European Journal of Mineralogy最新文献

{"title":"Synthesis of jadarite in the Li2O–Na2O–B2O3–SiO2–NaCl–H2O system: FTIR, Raman, and Li and B K-edge XANES characterizations and theoretical calculations","authors":"Xiuzhen Xie, H. Kuang, Eli Wiens, Reza Deevsalar, Ayetullah Tunc, Sarah Purdy, Lucia Zuin, John S. Tse, Jin-Xiao Mi, Yuanming Pan","doi":"10.5194/ejm-36-139-2024","DOIUrl":"https://doi.org/10.5194/ejm-36-139-2024","url":null,"abstract":"Abstract. The occurrence of jadarite (LiNaSiB3O7OH) as a major ore mineral in the world-class lithium–boron deposit of the Miocene Jadar lacustrine basin (western Serbia) raises interesting questions about its formation conditions and potential associations for lithium mineralization in other sedimentary basins. This contribution reports on the first successful synthesis of jadarite in the Li2O–Na2O–B2O3–SiO2–NaCl–H2O system at temperatures from 180 to 230 ∘C and pH values from 6 to 12. Synthetic jadarite has been characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, laser Raman spectroscopy, and synchrotron Li and B K-edge X-ray absorption near-edge structure (XANES). First-principles theoretical calculations reproduce the measured FTIR and Raman spectra and allow definitive assignments of vibration modes. Similarly, the measured Li and B K-edge XANES spectra are reasonably reproduced by first-principles theoretical calculations. Our synthesis results, together with its association with searlesite in the Jadar basin, suggest jadarite forms in deep sediments derived from Li-rich alkaline brines under high-temperature diagenetic conditions.\u0000","PeriodicalId":507154,"journal":{"name":"European Journal of Mineralogy","volume":"85 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140486048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Review of melt inclusions in lunar rocks: constraints on melt and mantle composition and magmatic processes","authors":"Youxue Zhang","doi":"10.5194/ejm-36-123-2024","DOIUrl":"https://doi.org/10.5194/ejm-36-123-2024","url":null,"abstract":"Abstract. Mineral-hosted melt inclusions provide a window into magmatic processes and pre-eruptive liquid compositions. Because melt inclusions are small (typically < 100 µm), the study of lunar melt inclusions is enabled by advancements of microbeam instrumental techniques. In the 1970s immediately following the Apollo and Luna missions, major and minor oxide concentrations of lunar melt inclusions were measured using electron microprobes. The data were used to understand magma evolution, and they revealed the immiscibility of two silicate liquids in the late stage of lunar magma evolution. More recently, the development of secondary ion mass spectrometry as well as laser ablation–inductively coupled plasma–mass spectrometry has enabled the measurement of key volatile elements and other trace elements in lunar melt inclusions, down to about the 0.1 ppm level. The applications of these instruments have ushered in a new wave of lunar melt inclusion studies. Recent advances have gone hand in hand with improved understanding of post-entrapment loss of volatiles. These studies have provided deep insights into pre-eruptive volatiles in lunar basalts, the abundance of volatiles in the lunar mantle, the isotopic ratios of some volatile elements, and the partition of trace elements between host olivine and melt inclusions. The recent studies of lunar melt inclusions have played a critical role in establishing a new paradigm of a fairly wet Moon with about 100 ppm H2O in the bulk silicate Moon (rather than a “bone-dry” Moon) and have been instrumental in developing an improved understanding of the origin and evolution of the Moon.\u0000","PeriodicalId":507154,"journal":{"name":"European Journal of Mineralogy","volume":"55 29","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139594739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Île Dumet (Armorican Massif, France) and its glaucophane eclogites: the little sister of Île de Groix","authors":"G. Godard, David C. Smith, Damien Jaujard, S. Doukkari","doi":"10.5194/ejm-36-99-2024","DOIUrl":"https://doi.org/10.5194/ejm-36-99-2024","url":null,"abstract":"Abstract. Blueschist-facies rocks are scarce within the Variscan orogen. Two main occurrences are known in the Armorican Massif (NW France), at Île de Groix and Bois-de-Céné. Another glaucophane occurrence was discovered in 1988 but went unnoticed; it is located on Île Dumet, an uninhabited island off the coast of southern Brittany, in the estuary of the river Vilaine. Orthogneiss occurs on the SW half of the island; the original granitoid magma had intruded mica schists on the NE half, where numerous 1 to 10 m long boudins of mafic rocks occur. These lenses are typically retrogressed into plagioclase-bearing amphibolite, but a few contain remnants of glaucophane-bearing eclogite, which also occurs as numerous loose blocks along the NE coast of the island, suggesting that the best-preserved eclogites lie in situ offshore in that direction. The glaucophane eclogites contain garnet, omphacite, quartz, amphibole, clinozoisite/epidote, minor phengite, paragonite, rutile and rare apatite. Prograde metamorphic evolution is indicated by garnet crystals zoned from Mn-rich cores to Mg-richer rims (typically (core→rim): Alm44→58 Prp1→12 Grs33→29 Sps22→1) and amphibole grains with glaucophane nuclei and Ca–Na-amphibole overgrowths that show sharp transitions, supporting evolution through a solvus, as predicted by the thermodynamic modelling. Modelling of the P–T conditions using the P–T pseudosection technique indicates a peak of metamorphism at about 620 ∘C and 16 kbar. The retrograde evolution of the metabasites is evidenced by the late formation of albite, titanite and ferro-actinolite. The surrounding mica schists, composed of quartz, garnet, phengite, paragonite and chlorite, were also largely retrogressed during exhumation. The orthogneiss of the SW part of the island does not show clear evidence of high-pressure metamorphism, since the magmatic feldspars are still preserved, similarly to the orthogneiss of Les Sables Rouges on the island of Groix. Île Dumet and the western part of the Vilaine estuary represent a blueschist-facies equivalent to Île de Groix (Brittany) and Bois-de-Céné (Vendée) on the mainland. All three occurrences occupy the centres of wide synforms whose concentric units are, from rims to core (i.e. from base to top), (a) a high-T migmatitic basement; (b) Cambro-Ordovician metasediments and acid metavolcanites (“porphyroids”); and (c) blueschist-facies mica schists and metabasites, serpentinites, and minor orthogneisses derived from a pre-Variscan oceanic accretionary prism. There are about 10 similar occurrences within the Ibero-Armorican Arc, forming a discontinuous high-pressure belt, but most of them have remained unnoticed due to a high degree of retrogression.\u0000","PeriodicalId":507154,"journal":{"name":"European Journal of Mineralogy","volume":"1 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139613650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OxyEMG: an application for determination of the oxyspinel group end-members based on electron microprobe analyses","authors":"Gabriela R. Ferracutti, Lucía M. Asiain, Antonella S. Antonini, Juan E. Tanzola, M. L. Ganuza","doi":"10.5194/ejm-36-87-2024","DOIUrl":"https://doi.org/10.5194/ejm-36-87-2024","url":null,"abstract":"Abstract. The Oxyspinel group End-Member Generator (OxyEMG) is an improved version of the EMG application. This new version allows for calculating, based on electron microprobe analysis (EMPA), the proportions of 31 end-member components in an oxyspinel composition. These components are MgAl2O4 (spinel), FeAl2O4 (hercynite), MnAl2O4 (galaxite), ZnAl2O4 (gahnite), NiAl2O4 (chihmingite), CuAl2O4 (thermaerogenite), MgFe2O4 (magnesioferrite), Fe3O4 (magnetite), MnFe2O4 (jacobsite), ZnFe2O4 (franklinite), NiFe2O4 (trevorite), CuFe2O4 (cuprospinel), FeMn2O4, MgMn2O4, Mn3O4 (hausmannite), ZnMn2O4 (hetaerolite), MgCr2O4 (magnesiochromite), FeCr2O4 (chromite), MnCr2O4 (manganochromite), ZnCr2O4 (zincochromite), NiCr2O4 (nichromite), CoCr2O4 (cochromite), MgV2O4 (magnesiocoulsonite), FeV2O4 (coulsonite), MnV2O4 (vuorelainenite), Co3O4 (guite), TiMg2O4 (qandilite), TiFe2O4 (ulvöspinel), SiMg2O4 (ringwoodite), SiFe2O4 (ahrensite) and GeFe2O4 (brunogeierite). Compared with the older version, OxyEMG allows for (a) calculating 12 additional oxyspinel group end-member compositions (chihmingite, thermaerogenite, hausmannite, hetaerolite, FeMn2O4, MgMn2O4, cuprospinel, cochromite, guite, ringwoodite, ahrensite and brunogeierite), (b) discriminating the cation valency not only for Fe2+–Fe3+ but also for Mn2+–Mn3+ and Co2+–Co3+, and (c) changing the method to calculate the components of the magnetite and ulvöspinel prisms. As in EMG, this new version is an application that does not require an installation process and was created with the purpose of performing calculations to obtain cation proportions (per formula unit, p.f.u.), end-members of the oxyspinel group, a ΣR3+ value, a ΣR2+ value, ΣR3+ / ΣR2+ ratios, redistribution proportions for the corresponding end-members in the magnetite or ulvöspinel prisms, and a data validation section to check the results.\u0000","PeriodicalId":507154,"journal":{"name":"European Journal of Mineralogy","volume":" 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139617250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}