic (Late Baikalian) Complexes in the Kichera Zone, Baikal-Vitim Belt, Northern Baikal Area: Geological, Geochronological, and Nd Isotope Data","authors":"A. A. Andreev,&nbsp;E. Yu. Rytsk,&nbsp;S. D. Velikoslavinskii,&nbsp;E. V. Tolmacheva,&nbsp;E. S. Bogomolov,&nbsp;Y. M. Lebedeva,&nbsp;A. M. Fedoseenko","doi":"10.1134/S0869591122040026","DOIUrl":"10.1134/S0869591122040026","url":null,"abstract":"<p>The paper presents data on the geological structure of the Kichera zone of the Baikal–Vitim belt (BVB) at the boundary between the marginal part of the Siberian craton and the Barguzin–Vitim superterrane of the Central Asian Orogenic Belt. Early Neoproterozoic (Early Baikalian) and Late Neoproterozoic (Late Baikalian) structures and complexes are identified and characterized in the Kichera zone of the BVB. Data are presented on the geochemistry of the rocks and on their U–Pb isotope age (zircon, SIMS and ID-TIMS) and on the Nd isotope characteristics of rocks from various parts of the Kichera zone, including representative rock association of the Nyurundukan migmatite–tonalite–metabasite complex with MORB-type tholeiites and tholeiites with intraplate geochemical features. It is shown that the sources of the Early Neoproterozoic complexes of the Kichera zone, which were metamorphosed at 0.76–0.74 Ga as a result of accretion events in the marginal part of the craton, were dominated by Early Precambrian recycled crustal material. The Late Neoproterozoic complexes typomorphic of the Kichera zone were formed in the Cryogenian–Ediacaran (720–545 Ma) from prevailing juvenile sources. Our data suggest that the metabasites of the Nyurundukan complex were formed in an environment of segmented troughs of the pull-apart paleorift system of the Kichera zone and can be compared with a reduced complex of continental-margin ophiolites transformed at 630 ± 7 to 615 ± 3 Ma. The destruction of the ancient continental crust of the craton ended with the formation and exhumation of deep rocks in the Late Ediacaran, the emplacement of adakite granites of the postcollisional geochemical type, and the formation of grabens filled with a terrigenous complex. The juvenile and riftogenic crust produced during the Late Neoproterozoic tectonic evolution of the Kichera rift zone does not show any features of mature continental-type crust.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5278612","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":"Rhodium Solubility in Silicate Melts","authors":"A. A. Borisov","doi":"10.1134/S0869591122030031","DOIUrl":"10.1134/S0869591122030031","url":null,"abstract":"<p>All published experimental data on Rh solubility in silicate melts were combined to derive an equation relating Rh solubility to temperature, oxygen fugacity, and a melt composition. It is demonstrated that Rh is dissolved in a melt dominantly as Rh²⁺ in the entire experimental <i>f</i>O₂ range, from pure oxygen to QFM + 2 (QFM is the quartz–magnetite–fayalite buffer). The temperature dependence of Rh solubility is anomalous. Similar to the solubilities of other noble metals, Rh solubility at a constant <i>f</i>O₂ increases with increasing temperature. The Rh metal/silicate partition coefficient was calculated (<span>(D_{{{text{Me/Sil}}}}^{{{text{Rh}}}})</span> ≈ 3.5 × 10⁷) for the expected conditions of Earth differentiation into a core and mantle. It is demonstrated that the late chondritic veneer model is able to best explain high Rh contents in upper mantle rocks. The suggested equation makes it possible to discard experimental glasses contaminated with metallic Rh micronuggets and thus to get rid of at least the most gross errors in the determination of Rh partition coefficients between rock-forming minerals and melt.</p>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2022-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4938791","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}