DOCSLIB.ORG

CONTENTS G Through I

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
CONTENTS G Through I 69th Annual Meteoritical Society Meeting (2006) alpha_g-i.pdf CONTENTS G through I Iron and Nickel in Ureilite Silicates — Chemistry and Isotopes A. Gabriel, G. Quitté, R. Schönberg, J. Schüßler, and A. Pack.............................................................. 5326 Spectroscopy and the Asteroid-Meteorite Link: A Perspective After Three Decades M. J. Gaffey............................................................................................................................................ 5357 Petrology and Geochemistry of the NWA 3368 Eucrite K. G. Gardner, D. S. Lauretta, D. H. Hill, J. S. Goreva, K. J. Domanik, I. A. Franchi, and M. J. Drake ............................................................................................................... 5152 Composition in the Protosolar and Local Interstellar Clouds — Implications for the Chemical Evolution in the Galaxy During the Last 5 Gyr J. Geiss and G. Gloeckler....................................................................................................................... 5134 Equilibrated Ordinary Chondrite-like Micrometeorites M. J. Genge ............................................................................................................................................ 5070 Stable Iron Isotope Analyses of Metal Grains in Ordinary Chondrites by MC-ICP-MS K. J. Gildea, R. Burgess, I. Lyon, and D. W. Sears ................................................................................ 5284 Iron Oxidation State in Australasian Micro-Tektites by High-Resolution XANES Spectroscopy and Kβ-detected XANES Spectroscopy G. Giuli, S. G. Eeckhout, C. Koeberl, E. Paris, and G. Pratesi ............................................................. 5150 Iron Oxidation State in Impact Glass from the Cretaceous/Tertiary Boundary at Beloc (Haiti) by High-Resolution XANES Spectroscopy: Implications on the Formation Conditions G. Giuli, S. G. Eeckhout, C. Koeberl, G. Pratesi, and E. Paris ............................................................. 5149 Divalent Vanadium in Vigarano CV3 Meteorite Chondrule G. Giuli, G. Pratesi, S. G. Eeckhout, and E. Paris................................................................................. 5148 The JaH 091 Strewnfield E. Gnos, M. Eggimann, A. Al-Kathiri, and B. A. Hofmann .................................................................... 5112 The KREEP-rich Imbrium Impact Melt Breccia of the Lunar Meteorite Sayh Al Uhaymir 169 E. Gnos, B. A. Hofmann, A. Al-Kathiri, and M. J. Whitehouse .............................................................. 5111 Effects of Falling Impact Ejecta on the Post-Chicxulub Atmosphere T. J. Goldin and H. J. Melosh ................................................................................................................ 5073 Constraining Volatile Abundance in Chondritic Components S. H. Gordon, P. A. Bland, S. J. Hammond, and N. W. Rogers.............................................................. 5213 Li-Be Isotope Systematic in Efremovka CAIs J. N. Goswami and M. P. Deomurari..................................................................................................... 5342 An 16O CAI-like Particle Among Antarctic Micrometeorites M. Gounelle, M. Chaussidon, C. Engrand, J. Duprat, and H. Leroux ................................................... 5279 Depth-dependant Fractionation of Light Solar Wind Noble Gases in a Genesis Target A. Grimberg, F. Bühler, P. Bochsler, D. S. Burnett, H. Baur, and R. Wieler......................................... 5187 69th Annual Meteoritical Society Meeting (2006) alpha_g-i.pdf Osbornite in CB/CH-like Carbonaceous Chondrite Isheyevo V. I. Grokhovsky..................................................................................................................................... 5231 In-situ Fe-XANES Study of Grains Trapped in Aerogel: An Analytical Test for the Interpretation of Stardust Samples Analyses F. Grossemy, J. Borg, and A. Simionovici.............................................................................................. 5276 A Spectacular Compound Chondrule-CAI in Northwest Africa 2918, a New CO3.1 Chondrite J. N. Grossman, G. J. MacPherson, E. P. Vicenzi, and C. M. O’D. Alexander ..................................... 5283 Identification of Reidite from the Ries Impact Crater Using Micro-Raman Spectroscopy: A Review A. Gucsik ................................................................................................................................................ 5103 The High-Energy View of Star Formation M. Güdel................................................................................................................................................. 5099 Water in Bencubbin N. Guilhaumou, C. Fiéni, C. Perron, B. Ghasharova, and Y.-L. Mathis................................................ 5223 Experiments on Chondrule Formation by “Lightning” C. Güttler, T. Poppe, J. Blum, T. Springborn, and J. Wasson................................................................ 5124 Titanium Isotopic Ratios in KJG Presolar SiC Grains from Murchison F. Gyngard, S. Amari, M. Jadhav, K. Marhas, E. Zinner, and R. S. Lewis............................................ 5334 From Size Sorting of Chondrules to Accretion of Parent Bodies — The Effects of Photophoresis H. Haack, O. Krauss, and G. Wurm....................................................................................................... 5199 Mass-fractionation Induced by the Genesis Solar Wind Concentrator: Analysis of Neon Isotopes by UV Laser Ablation V. S. Heber, R. C. Wiens, C. Olinger, D. S. Burnett, H. Baur, U. Wiechert, and R. Wieler..................................................................................................................... 5314 Rare Presolar Silicon Carbide Grains from Novae: An Automated Search by NanoSIMS Ph. R. Heck, P. Hoppe, E. Gröner, K. K. Marhas, H. Baur, and R. Wieler ........................................... 5054 Solar Noble Gases in 470 Myr Old Fossil Micrometeorites Ph. R. Heck, B. Schmitz, H. Baur, and R. Wieler ................................................................................... 5055 Dust in Protoplanetary Disks Th. Henning............................................................................................................................................ 5392 An Occurrence of Jarosite in MIL 03346: Implications for Conditions of Martian Aqueous Alteration C. D. K. Herd ......................................................................................................................................... 5027 Some Methods to Systematically Document the Components of Chondrites R. K. Herd, P. A. Hunt, and K. E. Venance ............................................................................................ 5362 History of Metal Veins in Acapulcoite-lodranite Clan Meteorite GRA 95209 J. S. Herrin, D. W. Mittlefehldt, and M. Humayun................................................................................. 5374 Laboratory Adsorbed Nitrogen and Noble Gases — Are We on the Safe Side? S. Herrmann, S. P. Schwenzer, and U. Ott............................................................................................. 5131 69th Annual Meteoritical Society Meeting (2006) alpha_g-i.pdf Bulk Composition of Chondrules in Carbonaceous Chondrites D. C. Hezel, H. Palme, and R. Kießwetter ............................................................................................. 5303 Neodymium, Samarium and Gadolinium Isotopic Studies of Lunar Meteorites Dhofar 489 and NWA 032 H. Hidaka and S. Yoneda ....................................................................................................................... 5169 A Possible Meteorite Lag Deposit After Continental Glaciation in Southeastern Manitoba A. R. Hildebrand, M. Beech, S. A. Kissin, and G. B. Quade................................................................... 5378 Why Does Angra Dos Reis Have an Anomalous (Type B) NIR Spectrum? E. J. Hoffman.......................................................................................................................................... 5319 New Finds of Shatter Cones in Distal Ries Ejecta, Bernhardzell, Eastern Switzerland B. A. Hofmann and E. Gnos ................................................................................................................... 5127 The Twannberg, Switzerland IIG Iron: New Finds, CRE Ages and a Glacial Scenario B. A. Hofmann, S. Lorenzetti, O. Eugster, F. Serefiddin, D. Hu, G. F. Herzog, and E. Gnos..................................................................................................................... 5128 Petrology and REE Geochemistry of the Lunar Meteorite Sayh Al Uhaymir 300 W. Hsu, Y. Guan, T. Ushikubo, R. Bartoschewitz, A. Zhang, Th. Kurtz, and P. Kurtz........................... 5200 Sulfide Variations in CR Chondrites H. Huber and A. E. Rubin ...................................................................................................................... 5371 Layered Tektites and Adjacent Soils from SE Thailand H. Huber and J. T. Wasson .................................................................................................................... 5370 Selenium and Sulphur Distribution in the Anomalous CK Chondrite EET 99430 H. Huber, H. A. Ishii, and S. Brennan.................................................................................................... 5324 The Exposure History of the Very Large L6 Chondrite
Load more

Recommended publications
  • Carnegie/DOE Alliance Center (CDAC): a CENTER of EXCELLENCE for HIGH PRESSURE SCIENCE and TECHNOLOGY
    CARNEGIE/DOE ALLIANCE CENTER A Center of Excellence for High Pressure Science and Technology Supported by the Stockpile Stewardship Academic Alliances Program of DOE/NNSA Year Three Annual Report September 2006 Russell J. Hemley, Director Ho-kwang Mao, Associate Director Stephen A. Gramsch, Coordinator Carnegie/DOE Alliance Center (CDAC): A CENTER OF EXCELLENCE FOR HIGH PRESSURE SCIENCE AND TECHNOLOGY YEAR THREE ANNUAL REPORT 1. Overview 1.1 Mission of CDAC 3 1.2 Highlights from Year 3 4 1.3 Year 3 Work Plan and Milestones 6 2. Scientific Progress 2.1 High P-T Phase Relations and Structures 10 2.2 P-V-T EOS Measurements 19 2.3 Phonons, Vibrational Thermodynamics and Elasticity 22 2.4 Plasticity, Yield Strength and Deformation 26 2.5 Electronic and Magnetic Structure and Dynamics 27 2.6 High P-T Chemistry 36 3. Education, Training, and Outreach 3.1 CDAC Graduate Students and Post-doctoral Associates 40 3.2 CDAC Collaborators 43 3.3 Undergraduate Student Participation 47 3.4 DC Area High School Outreach 49 3.5 Synergy of 21st Century High-Pressure Science and Technology Workshop 50 3.6 Visitors to CDAC 56 3.7 High Pressure Seminars 58 4. Technology Development 4.1 High P-T Experimental Techniques 60 4.2 Facilities at Brookhaven, LANSCE, and Carnegie 64 4.3 Commissioning and Activities at HPCAT 66 5. Interactions with NNSA/DP National Laboratories 5.1 Overview 67 5.2 Academic Alliance and Laboratory Collaborations 69 6. Management and Oversight 6.1 CDAC Organization and Staff 71 6.2 CDAC Oversight 73 6.3 Second Year Review 74 7.
    [Show full text]
  • The Tennessee Meteorite Impact Sites and Changing Perspectives on Impact Cratering
    UNIVERSITY OF SOUTHERN QUEENSLAND THE TENNESSEE METEORITE IMPACT SITES AND CHANGING PERSPECTIVES ON IMPACT CRATERING A dissertation submitted by Janaruth Harling Ford B.A. Cum Laude (Vanderbilt University), M. Astron. (University of Western Sydney) For the award of Doctor of Philosophy 2015 ABSTRACT Terrestrial impact structures offer astronomers and geologists opportunities to study the impact cratering process. Tennessee has four structures of interest. Information gained over the last century and a half concerning these sites is scattered throughout astronomical, geological and other specialized scientific journals, books, and literature, some of which are elusive. Gathering and compiling this widely- spread information into one historical document benefits the scientific community in general. The Wells Creek Structure is a proven impact site, and has been referred to as the ‘syntype’ cryptoexplosion structure for the United State. It was the first impact structure in the United States in which shatter cones were identified and was probably the subject of the first detailed geological report on a cryptoexplosive structure in the United States. The Wells Creek Structure displays bilateral symmetry, and three smaller ‘craters’ lie to the north of the main Wells Creek structure along its axis of symmetry. The question remains as to whether or not these structures have a common origin with the Wells Creek structure. The Flynn Creek Structure, another proven impact site, was first mentioned as a site of disturbance in Safford’s 1869 report on the geology of Tennessee. It has been noted as the terrestrial feature that bears the closest resemblance to a typical lunar crater, even though it is the probable result of a shallow marine impact.
    [Show full text]
  • Shocked Monazite Chronometry: Integrating Microstructural and in Situ Isotopic Age Data for Determining Precise Impact Ages
    Contrib Mineral Petrol (2017) 172:11 DOI 10.1007/s00410-017-1328-2 ORIGINAL PAPER Shocked monazite chronometry: integrating microstructural and in situ isotopic age data for determining precise impact ages Timmons M. Erickson1 · Nicholas E. Timms1 · Christopher L. Kirkland1 · Eric Tohver2 · Aaron J. Cavosie1,3 · Mark A. Pearce4 · Steven M. Reddy1 Received: 30 August 2016 / Accepted: 10 January 2017 © Springer-Verlag Berlin Heidelberg 2017 Monazite is a robust geochronometer and {110}, {212}, and type two (irrational) twin planes with Abstract ̄ ̄ ̄ ̄ occurs in a wide range of rock types. Monazite also records rational shear directions in [011] and [110]. SIMS U–Th– shock deformation from meteorite impact but the effects Pb analyses of the plastically deformed parent domains of impact-related microstructures on the U–Th–Pb sys- reveal discordant age arrays, where discordance scales with tematics remain poorly constrained. We have, therefore, increasing plastic strain. The correlation between discord- analyzed shock-deformed monazite grains from the central ance and strain is likely a result of the formation of fast uplift of the Vredefort impact structure, South Africa, and diffusion pathways during the shock event. Neoblasts in impact melt from the Araguainha impact structure, Brazil, granular monazite domains are strain-free, having grown using electron backscatter diffraction, electron microprobe during the impact events via consumption of strained par- elemental mapping, and secondary ion mass spectrometry ent grains. Neoblastic monazite from the Inlandsee leu- (SIMS). Crystallographic orientation mapping of monazite cogranofels at Vredefort records a 207Pb/206Pb age of grains from both impact structures reveals a similar com- 2010 ± 15 Ma (2σ, n = 9), consistent with previous impact bination of crystal-plastic deformation features, includ- age estimates of 2020 Ma.
    [Show full text]
  • Ebberly Ann Maclagan
    Constraints on emplacement and timing of the Steen River impact structure, Alberta, Canada by Ebberly Ann MacLagan A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science Department of Earth and Atmospheric Sciences University of Alberta © Ebberly Ann MacLagan, 2018 ABSTRACT The Steen River impact structure (SRIS) is a buried, complex crater located in NW Alberta, Canada. It was discovered in the mid 1900’s and was initially thought to be an endogenic igneous intrusion. With the growth of impact studies on Earth and other planets, the SRIS was recognized as such in the 1960’s. Since then, numerous exploratory wells have been drilled in and around the structure to assess its economic potential. While many of these wells are proprietary, three cores collected in 2000 are available for research and have been the focus of the most recent SRIS studies. A ubiquitous product of impact events is impact breccia, which may contain clasts of target material and melt. At the well-studied Ries impact structure in Germany, this breccia is classified as suevite. The impact breccia observed at the SRIS is similar to the Ries suevite; however, the term “suevite” has been applied to many impact structures and its formation mechanism is still debated. In previous studies, three cores from the SRIS (ST001, ST002, and ST003) were logged by hand and characterized in detail using thin sections; however, a representative, yet detailed, mineralogical overview of the core was lacking. In this thesis, hyperspectral imaging was used to quickly scan the three cores and make detailed mineralogical maps of each.
    [Show full text]
  • New Insights Into the Zircon-Reidite Phase Transition
    American Mineralogist, Volume 104, pages 830–837, 2019 New insights into the zircon-reidite phase transition CLAUDIA STANGARONE1,†, ROSS J. ANGEL1,*, MAURO PRENCIPE2, BORIANA MIHAILOVA3, AND MATTEO ALVARO1 1Department of Earth and Environmental Sciences, University of Pavia, Via A. Ferrata 1, I-27100 Pavia, Italy 2Earth Sciences Department, University of Torino, Via Valperga Caluso 35, I-10125 Torino, Italy 3Department of Earth Sciences, University of Hamburg, Grindelallee 48, D-20146 Hamburg, Germany ABSTRACT The structure, the elastic properties, and the Raman frequencies of the zircon and reidite polymorphs of ZrSiO4 were calculated as a function of hydrostatic pressure up to 30 GPa using HF/DFT ab initio calculations at static equilibrium (0 K). The softening of a silent (B1u) mode of zircon leads to a phase transition to a “high-pressure–low-symmetry” (HPLS) ZrSiO4 polymorph with space group I42d and cell parameters a = 6.4512 Å, c = 5.9121 Å, and V = 246.05 Å3 (at 20 GPa). The primary coordina- tion of SiO4 and ZrO8 groups in the structure of zircon is maintained in the high-pressure phase, and the new phase deviates from that of zircon by the rotation of SiO4 tetrahedra and small distortions of the ZrO8 dodecahedra. The new polymorph is stable with respect to zircon at 20 GPa and remains a dynamically stable structure up to at least 30 GPa. On pressure release, the new phase reverts back to the zircon structure and, therefore, cannot be quenched in experiments. In contrast, the transformation from zircon to reidite is reconstructive in nature and results in a first-order transition with a volume and density change of about 9%.
    [Show full text]
  • Evidence for Subsolidus Quartz-Coesite Transformation in Impact Ejecta from the Australasian Tektite Strewn field
    Available online at www.sciencedirect.com ScienceDirect Geochimica et Cosmochimica Acta 264 (2019) 105–117 www.elsevier.com/locate/gca Evidence for subsolidus quartz-coesite transformation in impact ejecta from the Australasian tektite strewn field Fabrizio Campanale a,b,⇑, Enrico Mugnaioli b, Luigi Folco a, Mauro Gemmi b Martin R. Lee c, Luke Daly c,e,f, Billy P. Glass d a Dipartimento di Scienze della Terra, Universita` di Pisa, V. S. Maria 53, 56126 Pisa, Italy b Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia (IIT), Piazza San Silvestro 12, 56127 Pisa, Italy c Department of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK d Department of Geosciences, University of Delaware, Newark, DE, USA e Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney 2006, NSW, Australia f Space Science and Technology Centre, School of Earth and Planetary Science, Curtin University, Bentley, 6102 WA, Australia Received 1 April 2019; accepted in revised form 11 August 2019; Available online 21 August 2019 Abstract Coesite, a high-pressure silica polymorph, is a diagnostic indicator of impact cratering in quartz-bearing target rocks. The formation mechanism of coesite during hypervelocity impacts has been debated since its discovery in impact rocks in the 1960s. Electron diffraction analysis coupled with scanning electron microscopy and Raman spectroscopy of shocked silica grains from the Australasian tektite/microtektite strewn field reveals fine-grained intergrowths of coesite plus quartz bearing planar deformation features (PDFs).À Quartz and euhedral microcrystalline coesite are in direct contact, showing a recurrent pseudo iso-orientation, with the ½111* vector of quartz near parallel to the [0 1 0]* vector of coesite.
    [Show full text]
  • Infrared and Raman Spectra of Zrsio4 Experimentally Shocked at High Pressures
    Mineralogical Magazine, October 2004, Vol. 68(5), pp. 801–811 Infrared and Raman spectra of ZrSiO4 experimentally shocked at high pressures 1 2, 1 2 2 2 A. GUCSIK ,M.ZHANG *, C. KOEBERL ,E.K.H.SALJE ,S.A.T.REDFERN AND J. M. PRUNEDA 1 Institute of Geological Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria 2 Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK ABSTRACT Zircon- and reidite-type ZrSiO4 produced by shock recovery experiments at different pressures have been studied using infrared (IR) and Raman spectroscopy. The n3 vibration of theSiO 4 group in shocked natural zircon shows a spectral change similar to that seen in radiation-damaged zircon: a decrease in frequency and increase in linewidth. The observation could imply a possible similar defective crystal structure between the damaged and shocked zircon. The shock-pressure-induced structural phasetransition from zircon ( I41/amd) to reidite (I41/a) is proven by the occurrence of additional IR and Raman bands. Although theSiO 4 groups in both zircon- and reidite-ZrSiO4 are isolated, the more condensed scheelite gives rise to SiÀO stretching bands at lower frequencies, suggesting a weakening of the bond strength. Low-temperature IR data of the reidite-type ZrSiO4 show an insignificant effect of cooling on the phonon modes, suggesting that the structural response of reidite to cooling-induced compression is weak and its thermal expansion is very small. KEYWORDS: ZrSiO4, zircon, reidite, scheelite structure, high pressure,
    [Show full text]
  • Shock-Metamorphosed Zircon in Terrestrial Impact Craters
    Meteoritics & Planetary Science 41, Nr 3, 433–454 (2006) Abstract available online at http://meteoritics.org Shock-metamorphosed zircon in terrestrial impact craters A. WITTMANN*, T. KENKMANN, R. T. SCHMITT, and D. ST÷FFLER Institut f¸r Mineralogie, Museum f¸r Naturkunde, Humboldt Universit‰t zu Berlin, Invalidenstrasse 43, 10115 Berlin, Germany *Corresponding author. E-mail: [email protected] (Received 06 June 2005; revision accepted 11 October 2005) Abstract–To ascertain the progressive stages of shock metamorphism of zircon, samples from three well-studied impact craters were analyzed by optical microscopy, scanning electron microscopy (SEM), and Raman spectroscopy in thin section and grain separates. These samples are comprised of well-preserved, rapidly quenched impactites from the Ries crater, Germany, strongly annealed impactites from the Popigai crater, Siberia, and altered, variably quenched impactites from the Chicxulub crater, Mexico. The natural samples were compared with samples of experimentally shock-metamorphosed zircon. Below 20 GPa, zircon exhibits no distinct shock features. Above 20 GPa, optically resolvable planar microstructures occur together with the high-pressure polymorph reidite, which was only retained in the Ries samples. Decomposition of zircon to ZrO2 only occurs in shock stage IV melt fragments that were rapidly quenched. This is not only a result of post-shock temperatures in excess of ∼1700 °C but could also be shock pressure–induced, which is indicated by possible relics of a high-pressure polymorph of ZrO2. However, ZrO2 was found to revert to zircon with a granular texture during devitrification of impact melts. Other granular textures represent recrystallized amorphous ZrSiO4 and reidite that reverted to zircon.
    [Show full text]
  • New Insights Into the Zircon-Reidite Phase Transition
    This is a preprint, the final version is subject to change, of the American Mineralogist (MSA) Cite as Authors (Year) Title. American Mineralogist, in press. DOI: https://doi.org/10.2138/am-2019-6827 1 REVISION 1 2 New insights into the zircon-reidite phase transition 3 Claudia Stangarone1*, Ross J. Angel1, Mauro Prencipe2, Boriana Mihailova3, Matteo Alvaro1 4 1 Department of Earth and Environmental Sciences, University of Pavia, Via A. Ferrata 1, I-27100 Pavia, Italy, 5 2 Earth Sciences Department, University of Torino, Via Valperga Caluso 35, I-10125 Torino, Italy 6 3 Department of Earth Sciences, University of Hamburg, Grindelallee 48, D-20146 Hamburg, Germany 7 *Current address: Institute for Planetary Research, Deutschen Zentrums für Luft- und Raumfahrt, Rutherfordstraße 2, 8 D-12489 Berlin, Germany 9 10 Corresponding author: R.J. Angel, [email protected] 11 Submitted to American Mineralogist: 27-Sept-2018 12 Revised version of 8-March-2019 13 14 ABSTRACT 15 The structure, the elastic properties and the Raman frequencies of the zircon and reidite polymorphs 16 of ZrSiO4 were calculated as a function of hydrostatic pressure up to 30 GPa using HF/DFT ab-initio 17 calculations at static equilibrium (0 K). The softening of a silent (B1u) mode of zircon leads to a phase 18 transition to a “high-pressure - low-symmetry” (HPLS) ZrSiO4 polymorph with space group �4#2� 19 and cell parameters a=6.4512 Å c=5.9121Å V = 246.05Å3 (at 20 GPa). The primary coordination of 20 SiO4 and ZrO8 groups in the structure of zircon is maintained in the high-pressure phase, and the new 21 phase deviates from that of zircon by the rotation of SiO4 tetrahedra and small distortions of the ZrO8 22 dodecahedra.
    [Show full text]
  • Abstracts A-L.Fm
    Meteoritics & Planetary Science 41, Nr 8, Supplement, A13–A199 (2006) http://meteoritics.org Abstracts 5367 5372 CHARACTERIZATION OF ASTEROIDAL BASALTS THROUGH ONSET OF AQUEOUS ALTERATION IN PRIMITIVE CR REFLECTANCE SPECTROSCOPY AND IMPLICATIONS FOR THE CHONDRITES DAWN MISSION N. M. Abreu and A. J. Brearley. Department of Earth and Planetary Sciences, P. A. Abell 1, D. W. Mittlefehldt1, and M. J. Gaffey2. 1Astromaterials Research University of New Mexico, Albuquerque, New Mexico 87131, USA. E-mail: and Exploration Science, NASA Johnson Space Center, Houston, Texas [email protected] 77058, USA. 2Department of Space Studies, University of North Dakota, Grand Forks, North Dakota 58202, USA Introduction: Although some CR chondrites show evidence of significant aqueous alteration [1], our studies [2] have identified CR Introduction: There are currently five known groups of basaltic chondrites that exhibit only minimal degrees of aqueous alteration. These achondrites that represent material from distinct differentiated parent bodies. meteorites have the potential to provide insights into the earliest stages of These are the howardite-eucrite-diogenite (HED) clan, mesosiderite silicates, aqueous alteration and the characteristics of organic material that has not angrites, Ibitira, and Northwest Africa (NWA) 011 [1]. Spectroscopically, all been affected by aqueous alteration, i.e., contains a relatively pristine record these basaltic achondrite groups have absorption bands located near 1 and 2 of carbonaceous material present in nebular dust. The CR chondrites are of microns due to the presence of pyroxene. Some of these meteorite types have special significance in this regard, because they contain the most primitive spectra that are quite similar, but nevertheless have characteristics (e.g., carbonaceous material currently known [3].
    [Show full text]
  • Development and Application of Atom Probe Tomography to Complex Zircon Grains
    Faculty of Science and Engineering School of Earth and Planetary Sciences Development and application of atom probe tomography to complex zircon grains Stephanie Dannett Montalvo Delgado 0000-0003-0601-2881 This thesis is presented for the Degree of Doctor of Philosophy of Curtin University March 2020 DECLARATION To the best of my knowledge and belief this thesis contains no material previously published by any other person except where due acknowledgment has been made. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. Signature: Date: 18/03/2020 iii DEDICATION To my partner Danny Fleming. You are an amazing person, always there to support me, even through tough times. Without you this thesis would not have been completed. For that and much more, I thank you. v ABSTRACT Atom probe tomography (APT) is a 3D analytical technique that provides the elemental composition of materials at sub-nanometre resolutions. Although originally developed for material science applications, recent advances in APT technology has expanded the applicability to other disciplines, including geological samples. The high spatial resolution of APT opens new avenues of geochemical studies. The few APT studies conducted on zircon have focussed on the nanogeochemistry and nanogeochronology of standards, igneous and metamorphic grains. However, the current applications of APT with zircon grains are limited with no systematic studies conducted on complex grains. This project is aimed at further developing APT techniques to zircon through the novel application of APT to meteoritic, altered and shocked zircon grains. Microscale zircon grains from the Bunburra Rockhole meteorite were analysed using APT to better understand the origin and formation history of the meteorite.
    [Show full text]
  • Reidite Zr(Sio4)
    Reidite Zr(SiO4) Crystal Data: Tetragonal. Point Group: 4/m. As elongate skeletal crystals to 10 mm. Physical Properties: Cleavage: None. Fracture: Even. Tenacity: Brittle. Hardness = ~7.5 D(meas.) = n.d. D(calc.) = ~5.2 Optical Properties: Transparent. Color: White in reflected light; pale brownish green in transmitted light. Streak: White. Luster: Adamantine. Optical Class: Uniaxial (+). n >> 1.64. Parallel extinction and length slow. Cell Data: Space Group: I41/a. a = 4.738(1) c = 10.506(2) Z = 4 X-ray Powder Pattern: ODP Site 904, New Jersey continental shelf, USA. 2.81 (100), 1.755 (60), 2.065 (50), 1.441 (50), 1.55 (45), 4.30 (40), 3.29 (40) Chemistry: (1) SiO2 31.44 ZrO2 65.92 HfO2 1.25 TiO2 0.06 FeO 0.09 Al2O3 0.01 MgO 0.09 Total 98.86 (1) Impact ejecta layer, USA continental shelf; average of 5 electron microprobe analyses; corresponds to (Zr1.01Hf0.01)Si0.99O4. Polymorphism & Series: A quenchable high-pressure polymorph of zircon. Occurrence: Epitaxially oriented in shock-metamorphosed zircons in an impact ejecta layer in marine sediment on the upper continental slope; detrital in clastic sedimentary rocks. Association: Impact glass (tektites), shocked quartz and feldspar with multiple sets of planar deformation features, coesite, stishovite. Distribution: From the USA upper continental slope off New Jersey (Deep Sea Drilling Project Site 612, Hole 903C, and Hole 904A) and off Maryland ( Deep Sea Drilling Project Site 1073 Hole A). On Barbados at Bath Cliff. From numerous impact structures, including the Woodleigh impact structure (Western Australia); the Vredefort impact structure (South Africa); Meteor Crater, (Arizona) and Rock Elm impact crater (western Wisconsin), USA; and the Haughton impact structure on Devon Island, Nunavut, Arctic Canada.
    [Show full text]