Mineralogy and Petrology最新文献

{"title":"Plume related kimberlites and carbonatites","authors":"L. Kogarko","doi":"10.1007/s00710-022-00789-9","DOIUrl":"https://doi.org/10.1007/s00710-022-00789-9","url":null,"abstract":"","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46186874","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":"Petrogenetic relationships between peraluminous granites and Li- Cs-Ta rich pegmatites in south Issia zone (Central-West of Côte d’Ivoire): Petrography, Mineralogy, Geochemistry and zircon U–Pb Geochronology","authors":"Joseph Koffi Brou,&nbsp;Marieke Van Lichtervelde,&nbsp;Nicaise Alain Kouamelan,&nbsp;David Baratoux,&nbsp;Nicolas Thébaud","doi":"10.1007/s00710-022-00790-2","DOIUrl":"10.1007/s00710-022-00790-2","url":null,"abstract":"<div><p>The Issia batholith extends over 100 km in central Ivory Coast and is surrounded by important placer deposits of columbite-tantalite associated with deeply altered lithium-cesium-tantalum pegmatites. The genetic link between the granitic complex and the mineralized lithium-cesium-tantalum pegmatites at the origin of the coltan placers is not straightforward, considering the significant age difference (~ 40 Ma) between one of the granites and the coltan mineralization. In order to constrain the link between the granitic intrusions and the coltan placers, we have completed a petrological and geochemical study on eighteen granitic outcrops. Some granites are crosscut by pegmatite dykes, but neither the granites nor their intruding pegmatites dykes exibit primary Nb–Ta mineralization. Our results reveal three granite series (G1, G2, G3). The biotite-dominant G1 granites are the least fractionated, metaluminous to peraluminous, with trace element compositions close to average upper continental crust. The G2 and G3 granites are muscovite-rich, peraluminous with intermediate phosphorus contents up to 0.5 wt% P₂O₅. G2 and G3 have similar compositions except for lower Cs and Ta and higher Th, Hf and Zr in G2. G2 and G3 are strongly fractionated with up to 22 ppm Be, 57 ppm Cs, 505 ppm Rb, 16 ppm Sn, 11 ppm Ta, and a Nb/Ta ratio &lt; 1. The G3 granite and its intruding pegmatite dykes contain abundant tourmaline, garnet and Nb–Ta-rich ilmenite. We conclude that the G2 and G3 granite groups are genetically linked through fractional crystallization. Three hypotheses can explain the formation of the Li-Cs-Ta-rich liquids: (1) A fractional crystallization model where the G2-G3-pegmatite series evolves by fractional crystallization of an anatectic melt produced by melting of metasediments, (2) an anatectic model where all granites and pegmatites were formed by direct anatexis, and their strong differentiation degree would reflect an enriched metasedimentary source, (3) a granitic origin where melting of the most fractionated G3 granite produced the Li-Cs-Ta-rich liquids ~ 40 Myrs after the granite cooling. Geochronological results and textural evidence of granite melting tend to favor the third model, which indicates that crust re-heating occurred ~ 40 Ma after the emplacement of the Issia granitic complex.\u0000</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00710-022-00790-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4234827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accessory Cr-spinel from peridotite massifs of the South Urals: morphology, composition and origin","authors":"Dmitry E. Saveliev,&nbsp;Vladimir V. Shilovskikh,&nbsp;Darkhan K. Makatov,&nbsp;Ruslan A. Gataullin","doi":"10.1007/s00710-022-00791-1","DOIUrl":"10.1007/s00710-022-00791-1","url":null,"abstract":"<div><p>The features of morphology and composition of accessory Cr-spinels from four ophiolitic peridotite massifs of the Southern Urals are considered. Massifs are localized in the Main Uralian Fault zone (Nurali, Mindyak), at its junction with the Sakmar zone (Kempirsai) and in the northern part of the Zilair zone (Kraka). The Kraka, Nurali and Mindyak massifs are composed mainly of lherzolites with subordinate harzburgites and dunites, while harzburgites predominate in the Kempirsai massif and dunites with large chromitite deposits are significantly developed in its southeastern part. The PT–<i>f</i>O₂ formation conditions of lherzolites correspond to the upper mantle below a rift structure: temperature of 700–1000 °C, pressure of 5–12 kbar, and oxygen fugacity varying from –2 to + 0.5 ΔFMQ. The compositional variations of Cr-spinels from primitive lherzolite (Cr# 0.15–0.30, Mg#0.6–0.8) to harzburgite (Cr# 0.3–0.6, Mg#0.5–0.7) and dunite (Cr# 0.6–0.8, Mg#0.4–0.7) and the increase in Mg# value of olivine are a result of synchronous processes of partial melting and plastic flow of the material in the upper mantle. Four main morphological Cr-spinel types are distinguished in lherzolites: (1) fine rods and lamellae within silicate grains and along their boundaries, (2) anhedral and holly-leaf grains closely intergrown with restitic olivine and enstatite, (3) anhedral and subhedral grains in an assemblage with plagioclase and diopside and (4) euhedral grains in dunites. The formation of type 1 grains is interpreted as a result of deformation-induced segregation of trace elements on structural defects of silicates with consequent crystallization of newly formed minerals. The advanced stages of solid-phase transformation produce the larger anhedral and holly-leaf grains in peridotites and euhedral grains in dunites (types 2 and 4 grains). The decompression replacement of a precursor high-pressure mineral (garnet?) is suggested for the formation of the Cr-spinel–plagioclase aggregates. The subhedral and euhedral grains in the assemblage with plagioclase and clinopyroxene could have formed as a result of crystallization from percolating melts or their reaction with restite.</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5029395","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":"40Ar–39 Ar dating, whole-rock and Sr-Nd isotope geochemistry of the Middle Eocene calc-alkaline volcanic rocks in the Bayburt area, Eastern Pontides (NE Turkey): Implications for magma evolution in an extension-related setting","authors":"Abdullah Kaygusuz,&nbsp;Cem Yücel,&nbsp;Emre Aydınçakır,&nbsp;Mehmet Ali Gücer,&nbsp;Gilles Ruffet","doi":"10.1007/s00710-022-00788-w","DOIUrl":"10.1007/s00710-022-00788-w","url":null,"abstract":"<div><p>Discussions continue about whether Middle Eocene magmatism in the Eastern Pontides is associated with collision or subduction. This paper presents new whole-rock geochemistry, Sr-Nd isotopic and ⁴⁰Ar-³⁹Ar age data for Middle Eocene volcanic rocks from the Bayburt area of the Eastern Pontides (NE Turkey) to investigate their sources and evolutionary history. The new ⁴⁰Ar–³⁹Ar ages reveal that these volcanic rocks erupted between 44.6 ± 0.1 Ma and 43.5 ± 0.1 Ma, within the Lutetian (Middle Eocene). The studied volcanic rocks are composed of basalt, andesite, basaltic andesite and minor dacite lava and pyroclastic rocks. These rocks consist of plagioclase, amphibole, pyroxene, olivine, biotite, sanidine and minor quartz phenocrysts with Fe-Ti oxides. They have microlithic, hyalo-microlithic, porphyritic and rarely glomeroporphyritic textures. The volcanic rocks have low to high-K calc-alkaline affinities. They display enrichment in large-ion lithophile elements and depletion in high-field strength elements with high Th/Yb ratios, which indicate that the magmas forming the volcanic rocks were derived from lithospheric mantle sources enriched by mostly slab-derived fluids in the spinel stability field. ⁸⁷Sr/⁸⁶Sr_(i) values vary between 0.70485 and 0.70551 and ¹⁴³Nd/¹⁴⁴Nd_(i) values vary between 0.51255 and 0.51267. These data correspond to the mantle array on the isotope ratio diagram. The main solidification processes consist of fractional crystallization with minor assimilation. In light of the data obtained in this study together with data from previous studies, petrogenetic character of the Middle Eocene magmas from the southern parts of the Eastern Pontides may be explained by melting of an enriched lithospheric mantle source initially metasomatized by subduction fluids in a post-collisional extensional-related tectonic setting.</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4899373","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":"Geochemical and zircon U-Pb geochronological constraints on late mesozoic Paleo-Pacific subduction-related volcanism in southern Vietnam","authors":"Anh T.Q. Nong,&nbsp;Christoph A. Hauzenberger,&nbsp;Daniela Gallhofer,&nbsp;Etienne Skrzypek,&nbsp;Sang Q. Dinh","doi":"10.1007/s00710-022-00785-z","DOIUrl":"10.1007/s00710-022-00785-z","url":null,"abstract":"<div><p>Late Mesozoic volcanic rocks comprising mainly basalt and basaltic-andesite to dacite occur in south-central Vietnam (Dalat zone) and to a lesser extent in southwestern Vietnam (Bay Nui area). Mineral and whole-rock chemistry indicate a calc-alkaline affinity for samples in the Dalat zone and a high-K calc-alkaline to shoshonitic affinity for rocks in the Bay Nui area. Mineral characteristics and variation diagrams of selected elements suggest that fractional crystallization dominated during magma differentiation. The Bay Nui volcanic rocks generally are more enriched in potassium and LILEs (large-ion lithophile elements) than volcanic rocks from the Dalat zone, which may indicate a more evolved nature or crustal assimilation. The similar chemical characteristics and eruption/emplacement age range of volcanic and plutonic rocks (ca. 90–110 Ma) of equal silica concentration indicate that the magma feeding the volcanic eruptions had the same source as that of the plutonic rocks. The observed mineral and whole-rock compositions with enrichment in LILEs, depletion in HFSEs (high field strength elements), and noticeably negative Nb, Ta, and Ti anomalies are characteristic for arc signatures. Zircon U-Pb geochronological data for the volcanic rocks indicate an age range of 95–105 Ma for the eruption. These geochemical and geochronological data link this Late Mesozoic volcanism with continental arc magmatism driven by the subduction of the Paleo-Pacific beneath eastern Indochina. Zircon xenocrysts with a likely magmatic origin cluster around 350 Ma and 250 Ma, indicating two earlier magmatic events most likely related to the subduction of the Paleo-Tethys beneath western Indochina and the subsequent Indosinian orogeny.</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00710-022-00785-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4859965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reply to the comment by F. Sajjadi Alehashem and M. Moazzen","authors":"Rasoul Sheikhi Gheshlaghi,&nbsp;Mansour Ghorbani,&nbsp;Reza Deevsalar","doi":"10.1007/s00710-022-00784-0","DOIUrl":"10.1007/s00710-022-00784-0","url":null,"abstract":"","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00710-022-00784-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4865028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orishchinite, a new terrestrial phosphide, the Ni-dominant analogue of allabogdanite","authors":"Sergey N. Britvin,&nbsp;Mikhail N. Murashko,&nbsp;Yevgeny Vapnik,&nbsp;Anatoly N. Zaitsev,&nbsp;Vladimir V. Shilovskikh,&nbsp;Maria G. Krzhizhanovskaya,&nbsp;Liudmila A. Gorelova,&nbsp;Oleg S. Vereshchagin,&nbsp;Evgeny A. Vasilev,&nbsp;Natalia S. Vlasenko","doi":"10.1007/s00710-022-00787-x","DOIUrl":"10.1007/s00710-022-00787-x","url":null,"abstract":"<div><p>Orishchinite is a new terrestrial phosphide discovered in pyrometamorphic rocks of the Daba-Siwaqa combustion complex in West Jordan. The mineral occurs as an accessory phase in the fused clinopyroxene-plagioclase rock (paralava) texturally resembling gabbro-dolerite. Orishchinite forms resorbed equant grains up to 0.2 mm outrimmed with 0.1–0.2 thick zones of substituting murashkoite, FeP. Chemical composition (electron microprobe, wt%): Ni 38.49, Fe 22.38, Co 0.47, Mo 18.80, P 19.46, Total 99.60, corresponding to the empirical formula (Ni_1.04Fe_0.64Mo_0.31Co_0.01)_Σ2.00P on the basis of 3 <i>apfu</i>. The simplified formula is (Ni,Fe,Mo)₂P and the ideal one is Ni₂P. Macroscopically, orishchinite grains have yellowish-white colour with metallic lustre. The mineral is brittle. In reflected light, orishchinite is yellowish-white and non-pleochroic. It is very weakly anisotropic (Δ<i>R</i>₅₈₉ = 1.3%). Reflectance values for the wavelengths recommended by the Commission on Ore Mineralogy of the International Mineralogical Association are [<i>R</i>_max/<i>R</i>_min (%), λ (nm)]: 48.1/47.5, 470; 50.6/49.4, 546; 52.1/50.8, 589; 54.4/52.9.1, 650. The crystal structure was solved and refined to <i>R</i>₁ = 0.016 based on 224 unique observed [<i>I</i> ≥ 2σ(<i>I</i>)] reflections. Orishchinite is orthorhombic, space group <i>Pnma</i>, <i>a</i> 5.8020(7), <i>b</i> 3.5933(4), <i>c</i> 6.7558(8) Å, <i>V</i> 140.85(3) ų, <i>Z</i> = 4, <i>D</i>_x = 7.695 g cm^-3. The strongest lines of the powder X-ray diffraction pattern [(<i>d</i>, Å) (<i>I</i>, %) (<i>hkl</i>)] are: 2.265(100)(112), 2.201(16)(202), 2.142(55)(211), 2.100(35)(103), 1.909(21)(013), 1.811(19)(113), 1.796(31)(020). Orishchinite is dimorphous with transjordanite (hexagonal Ni₂P) and can be considered the Ni-dominant analogue of allabogdanite.</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00710-022-00787-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4494321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variscan lamprophyres of the South Armorican Domain and comparison with lamprophyres of the Western European Variscan belt","authors":"André Pouclet,&nbsp;Jacques-Marie Bardintzeff,&nbsp;Hervé Bellon","doi":"10.1007/s00710-022-00786-y","DOIUrl":"10.1007/s00710-022-00786-y","url":null,"abstract":"<div><p>Late to post-orogenic lamprophyres of the European Variscides attest variable compositions of the mantle beneath the structural zones of the belt. These compositions resulted from different contributions of mantle components involving geotectonic processes during the orogeny, such as oceanic subduction of mafic crust and sediments, continental subduction, collision with mantle input, and delamination of overriding plates. For documenting these processes, we have surveyed three sites of lamprophyre intrusions in the Vendean part of the South Armorican tectonic Zone with spessartite sills and minette dykes, and a fourth site in the West-Armorican kersantite swarm. The age of spessartite is estimated between 320 and 315 Ma on the base of structural relationships with the dated neighbouring granite. Dykes of minette share similar intrusive setting along the post-orogenic NW–SE dextral shear zones. One dyke is dated at 286.2 ± 6.6 Ma (Early Permian) by K/Ar method. The Western Brittany kersantite swarm is Middle to Late Carboniferous in age. All these rocks display common mineral and chemical compositions of lamprophyres. A review of the Variscan European lamprophyres is conducted in order to document their geochemical fingerprints compared with those of the studied samples.</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4164277","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":"Comment on “Petrogenesis of gem sapphire in a pegmatite-aplite vein from the Alvand batholith, Western Iran” (2020) by R. Sheikhi Gheshlaghi, M. Ghorbani, A. A. Sepahi, R. Deevsalar and R. Shinjo","authors":"Fariba Sajjadi Alehashem,&nbsp;Mohssen Moazzen","doi":"10.1007/s00710-022-00782-2","DOIUrl":"10.1007/s00710-022-00782-2","url":null,"abstract":"<div><p>Corundum crystals of semi-gem quality (sapphire) formed in a syenitic dyke around the plutonic rocks in the Alvand igneous-metamorphic complex were studied by Sheikhi Gheshlaghi et al. (2020). These authors studied field relations and petrography of a corundum-bearing pegmatite, and proposed a genetic model for corundum formation. Although studies on whole rock chemistry of corundum-bearing pegmatites and oxygen isotope data for corundum by these authors are valuable, some of their reports and findings – such as the sharp contact between corundum-bearing pegmatite and Alvand syenite, the lack of tourmaline group minerals in corundum-bearing pegmatite, the presence of syngeneic quartz inclusion in corundum and the genesis of corundum as a result of kyanite break down – are in contrast with our own observations and findings. Neither the P-T conditions, nor the volatile-bearing minerals present, are in favour of formation of corundum from kyanite breakdown. Based on present authors’ studies, mineral chemistry of corundum in the Alvand area clearly indicates magmatic origin.</p></div>","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4389714","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":"Carbonatite-melilitite-phosphate immiscible melts from the aragonite stability field entrained from the mantle by a Pliocene basalt","authors":"V. Hurai, M. Huraiová, G. Habler, M. Horschinegg, R. Milovský, S. Milovská, M. Hain, R. Abart","doi":"10.1007/s00710-022-00783-1","DOIUrl":"https://doi.org/10.1007/s00710-022-00783-1","url":null,"abstract":"","PeriodicalId":18547,"journal":{"name":"Mineralogy and Petrology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44886741","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}