DOCSLIB.ORG

Three-Dimensional Features of Chondritic Meteorites : Applying Micro-Computed Tomography to Extraterres- Trial Material

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

ORBIT-OnlineRepository ofBirkbeckInstitutionalTheses Enabling Open Access to Birkbeck’s Research Degree output Three-dimensional features of chondritic meteorites : applying micro-computed tomography to extraterres- trial material https://eprints.bbk.ac.uk/id/eprint/40303/ Version: Full Version Citation: Almeida, Natasha Vasiliki (2018) Three-dimensional features of chondritic meteorites : applying micro-computed tomography to ex- traterrestrial material. [Thesis] (Unpublished) c 2020 The Author(s) All material available through ORBIT is protected by intellectual property law, including copy- right law. Any use made of the contents should comply with the relevant law. Deposit Guide Contact: email Three-dimensional features of chondritic meteorites: applying micro-computed tomography to extraterrestrial material Natasha Vasilki Almeida (MSci. Hons Planetary Science & MA Museum Studies, UCL) Supervisors: Professor Sara Russell (NHM), Dr Caroline Smith (NHM), & Professor Hilary Downes (Birkbeck College London) July 2017 A thesis submitted to Birkbeck College, University of London, for the degree of Doctor of Philosophy I, Natasha Vasiliki Almeida, confirm that the work submitted in this thesis is my own. Where information has been derived from other sources, this is clearly indicated in the text. 2 Abstract This work examines the application of X-ray computed tomography (XCT) in meteoritics. This powerful technique uses the attenuation of X-rays passing through a sample to map it in three dimensions, allowing for the imaging and quantification of phases and features without the need for destructive sampling. XCT is a novel method with its applications to planetary science only recently recognised and not extensively explored. As such, this study presents two examples of using XCT to both elucidate its potential, and better understand the constituents of chondritic meteorites and the processes experienced on their parent bodies. To test the reliability of XCT, the data are conjoined with standard analytical techniques. Firstly, the 3D fabric and textural properties of 17 L chondrites of varying petrological type and shock stage are described. Specifically, porosity is imaged, quantified and compared with pycnometry data. For each chondrite, the size distribution and orientations of metal grains are reconstructed and correlated with the degree and direction of anisotropy of magnetic susceptibility in the sample. Both porosity and metal grain fabrics reveal trends with progressive thermal and shock metamorphism. The mechanisms accounting for such correlation are explored. Secondly, XCT is used to survey fragments of the Barwell L6 meteorite to identify and locate igneous inclusions. From this data, several inclusions were then subsampled and further geochemically investigated, including oxygen isotopic compositions, hafnium-tungsten systematics, and trace element analysis. Studied inclusions are found to be similar in composition and age to chondrules, but depleted in metal. A possible formation scenario is proposed and the potential link to chondrule formation is discussed. Using these examples, the factors influencing the accuracy of XCT data acquisition and processing are described. The benefits and limitations of the technique, with respect to the analysis of extraterrestrial material and implications for future use, are also considered. 3 Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science - by far the most successful claim to knowledge accessible to humans - teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptotic approach to the Universe, but with the proviso that absolute certainty will always elude us. - Carl Sagan, The Demon-Haunted World (1995). 4 Acknowledgements Firstly, many thanks to my supervisors for the life-changing opportunity, the helpful discussions, the patience, and the ‘open door policy’. Caroline, your encouragement has been a driving force behind my development as a curator – thank you for always pushing me forward, and for the laughs along the way. Sara, you always found time to listen to my thoughts and to support me in every way, whilst being an inspiration for women in our field. Hilary, your seeming disdain for my use of the Oxford comma is only surpassed by your never-failing belief in my success and ability. Immense thanks to you all and I look forward to working together in the years to come. Many thanks to my collaborators during the past four years – Ryan Zeigler, Jérôme Gattacceca, Jan Hellmann, Thorsten Kleine and Richard Greenwood. The opportunity to work with you, and in your laboratories, has been both a pleasure and a privilege. Similarly, I am grateful to Martin Lee and Matt Genge - their advice and challenges during the examination process have been much appreciated. This work would not have been possible without studentship funding from the Science and Technology Facilities Council, and funding for a Transnational Access visit to the University of Münster, awarded by the EU Europlanet 2020 Research Infrastructure. Thanks to the lovely folk in the labs for their great advice, teaching, patience and good company – John, Tony (the Meteorite Slayer), Alex, Emma, Farah, Will, Anton, Tomasz, Brett, Amin, Stas, and Callum. I would also like to thank Andy Fleet and Richard Herrington – and with them, the whole Earth Sciences department at the Natural History Museum – for a multitude of reasons, not least access to specimens, funding to attend conferences, support with everyday work and for providing a home for the past four years. I would like to honour all my friends at the NHM, but particularly Bex, Julie, Mr Brown, Claire, Mike S., Zoë, Mike R., and all my fellow curators (especially the Lyme Regis crew!). I am hugely indebted to those in the Meteorites team at the NHM that have kept me sane and shared many a Gin Friday. Much love for Epi, Penny, Jenny (hello to Jason Isaacs), Ashley, Enrica, Jay, Matthias, Paul, Nachiketa, and Helena. 5 Special mentions must go to those who have enriched my life immeasurably during this Ph.D. training. Debs – without whom I would never have walked through the door to Mineralley and who convinced me I was good enough (whilst also sharing a rendition of Black Sabbath on the kazoo). Dan – whose humour, kindness, music taste, and XCT smarts saw me through many a late night in the lab. Agata – whose willingness to share ideas, teach me to classify shock, and build my confidence, has shown me the great pleasure of working with true friends. As in all aspects of life, my family are key to my success in this endeavour - feeling loved is such a privilege. Thanks to Debbie and Phil for treating me as one of their own, and to my brother, Antonio, whose pride in me has been a constant source of strength. And of course my nieces, Sophie and Rebecca, who have provided much-needed joy and fun! I would like to dedicate this work to my mother, Elli Constantatou, and partner, Chris Le Monde. Both have held my hands throughout and I cannot express how much they mean to me. To my Pappou, Gerasimos Constantatos (1921-2015), and Yaya, Vasiliki Constantatou (1935-1995), who are always in my mind and drive me to be the best I can be. Σ’αγαπώ πάρα πολύ. Lastly, to those we lost along the way – Gerasimos, Ismini, Teresa, Tony and Nigel – thank you. 6 Table of Contents 1 Introduction 1.1 Meteorites ........................................................................................................ 20 1.2 Formation and timescales of the Solar System ............................................... 21 1.3 Meteorite classification .................................................................................... 23 1.4 Chondrules ...................................................................................................... 27 1.4.1 Types of chondrules ................................................................................. 27 1.4.2 Chondrule formation ................................................................................. 31 1.5 Ordinary chondrites ......................................................................................... 34 1.6 Metamorphism ................................................................................................. 35 1.6.1 Thermal metamorphism ............................................................................ 35 1.6.2. Shock metamorphism ............................................................................... 40 1.7 X-ray Computed Tomography (XCT) .............................................................. 43 1.7.1 3D vs 2D ................................................................................................... 43 1.7.2 Applications in planetary science .............................................................. 44 1.7.3 Mineralogy ................................................................................................ 45 1.7.4 Features of chondrites in 3D ..................................................................... 47 1.8 Curation ........................................................................................................... 51 1.9 Research Justification ..................................................................................... 53 1.10 Research Aim and Objectives ...................................................................... 55 Objectives .............................................................................................................
Recommended publications
  • Open Research Online Oro.Open.Ac.Uk

    Open Research Online Oro.Open.Ac.Uk

    Open Research Online The Open University’s repository of research publications and other research outputs The Moss (CO3) meteorite: an integrated isotopic, organic and mineralogical study Conference or Workshop Item How to cite: Greenwood, R. C.; Pearson, V. K.; Verchovsky, A. B.; Johnson, D.; Franchi, I. A.; Roaldset, E.; Raade, G. and Bartoschewitz, R. (2007). The Moss (CO3) meteorite: an integrated isotopic, organic and mineralogical study. In: 38th Lunar and Planetary Science Conference (Lunar and Planetary Science XXXVIII), 12-16 Mar 2007, Houston, Texas. For guidance on citations see FAQs. c [not recorded] Version: [not recorded] Link(s) to article on publisher’s website: http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2267.pdf Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online’s data policy on reuse of materials please consult the policies page. oro.open.ac.uk Lunar and Planetary Science XXXVIII (2007) 2267.pdf THE MOSS (CO3) METEORITE: AN INTEGRATED ISOTOPIC, ORGANIC AND MINERALOGICAL STUDY. R. C. Greenwood1, V. K. Pearson1, A. B. Verchovsky1, D. Johnson1, I. A. Franchi1, E. Roaldset2, G. Raade2 and R. Bartoschewitz3, 1Planetary and Space Sciences Research Institute, Open University, Milton Keynes, MK7 6AA, UK. E-mail: [email protected]; 2Naturhistorisk museum, Universitetet i Oslo, Postboks 1172 Blindern, 0318 Oslo, Norway; 3Meteorite Laboratory, Lehmweg 53, D-38518 Gifhorn, Germany. Introduction: Following a bright fireball and a oxygen three-isotope diagram (Fig.1) previously ana- loud explosion the Moss meteorite fell on 14 July 2006 lyzed CO3 falls plot as a tight central cluster with CO3 at approximately 10:20am in the Moss-Rygge area on finds on either side [7].
  • New Major and Trace Element Data from Acapulcoite-Lodranite Clan

    New Major and Trace Element Data from Acapulcoite-Lodranite Clan

    52nd Lunar and Planetary Science Conference 2021 (LPI Contrib. No. 2548) 1307.pdf New Major and Trace Element Data from Acapulcoite-Lodranite Clan Meteorites: Evidence for Melt-Rock Reaction Events and Early Collisional Fragmentation of the Parent Body Michael P. Lucas1, Nick Dygert1, Nathaniel R. Miller2, and Harry Y. McSween1, 1Department of Earth & Planetary Sciences, University of Tennessee, Knoxville, [email protected], 2Department of Geological Sciences, Univer- sity of Texas at Austin. Introduction: New major and trace element data illumi- patterns exhibit negative Eu anomalies. REE patterns are nate the magmatic and thermal evolution of the acapul- generally consistent among the three groups, however coite-lodranite parent body (ALPB). We observe major comparison of calculated equilibrium melts for acapulco- and trace element disequilibrium in the acapulcoite and ite and transitional cpx and opx demonstrates disequilib- transitional groups that provide evidence for melt infil- rium partitioning in those samples, especially for light- tration and melt-rock reaction processes. In lodranites, REEs in cpx. In contrast, lodranites are in apparent trace which represent sources of the infiltrating melts, we ob- element equilibrium (Fig 1b). They are depleted in serve rapid cooling from high temperatures (hereafter REE+Y relative to acapulcoite-transitional samples in temps), consistent with collisional fragmentation of the cpx (Fig. 1a), and display consistent REE abundances parent body during differentiation. except NWA 5488, which
  • Hf–W Thermochronometry: II. Accretion and Thermal History of the Acapulcoite–Lodranite Parent Body

    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.
  • 19660017397.Pdf

    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.
  • Asteroids 2867 Steins and 21 Lutetia: Surface Composition from Far Infrared Observations with the Spitzer Space Telescope

    Asteroids 2867 Steins and 21 Lutetia: Surface Composition from Far Infrared Observations with the Spitzer Space Telescope

    A&A 477, 665–670 (2008) Astronomy DOI: 10.1051/0004-6361:20078085 & c ESO 2007 Astrophysics Asteroids 2867 Steins and 21 Lutetia: surface composition from far infrared observations with the Spitzer space telescope M. A. Barucci1, S. Fornasier1,2,E.Dotto3,P.L.Lamy4, L. Jorda4, O. Groussin4,J.R.Brucato5, J. Carvano6, A. Alvarez-Candal1, D. Cruikshank7, and M. Fulchignoni1,2 1 LESIA, Observatoire de Paris, 92195 Meudon Principal Cedex, France e-mail: [email protected] 2 Université Paris Diderot, Paris VII, France 3 INAF, Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio Catone, Roma, Italy 4 Laboratoire d’Astrophysique de Marseille, BP 8, 13376 Marseille Cedex 12, France 5 INAF, Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy 6 Observatorio National (COAA), rua Gal. José Cristino 77, CEP20921–400 Rio de Janeiro, Brazil 7 NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035-1000, USA Received 14 June 2007 / Accepted 3 October 2007 ABSTRACT Aims. The aim of this paper is to investigate the surface composition of the two asteroids 21 Lutetia and 2867 Steins, targets of the Rosetta space mission. Methods. We observed the two asteroids through their full rotational periods with the Infrared Spectrograph of the Spitzer Space Telescope to investigate the surface properties. The analysis of their thermal emission spectra was carried out to detect emissivity features that diagnose the surface composition. Results. For both asteroids, the Christiansen peak, the Reststrahlen, and the Transparency features were detected. The thermal emissiv- ity shows a clear analogy to carbonaceous chondrite meteorites, in particular to the CO–CV types for 21 Lutetia, while for 2867 Steins, already suggested as belonging to the E-type asteroids, the similarity to the enstatite achondrite meteorite is confirmed.
  • Meteorites, Asteroids, and Comets

    Meteorites, Asteroids, and Comets

    Space Sci Rev (2018) 214:36 https://doi.org/10.1007/s11214-018-0474-9 Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets Conel M.O’D. Alexander1 · Kevin D. McKeegan2 · Kathrin Altwegg3 Received: 10 January 2018 / Accepted: 11 January 2018 / Published online: 23 January 2018 © Springer Science+Business Media B.V., part of Springer Nature 2018 Abstract Asteroids and comets are the remnants of the swarm of planetesimals from which the planets ultimately formed, and they retain records of processes that operated prior to and during planet formation. They are also likely the sources of most of the water and other volatiles accreted by Earth. In this review, we discuss the nature and probable origins of asteroids and comets based on data from remote observations, in situ measurements by spacecraft, and laboratory analyses of meteorites derived from asteroids. The asteroidal par- ent bodies of meteorites formed ≤ 4 Ma after Solar System formation while there was still a gas disk present. It seems increasingly likely that the parent bodies of meteorites spectro- scopically linked with the E-, S-, M- and V-type asteroids formed sunward of Jupiter’s orbit, while those associated with C- and, possibly, D-type asteroids formed further out, beyond Jupiter but probably not beyond Saturn’s orbit. Comets formed further from the Sun than any of the meteorite parent bodies, and retain much higher abundances of interstellar mate- rial. CI and CM group meteorites are probably related to the most common C-type asteroids, and based on isotopic evidence they, rather than comets, are the most likely sources of the H and N accreted by the terrestrial planets.
  • Chondrule Sizes, We Have Compiled and Provide Commentary on Available Chondrule Dimension Literature Data

    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.
  • To Here from Eternity: the Story of the Bovedy, Crumlin and Leighlinbridge Meteorites

    To Here from Eternity: the Story of the Bovedy, Crumlin and Leighlinbridge Meteorites

    TO HERE FROM ETERNITY The story of the Bovedy, Crumlin and Leighlinbridge meteorites Mike Simms, Ulster Museum Friday 25th April 1969 9.25 p.m. A fireball streaks across the night sky Friday 25th April 1969 9.25 p.m. A fireball streaks across the night sky It takes less than a minute to cross the UK! …and barely 15 seconds to cross Northern Ireland A small rock smashes a roof near Lisburn A bigger one lands in a field near Garvagh. These are meteorites - the first found in Ireland since 1902, and the last for another 30 years. Where else have they fallen in Ireland? Only 8 meteorite falls in 230 years! The Bovedy, Crumlin and Leighlinbridge meteorites all fell in the 20th Century Bovedy meteorite all are L3 Ordinary Chondrite Type L Ordinary Chondrites Crumlin meteorite (these are slices) L5 Ordinary Chondrite Leighlinbridge meteorite L6 Ordinary Chondrite Types of meteorites and their abundance (%) Stony Meteorites Falls Finds Ordinary Chondrites 76.9% 50.9% Carbonaceous Chondrites 3.7% Other chondrite types 1.7% Achondrites 7.7% Ungrouped 4.3% Irons 4.2% 20.8% Stony-irons 1.3% …which is why they are called Ordinary Chondrites. Types of Ordinary Chondrite (each comes from its own parent planet) Type H (High in iron) Mooresfort 1810 Limerick 1813 Killeter 1844 Dundrum 1865 Crumlin 1902 Bovedy 1969 Leighlinbridge 1999 Type L (Low in iron) In the beginning, >4568 million years ago… Star formation triggered by a supernova Al26 Fe60 The Sun forms. Planets accrete and melt. Planetismal accretion Melting (due to Al26 and Fe60) Differentiation Pallasite meteorites (planet mantle) Iron meteorites (planet core) Achondrite meteorites (planet crust) Pallasite meteorites (planet mantle) But none of these are chondrite meteorites… Iron meteorites (planet core) Achondrite meteorites (planet crust) How and when did the chondrules form? Sprucefield slice Splashes from the collision of molten planetismals.
  • Petrogenesis of Acapulcoites and Lodranites: a Shock-Melting Model

    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.
  • March 21–25, 2016

    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,
  • The Mineralogical Magazine Journal

    The Mineralogical Magazine Journal

    THE MINERALOGICAL MAGAZINE AND JOURNAL OF THE MINERALOGICAL SOCIETY. 1~o. 40. OCTOBER 1889. Vol. VIII. On the Meteorites which have been found iu the Desert of Atacama and its neighbourhood. By L. FLETCHER, M.A., F.R.S., Keeper of Minerals in the British Museum. (With a Map of the District, Plate X.) [Read March 12th and May 7th, ]889.J 1. THE immediate object of the present paper is to place on record J- the history and characters of several Atacama meteorites of which no description has yet been published; but incidentally it is con- venient at the same time to consider the relationship of these masses to others from the same region, which either have been already described, or at least are stated to be preserved in one or more of the known Meteo. rite-Collections. 2. The term " Desert of Atacama " is generally applied to that part of western South America which lies between the towns of Copiapo and Cobija, about 330 miles distant from each other, and which extends island as far as the Indian hamlet of Antofagasta, about 180 miles from 224 L. FLETCHER ON THE METEORITES OF ATACAMA. the coast. The Atacama meteorites preserved in the Collections have been found at several places widely separated throughout the Desert. 3. A critical examination of the descriptive literature, and a compari- son of the manuscript and printed meteorite-lists, which have been placed at my service, lead to the conclusion that all the meteoritic frag- ments from Atacama now preserved in the known Collections belong to one or other of at most thirteen meteorites, which, for reasons given below, are referred to in this paper under the following names :-- 1.
  • Curt Teich Postcard Archives Towns and Cities

    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