 | | Journal (article/letter/editorial) | | MUIR and c. E. T I L L E Y , with chemical analyses by j. H. SCOON Department of Mineralogy and Petrology...dredge hauls along with colonial branching corals and foraminifera from the central part of the Mid-Atlantic...the rocks come from two localities 5 miles apart and were collected during the autumn cruise of R.R.S...basalts or dolerites carrying a single pyroxene phase and most have transitional or slightly alkaline affinities...represented. Many of the specimens have chilled selvedges and can be shown to be pillow lavas. Important features |  | | Journal (article/letter/editorial) | | Abstract The dominant petrochemical evolution of St. Helena volcanics is from undersaturated alkali olivine...nepheline normative trachybasalt and trachyandesite to trachyte and phonolite. A unique lava is described...extreme iron enrichment and internal fractionation towards a granitic mesostasis, and hence is quite unlike...volcanic rocks from this or any other Atlantic island. The unique chemistry is also reflected in the...remain enigmatic. Introduction St. Helena is a volcanic island situated in the South Atlantic (5'40'W; |  | | Journal (article/letter/editorial) | | silicate melt inclusions in Ascension Island granite xenoliths J. D. WEBSTER1,* and C. R. REBBERT2 1 Department...Department of Earth and Planetary Sciences, American Museum of Natural History, Central Park West at 79th...alkaline volcanic rocks of Ascension Island were analyzed for 29 major, minor, and trace elements. For most...are similar to those of the volcanic whole rocks and the xenoliths; we interpret the glasses to be chemically...alkaline; contain low S and P abundances; and are enriched in H2O, Cl, F, and Na relative to K. Inclusions |  | | Journal (article/letter/editorial) | | Lavas and Associated Plutonic Inclusions of Ascension Island by CHRIS HARRIS1 Dept. of Geology and Mineralogy...in revisedform 5 May 1983) INTRODUCTION Ascension Island is a large composite volcano situated at approximately...the South Atlantic Ocean (Fig. 1). The Island is 98 km2 in area and represents the uppermost portion of...March 29, 2014 ABSTRACT The lavas and pyroclastics of Ascension Island contain a suite of plutonic inclusions...trachyandesite and trachyte to comendite. Basalt sensu stricto is relatively rare and there is a scarcity |  | | Report (volume) | | Carlton Victoria 3053, Australia DISTRIBUTORS USA and Canada Blackwell Scientific Publications Inc PO Box...granted by The Geological Society for libraries and other users registered with the Copyright Clearance...Typeset, printed and bound in Great Britain by William Clowes Limited, Beccles and London Library of...metasomatism--perspective and prospect vii ix 1 MENZIES, M. Alkaline rocks and their inclusions: a window...experimental studies 29 LE Bhs, M. J. Nephelinites and carbonatites 53 TWYMAN, J. D. & GITTINS, J. Alkalic |  | | Journal (article/letter/editorial) | | Crustal Contamination CHRIS HARRIS1∗, JULIAN S. MARSH2 AND SIMON C. MILNER3 1 DEPARTMENT OF GEOLOGICAL SCIENCES...sub-alkaline suite, (2) an outer quartz syenite suite, and (3) an inner silicaundersaturated suite dominated...explained by fractional crystallization, but Sr- and O-isotope data indicate that these rocks contain...syenites trend towards the 0·1 GPa phonolite minimum and appear to have evolved by closed system fractional...element and Nd- and Sr-isotope characteristics that are similar to those of basanites from Tristan da Cunha |  | Moreno, J.A., Molina, J.F., Bea, F., Abu Anbar, M., Montero, P. (2016) Th-REE- and Nb-Ta-accessory minerals in post-collisional Ediacaran felsic rocks from the Katerina Ring Complex (S. Sinai, Egypt): An assessment for the fractionation of Y/Nb, Th/Nb, La/Nb and Ce/Pb in highly evolved A-type granites. Lithos, 258. 173-196 doi:10.1016/j.lithos.2016.04.020 | Journal (article/letter/editorial) | | Th-REE- and Nb-Ta-accessory minerals in post-collisional Ediacaran felsic rocks from...assessment for the fractionation of Y/Nb, Th/Nb, La/Nb and Ce/Pb in highly evolved A-type granites J.A. Moreno...F., Bea, F., Anbar, M. Abu, Montero, P., Th-REE- and Nb-Ta-accessory minerals in post-collisional Ediacaran...assessment for the fractionation of Y/Nb, Th/Nb, La/Nb and Ce/Pb in highly evolved A-type granites, LITHOS (2016)...manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published |  | | Journal (article/letter/editorial) | | Magmatic Inclusions in the Plutonic Ejecta of Ascension Island by CHRIS HARRIS* (Received 25 May 1984; revised...Plutonic blocks' in the volcanic and pyroclastic rocks of Ascension Island contain a variety of silicate... mainly in the intermediate (monzonite-syenite) and granite types. The silicate melt inclusions consist...density CO2 + H 2 0 inclusions, predominantly vapour and (iii) high density approximately pure H2O inclusions...5 wt. per cent H2O before saturation was reached and homogenization temperatures show the trapping of |  | White, J. C., Ren, M., Parker, D. F. (2005) VARIATION IN MINERALOGY, TEMPERATURE, AND OXYGEN FUGACITY IN A SUITE OF STRONGLY PERALKALINE LAVAS AND TUFFS, PANTELLERIA, ITALY. The Canadian Mineralogist, 43 (4) 1331-1347 doi:10.2113/gscanmin.43.4.1331 | Journal (article/letter/editorial) | | MINERALOGY, TEMPERATURE, AND OXYGEN FUGACITY IN A SUITE OF STRONGLY PERALKALINE LAVAS AND TUFFS, PANTELLERIA...ABSTRACT Eight samples of pantelleritic lava and tuff and a lithic inclusion of trachyte from Pantelleria...the presence of fayalite, aenigmatite, ilmenite, and magnetite: (1) augite + fayalite + ilmenite + magnetite...augite + fayalite + ilmenite, (3) hedenbergite or sodian hedenbergite + fayalite + ilmenite + aenigmatite...sodian hedenbergite or aegirine-augite + ilmenite + aenigmatite + quartz ± ferrorichterite, and (5) aegirine-augite |  | | Journal (article/letter/editorial) | | leading to unmixing of carbonatites on Brava Island (Cape Verde) and a general model of carbonatite genesis...Heidelberg 2016 Abstract The carbonatites of Brava Island, Cape Verde hot spot, allow to investigate whether...fractions or form through extreme fractionation and/or liquid immiscibility from CO2-bearing silicate...silicate magmas. The intrusive carbonatites on Brava Island are part of a strongly silica-undersaturated pyroxenite...combeite–foiditite, carbonatite series. The major and trace element composition of this suite is reproduced |  | | Journal (article/letter/editorial) | | S.P. TurneP, J.D. Foden ~ and R.S. Morrison" "The Department of Geology and Geophysics. Ut~iversio,of...Australia bGeological Survey. Department of Mine~ and Energ3". GPO Box 2655 Alwe Springs, N, T.. 5 750...1991; revised and accepted January 31, 1992) LITHOS ~ ~ Turner, S.P., Foden, J.D. and Morrison. R.S...petrogenetic schemes have been proposed for A-type granitic and volcanic rocks, many involving melting of l-type...models can be shown to have several shortcomings and whilst there may be various kinds of A-type magmas |  | | Journal (article/letter/editorial) | | Contr. Mineral. and Petrol. 28, 340---351 (1970) 9 by Springer-Verlag 1970 Petrochemical Variations...(Comendite) Obsidians from the Oceans and Continents D. K. B ~ L v . r and R. M~CDO~ALD * Department of Geology...Abstract. Eleven new analyses and modes of comendite obsidians are presented, and compared with all available...commonly alkali feldspar. The oxides Si02, M~O3, Na~O and K~O total over ninety percent by weight in all analyses...projected into the system Na~OK20-AI~Oa-SiO2, oceanic and continental samples group differently. Oceanic specimens |  | | Journal (article/letter/editorial) | | Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office:...Publication details, including instructions for authors and subscription information: http://www.tandfonline...Yevdokimov b a Institute of Precambrian Geology and Geochronology , USSR Academy of Sciences , Leningrad...platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties...opinions and views expressed in this publication are the opinions and views of the authors, and are not |  | | Journal (article/letter/editorial) | | Subjects in lower-case roman, and Localities in italics. The minerals, localities, and authors mentioned in the...reports of the I.M.A. Commission on New Minerals and in the 25th List of new m i n e r a l n a m e s (...lithian, synthesis, equilibrium with eucryptite and with fl-spodumene, 578. Alluaudite, Rhodesia, 50...Botswana, anal., opt., X-ray, sp. gr., 775; Norway and Sweden, anal. (TiO 2 only), opt., X-ray, 775. Animas...Sb4ObC1~ and SbsOnC] 2 (onoratoite), 1037. Apatite, equilibrium studies of, 539; Rhodesia and Uga~da, opt |  | | Journal (article/letter/editorial) | | differentiation * EDWIN ROEDDER Department of Earth and Planetary Science, Harvard University, Cambridge...review of recent work on melt inclusions in diamond and in normal magmatic environments, the nature of the...latestage water-rich fluids (yielding quartz veins and ore deposits), the composition of the residual liquid...polycomponent solutions (fluids), differing in properties and generally in composition. I believe that the great...silicate melt/low density vapor (i.e., vesiculation ), and, as presented in more detail in this paper, various |  | | Journal (article/letter/editorial) | | Peralkaline Silicic Magmas and Petrogenetic Implications BRUNO SCAILLET1∗ AND RAY MACDONALD2 1 INSTITUT...tite solid buffer, temperatures between 740 and 660°C, and melt evolution under near H2O saturation conditions...have been established at 150 and 50 MPa, at oxygen fugacities of NNO − 1·6 and NNO + 3·6 (log fO2 relative...buffer), between 800 and 660°C and for melt H2O contents ranging between saturation and nominally anhydrous...fields of fayalite, sodic amphiboles, chevkinite and fluorite in natural hydrous silicic magmas are established |  | Brenna, Marco, Nakada, Setsuya, Miura, Daisuke, Toshida, Kiyoshi, Ito, Hisatoshi, Hokanishi, Natsumi, Nakai, Shun’ichi (2015) A trachyte–syenite core within a basaltic nest: filtering of primitive injections by a multi-stage magma plumbing system (Oki-Dōzen, south-west Japan) Contributions to Mineralogy and Petrology, 170 (2) doi:10.1007/s00410-015-1181-0 | Journal (article/letter/editorial) | | succession of basaltic to trachybasaltic lavas and pyroclastic rocks and dispersed trachytic bodies. The central...present whole-rock major and trace element chemistry, Sr–Nd–Pb isotopic compositions and petrological data from...from the central trachytic volcanic complex and the intrusive syenite body, as well as from the outer...also present and discuss a new set of zircon U/Pb ages collected from the central trachyte and syenite bodies...through crystal fractionation and minor crustal assimilation occurred in crustal and shallow sub-volcanic magma |  | | Journal (article/letter/editorial) | | FRANCESCHELLI1*, GABRIELE CRUCIANI1, MARIANO PUXEDDU2 and DANIELA UTZERI1 1 Dipartimento di Scienze della...proportions of plagioclase and pyroxene igneous relics and metamorphic minerals. Major and trace element data...high TiO2 and P2O5 and low K and Rb contents, as well as light rare-earth elements, Nb and Ta enrichment...enrichment, suggest an alkaline affinity for the gabbro and emplacement in a within-plate tectonic setting. The...ocean island alkali basalt-like asthenospheric mantle source enriched with incompatible elements and uncontaminated |  | | Journal (article/letter/editorial) | | chloride liquids Jim D. Webster * Department of Earth and Planetary Sciences, American Museum of Natural History...Cl-enriched volatile phase that occurs in magmas, and the exsolution of this phase has important consequences...consequences for processes of hydrothermal mineralization and for volcanic emission of Cl to the atmosphere. To...felsic to mafic magmas, the volatile abundances and (Cl/H2O) ratios of more than 1000 silicate melt inclusions...compared with predicted and experimentally determined solubilities of Cl and H2O and associated (Cl/H2O) |  | | Journal (article/letter/editorial) | | online 6 June 2006 Abstract The phase relationships and compositions of a pantellerite from the Eburru complex...Kenya Rift Valley have been determined at 150 MPa and under reducing conditions, 2 log units below the...temperature and melt water content on phase relationships have been explored. Alkali feldspar and quartz crystallise...melt water content. Below 700 °C, sodic amphibole and clinopyroxene also crystallise; the amphibole being...alkali feldspar and quartz in a crystal-poor pantellerite implies temperatures below 700 °C and melt water |  | LEGENDRE, C., MAURY, R. C., CAROFF, M., GUILLOU, H., COTTEN, J., CHAUVEL, C., BOLLINGER, C., HÉMOND, C., GUILLE, G., BLAIS, S., ROSSI, P., SAVANIER, D. (2005) Origin of Exceptionally Abundant Phonolites on Ua Pou Island (Marquesas, French Polynesia): Partial Melting of Basanites Followed by Crustal Contamination. Journal of Petrology, 46 (9) 1925-1962 doi:10.1093/petrology/egi043 | Journal (article/letter/editorial) | | of Exceptionally Abundant Phonolites on Ua Pou Island (Marquesas, French Polynesia): Partial Melting...cover 65% of the surface of the island whereas mafic lavas cover 27% and intermediate ones 8%. The silica-undersaturated...primitive basanites, leaving an amphibole-rich residuum and producing tephriphonolitic magmas. These tephriphonolitic...E-mail: christelle.legendre@univ-nantes.fr (Group C) and extreme fractionation coupled with assimilation of...volcanics). They are generally associated in space and time with basanitic lavas, whereas trachytes are |  | Owen-Smith, T.M., Ashwal, L.D., Torsvik, T.H., Ganerød, M., Nebel, O., Webb, S.J., Werner, S.C. (2013) Seychelles alkaline suite records the culmination of Deccan Traps continental flood volcanism. Lithos, 182. 33-47 doi:10.1016/j.lithos.2013.09.011 | Journal (article/letter/editorial) | | WITS 2050, South Africa Centre for Earth Evolution and Dynamics (CEED), University of Oslo, PO Box 1047...mantle plume Seychelles a b s t r a c t Silhouette and North Islands in the Seychelles represent an alkaline...plutonic–volcanic complex, dated at 63 to 63.5 Ma by U–Pb zircon and 40Ar/39Ar methods. This magmatism coincides with...continental flood volcanism in India (67 to 63 Ma), and thus a causal link has been suggested. Recent reconstructions...the Seychelles islands adjacent to the Laxmi Ridge and at the western margin of the Réunion mantle plume |  | Chakrabarty, A., Mitchell, R. H., Ren, M., Saha, P. K., Pal, S., Pruseth, K. L., Sen, A. K. (2016) Magmatic, hydrothermal and subsolidus evolution of the agpaitic nepheline syenites of the Sushina Hill Complex, India: implications for the metamorphism of peralkaline syenites. Mineralogical Magazine, 80 (7) 1161-1193 doi:10.1180/minmag.2016.080.057 | Journal (article/letter/editorial) | | Vol. 80(7), pp. 1161–1193 Magmatic, hydrothermal and subsolidus evolution of the agpaitic nepheline syenites...MITCHELL2, M. REN3, P. K. SAHA1, S. PAL1, K. L. PRUSETH4 AND A. K. SEN5 1 2 3 4 5 Department of Geology, Durgapur...Nevada, Las Vegas, Nevada, USA Department of Geology and Geophysics, Indian Institute of Technology Kharagpur...is the only agpaitic complex, reported from India and is characterized by a eudialyte-rinkite-bearing nepheline...of evolution from magmatic to hydrothermal stages and low-temperature subsolidus reequilibration assemblage |  | | Journal (article/letter/editorial) | | Islands) F. RIDOLFI1, A. RENZULLI1,*, P. SANTI1 1 2 AND B. G. J. UPTON2 Istituto di Vulcanologia e Geochimica...Urbino, I-61029 Urbino, Italy Department of Geology and Geophysics, University of Edinburgh, EH9 3JW Edinburgh...Islands) are divisible into (1) silica-undersaturated and (2) silica-saturated/oversaturated groups. The first...syenites of both groups crystallized at shallow depths and whole-rock geochemistry shows that they have compositions...during which most of the feldspar growth occurred; and (3) a late interstitial stage. Crystallization of |  | | Journal (article/letter/editorial) | | Rhyolites of the Kenya Rift Valley BRUNO SCAILLET1* AND RAY MACDONALD2 INSTITUT DES SCIENCES DE LA TERRE...fayalite---magnetite--quartz buffer) and at high fF2 inhibits calcic clinopyroxene and yields residual liquids that...relatively low SiO2 (66 wt %) and Al2O3 (74 wt %), and high FeO (102 wt %) and Na2O (84 wt %) contents...trachytes, rhyolites and phonolites. Such rocks commonly occur, in both continental and oceanic settings...(Ayalew et al., 2002). However, in some volcanoes and volcanic fields, peralkaline salic rocks can be the |
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