DOCSLIB.ORG

Non-Metamict Aeschynite-(Y), Polycrase-(Y), and Samarskite-(Y) in NYF Pegmatites from Arvogno, Vigezzo Valley (Central Alps, Italy)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Non-Metamict Aeschynite-(Y), Polycrase-(Y), and Samarskite-(Y) in NYF Pegmatites from Arvogno, Vigezzo Valley (Central Alps, Italy) minerals Article Non-Metamict Aeschynite-(Y), Polycrase-(Y), and Samarskite-(Y) in NYF Pegmatites from Arvogno, Vigezzo Valley (Central Alps, Italy) Alessandro Guastoni 1,*, Luciano Secco 1, Radek Škoda 2 , Fabrizio Nestola 1 , Mariangela Schiazza 3 , Milan Novák 2 and Giorgio Pennacchioni 1 1 Department of Geosciences, Padova University, Via Gradenigo 6, 35131-I Padova, Italy; [email protected] (L.S.); [email protected] (F.N.); [email protected] (G.P.) 2 Department of Geological Sciences, Faculty of Science, Masaryk University, Kotlarska 2 CZ 611 37, Brno, Czech Republic; [email protected] (R.Š.); [email protected] (M.N.) 3 DiSPuTer, Chieti-Pescara University, Via dei Vestini 31, 66100-I Chieti, Italy; [email protected] * Correspondence: [email protected]; Tel.: +39-0498272006 Received: 19 April 2019; Accepted: 16 May 2019; Published: 21 May 2019 Abstract: At Arvogno, Vigezzo valley in the Central Alps, Italy, pegmatite dikes are unique in the scenario of a tertiary alpine pegmatite field because they show marked geochemical and mineralogical niobium–yttrium–fluorine features. These pegmatites contain AB2O6 aeschynite group minerals and ABX2O8 euxenite group minerals as typical accessory minerals including aeschynite-(Y), polycrase-(Y), and samarskite-(Y). They are associated with additional typical minerals such as fluorite, Y-dominant silicates, and xenotime-(Y). The Y–Nb–Ti–Ta AB2O6 and ABX2O8 oxides at the Arvogno pegmatites did not exhibit any textural and compositional features of oxidation or weathering. They are characterized by low self-radiation-induced structural damage, leading to the acquisition of unit-cell data for aeschynite-(Y), polycrase-(Y), and samarskite-(Y) by single-crystal X-ray diffraction. Aeschynite-(Y) and polycrase-(Y) crystals allowed for both to provide space groups whereas samarskite-(Y) was the first crystal from pegmatites for which cell-data were obtained at room temperature but did not allow for the accurate determination of the space group. According to the chemical compositions defined by Ti-dominant content at the B-site, the cell parameters, respectively, corresponded to polycrase-(Y), aeschynite-(Y), and the monoclinic cell of samarskite-(Y). Emplacement of Alpine pegmatites can be related to the progressive regional metamorphic rejuvenation from east to west in the Central Alps, considering the progressive cooling of the thermal Lepontine Barrovian metamorphic dome. Previous studies considered magmatic pulses that led to emplace the pegmatite field in the Central Alps. As an example, the pegmatites that intruded the Bergell massif were aged at 28–25 millions of years or younger, around 20–22 m.y. Keywords: aeschynite-(Y); Arvogno; Central Alps; euxenite-(Y); NYF pegmatites; polycrase-(Y); samarskite-(Y); Vigezzo valley 1. Introduction Complex REE–Nb–Ta–Ti oxides (aeschynite-, euxenite-, and samarskite-group minerals) are uncommon but locally important accessory phases occurring typically in the NYF (niobium, yttrium, fluorine) family and REL–REE (rare-element and rare earths) class (as per the listed pegmatites of allanite-, euxenite-, and gadolinite-type by Cernˇ ý and Ercit [1]). Aeschynite- and euxenite-group minerals have a general formula AB2O6 where the eight-fold coordinated A-site, a square antiprism, is occupied by Y, REE, Ca, U, Th, Fe, while the six-fold coordinated B-site has a typical octahedra to form double chains in a zigzag pattern along the b-axis [2] occupied by Ti, Nb, Ta. and W. Aeschynite-group Minerals 2019, 9, 313; doi:10.3390/min9050313 www.mdpi.com/journal/minerals Minerals 2019, 9, 313 2 of 23 Minerals 2019, 9, x FOR PEER REVIEW 2 of 21 mineralsform double (AGMs) chains and in euxenite-group a zigzag pattern minerals along (EGMs)the b-axis are [2] orthorhombic, occupied by Ti, but Nb, the Ta. BO 6andstacking W. octahedraAeschynite-group is different, minerals leading (AGMs) to the Pbnm and spaceeuxenite-g grouproup in AGMsminerals and (EGMs) to the arePbcn orthorhombic,space group but in EGMs.the Historically,BO6 stacking samarskite-group octahedra is different, minerals leading have to the Pbnm general space formula group ABOin AGMs4 and and an toα -PbOthe Pbcn2 primitive space structuregroup [in3, 4EGMs.]; Nb isHistorically, dominant atsamarskite-group the six-fold coordinated minerals have B-site, the and general the A-site formula is mostlyABO4 and occupied an byα REE,-PbO Ca,2 primitive U, Fe2+ structure, and Fe 3[3,4];+, although Nb is dominant some studies at the six-fold placed Fecoordinated3+ in the B-siteB-site, andand the Ti can A-site occupy is bothmostly sites occupied [5]. The by A-site REE, inCa, samarskite U, Fe2+, and isFe occupied3+, although by some REE, studies usually placed with Fe a3+ dominancein the B-site and of Y, Ti but samarskite-(Yb)can occupy both has sites also [5]. been The reported A-site in [ 6samarskite]. is occupied by REE, usually with a dominance of Y,Kjelmann but samarskite-(Yb) [7] proposed has a also new been nomenclature reported [6]. for samarskite-group minerals with a general formula Kjelmann [7] proposed a new nomenclature for samarskite-group minerals with a general ABC2O8. Recently, a new structural investigation of non-metamict samarskite-(Y) from Laacher See, formula ABC2O8. Recently, a new structural investigation of non-metamict samarskite-(Y) from Eifel volcanic region, Germany, revealed a unique cation-ordered niobate structure related to layered, Laacher See, Eifel volcanic region, Germany, revealed a unique cation-ordered niobate structure double tungstenates ABW2O8 by Britvin et al. [8]. These authors refined the crystal structure of related to layered, double tungstenates ABW2O8 by Britvin et al. [8]. These3 authors+ refined the crystal samarskite-(Y) as monoclinic P2/c and redefined the ideal formula to YFe Nb2O8. The nomenclature structure of samarskite-(Y) as monoclinic P2/c and redefined the ideal formula to YFe3+Nb2O8. The wasnomenclature approved by thewas Commissionapproved by on Newthe Minerals,Commission Nomenclature on New Minerals, and Classification, Nomenclature International and MineralogicalClassification, Association International (IMA-CNMNC) Mineralogical and Association is leading to (IMA-CNMNC) the end-member and formula is leading of samarskite-(Y), to the basedend-member on an ordered formula formula, of samarskite-(Y), ABX2O8. based on an ordered formula, ABX2O8. 4+ 4+ Yttrium-rareYttrium-rare earths-oxide earths-oxide minerals minerals typically typically contain contain elevated elevated concentrations concentrations of of U Uand4+ and Th Th4+and undergoand undergo self-radiation-induced self-radiation-induced structural structural damage damage leading leading to amorphization to amorphization of formerly of formerly crystalline lattice.crystalline This crystalline-to-amorphous lattice. This crystalline-to-amorphous transition (metamictization) transition (metamictization) is followed by substantialis followed changes by of physicalsubstantial properties changes [ 9of,10 ].physical Such metamict properties phases [9,10]. are Such very pronemetamict to hydrothermal phases are very alteration, prone whichto commonlyhydrothermal leads alteration, to substantial which changes commonly in the leads chemical to substantial composition changes of ainff ectedthe chemical domains composition [11–15]. ofThe affected Arvogno domains pegmatite [11–15]. dikes (Figure1) are unique within the tertiary alpine pegmatite field [ 16,17] showingThe marked Arvogno geochemical pegmatite and dikes mineralogical (Figure 1) are NYF unique features. within These the pegmatites tertiary alpine contain pegmatite aeschynite-(Y), field polycrase-(Y),[16,17] showing and samarskite-(Y)marked geochemical associated and withmineralogical further typical NYF features. NYF minerals These suchpegmatites as Y-rich contain fluorite, Y-richaeschynite-(Y), spessartine, polycrase-(Y), allanite-group and minerals, samarskite-(Y) gadolinite-(Y), associated and with xenotime-(Y). further typical This NYF mineral minerals assemblage such as Y-rich fluorite, Y-rich spessartine, allanite-group minerals, gadolinite-(Y), and xenotime-(Y). This and the chemical composition of minerals suggest that the examined pegmatites are typical examples mineral assemblage and the chemical composition of minerals suggest that the examined pegmatites of the NYF family enriched in Nb, Y, and other REE and F, fitting very well the definition of the NYF are typical examples of the NYF family enriched in Nb, Y, and other REE and F, fitting very well the family [18,19]. definition of the NYF family [18,19]. FigureFigure 1. Simplified1. Simplified structural structural map map of the of Centralthe Central Alps Alps with with the field the offield the of Alpine the Alpine pegmatites pegmatites showing theshowing locations the of locations the Vigezzo, of the Vigezzo, Codera, Codera, and the and Bodengo the Bodengo areas. areas. The The thick thick black black lines lines represent represent the Periadriaticthe Periadriatic Fault (FaultPF), the(PF Giudicarie), the Giudicarie Fault Fault (GF), ( andGF), theand Engadinethe Engadine Fault Fault (EF ).(EF The). The light-grey light-grey areas representareas represent quaternary quaternary deposits deposits along major along valleys. major valley The tertiarys. The tertiary batholith batholith of Bergell of (Br)Bergell is in (Br) dark-grey, is in dark-grey, and the smaller, younger Novate stockwork intrusion (No) is in black. A detailed and the smaller, younger Novate stockwork
Load more

Recommended publications
  • Washington State Minerals Checklist
    Division of Geology and Earth Resources MS 47007; Olympia, WA 98504-7007 Washington State 360-902-1450; 360-902-1785 fax E-mail: [email protected] Website: http://www.dnr.wa.gov/geology Minerals Checklist Note: Mineral names in parentheses are the preferred species names. Compiled by Raymond Lasmanis o Acanthite o Arsenopalladinite o Bustamite o Clinohumite o Enstatite o Harmotome o Actinolite o Arsenopyrite o Bytownite o Clinoptilolite o Epidesmine (Stilbite) o Hastingsite o Adularia o Arsenosulvanite (Plagioclase) o Clinozoisite o Epidote o Hausmannite (Orthoclase) o Arsenpolybasite o Cairngorm (Quartz) o Cobaltite o Epistilbite o Hedenbergite o Aegirine o Astrophyllite o Calamine o Cochromite o Epsomite o Hedleyite o Aenigmatite o Atacamite (Hemimorphite) o Coffinite o Erionite o Hematite o Aeschynite o Atokite o Calaverite o Columbite o Erythrite o Hemimorphite o Agardite-Y o Augite o Calciohilairite (Ferrocolumbite) o Euchroite o Hercynite o Agate (Quartz) o Aurostibite o Calcite, see also o Conichalcite o Euxenite o Hessite o Aguilarite o Austinite Manganocalcite o Connellite o Euxenite-Y o Heulandite o Aktashite o Onyx o Copiapite o o Autunite o Fairchildite Hexahydrite o Alabandite o Caledonite o Copper o o Awaruite o Famatinite Hibschite o Albite o Cancrinite o Copper-zinc o o Axinite group o Fayalite Hillebrandite o Algodonite o Carnelian (Quartz) o Coquandite o o Azurite o Feldspar group Hisingerite o Allanite o Cassiterite o Cordierite o o Barite o Ferberite Hongshiite o Allanite-Ce o Catapleiite o Corrensite o o Bastnäsite
    [Show full text]
  • Die Centovalli-Bahn Locarno-Domodossola
    Die Centovalli-Bahn Locarno-Domodossola Autor(en): Passet, Max Objekttyp: Article Zeitschrift: Schweizerische Bauzeitung Band (Jahr): 93/94 (1929) Heft 1 PDF erstellt am: 27.09.2021 Persistenter Link: http://doi.org/10.5169/seals-43373 Nutzungsbedingungen Die ETH-Bibliothek ist Anbieterin der digitalisierten Zeitschriften. Sie besitzt keine Urheberrechte an den Inhalten der Zeitschriften. Die Rechte liegen in der Regel bei den Herausgebern. Die auf der Plattform e-periodica veröffentlichten Dokumente stehen für nicht-kommerzielle Zwecke in Lehre und Forschung sowie für die private Nutzung frei zur Verfügung. Einzelne Dateien oder Ausdrucke aus diesem Angebot können zusammen mit diesen Nutzungsbedingungen und den korrekten Herkunftsbezeichnungen weitergegeben werden. Das Veröffentlichen von Bildern in Print- und Online-Publikationen ist nur mit vorheriger Genehmigung der Rechteinhaber erlaubt. Die systematische Speicherung von Teilen des elektronischen Angebots auf anderen Servern bedarf ebenfalls des schriftlichen Einverständnisses der Rechteinhaber. Haftungsausschluss Alle Angaben erfolgen ohne Gewähr für Vollständigkeit oder Richtigkeit. Es wird keine Haftung übernommen für Schäden durch die Verwendung von Informationen aus diesem Online-Angebot oder durch das Fehlen von Informationen. Dies gilt auch für Inhalte Dritter, die über dieses Angebot zugänglich sind. Ein Dienst der ETH-Bibliothek ETH Zürich, Rämistrasse 101, 8092 Zürich, Schweiz, www.library.ethz.ch http://www.e-periodica.ch 6. Juli 1929. SCHWEIZERISCHE BAUZEITUNG INHALT: Die Centovalli-Bahn Locarno-Domodossola (mit Tafeln 1 und 2). Technische Hochschule. Der schweizerische Geometerverein. Schweizerische Bundes- — Zugbildung und Effektschwankung im elektrischen Bahnbetrieb. — Neubau für bahnen Vom neuen Aufnahmegebäude des Bahnhofs Genf-Cornavin. Eidgenössische ¦das Naturhistorische Museum in Chur. — Mitteilungen: Von Versuchen über den Technische Hochschule. — Wettbewerbe: Gesellschaftshaus in Ennenda (Glarus).
    [Show full text]
  • Mineral Collecting Sites in North Carolina by W
    .'.' .., Mineral Collecting Sites in North Carolina By W. F. Wilson and B. J. McKenzie RUTILE GUMMITE IN GARNET RUBY CORUNDUM GOLD TORBERNITE GARNET IN MICA ANATASE RUTILE AJTUNITE AND TORBERNITE THULITE AND PYRITE MONAZITE EMERALD CUPRITE SMOKY QUARTZ ZIRCON TORBERNITE ~/ UBRAR'l USE ONLV ,~O NOT REMOVE. fROM LIBRARY N. C. GEOLOGICAL SUHVEY Information Circular 24 Mineral Collecting Sites in North Carolina By W. F. Wilson and B. J. McKenzie Raleigh 1978 Second Printing 1980. Additional copies of this publication may be obtained from: North CarOlina Department of Natural Resources and Community Development Geological Survey Section P. O. Box 27687 ~ Raleigh. N. C. 27611 1823 --~- GEOLOGICAL SURVEY SECTION The Geological Survey Section shall, by law"...make such exami­ nation, survey, and mapping of the geology, mineralogy, and topo­ graphy of the state, including their industrial and economic utilization as it may consider necessary." In carrying out its duties under this law, the section promotes the wise conservation and use of mineral resources by industry, commerce, agriculture, and other governmental agencies for the general welfare of the citizens of North Carolina. The Section conducts a number of basic and applied research projects in environmental resource planning, mineral resource explora­ tion, mineral statistics, and systematic geologic mapping. Services constitute a major portion ofthe Sections's activities and include identi­ fying rock and mineral samples submitted by the citizens of the state and providing consulting services and specially prepared reports to other agencies that require geological information. The Geological Survey Section publishes results of research in a series of Bulletins, Economic Papers, Information Circulars, Educa­ tional Series, Geologic Maps, and Special Publications.
    [Show full text]
  • Niobian Rutile and Its Associations at Jolotca, Ditrau Alkaline Intrusive Massif, East Carpathians, Romania
    THE PUBLISHING HOUSE GEONOMY OF THE ROMANIAN ACADEMY Review article NIOBIAN RUTILE AND ITS ASSOCIATIONS AT JOLOTCA, DITRAU ALKALINE INTRUSIVE MASSIF, EAST CARPATHIANS, ROMANIA Paulina HIRTOPANU1, Robert J. FAIRHURST2 and Gyula JAKAB3 1Department of Mineralogy, University of Bucharest, 1, Nicolae Balcescu Blv., 010041 Bucharest, RO; 2Technical Laboratory at Lhoist North America, Inc., 3700 Hulen Street, Forth Worth, Texas 76107, US; 3IG Mineral Gheorgheni, Romania Corresponding author: Paulina HIRTOPANU, E-mail: [email protected] Accepted December 17, 2014 The Nb-rutile at Jolotca, situated in Ditrau alkaline intrusive complex occurs as intergrowths with ilmenite, Mn-ilmenite, Fe-pyrophanite and has ferrocolumbite, manganocolumbite, aeshynite-(Ce), aeshynite-(Nd), fergusonite-(Y), euxenite-(Y) and polycrase-(Y) exsolutions. The textural relations in this association show the replacement of niobian rutile by ilmenite and Mn ilmenite. Niobian rutile is the oldest mineral. Ilmenite and Mn-ilmenite occur as lamellar exsolutions in niobian rutile and as veins, and separately, in grains as solid solution with Fe-pyrophanite. The range of Nb2O5 content in Nb rutile varies generally from 2 to 15% wt. Sometimes, the values of Nb2O5 (up to 37.5% wt) are higher than any previously recorded for rutile from alkaline suites, pegmatites and carbonatites, having a chemical composition similar to that of old name „ilmenorutile”. Because of such a big difference in chemical composition, and the different kind of appearances of the two rutiles, they can be separated into two Nb rutile generations. The first niobian rutile (niobian rutile I) formed on old rutile, has low Nb2O5 (10-15wt%), and oscillatory composition. Its composition is characteristically close to stoichiometric TiO2.
    [Show full text]
  • Auf Den Wegen Rund Um Die Alpe Saléi Oberhalb Von Vergeletto Lernt Man Das Onsernonetal Besonders Gut Kennen: Es Zeigt Sich Einsam Und Durchwegs Gut Begehbar
    Auf den Wegen rund um die Alpe Saléi oberhalb von Vergeletto lernt man das Onsernonetal besonders gut kennen: Es zeigt sich einsam und durchwegs gut begehbar. 20 BERGWELTEN Stille Tage im Tessin Jenseits allen Touristenrummels bietet das Onsernonetal Flanierkilometer in schattigen Höhen und eine Aufbruchstimmung, die schweizweit ihresgleichen sucht. TEXT: UTA DE MONTE FOTOS: MARCO ROSSI BERGWELTEN 21 Links: Das Valle di Vergeletto ist ein wildromantisches Seitental des Onsernonetals. Rechts: Aaron und Paolo geniessen nach dem Lamatrekking am Monte Comino die Pause in der Hängematte. homas sitzt auf dem kleinen strahlt gleichzeitig auch das gemütliche mit erfrischenden Wasserfällen zum Out­ Balkon der Villa Edera und Ambiente, den lässigen Lebensstil sowie door­Bad bereit. Kleine Dörfer mit traditi­ tippt eifrig auf seinem Smart­ die weltoffene Atmosphäre aus, die man onellen Steinhäusern kleben wie Nester an T phone herum. Er seufzt, fährt von Backpacker­Unterkünften in der wei­ den oberen Hanglagen und recken ihre sich nervös mit den Händen durch den ten Welt so kennt. schlanken, spitzen Kirchtürme imposant schwarzen Lockenkopf, löscht seine Ein­ Nicht zuletzt ihre Lage trägt dazu bei, in die Höhe. gabe und blickt über das geschwungene dass man sich hier ein klein wenig ent­ Eisen geländer ins Onsernonetal. «Wie soll rückt fühlt: Spitze Zacken in der Ferne KLAR IM KOPF, GLÜCK AM BERG ich das nur beschreiben?» Thomas beisst winken im Licht des Vollmondes aus Ita­ Das Tal ist eng, die Fahrbahn schmal, wes­ sich auf die Unterlippe, dann schaut mich lien herüber; auf der Gegenseite strahlen halb viele Reisende den Postautoverkehr der sportliche St. Galler Jungförster, der die Laternen von Locarno und Ascona in nutzen, um die Region zu erkunden.
    [Show full text]
  • O, a New Mineral of the Titanite Group from the Piława Górna Pegmatite, the Góry Sowie Block, Southwestern Poland
    Mineralogical Magazine, June 2017, Vol. 81(3), pp. 591–610 Żabińskiite, ideally Ca(Al0.5Ta 0.5)(SiO4)O, a new mineral of the titanite group from the Piława Górna pegmatite, the Góry Sowie Block, southwestern Poland 1,* 2 3 3 4 ADAM PIECZKA ,FRANK C. HAWTHORNE ,CHI MA ,GEORGE R. ROSSMAN ,ELIGIUSZ SZEŁĘG , 5 5 6 6 7 ADAM SZUSZKIEWICZ ,KRZYSZTOF TURNIAK ,KRZYSZTOF NEJBERT ,SŁAWOMIR S. ILNICKI ,PHILIPPE BUFFAT AND 7 BOGDAN RUTKOWSKI 1 AGH University of Science and Technology, Department of Mineralogy, Petrography and Geochemistry, 30-059 Kraków, Mickiewicza 30, Poland 2 Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada 3 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91125-2500, California, USA 4 University of Silesia, Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, 41-200 Sosnowiec, Bedzin̨ ská 60, Poland 5 University of Wrocław, Institute of Geological Sciences, 50-204 Wrocław, M. Borna 9, Poland 6 University of Warsaw, Faculty of Geology, Institute of Geochemistry, Mineralogy and Petrology, 02-089 Warszawa, Żwirki and Wigury 93, Poland 7 AGH University of Science and Technology, International Centre of Electron Microscopy for Materials Science, Department of Physical and Powder Metallurgy, 30-059 Kraków, Mickiewicza 30, Poland [Received 7 January 2016; Accepted 21 April 2016; Associate Editor: Ed Grew] ABSTRACT Ż ́ ł abinskiite, ideally Ca(Al0.5Ta0.5)(SiO4)O, was found in a Variscan granitic pegmatite at Pi awa Górna, Lower Silesia, SW Poland. The mineral occurs along with (Al,Ta,Nb)- and (Al,F)-bearing titanites, a pyrochlore-supergroup mineral and a K-mica in compositionally inhomogeneous aggregates, ∼120 μm× 70 μm in size, in a fractured crystal of zircon intergrown with polycrase-(Y) and euxenite-(Y).
    [Show full text]
  • A Glossary of Uranium- and Thorium-Bearing Minerals
    GEOLOGICAL SURVEY CIRCULAR 74 April 1950 A GLOSSARY OF URANIUM­ AND THORIUM-BEARING MINERALS By Judith Weiss Frondel and Michael F1eischer UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary GEOLOGICAL SURVEY W. E. Wrather, Director WASHINGTON. D. C. Free on application to the Director, Geological Survey, Washington 25, D. C. A GLOSSAR-Y OF URANIUM- AND THORIUM-BEARING MINERALS By Judith Weiss Fronde! and Michael Fleischer CONTENTS Introduction ••oooooooooo••••••oo•-•oo•••oo••••••••••oooo•oo••oooooo••oo•oo•oo•oooo••oooooooo•oo• 1 .A. Uranium and thorium minerals oooo oo oo ......................... oo .... oo oo oo oo oo oooooo oo 2 B. Minerals with minor amounts of uranium and thorium 000000000000000000000000.... 10 C. Minerals that should be tested for uranium and thorium ...... 00 .. 00000000000000 14 D. Minerals that are non-uranium- or non-thorium­ bearing, but that have been reported to contain impurities or intergrowths of uranium, thorium, or rare-earth minerals oooooo•oo ............ oo ... oo .. oooooo'""""oo" .. 0000 16 Index oo ...... oooooo•oo••••oo•oooo•oo•oooo•·~· .. •oooo•oooooooooooo•oooooo•oooooo•oooo••oo•••oooo••• 18 INTRODUCTION The U. S. ·Geological Survey has for some time been making a systematic survey of da~ pertaining to uranium and thorium minerals and to those minerals that contain trace1 or more of uranium and thorium. This survey consists of collecting authoritative chemical, optical, and X-ray diffraction data from the literature and of adding to these data, where inadequate, by work in the laboratory. The results will he reported from time to time, and the authors welcome in- formation on additional data and names.
    [Show full text]
  • Investigations Into the Synthesis, Characterisation and Uranium Extraction of the Pyrochlore Mineral Betafite
    Investigations into the Synthesis, Characterisation and Uranium Extraction of the Pyrochlore Mineral Betafite. A thesis submitted for the fulfilment of the requirements for the degree of Doctor of Philosophy (Ph.D.) Scott Alan McMaster B.Sc (App Chem) B.Sc (App Sci) (Hons) School of Applied Sciences College of Science, Engineering and Health RMIT University February 2016 II I Document of authenticity I certify that except where due acknowledgement has been made, the work is that of the author alone; the work has not been submitted previously, in whole or in part, to qualify for any other academic award; the content of the thesis is a result of work which has been carried out since the official commencement date of the approved research program; and, any editorial work, paid or unpaid, carried out by a third party is acknowledged. Scott A. McMaster February 2016 II Acknowledgements The research conducted in this thesis would not have been possible without the help of a number of people, and I would like to take this opportunity to personally thank them. Firstly, I’d like to thank my primary supervisor Dr. James Tardio; you have provided me with endless support and help throughout my 3rd year undergraduate research, honours and PhD candidature. Your enthusiasm, ideas, and patience have been essential in producing a thesis I can say I’m truly proud of. To Prof. Suresh Bhargava, I cannot thank you for your guidance and the opportunities that you have given me enough. You have taught me so much about being a good scientific communicator which I believe is one of the most valuable qualities I have gained throughout my candidature, for that I am extremely grateful.
    [Show full text]
  • Speciale Tessiner Zeitung
    Herbst 2014 Seit 1908, früher Extra-Ausgabe DerDer wildewilde SüdenSüden derder SchweizSchweiz Das Projekt im Locarnese als offizieller Kandidat für einen Nationalpark © G. Lob er Nationalpark des Locarnese liegt im “Wilden Geblieben von der einst blühenden alpinen Kultur sind gewaltige beraubend hinunter ins Centovalli, das Tal der Hundert Seitentä- Süden” der Schweiz: dort, wo die afrikanische Terrassierungen aus Trockenmauern, Tausende im Wald zerstreu- ler, zur Schlucht des Flusses Melezza. Weiter geht es über einen Kontinentalplatte auf die europäische stosst. Es ist te Rustici, sowie Dutzende intakter Dörfer, welche fast alle im alten Saumpfad ins wilde Onsernonetal. Zwei ganz besondere Ex- ein Gebiet der Extreme, steil und zerklüftet, mit Schweizer Bundesinventar der schützenswerten Ortsbilder aufge- klaven des Nationalparks sind Linescio, das mit seinen 25 Kilo- Dtiefen Schluchten und reissenden Gewässern. Der führt sind. meter langen Terrassierungen aus Trockenmauern an die berühm- Wald gleicht manchmal schon einem Urwald. Wer Wildnis und Abenteuer sucht, braucht also nicht in ferne Län- ten InkaTerrassen von Macchu Picchu erinnert, und das 1244 von Früher war dieses Gebiet dicht besiedelt. Doch die kargen Berg- der zu reisen: Er findet einen Hauch von Urwald, Grand Canyon deutschsprachigen Walser Immigranten gegründete Bosco Gurin. hänge waren nie ertragreich, Hunger war die Folge. Buben wur- und Macchu Picchu sozusagen vor der Haustür. Wenige Hundert Die “Tessiner Zeitung” widmet diese Extra-Beilage dem Natio- den als Kaminfeger verdingt. Viele Menschen emigrierten. Im Ver- Meter oberhalb Asconas und Brissagos fängt der Wald des Natio- nalparkprojekt Locarnese, das sich seit 2011 als offizieller Kandi- lauf des 20. Jahrhunderts wurden grosse Teile der landwirtschaft- nalparks des Locarnese an.
    [Show full text]
  • La Riserva Forestale Dell'onsernone La Grande Foresta, Regno Dell'abete
    La Riserva forestale dell'Onsernone La grande foresta, regno dell’abete bianco In breve Categoria Riserva integrale Comune Onsernone Ente gestore Comune di Onsernone Patriziato Generale d’Onsernone (656 ettari), Comune di Proprietari Onsernone (99 ettari), privati (20 ettari) e Cantone Ticino (14 ettari) Anno di istituzione 2002 Area 789 ettari Altitudine 640-1760 m.s.l.m. Principali alberi Abete bianco, abete rosso, faggio e larice Descrizione La Riserva forestale dell'Onsernone comprende vasta parte dell’esteso e isolato versante destro dell’alta Valle Onsernone, chiamato Oviga. A fronte ha gli abitati di Crana, Vocaglia, Corbella, Comologno e Spruga. Si estende dalle gole dell’Isorno ai lariceti sottostanti l’Alpe Ruscada, fino al confine di Stato. Dislivello: 1000 metri. Il paesaggio è forte, grandioso, del tutto privo di infrastrutture tecniche. Il carattere di naturalità è percepibile in tutto e per tutto. Sono luoghi selvaggi, il dominio della natura. Un mare di alberi, in cui danno il tono le chiome verde scuro degli abeti bianchi ancorati alla montagna. Il paesaggio evidenzia l’azione congiunta dei ghiacciai e delle acque sulle rocce di origine granitica. Le linee sono morbide, i crinali si stagliano sinuosi contro il cielo. I valloni, le sporgenze e rientranze, le balze rocciose, gli ampi fianchi della montagna, la grande foresta (a tratti striata dai canaloni verticali tipici del bosco di montagna, in cui d’inverno si scarica la neve), tutto rientra nell’immagine unitaria di un mondo intatto. Dalle profondità della montagna scaturisce l’acqua che alimenta la fonte termale ai Bagni di Craveggia in Testo di: R.
    [Show full text]
  • A Specific Gravity Index for Minerats
    A SPECIFICGRAVITY INDEX FOR MINERATS c. A. MURSKyI ern R. M. THOMPSON, Un'fuersityof Bri.ti,sh Col,umb,in,Voncouver, Canad,a This work was undertaken in order to provide a practical, and as far as possible,a complete list of specific gravities of minerals. An accurate speciflc cravity determination can usually be made quickly and this information when combined with other physical properties commonly leads to rapid mineral identification. Early complete but now outdated specific gravity lists are those of Miers given in his mineralogy textbook (1902),and Spencer(M,i,n. Mag.,2!, pp. 382-865,I}ZZ). A more recent list by Hurlbut (Dana's Manuatr of M,i,neral,ogy,LgE2) is incomplete and others are limited to rock forming minerals,Trdger (Tabel,l,enntr-optischen Best'i,mmungd,er geste,i,nsb.ildend,en M,ineral,e, 1952) and Morey (Encycto- ped,iaof Cherni,cal,Technol,ogy, Vol. 12, 19b4). In his mineral identification tables, smith (rd,entifi,cati,onand. qual,itatioe cherai,cal,anal,ys'i,s of mineral,s,second edition, New york, 19bB) groups minerals on the basis of specificgravity but in each of the twelve groups the minerals are listed in order of decreasinghardness. The present work should not be regarded as an index of all known minerals as the specificgravities of many minerals are unknown or known only approximately and are omitted from the current list. The list, in order of increasing specific gravity, includes all minerals without regard to other physical properties or to chemical composition. The designation I or II after the name indicates that the mineral falls in the classesof minerals describedin Dana Systemof M'ineralogyEdition 7, volume I (Native elements, sulphides, oxides, etc.) or II (Halides, carbonates, etc.) (L944 and 1951).
    [Show full text]
  • Punti Raccolta Della Valle Onsernone
    Comuni di Isorno, Mosogno, Onsernone, Gresso e Vergeletto Riorganizzazione della raccolta dei rifiuti Valle Onsernone 3.3 Carta La raccolta della carta nella Valle Onsernone è eseguita con cadenza di 1 volta al mese; durante la raccolta sono vuotati i contenitori nei punti di raccolta adibiti alla carta (contenitori standard da 700 l) e raccolta la carta lungo il percorso di raccolta (porta a porta). Al momento del sopralluogo (data: 14.10.2015), avvenuto una settimana prima della data prevista per la raccolta mensile della carta (22.10.2015), i contenitori adibiti alla raccolta della carta erano pieni. Si ritiene che la capienza dei contenitori della carta ripartiti nel territorio della valle non sia sufficiente per una vuotatura mensile. Qualche esempio di contenitore non sufficiente alla raccolta della carta è presentato nelle foto che seguono. 4 Parcheggio Auressio 11 Parcheggio Berzona 13 Seghellina 60 Cima Figura 6: Raccolta carta. EcoControl SA Pagina 12 di 23 Comuni di Isorno, Mosogno, Onsernone, Gresso e Vergeletto Riorganizzazione della raccolta dei rifiuti Valle Onsernone 3.4 Ingombranti Le giornate degli ingombranti sono divise nelle tre regioni della Valle: Comologno, Grana e Russo Vergeletto, Gresso e Mosogno Berzona, Loco e Auressio La raccolta è eseguita due volte l’anno (primavera e autunno) in ognuna delle tre regioni. Durante le giornate di raccolta è possibile depositare gli ingombranti in alcune piazze adibite alla raccolta del rifiuto. Le piazze di raccolta non sono controllate. Dal sopralluogo eseguito in ottobre 2015 sono emerse molte problematiche legate alla raccolta degli ingombranti. In generale, nel territorio sono raccolti grandi quantitativi di ingombranti che non provengono dalle economie domestiche: oltre ai comuni ingombranti di origine domestica non riciclabili sono depositati materiali da demolizione, finestre, porte, elettrodomestici, ecc.
    [Show full text]