DOCSLIB.ORG

Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-Ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-Ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2008 Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy Tasha L. Dunn University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Geology Commons Recommended Citation Dunn, Tasha L., "Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy. " PhD diss., University of Tennessee, 2008. https://trace.tennessee.edu/utk_graddiss/379 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Tasha L. Dunn entitled "Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Geology. Harry Y. McSween, Jr., Major Professor We have read this dissertation and recommend its acceptance: Lawrence A. Taylor, Theodore C. Labotka, John Z. Larese, Timothy J. McCoy Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a dissertation written by Tasha Laurrelle Dunn entitled” Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy.” I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted for partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Geology. Harry Y. McSween, Jr., Major Professor _________________________________ We have read this dissertation and recommend its acceptance: Lawrence A. Taylor _______________________________ Theodore C. Labotka _______________________________ John Z. Larese _______________________________ Timothy J. McCoy _________________________________ Accepted for the Council: Carolyn R. Hodges, Vice Provost and Dean of the Graduate School ______________________________________ (Original signatures are on file with official student records.) Determination of Mineral Abundances in Ordinary Chondrites Using Powder X-ray Diffraction: Applications to Parent Body Processes and Asteroid Spectroscopy A Dissertation Presented for the Doctor of Philosophy Degree University of Tennessee, Knoxville Tasha Laurrelle Dunn May 2008 DEDICATION This is for the individuals who have dedicated their lives to the teaching of others. You have all given me my most prized possession – my education. For that, I thank you. For the faculty and staff of: Hendrix Drive Elementary (1983-1989), Forest Park Middle School (1989-1992), and Forest Park High School (1992-1996) “We think of the effective teachers we have had over the years with a sense of recognition, but those who have touched our humanity we remember with a deep sense of gratitude.” - Anonymous student ii ACKNOWLEDGMENTS This dissertation would not have been possible without guidance of my advisor, Dr. Hap McSween. Hap’s enthusiasm for this project was contagious, and I feel lucky to have worked on a project that was both exciting to me and valuable to science. I would especially like to thank Hap for his very generous financial support through the years, without which my research would not have been possible. I would also like to thank my committee members, Dr. Larry Taylor, Dr. Ted Labotka, Dr. Tim McCoy, and Dr. John Larese, each of whom contributed to the completion of my degree in their own unique way. In particular I would like to thank Larry Taylor and Tim McCoy for helping me to grow as a scientist. I am especially grateful to Larry for his confidence in me and the opportunities he has made available to me because of it. I am also very thankful for Tim’s many insightful comments and suggestions on early versions of this dissertation. I also owe a great deal of gratitude to several individuals who have assisted in various aspects of my research. Foremost I thank Dr. Gordon Gressey at the Natural History Museum in London, without whom I could not have successfully completed this project. Thanks also to my other friends across the pond, Dr. Phil Band and Dr. Gretchen Benedix, for making me feel at home during my trips to the UK. Cheers! Special thanks to Linda Welzenbach at Smithsonian Institute and Dr. Caroline Smith at the Natural History Museum for assisting me the acquisition of the meteorites used in this project. I also owe a great deal of gratitude to microprobe technician Allan Patchen for his assistance, guidance, and yearly resupply of Girl Scout cookies. Thanks also to Sigma Xi for their financial support. I would like to thank my friends at the University of Tennessee who have joined me on this journey through graduate school. Thanks to Rhiannon Mayne for being my friend, ally, and conference roommate despite my misuse of the “Queen’s English.” Together she, I, and George iii the rabbit have had many adventures. Thanks to Emily Goodman for being equally as fabulous as I am, for disliking the same people I do, and for being a true friend and confidant. Thanks to Whitney Kocis (WHITNEY!!) for her friendship and for sharing my appreciation for “The Gilmore Girls” and my “nerdiness” score (32%). Minerals in Everyday Life will not be the same without us. Thanks also to Yang Lui, one of the most brilliant people I know, for her guidance. Now I too am a planetary scientist! Finally to “my person” Bill Deane - thanks for everything. Thanks also to my friends and family back home in Atlanta and elsewhere for their support. I would especially like to thank Susanne Ross for being not only a friend but a mentor. Your friendship means a great deal to me, and I thank you. (I think this deserves a Red Rock.) Thanks to Chrissy Cataldo, for keeping me grounded and for making the last several months of my time here the best yet. Thanks also to Cindy and Alan Kerstetter, for supporting me in all aspects of my life. Finally, thanks to my mom, to whom I owe everything. I love you to the asteroid belt and back. iv ABSTRACT The ordinary chondrites, the most abundant group of meteorites, are divided into three chemical groups (H, L, and LL), which are distinguished based on variations in bulk composition and iron content. Although ordinary chondrites are relatively abundant, our understanding of their formation has been hampered by an inability to accurately measure the abundances of minerals that they contain. Here I use power x-ray diffraction (XRD) to quantify the modal abundances of 48 unbrecciated ordinary chondrite falls, which represent the complete petrologic range of equilibrated ordinary chondrites (types 4-6). Although the degree of metamorphism varies within each ordinary chondrite group, many details regarding the geochemical and thermal changes that take place during this process are not well understood. Using XRD-measured modal mineral abundances and chemical analyses, we evaluate the redox state and peak metamorphic temperatures in ordinary chondrite parent bodies in order to develop quantitative thermal evolution models of ordinary chondrite parent asteroids. Modal abundances and mineral compositions measured in this study indicate that progressive oxidation of the ordinary chondrites likely occurred during metamorphism. Results also suggest that plagioclase crystallizes early in the metamorphic sequence, indicating that peak temperatures derived using the two-pyroxene geothermometer are more accurate than those calculated using the plagioclase geothermometer. I also utilize ordinary chondrite modal abundances to develop new calibrations for deriving mineralogy from meteorite and asteroid spectra. Most previous studies examining the mineralogical characteristics of VISNIR asteroid spectra have focused on olivine and pyroxene proportions in single-pyroxene mixtures; therefore, current calibrations for deriving composition mineral abundances may be poorly suited for asteroids containing more than one pyroxene. It is v important that calibrations are correct, because mineral abundances derived from visible/near- infrared (VISNIR) spectra are used to classify asteroids, identify meteorite parent bodies, and understand the structure of the asteroid belt. Mineral abundances derived using my calibrations correlate well with measured data for all ordinary chondrites groups, and also appear to be valid for other meteorites and asteroids with mineral abundances and chemistries similar to those of the ordinary chondrites. vi TABLE OF CONTENTS Part Page I. INTRODUCTION 1. Overview……………………………………………………………………………………………………….2 2. Analysis of Ordinary Chondrites Using Powder X-Ray Diffraction: Modal Mineral Abundances (Part II)……….............................................................3 3. Analysis
Load more

Recommended publications
  • Hf–W Thermochronometry: II. Accretion and Thermal History of the Acapulcoite–Lodranite Parent Body
    Earth and Planetary Science Letters 284 (2009) 168–178 Contents lists available at ScienceDirect Earth and Planetary Science Letters journal homepage: www.elsevier.com/locate/epsl Hf–W thermochronometry: II. Accretion and thermal history of the acapulcoite–lodranite parent body Mathieu Touboul a,⁎, Thorsten Kleine a, Bernard Bourdon a, James A. Van Orman b, Colin Maden a, Jutta Zipfel c a Institute of Isotope Geochemistry and Mineral Resources, ETH Zurich, Clausiusstrasse 25, 8092 Zurich, Switzerland b Department of Geological Sciences, Case Western Reserve University, Cleveland, OH, USA c Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt am Main, Germany article info abstract Article history: Acapulcoites and lodranites are highly metamorphosed to partially molten meteorites with mineral and bulk Received 11 November 2008 compositions similar to those of ordinary chondrites. These properties place the acapulcoites and lodranites Received in revised form 8 April 2009 between the unmelted chondrites and the differentiated meteorites and as such acapulcoites–lodranites are Accepted 9 April 2009 of special interest for understanding the initial stages of asteroid differentiation as well as the role of 26Al Available online 3 June 2009 heating in the thermal history of asteroids. To constrain the accretion timescale and thermal history of the Editor: R.W. Carlson acapulcoite–lodranite parent body, and to compare these results to the thermal histories of other meteorite parent bodies, the Hf–W system was applied to several acapulcoites and lodranites. Acapulcoites Dhofar 125 Keywords: – Δ chronology and NWA 2775 and lodranite NWA 2627 have indistinguishable Hf W ages of tCAI =5.2±0.9 Ma and Δ isochron tCAI =5.7±1.0 Ma, corresponding to absolute ages of 4563.1±0.8 Ma and 4562.6±0.9 Ma.
    [Show full text]
  • 19660017397.Pdf
    .. & METEORITIC RUTILE Peter R. Buseck Departments of Geology and Chemistry Arizona State University Tempe, Arizona Klaus Keil Space Sciences Division National Aeronautics and Space Administration Ames Research Center Mof fett Field, California r ABSTRACT Rutile has not been widely recognized as a meteoritic constituent. show, Recent microscopic and electron microprobe studies however, that Ti02 . is a reasonably widespread phase, albeit in minor amounts. X-ray diffraction studies confirm the Ti02 to be rutile. It was observed in the following meteorites - Allegan, Bondoc, Estherville, Farmington, and Vaca Muerta, The rutile is associated primarily with ilmenite and chromite, in some cases as exsolution lamellae. Accepted for publication by American Mineralogist . Rutile, as a meteoritic phase, is not widely known. In their sunanary . of meteorite mineralogy neither Mason (1962) nor Ramdohr (1963) report rutile as a mineral occurring in meteorites, although Ramdohr did describe a similar phase from the Faxmington meteorite in his list of "unidentified minerals," He suggested (correctly) that his "mineral D" dght be rutile. He also ob- served it in several mesosiderites. The mineral was recently mentioned to occur in Vaca Huerta (Fleischer, et al., 1965) and in Odessa (El Goresy, 1965). We have found rutile in the meteorites Allegan, Bondoc, Estherville, Farming- ton, and Vaca Muerta; although nowhere an abundant phase, it appears to be rather widespread. Of the several meteorites in which it was observed, rutile is the most abundant in the Farmington L-group chondrite. There it occurs in fine lamellae in ilmenite. The ilmenite is only sparsely distributed within the . meteorite although wherever it does occur it is in moderately large clusters - up to 0.5 mn in diameter - and it then is usually associated with chromite as well as rutile (Buseck, et al., 1965), Optically, the rutile has a faintly bluish tinge when viewed in reflected, plane-polarized light with immersion objectives.
    [Show full text]
  • Petrography and Mineral Chemistry of Escalón Meteorite, an H4 Chondrite, México
    148 Reyes-SalasRevista Mexicana et al. de Ciencias Geológicas, v. 27, núm. 1, 2010, p. 148-161 Petrography and mineral chemistry of Escalón meteorite, an H4 chondrite, México Adela M. Reyes-Salas1,*, Gerardo Sánchez-Rubio1, Patricia Altuzar-Coello2, Fernando Ortega-Gutiérrez1, Daniel Flores-Gutiérrez3, Karina Cervantes-de la Cruz1, Eugenio Reyes4, and Carlos Linares5 1 Universidad Nacional Autónoma de México, Instituto de Geología, Del. Coyoacán, 04510 México D.F., Mexico. 2 Universidad Nacional Autónoma de México, Centro de Investigación en Energía, Campus Temixco, Priv. Xochicalco s/n, 62580 Temixco Morelos, Mexico. 3 Universidad Nacional Autónoma de México, Instituto de Astronomía, Del. Coyoacán, 04510 México D.F., Mexico. 4 Universidad Nacional Autónoma de México, Facultad de Química, Del. Coyoacán, 04510 México D.F., Mexico. 5 Universidad Nacional Autónoma de México, Instituto de Geofísica, Del. Coyoacán, 04510 México D.F., Mexico. * [email protected] ABSTRACT The Escalón meteorite, a crusted mass weighing 54.3 g, was recovered near Zona del Silencio in Escalón, state of Chihuahua, México. The stone is an ordinary chondrite belonging to the high iron group H, type 4. Electron microprobe analyses of olivine (Fa18.1) and pyroxene (Fs16.5), phosphate, plagioclase, opaque phases, matrix and chondrule glasses are presented. The metal phases present are kamacite (6.08 % Ni), taenite (31.66 % Ni), high nickel taenite (50.01 % Ni) and traces of native Cu. The chondrules average apparent diameter measures 0.62 mm. X-ray diffraction pattern shows olivine, pyroxene and kamacite. Alkaline-type glass is found mainly in chondrules. This meteorite is a stage S3, shock-blackened chondrite with weathering grade W0.
    [Show full text]
  • Zinc and Copper Isotopic Fractionation During Planetary Differentiation Heng Chen Washington University in St
    Washington University in St. Louis Washington University Open Scholarship Arts & Sciences Electronic Theses and Dissertations Arts & Sciences Winter 12-15-2014 Zinc and Copper Isotopic Fractionation during Planetary Differentiation Heng Chen Washington University in St. Louis Follow this and additional works at: https://openscholarship.wustl.edu/art_sci_etds Part of the Earth Sciences Commons Recommended Citation Chen, Heng, "Zinc and Copper Isotopic Fractionation during Planetary Differentiation" (2014). Arts & Sciences Electronic Theses and Dissertations. 360. https://openscholarship.wustl.edu/art_sci_etds/360 This Dissertation is brought to you for free and open access by the Arts & Sciences at Washington University Open Scholarship. It has been accepted for inclusion in Arts & Sciences Electronic Theses and Dissertations by an authorized administrator of Washington University Open Scholarship. For more information, please contact [email protected]. WASHINGTON UNIVERSITY IN ST. LOUIS Department of Earth and Planetary Sciences Dissertation Examination Committee: Bradley L. Jolliff, Chair Jeffrey G. Catalano Bruce Fegley, Jr. Michael J. Krawczynski Frédéric Moynier Zinc and Copper Isotopic Fractionation during Planetary Differentiation by Heng Chen A dissertation presented to the Graduate School of Arts & Sciences of Washington University in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2014 St. Louis, Missouri Copyright © 2014, Heng Chen All rights reserved. Table of Contents LIST OF FIGURES
    [Show full text]
  • Chondrule Sizes, We Have Compiled and Provide Commentary on Available Chondrule Dimension Literature Data
    Invited review Chondrule size and related physical properties: a compilation and evaluation of current data across all meteorite groups. Jon M. Friedricha,b,*, Michael K. Weisbergb,c,d, Denton S. Ebelb,d,e, Alison E. Biltzf, Bernadette M. Corbettf, Ivan V. Iotzovf, Wajiha S. Khanf, Matthew D. Wolmanf a Department of Chemistry, Fordham University, Bronx, NY 10458 USA b Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 10024 USA c Department of Physical Sciences, Kingsborough College of the City University of New York, Brooklyn, NY 11235, USA d Graduate Center of the City University of New York, 365 5th Ave, New York, NY 10016 USA e Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964 USA f Fordham College at Rose Hill, Fordham University, Bronx, NY 10458 USA In press in Chemie der Erde – Geochemistry 21 August 2014 *Corresponding Author. Tel: +718 817 4446; fax: +718 817 4432. E-mail address: [email protected] 2 ABSTRACT The examination of the physical properties of chondrules has generally received less emphasis than other properties of meteorites such as their mineralogy, petrology, and chemical and isotopic compositions. Among the various physical properties of chondrules, chondrule size is especially important for the classification of chondrites into chemical groups, since each chemical group possesses a distinct size-frequency distribution of chondrules. Knowledge of the physical properties of chondrules is also vital for the development of astrophysical models for chondrule formation, and for understanding how to utilize asteroidal resources in space exploration. To examine our current knowledge of chondrule sizes, we have compiled and provide commentary on available chondrule dimension literature data.
    [Show full text]
  • Petrogenesis of Acapulcoites and Lodranites: a Shock-Melting Model
    Geochimica et Cosmochimica Acta 71 (2007) 2383–2401 www.elsevier.com/locate/gca Petrogenesis of acapulcoites and lodranites: A shock-melting model Alan E. Rubin * Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, USA Received 31 May 2006; accepted in revised form 20 February 2007; available online 23 February 2007 Abstract Acapulcoites are modeled as having formed by shock melting CR-like carbonaceous chondrite precursors; the degree of melting of some acapulcoites was low enough to allow the preservation of 3–6 vol % relict chondrules. Shock effects in aca- pulcoites include veins of metallic Fe–Ni and troilite, polycrystalline kamacite, fine-grained metal–troilite assemblages, metal- lic Cu, and irregularly shaped troilite grains within metallic Fe–Ni. While at elevated temperatures, acapulcoites experienced appreciable reduction. Because graphite is present in some acapulcoites and lodranites, it seems likely that carbon was the principal reducing agent. Reduction is responsible for the low contents of olivine Fa (4–14 mol %) and low-Ca pyroxene Fs (3–13 mol %) in the acapulcoites, the observation that, in more than two-thirds of the acapulcoites, the Fa value is lower than the Fs value (in contrast to the case for equilibrated ordinary chondrites), the low FeO/MnO ratios in acapulcoite olivine (16–18, compared to 32–38 in equilibrated H chondrites), the relatively high modal orthopyroxene/olivine ratios (e.g., 1.7 in Monument Draw compared to 0.74 in H chondrites), and reverse zoning in some mafic silicate grains. Lodranites formed in a similar manner to acapulcoites but suffered more extensive heating, loss of plagioclase, and loss of an Fe–Ni–S melt.
    [Show full text]
  • The Hamburg Meteorite Fall: Fireball Trajectory, Orbit and Dynamics
    The Hamburg Meteorite Fall: Fireball trajectory, orbit and dynamics P.G. Brown1,2*, D. Vida3, D.E. Moser4, M. Granvik5,6, W.J. Koshak7, D. Chu8, J. Steckloff9,10, A. Licata11, S. Hariri12, J. Mason13, M. Mazur3, W. Cooke14, and Z. Krzeminski1 *Corresponding author email: [email protected] ORCID ID: https://orcid.org/0000-0001-6130-7039 1Department of Physics and Astronomy, University of Western Ontario, London, Ontario, N6A 3K7, Canada 2Centre for Planetary Science and Exploration, University of Western Ontario, London, Ontario, N6A 5B7, Canada 3Department of Earth Sciences, University of Western Ontario, London, Ontario, N6A 3K7, Canada ( 4Jacobs Space Exploration Group, EV44/Meteoroid Environment Office, NASA Marshall Space Flight Center, Huntsville, AL 35812 USA 5Department of Physics, P.O. Box 64, 00014 University of Helsinki, Finland 6 Division of Space Technology, Luleå University of Technology, Kiruna, Box 848, S-98128, Sweden 7NASA Marshall Space Flight Center, ST11, Robert Cramer Research Hall, 320 Sparkman Drive, Huntsville, AL 35805, USA 8Chesapeake Aerospace LLC, Grasonville, MD 21638, USA 9Planetary Science Institute, Tucson, AZ, USA 10Department of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, TX, USA 11Farmington Community Stargazers, Farmington Hills, MI, USA 12Department of Physics and Astronomy, Eastern Michigan University, Ypsilanti, MI, USA 13Orchard Ridge Campus, Oakland Community College, Farmington Hills, MI, USA 14NASA Meteoroid Environment Office, Marshall Space Flight Center, Huntsville, Alabama 35812, USA Accepted to Meteoritics and Planetary Science, June 19, 2019 85 pages, 4 tables, 15 figures, 1 appendix. Original submission September, 2018. 1 Abstract The Hamburg (H4) meteorite fell on January 17, 2018 at 01:08 UT approximately 10km North of Ann Arbor, Michigan.
    [Show full text]
  • March 21–25, 2016
    FORTY-SEVENTH LUNAR AND PLANETARY SCIENCE CONFERENCE PROGRAM OF TECHNICAL SESSIONS MARCH 21–25, 2016 The Woodlands Waterway Marriott Hotel and Convention Center The Woodlands, Texas INSTITUTIONAL SUPPORT Universities Space Research Association Lunar and Planetary Institute National Aeronautics and Space Administration CONFERENCE CO-CHAIRS Stephen Mackwell, Lunar and Planetary Institute Eileen Stansbery, NASA Johnson Space Center PROGRAM COMMITTEE CHAIRS David Draper, NASA Johnson Space Center Walter Kiefer, Lunar and Planetary Institute PROGRAM COMMITTEE P. Doug Archer, NASA Johnson Space Center Nicolas LeCorvec, Lunar and Planetary Institute Katherine Bermingham, University of Maryland Yo Matsubara, Smithsonian Institute Janice Bishop, SETI and NASA Ames Research Center Francis McCubbin, NASA Johnson Space Center Jeremy Boyce, University of California, Los Angeles Andrew Needham, Carnegie Institution of Washington Lisa Danielson, NASA Johnson Space Center Lan-Anh Nguyen, NASA Johnson Space Center Deepak Dhingra, University of Idaho Paul Niles, NASA Johnson Space Center Stephen Elardo, Carnegie Institution of Washington Dorothy Oehler, NASA Johnson Space Center Marc Fries, NASA Johnson Space Center D. Alex Patthoff, Jet Propulsion Laboratory Cyrena Goodrich, Lunar and Planetary Institute Elizabeth Rampe, Aerodyne Industries, Jacobs JETS at John Gruener, NASA Johnson Space Center NASA Johnson Space Center Justin Hagerty, U.S. Geological Survey Carol Raymond, Jet Propulsion Laboratory Lindsay Hays, Jet Propulsion Laboratory Paul Schenk,
    [Show full text]
  • [802] PRINT ONLY: CHONDRITES and THEIR COMPONENTS Berzin S. V. Erokhin Yu. V. Khiller V. V. Ivanov K. S. Variations in Th
    47th Lunar and Planetary Science Conference (2016) sess802.pdf [802] PRINT ONLY: CHONDRITES AND THEIR COMPONENTS Berzin S. V. Erokhin Yu. V. Khiller V. V. Ivanov K. S. Variations in the Chemical Composition of Pentlandite in Different Ordinary Chondrites [#1056] The chemical composition properties of pentlandite from different ordinary chondrites was studied. Caporali S. Moggi-Cecchi V. Pratesi G. Franchi I. A. Greenwood R. C. Textural and Minerochemical Features of Dar al Gani 1067, a New CK Chondrite from Libya [#2016] This communication describes the chemical, petrological, and oxygen isotopic features of a newly approved carbonaceous chondrite from the Dar al Gani region (Libya). Cortés-Comellas J. Trigo-Rodríguez J. M. Llorca J. Moyano-Cambero C. E. UV-NIR Reflectance Spectra of Ordinary Chondrites to Better Understand Space Weathering Effects in S-Class Asteroids [#2610] We compare the UV-NIR spectra of S-type asteroids with several L and H ordinary chondrites, in order to better understand space weathering effects on spectra. Fisenko A. V. Semjonova L. F. Kinetics of C, N, Ar, and Xe Release During Combustion of the Small Metal-Sulphide Intergrows of Saratov (L4) Meteorite [#1071] It’s shown the metal-sulphide intergrows of Saratov chondrite contains Ar and Xe. They either are dissolved in pentlandite or are in its carbonaceous inclusions. Kalinina G. V. Pavlova T. A. Alexeev V. A. Some Features of the Distribution of VH-Nuclei Tracks of Galactic Cosmic Rays in Ordinary Chondrites [#1019] The tendency of decreasing of the average rate of track formation with increasing of cosmic ray exposure ages of meteorites is found and discussed.
    [Show full text]
  • Curt Teich Postcard Archives Towns and Cities
    Curt Teich Postcard Archives Towns and Cities Alaska Aialik Bay Alaska Highway Alcan Highway Anchorage Arctic Auk Lake Cape Prince of Wales Castle Rock Chilkoot Pass Columbia Glacier Cook Inlet Copper River Cordova Curry Dawson Denali Denali National Park Eagle Fairbanks Five Finger Rapids Gastineau Channel Glacier Bay Glenn Highway Haines Harding Gateway Homer Hoonah Hurricane Gulch Inland Passage Inside Passage Isabel Pass Juneau Katmai National Monument Kenai Kenai Lake Kenai Peninsula Kenai River Kechikan Ketchikan Creek Kodiak Kodiak Island Kotzebue Lake Atlin Lake Bennett Latouche Lynn Canal Matanuska Valley McKinley Park Mendenhall Glacier Miles Canyon Montgomery Mount Blackburn Mount Dewey Mount McKinley Mount McKinley Park Mount O’Neal Mount Sanford Muir Glacier Nome North Slope Noyes Island Nushagak Opelika Palmer Petersburg Pribilof Island Resurrection Bay Richardson Highway Rocy Point St. Michael Sawtooth Mountain Sentinal Island Seward Sitka Sitka National Park Skagway Southeastern Alaska Stikine Rier Sulzer Summit Swift Current Taku Glacier Taku Inlet Taku Lodge Tanana Tanana River Tok Tunnel Mountain Valdez White Pass Whitehorse Wrangell Wrangell Narrow Yukon Yukon River General Views—no specific location Alabama Albany Albertville Alexander City Andalusia Anniston Ashford Athens Attalla Auburn Batesville Bessemer Birmingham Blue Lake Blue Springs Boaz Bobler’s Creek Boyles Brewton Bridgeport Camden Camp Hill Camp Rucker Carbon Hill Castleberry Centerville Centre Chapman Chattahoochee Valley Cheaha State Park Choctaw County
    [Show full text]
  • Pyrrhotite and Pentlandite in Ll3 to Ll6 Chondrites: Determining Compositional and Microstructural Indicators of Formation Conditions
    49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083) 2621.pdf PYRRHOTITE AND PENTLANDITE IN LL3 TO LL6 CHONDRITES: DETERMINING COMPOSITIONAL AND MICROSTRUCTURAL INDICATORS OF FORMATION CONDITIONS. D. L. Schrader1 and T. J. Zega2, 1Center for Meteorite Studies, School of Earth and Space Exploration, Arizona State Uni- versity, Tempe, AZ 85287-1404, USA ([email protected]), 2Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, USA ([email protected]). Introduction: The compositions, textures, and electron microscope (FIB-SEM) at UAz and the JEOL crystal structures of sulfides can be used to constrain JXA-8530F Hyperprobe EPMA at Arizona State Uni- oxygen fugacity, aqueous, thermal, and cooling history versity (ASU). The FIB-SEM was also used to extract [e.g., 1–5]. The most abundant sulfides in extraterres- ~10 × 5 µm sections transecting the pyrrhotite- trial samples are the pyrrhotite group [(Fe,Ni,Co,Cr)1– pentlandite interfaces within sulfide grains from each xS], which can occur with pentlandite [(Fe,Ni,Co,Cr)9– meteorite, which were thinned to electron transparency xS8]. The pyrrhotite group sulfides are largely non- (<100 nm) using methods of [14]. FIB sections were stoichiometric and have a range of compositions then analyzed using the 200 keV aberration-corrected (0<x<0.125) and distinct crystal structures (polytypes). Hitachi HF5000 scanning transmission electron micro- The stoichiometric end members are 2C (troilite; FeS, scope (TEM) at UAz. hexagonal) and 4C (Fe7S8, monoclinic) pyrrhotite. There are also non-integral NC-pyrrhotites with inter- mediate compositions with 0<x<0.125 (all hexagonal); which includes the integral 5C (Fe9S10), 6C (Fe11S12), and 11C (Fe10S11) pyrrhotites [e.g., 6–8].
    [Show full text]
  • Spade: an H Chondrite Impact-Melt Breccia That Experienced Post-Shock Annealing
    Meteoritics & Planetary Science 38, Nr 10, 1507–1520 (2003) Abstract available online at http://meteoritics.org Spade: An H chondrite impact-melt breccia that experienced post-shock annealing Alan E. RUBIN 1* and Rhian H. JONES 2 1Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California 90095–1567, USA 2Institute of Meteoritics, Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA *Corresponding author. E-mail: [email protected] (Received 26 January 2003; revision accepted 19 October 2003) Abstract–The low modal abundances of relict chondrules (1.8 vol%) and of coarse (i.e., ³200 mm- size) isolated mafic silicate grains (1.8 vol%) in Spade relative to mean H6 chondrites (11.4 and 9.8 vol%, respectively) show Spade to be a rock that has experienced a significant degree of melting. Various petrographic features (e.g., chromite-plagioclase assemblages, chromite veinlets, silicate darkening) indicate that melting was caused by shock. Plagioclase was melted during the shock event and flowed so that it partially to completely surrounded nearby mafic silicate grains. During crystallization, plagioclase developed igneous zoning. Low-Ca pyroxene that crystallized from the melt (or equilibrated with the melt at high temperatures) acquired relatively high amounts of CaO. Metallic Fe-Ni cooled rapidly below the Fe-Ni solvus and transformed into martensite. Subsequent reheating of the rock caused transformation of martensite into abundant duplex plessite. Ambiguities exist in the shock stage assignment of Spade. The extensive silicate darkening, the occurrence of chromite-plagioclase assemblages, and the impact-melted characteristics of Spade are consistent with shock stage S6.
    [Show full text]