Meteor Impact Craters
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NEW HIGH-PRECISION POTASSIUM ISOTOPES of TEKTITES. Y. Jiang1,2, H
49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083) 1311.pdf NEW HIGH-PRECISION POTASSIUM ISOTOPES OF TEKTITES. Y. Jiang1,2, H. Chen2, B. Fegley, Jr.2, K. Lodders2, W. Hsu3, S. B. Jacobsen4, K. Wang (王昆)2. 1CAS Key Laboratory of Planetary Sciences, Purple Moun- tain Observatory, Chinese Academy of Sciences ([email protected]), 2Dept. Earth & Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis ([email protected]), 3Space Sci- ence Institute, Macau University of Science and Technology, 4Dept. Earth & Planetary Sciences, Harvard University. Introduction: Tektites are natural glassy objects crater of Hawaii (BHVO-1), are also analyzed. Hainan formed from the melting and rapid cooling of terrestri- Tektite is a typical splash-form tektite from Hainan al rocks during the high-energy impacts of meteorites, Island, China and of a dumbbell shape. We analyzed K comets, or asteroids upon the surface of the Earth [1]. isotopes of 15 chips along the longitudinal axis of its Chemical and isotopic compositions indicate that pre- profile, on a Neptune Plus MC-ICP-MS at Washington cursor components of tektites are the upper terrestrial University in St. Louis [14]. Except for Hainan tektite, continental crust, rather than extraterrestrial rocks. all other samples were only analyzed in bulk, with a Tektites are characterized by the depletion of volatile GV Instruments IsoProbe P MC-ICP-MS at Harvard elements and water, and heavy Cd, Sn, Zn and Cu iso- University following the description in [13]. K isotope topic compositions [2-5]. Since volatilities of elements compositions are reported using the per mil (‰) nota- 41 41 39 41 39 are defined by their 50% condensation temperature (Tc) tion, where δ K = ([( K/ K)sample/( K/ K)standard – of the solar nebula gas at 10-4 bars [6], there is no rea- 1]×1000). -
50 Years of Petrology
spe500-01 1st pgs page 1 The Geological Society of America 18888 201320 Special Paper 500 2013 CELEBRATING ADVANCES IN GEOSCIENCE Plates, planets, and phase changes: 50 years of petrology David Walker* Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA ABSTRACT Three advances of the previous half-century fundamentally altered petrology, along with the rest of the Earth sciences. Planetary exploration, plate tectonics, and a plethora of new tools all changed the way we understand, and the way we explore, our natural world. And yet the same large questions in petrology remain the same large questions. We now have more information and understanding, but we still wish to know the following. How do we account for the variety of rock types that are found? What does the variety and distribution of these materials in time and space tell us? Have there been secular changes to these patterns, and are there future implications? This review examines these bigger questions in the context of our new understand- ings and suggests the extent to which these questions have been answered. We now do know how the early evolution of planets can proceed from examples other than Earth, how the broad rock cycle of the present plate tectonic regime of Earth works, how the lithosphere atmosphere hydrosphere and biosphere have some connections to each other, and how our resources depend on all these things. We have learned that small planets, whose early histories have not been erased, go through a wholesale igneous processing essentially coeval with their formation. -
The Akimotoite–Majorite–Bridgmanite Triple Point Determined in Large Volume Press and Laser-Heated Diamond Anvil Cell
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 12 December 2019 doi:10.20944/preprints201912.0177.v1 Peer-reviewed version available at Minerals 2020, 10, 67; doi:10.3390/min10010067 Article The Akimotoite–Majorite–Bridgmanite Triple Point Determined in Large Volume Press and Laser-Heated Diamond Anvil Cell Britany L. Kulka1, Jonathan D. Dolinschi1, Kurt D. Leinenweber2, Vitali B. Prakapenka3, and Sang-Heon Shim1 1 School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA 2 Eyring Materials Center, Arizona State University, Tempe, Arizona, USA 3 GeoSoilEnviroCars, University of Chicago, Chicago, Illinois 60439, USA * Correspondence: [email protected] Abstract: The akimotoite–majorite–bridgmanite (Ak–Mj–Bm) triple point in MgSiO3 has been measured in large-volume press (LVP; COMPRES 8/3 assembly) and laser-heated diamond anvil cell (LHDAC). For the LVP data, we calculated pressures from the calibration by Leinenweber et al. [1]. For the LHDAC data, we conducted in situ determination of pressure at high temperature using the Pt scale by Dorogokupets and Dewaele [2] at synchrotron. The measured temperatures of the triple point are in good agreement between LVP and LHDAC at 1990–2000 K. However, the pressure for the triple point determined from the LVP is 3.9±0.6 GPa lower than that from the LHDAC dataset. The triple point determined through these experiments will provide an important reference point in the pressure-temperature space for future high-pressure experiments and allow mineral physicists to compare the pressure–temperature conditions measured in these two different experimental methods. Keywords: triple point; bridgmanite; akimotoite; majorite; large-volume press; laser-heated diamond anvil cell 1. -
The 3D.Y Knom Example Is /1"<
t Sixth International Congress on Glass - Washington, D. C., 1962. Fossil Glasses Produced by Inpact of Meteorites, Asteroids 2nd Possibly Comets with the Planet Xarth* A. J. Zzhen :&uon Insticute, Pittsburgh, ?ennsylvania (U. S. A. ) Sunnary / (to be trmslzted izto Frerzh and German) - i in recent thes one of the nost intriging aysteries of geGlogy has ceen the occurrence of aerodgnasicdly-shaped glasses on five continents of the earth. Tnese glasses mder discussion are obviously not of f-d- guritic origin. 3ecent research indicates that these glasses laom as tektites are the result of meteorite, esteroid, or sossibly comet hpact. Lqact glass?s, io generzl, differ Tram volcanic glasses in that they are lo;;.tr in ?,iater zontent, have laver gallium and germiun ccntents, and are rot necessarily ia mgnaticalljr unstable continental areas. These hpac- tites may be divided as follovs: (1)Glasses found in or near terrestrial neteorite craters. These glasses usually contain numerous s-,'nerules 02 nickel-iron, coesite, chunlks of partially melted meteoritic inatter and even stishovite. Shattered or fractured melted mi-nerals such as quarts are comxonly gresent. Aerodpaaic-shaping nay or nay not be present in this t-ne. &m?les are Canyon Diablo and Wabar Crster glasses. (2) Impzct- glasses zssociated with craters uitn no evidence of meteoritic mterial i? the @.ass or surrounding the explosisn site. The 3d.y knom example is /1"< Tnis vork vas supported by Xatiocal A-eroEautizs and Space P.dministretioq,$ 3esezrch Grant NsG-37-6O Supplement 1-62. Page 2 glass associated with AoueUoul Crater in the Western Sahara Desert. -
Investigating Possible Belize Tektites – Request of an Extended Database on Magnetic and Raman Spectroscopical Signature of Natural Glasses
47th Lunar and Planetary Science Conference (2016) 2482.pdf INVESTIGATING POSSIBLE BELIZE TEKTITES – REQUEST OF AN EXTENDED DATABASE ON MAGNETIC AND RAMAN SPECTROSCOPICAL SIGNATURE OF NATURAL GLASSES. V.H. Hoffmann1,2, Kaliwoda M.3, Hochleitner R.3, M. Funaki4, M. Torii5. 1Faculty of Geosciences, Dep. Geo- and Envi- ronm. Sciences, Univ. Munich; 2Dep. Geosciences, Univ. Tuebingen, 3MSCM, Munich, Germany; 4Tokyo, Japan; 5Okayama, Japan. Introduction m (gr) MS (10-9 m3/kg) Log MS Since 1992 findings of possible tektite glasses have- Belize A 1.35 123.5 2.09 been reported from Tikal region, Guatemala, and later Belize 1 0.61 131.5 2.12 from Belize, here most likely in situ. Therefore the Belize 2 0.67 128.5 2.11 existence of a Central American tektite strewn field Belize 3 0.42 178.7 2.25 was proposed [1,2]. Ages of between 780 and 820 ± Belize 4 0.33 212.8 2.33 40 ka have been determined for Belize glasses [3-5]. The radiometric age constraints are indistinguishable Belize 5 0.53 168.3 2.23 from the ages of the Australite-Indochinite tektite Belize 6 0.52 195.4 2.29 strewn field (~770 ka). However, additional investiga- Belize 7 0.36 170.5 2.23 tions on Belize glasses reported different geochemical Belize 8 0.56 129.0 2.11 signatures in comparison to the Australite-Indochinite Range 123.5 – 212.8 2.09 – 2.33 tektites [6-10]. Pantasma structure in Nicaragua was Average 159.8 2.20 proposed as a possible impact crater [11]. -
The Nakhlite Meteorites: Augite-Rich Igneous Rocks from Mars ARTICLE
ARTICLE IN PRESS Chemie der Erde 65 (2005) 203–270 www.elsevier.de/chemer INVITED REVIEW The nakhlite meteorites: Augite-rich igneous rocks from Mars Allan H. Treiman Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, TX 77058-1113, USA Received 22 October 2004; accepted 18 January 2005 Abstract The seven nakhlite meteorites are augite-rich igneous rocks that formed in flows or shallow intrusions of basaltic magma on Mars. They consist of euhedral to subhedral crystals of augite and olivine (to 1 cm long) in fine-grained mesostases. The augite crystals have homogeneous cores of Mg0 ¼ 63% and rims that are normally zoned to iron enrichment. The core–rim zoning is cut by iron-enriched zones along fractures and is replaced locally by ferroan low-Ca pyroxene. The core compositions of the olivines vary inversely with the steepness of their rim zoning – sharp rim zoning goes with the most magnesian cores (Mg0 ¼ 42%), homogeneous olivines are the most ferroan. The olivine and augite crystals contain multiphase inclusions representing trapped magma. Among the olivine and augite crystals is mesostasis, composed principally of plagioclase and/or glass, with euhedra of titanomagnetite and many minor minerals. Olivine and mesostasis glass are partially replaced by veinlets and patches of iddingsite, a mixture of smectite clays, iron oxy-hydroxides and carbonate minerals. In the mesostasis are rare patches of a salt alteration assemblage: halite, siderite, and anhydrite/ gypsum. The nakhlites are little shocked, but have been affected chemically and biologically by their residence on Earth. Differences among the chemical compositions of the nakhlites can be ascribed mostly to different proportions of augite, olivine, and mesostasis. -
Cleavage Induced Akimotoite Transformation in Shocked Chondrites
Modern Analytical Methods I (2014) 4009.pdf CLEAVAGE INDUCED AKIMOTOITE TRANSFORMATION IN SHOCKED CHONDRITES. SZ. Nagy 1, I. Gyollai 2, A. Gucsik 3, SZ. Bérczi 4 1Szeged University, Department of Mineralogy, Geochemistry and Petrology, Egyetem u. 2-4., 6720 Szeged, Hunga- ry. 2Geochemical Research Institute, Budaörsi út 45., 1112 Budapest, Hungary. 3MTA Konkoly-Thege Miklós Astronomical Research Institute, Konkoly-Thege Miklós út 15-17., 1121 Budapest, Hungary. 4Eötvös Lorand University, Department of Material Physics, Pázmány Péter sétány 1/A, 1117 Budapest, Hungary. Introduction: Shock-events by asteroidal colli- very high melting point (2450 °C) of oldhamite infers sions may cause the effect of high-pressure metamor- its formation as an early nebular condensate. In the phism on the mineral assemblages [1]. The low-Ca shocked chondrites the oldhamite phase has been pro- pyroxene can transform to its high-pressure phases duced by shock vein formation. The present of the old- including the followings of jadeite, majorite-pyrope ss , hamite is an evidence for the very high-temperature majorite, akimotoite, Mg-perovskite and pyroxene condition during the shock-vein formation rather that glass depending on the shock-metamorphic conditions. supposed in earlier work [2]. A mixed-type pyroxene In this study we have examined a new microstructure chondrule (~1 mm in diameter) contains a number of form of akimotoite in NWA 5011 meteorite to clarify subchondrules observed in the sample. One of the sub- pyroxene-akimotoite phase transformation during chondrules exhibits a dense cleavage network, where shock-metamorphism. the angle between two directions of the cleavages is nearly perpendicular (87 °) (Fig. -
The Tissint Martian Meteorite As Evidence for the Largest Impact Excavation
ARTICLE Received 17 Jul 2012 | Accepted 20 Dec 2012 | Published 29 Jan 2013 DOI: 10.1038/ncomms2414 The Tissint Martian meteorite as evidence for the largest impact excavation Ioannis P. Baziotis1, Yang Liu1,2, Paul S. DeCarli3, H. Jay Melosh4, Harry Y. McSween1, Robert J. Bodnar5 & Lawrence A. Taylor1 High-pressure minerals in meteorites provide clues for the impact processes that excavated, launched and delivered these samples to Earth. Most Martian meteorites are suggested to have been excavated from 3 to 7 km diameter impact craters. Here we show that the Tissint meteorite, a 2011 meteorite fall, contains virtually all the high-pressure phases (seven minerals and two mineral glasses) that have been reported in isolated occurrences in other Martian meteorites. Particularly, one ringwoodite (75 Â 140 mm2) represents the largest grain observed in all Martian samples. Collectively, the ubiquitous high-pressure minerals of unusually large sizes in Tissint indicate that shock metamorphism was widely dispersed in this sample (B25 GPa and B2,000 1C). Using the size and growth kinetics of the ring- woodite grains, we infer an initial impact crater with B90 km diameter, with a factor of 2 uncertainty. These energetic conditions imply alteration of any possible low-T minerals in Tissint. 1 Planetary Geosciences Institute, Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, Tennessee 37996, USA. 2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA. 3 Poulter Laboratory, SRI International, Menlo Park, California 94025, USA. 4 Department of Earth, Atmospheric and Planetary Sciences, Purdue University, West Lafayette, Indiana 47907, USA. 5 Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, USA. -
Revision 4 Majorite–Olivine–High-Ca Pyroxene Assemblage in the Shock-Melt Veins of Pervomaisky L6 Chondrite
1 Revision 4 2 3 Majorite–olivine–high-Ca pyroxene assemblage in the shock-melt veins of 4 Pervomaisky L6 chondrite 5 6 IVAN S. BAZHAN 1, KONSTANTIN D. LITASOV 1,2, EIJI OHTANI 1,3 7 SHIN OZAWA 3 8 9 1 V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, 630090, Russia 10 2 Novosibirsk State University, Novosibirsk, 630090, Russia 11 3 Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku 12 University, Sendai 980-8578, Japan 13 14 ABSTRACT 15 High-pressure minerals - majorite-pyrope garnet and jadeite - were found in the Pervomaisky 16 L6 ordinary chondrite. Majorite-pyrope (79 mol% majorite) was observed within the fine-grained 17 silicate matrix of a shock-melt vein (SMV), coexisting with olivine and high-Ca pyroxene. This is 18 the first report of a garnet-olivine-high-Ca pyroxene assemblage that crystallized from the melt in 19 the SMV matrix of meteorite. PT-conditions of the formation of the SMV matrix with olivine 20 fragments are 13.5–15.0 GPa and 1750–2150 oC, the lowest parameters among all known majorite- 21 bearing (H, L)-chondrites. The estimated conditions include the olivine/(olivine + ringwoodite) 22 phase boundary and there is a possibility that observed olivine is the result of 23 wadsleyite/ringwoodite back-transformation during a cooling and decompression stage. In the 24 framework of this hypothesis, we discuss the problem of survival of the high-pressure phases at the 25 post-shock stage in the meteorites and propose two possible PT-paths: (1) the high-pressure mineral 26 is transformed to a low-pressure one during adiabatic decompression above the critical temperature 27 of direct transformation; and (2) quenching below the critical temperature of direct transformation 1 28 within the stability field of the high-pressure phase and further decompression. -
Dehydration Melting Below the Undersaturated Transition Zone W Panero, C Thomas, R
Dehydration Melting Below the Undersaturated Transition Zone W Panero, C Thomas, R. Myhill, J Pigott, C. Raepsaet, H. Bureau To cite this version: W Panero, C Thomas, R. Myhill, J Pigott, C. Raepsaet, et al.. Dehydration Melting Below the Undersaturated Transition Zone. Geochemistry, Geophysics, Geosystems, AGU and the Geochemical Society, 2020, 10.1029/2019GC008712. hal-02870076 HAL Id: hal-02870076 https://hal.archives-ouvertes.fr/hal-02870076 Submitted on 16 Jun 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. RESEARCH ARTICLE Dehydration Melting Below the Undersaturated 10.1029/2019GC008712 Transition Zone Key Points: W. R. Panero1, C. Thomas2, R. Myhill3, J. S. Pigott4, C. Raepsaet5, and H. Bureau6 • Seismic reflections at ~750 km depth beneath Tibet are inconsistent with 1School of Earth Sciences, Ohio State University, Columbus, OH, USA, 2Institut für Geophysik, Westfälische Wilhelms‐ several previously proposed causes 3 4 for impedance contrast Universität Münster, Münster, Germany, School of Earth Sciences, University of Bristol, Bristol, -
Mineral Evolution
American Mineralogist, Volume 93, pages 1693–1720, 2008 REVIEW PAPER Mineral evolution ROBERT M. HAZEN,1,* DOMINIC PAPINEAU,1 WOUTER BLEEKER,2 ROBERT T. DOWNS,3 JOHN M. FERRY,4 TIMOTHY J. MCCOY,5 DIMITRI A. SVERJENSKY,4 AND HEXIONG YANG3 1Geophysical Laboratory, Carnegie Institution, 5251 Broad Branch Road NW, Washington, D.C. 20015, U.S.A. 2Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A OE8, Canada 3Department of Geosciences, University of Arizona, 1040 East 4th Street, Tucson, Arizona 85721-0077, U.S.A. 4Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland 21218, U.S.A. 5Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, D.C. 20560, U.S.A. ABSTRACT The mineralogy of terrestrial planets evolves as a consequence of a range of physical, chemical, and biological processes. In pre-stellar molecular clouds, widely dispersed microscopic dust particles contain approximately a dozen refractory minerals that represent the starting point of planetary mineral evolution. Gravitational clumping into a protoplanetary disk, star formation, and the resultant heat- ing in the stellar nebula produce primary refractory constituents of chondritic meteorites, including chondrules and calcium-aluminum inclusions, with ~60 different mineral phases. Subsequent aque- ous and thermal alteration of chondrites, asteroidal accretion and differentiation, and the consequent formation of achondrites results in a mineralogical repertoire limited to ~250 different minerals found in unweathered meteorite samples. Following planetary accretion and differentiation, the initial mineral evolution of Earth’s crust depended on a sequence of geochemical and petrologic processes, including volcanism and degassing, fractional crystallization, crystal settling, assimilation reactions, regional and contact metamorphism, plate tectonics, and associated large-scale fluid-rock interactions. -
Mg, Fe)Sio3 Glass in the Suizhou Meteorite
Meteoritics & Planetary Science 39, Nr 11, 1797–1808 (2004) Abstract available online at http://meteoritics.org A shock-produced (Mg, Fe)SiO3 glass in the Suizhou meteorite Ming CHEN,1* Xiande XIE,1 and Ahmed EL GORESY2 1Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 510640 Guangzhou, China 2Max-Planck-Institut für Chemie, D-55128 Mainz, Germany *Corresponding author. E-mail: [email protected] (Received 24 February 2004; revision accepted 15 August 2004) Abstract–Ovoid grains consisting of glass of stoichiometric (Mg, Fe)SiO3 composition that is intimately associated with majorite were identified in the shock veins of the Suizhou meteorite. The glass is surrounded by a thick rim of polycrystalline majorite and is identical in composition to the parental low-Ca pyroxene and majorite. These ovoid grains are surrounded by a fine-grained matrix composed of majorite-pyrope garnet, ringwoodite, magnesiowüstite, metal, and troilite. This study strongly suggests that some precursor pyroxene grains inside the shock veins were transformed to perovskite within the pyroxene due to a relatively low temperature, while at the rim region pyroxene grains transformed to majorite due to a higher temperature. After pressure release, perovskite vitrified at post-shock temperature. The existence of vitrified perovskite indicates that the peak pressure in the shock veins exceeds 23 GPa. The post-shock temperature in the meteorite could have been above 477 °C. This study indicates that the occurrence of high-pressure minerals in the shock veins could not be used as a ubiquitous criterion for evaluating the shock stage of meteorites. INTRODUCTION also be transformed to amorphous phase or glass at shock- produced high pressure and temperature.