DOCSLIB.ORG

19820019331.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
19820019331.Pdf N O T I C E THIS DOCUMENT HAS BEEN REPRODUCED FROM MICROFICHE. ALTHOUGH IT IS RECOGNIZED THAT CERTAIN PORTIONS ARE ILLEGIBLE, IT IS BEING RELEASED IN THE INTEREST OF MAKING AVAILABLE AS MUCH INFORMATION AS POSSIBLE (NASA-C -16 9088) WOliKS110 P ON I(INAR BR ECCIAS AhJ) SO.4LS AND TIJE-ja METEORITIC ANAICJS N82-27207 (LUn4r and p.Lalletary 'Inst.) HC A09/MF A01 177 p CSCI 03B uncl. a z G3/91 24229 WORKSHOP ON 1,4 1 ' 1, M-O& *Q . In 5 )IINAR BRECCIAS AND SOILS ANDA. THEIR METEORITIC ANALOGS RECEIVED %SA STI ROW. NCO= LPI Technical Reortp Number 82-02 LUNAR AND PLANETARY INSTITUTE 3303 NASA ROAD I HOUSTON, TEXAS 7705$ iifI " l x zk ^, yy4 WORKSHOP ON Fi E LUNAR IBRECCIAS AND SOILS AND I I THEIR METEORITIC ANALOGS Edited by. G. Jeffrey Taylor Laurel L. Wilkening A Lunar and Planetary Institute Workshop November 9-11, 1981. Lunar and Planetary Institute 3303 NASA Road 1 Houston, Texas 77058 LPI Technical Report 82.02 (1 ^i I l^ r tli i Compiled in 1982 by the LUNAR AND PLANETARY INSTITUTE t The 'Institute Is operated by Universities Space Research Association under Contract NASW-3389 with the National Aeronautics and Space Administration, Material in this document r o y be copied Without restraint for library, abstract service, educational or personal research purposes; however, republication of any portion requires the written permission of the authors as well as appropriate acknowledgment of this publication, This report may be cited as; Taylor C, J. (1982) Workshop on Lunar Brecclas and Soils and Their Meteoritle Analogs, LPI Tech. Rpt, 82-02, Lunar and Planetary Institute, Houston. 172 pp. Papers in this report may be cited as; Author A. (1982) Title of part, in Workshop on Lunar Brorrias and Soils and Their Meleorll_le Analog-,v (C, J. Taylor, Ed,) p , ,, x—v . , L.' , .- 'feel:, n pt. e'=02, .Lunar and Planetary Institute, Houston, Y~ This report is distributed by; LIBRARY/ INFORMATION CENTER Lunar and Planetary Institute 3303 NASA Road l Houston, TX 77058 Mail order requestors will be invoiced for the cost of postage and handling. ERRATA FOR Workshop_on Lunar Mccias and Soils and Their Meteoritic Analogs The information on the second page of this volume concerning proper referencing of this publication is incorr-oct duo to the face that one of the editors' Pames was inadvertently left off. This volume should be correctly ref'orenced as; Taylor G. J. and L. L. Wilkening (1982) Workshop on Lunar Brcccias and SoiZs and Their huteoritic Analogs. LPI Tech. Rpt, 82-02, Lunar and Planetary Institute, Houston. 172 pp. Papers in this volume should be cited as; Author A. (1982) Title of part. In Workshop on Lunar Breacias and Soils and Their Aleteoritic Analogs (G. J. Taylor and L. L. Wilkening, Rds.) p. xx-yy. LPT 'Tech. Rpt. 82-02. Lunar and Planetary Institute, Houston. r Cover. Lunar (67015, left) and meteoritic (BTNA78004, right)breccias, Both rocks are fragmental breccias consisting of mechanically-interlocked rock and mineral clasts. The largest clast in the photograph of BTNA 78004 is_2 cm long; the largest one in 67015 is 1 cm long, i 7, Contents Preface i. Workshop Rationale and Format G. J, Taylor and L. L. Wilkening II, Program III, Discussion Summaries Petrology of breccias E. R, D, Scott and A. Basu Properties and dynamics of asteroidal regoliths and thi^ relation to B accretionary processes C. R. Chapman and L. L, Wilkening Chronometric constraints 12 C.M. Hohenberg Impact processes 14 S, K. Croft IV. Future Research Directions 17 G. Wetherill V, Abstracts of Keynote Talks and Contributed Abstracts 21 Impact dynamics of asteroidal brecciation 23 T. J. Ahrens and J. D, O'Keefe Chronology of breccias 26 D.D. Bogard Properties and dynamics of asteroidal regoliths and the relation 31 t6 accretionary processes C. R. Chapman and L L. Wilkening Pristinity problems on a basaltic achondrite parent (BAP): Chondritic 36 contamination of basalt clasts from Aolymict eucrites J. S. Delaney, M Prinz, G. E. Harlow, and C; E, Nehru Spectral uariations on asteroidal surfaces; Implications for composition 40 and surface processes M, J. Gaffey, T, King, and B. R. Hawke h ^E f =t Constraints on the irradiation history of the gas-rich meteorites 44 i J. N, Goswamt and K. Nishlizuml f The origin of achondrite breccias 49 R. H, Hewins Meddling the evolution of asteroidal regoliths 54 M' K. R, Housen K Volatile trace metal transport in planetary ragoliths 59 R. M. Housley and E. H. Orlin An extension of lunar rust petrogenesis to the uolatile element regime 62 of light-dark chondritic meteorites R. H, Hunter and L A, Taylor ri a' I` Composition and origin of chondritic breccias 65 K. Kell Roundness and sphericity of clasts in meteorites, lunar soil breccia, 84 i and lunar soils I K. Kordesh and A, Basu Evolution of an asteroidal regolith: Granulometry, mixing and maturity 87 Y, Langevin Space exposure of breccia components 94 t J. D, Macdougall Primary structures in lunar cores and regolith breccias 97 J S Na le H5 clast and unequilibrated host in Yamato 75028 chondrite 102 T. Ohta and H, Takeda Carbonaceous chondritest Do we see relics of planetesimal 105 formation in them? R. S. Rajan y Petrologic insights into the fragmentation history of asteroids 107 A. E. Rubin, G. J. Taylor, E, R. D, Scott, and K, Kell Nutshell guide to lunar breccias I11 G. Ryder I t Electron microprobe study of impact-melted regolith breccias 120 x:a O G. Sato, H, Takeda, K. Yanai, and H, Kojima k _..... .., ....0 .. .... s. c,. a ..^ e .. ...x.. .::3 ,4,....,^,.s. _. ;. iiisii.A,^" ..rifuaY _,,........_........^..._..®.r..._..... Ages of Serenitatis breccias 123 O. A, Schaeffer, R. Warasila, and T. C. Lxabolka k` Thermoluminescence of a gas-rich meteorite and the relationship 126 k between gas-rich and gas-poor meteorites ' D. W. G. Sears Primitiue breccias among Type 3 ordinary chondrites—origin and 130 relation to regolith breccias E. R. D, Scott and G. J. Taylor 1 About regolith dynamics and the ancient solar corpuscular radiation; 135 potential of lunar and meteoritic studies P, Signer, Ph, Rtique, and R, Wieler Terrestrial impact breccias 139 . D, Sttsffler Magnetic and thermal history of the brecciated chondrite Abee 147 i N, Sugiura and D. W, Strangway 1i Mineralogical characteristics of polymict breccias on the howardite 148 parent body and the moon H.Takeda Comment., Problems regarding meteorite and lunar chronology 152 M, Tatsumoto, D, M, Unruh, and P. J. Patchett l Petrologic comparison of lunar and meteoritic breccias 153 G. J, Taylor VI. List of Registered Attendees 169 I r r I Preface This report documents the results of a workshop on "Comparisons between Lunar Breccias and Soils and Their Meteoritic Analogs," which was held at the Lunar and Planetary Institute November 9-11, 1981, This workshop was the third in a series organized by the Lunar and Planetary Sample Team as part of the Highlands Initiative, an effort organized to help focus research aimed at understanding the early evolution of the moon's crust. However, in contrast to two previous workshops, Workshop on Apollo 16 (LPI Technical Report Number 81.01) and Workshop on Magmatic Processes in Early Planetary Crusts (LPI Technical Report Number 8201), this workshop was designed to use our knowledge about lunar brecclas to help sharpen our understanding of meteoritic breccias and, therefore, of meteorite parent bodies, , 1, Workshop Rationale and Format G, J. Taylor and L„ L, Wilkenins Lunar soils and brecclas have been studied In detail since the first samples were returned from the Apollo 11 mission, They have been analyzed for their chemicalcompos;»ions, mineralogy, petrology, physical characteristics, and cosmic-ray, solar-flare and solar .w .^ A exposure histories. Models describing the evolu. tion and dynamics of the present regolith and the ant; Ant megaregolith have been developed, used on comparisons with terrestrial impact craters, lunar brecclas have been 0assifled by their probable locations within or outside craters, The aim of the workshop was to use this extensiv y body of data and theory to help us understand the evolution of meteoriteparent bodies, Although meteoritic (,Nrecciashave also been studied In considerable detail, there never has been a concerted effort to compare diem to lunar soils and brecclas. Such comparisons can lead to a better understanding of a number of problems In planetary science; 1)The accretion of the planets and meteorite parent bodies must have Involved Impacts, Can we see evidence for these accretionary impacts? How would the brecclas produced differ from those formed at the present surfaces (the regolith; I.e. "gas-rich" brecclas)? Can we distinguish the effects of processes operat ing during accretion from those that operated before and after accretion? 2)How comparable are the properties of lunar and meteoritic regolith brecclas? What do differences in their respective solar•wind inventories tell us about the formation of lunar and meteoritic breccias? Do lunar and meteoritic breccias record different eras of solar activity? What are the significant differences in their exposure histories? How different are meteorite and lunar regoliths in their physical properties (e,g,, grain size)? 3) What can we learn about cratering processes on asteroids from studies of lunar and meteoritic breccias? Are differences between lunar and meteoritic brecclas due to differences In Impact velocities, the population of projectiles (fluxes, size distributions), or properties of the target materials? What effect does chemical composition have on regolith development? 4) How can we date the assembly of regolith (and other fragmental) breccias? What do breccia ages mean? Can we use them to learn about meteorite fluxes or the frequency of impacts in the asteroid belt? 5) What can volatiles tell us about processes on and in meteorite parent bodies? Many gas-rich lunar breccias have large concentrations of volatiles on grain surfaces.
Load more

Recommended publications
  • 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.
    [Show full text]
  • Meteorite Collections: Sample List
    Meteorite Collections: Sample List Institute of Meteoritics Department of Earth and Planetary Sciences University of New Mexico October 01, 2021 Institute of Meteoritics Meteorite Collection The IOM meteorite collection includes samples from approximately 600 different meteorites, representative of most meteorite types. The last printed copy of the collection's Catalog was published in 1990. We will no longer publish a printed catalog, but instead have produced this web-based Online Catalog, which presents the current catalog in searchable and downloadable forms. The database will be updated periodically. The date on the front page of this version of the catalog is the date that it was downloaded from the worldwide web. The catalog website is: Although we have made every effort to avoid inaccuracies, the database may still contain errors. Please contact the collection's Curator, Dr. Rhian Jones, ([email protected]) if you have any questions or comments. Cover photos: Top left: Thin section photomicrograph of the martian shergottite, Zagami (crossed nicols). Brightly colored crystals are pyroxene; black material is maskelynite (a form of plagioclase feldspar that has been rendered amorphous by high shock pressures). Photo is 1.5 mm across. (Photo by R. Jones.) Top right: The Pasamonte, New Mexico, eucrite (basalt). This individual stone is covered with shiny black fusion crust that formed as the stone fell through the earth's atmosphere. Photo is 8 cm across. (Photo by K. Nicols.) Bottom left: The Dora, New Mexico, pallasite. Orange crystals of olivine are set in a matrix of iron, nickel metal. Photo is 10 cm across. (Photo by K.
    [Show full text]
  • Meteorite Auction at the Tucson Gem and Mineral Show, 2006
    http://www.nyrockman.com/tucson-auction-2006.htm METEORITE AUCTION AT THE TUCSON GEM AND MINERAL SHOW, 2006 Founded by prominent collector Allan Lang in 1971, the R.A. Langheinrich Meteorite Collection is one of the foremost private collections in the world. Comprising hundreds of witnessed falls; unique historic documented meteorites — many with original museum numbers and specimen cards; large irons with unusual character; and lunar and planetary material, the collection is internationally recognized as an important reference and research resource. Many specimens were acquired by the collection through institutional trades with the world's major museums. Much of of the Langheinrich Meteorite Collection is viewable online in the R.A. Langheinrich Museum of Meteorites, and private viewings can be arranged by appointment. Occasionally, specimens from the collection are made available for sale to private collectors and institutions. The specimens shown below will be offered at auction on Saturday, February 4th, 2006 during the Tucson Gem and Mineral Show. CLICK ON IMAGES TO ENLARGE LOT 1R 24 WITNESSED FALL ALLENDE Large complete fusion-crusted individual 1,667 grams Stone, CV3.2 Fell Chihuahua, Mexico February 8, 1969 LOT 2 OT 24 WITNESSED FALL - MARTIAN METEORITE NAKHLA With Humboldt University Label 6.0 grams Stone, achondrite, nakhlite Fell Alexandria, Egypt June 28, 1911 LOT 3 WINONA 10.35 gram fragment Stone, winonaite (WIN) Found Coconino County, AZ, USA 1928 http://www.nyrockman.com/tucson-auction-2006.htm (1 z 10) [2008-05-26 18:19:13]
    [Show full text]
  • Significance of Calcium-Rich Differentiates in Chondritic Meteorites Pyrite-Haematite Alteration As a Source of Colour in Red Be
    Nature Vol. 255 June 5 1975 471 ' Walker, G. P. L., in Geodynamics of Iceland and the North Atlamic area (edit. elements makes confirmation of this impossible. Accepting by Kristjansson, L.), 189-201 (Reidel, Dordrecht, 1974). 9 Jakobsson, S. P., Lithos, 5, 365-386 (1972). this, it is likely that at least one planetary body had been 10 Sigurdsson H. Earth planet. Sci. Lett., 10, 129-135 (1970). 11 Ward, P. L., P~lmason, G., and Drake, C., J. geophys. Res., 74, 665-684 (1969). differentiated and partially fragmented so that its disrupted 12 Walker, G. P. L., in Geodynamics of lcel:md and the North Atlantic area (edit. material was incorporated into an L-group, chondritic, parent by Kristjansson, L.), 177-188 (Reidel, Dordrecht, 1974). 13 Walker, G. P. L., Q. Jl geol. Soc. Land., 119,29-60 (1963). body. Goodland has a short gas retention age which precludes 14 Einarsson, T., J. geophys. Res., 73, 7561-7576 (1968). 12 15 Hast, N., Tectonophysics, 8, 169-211 (1969). speculation about its early history ; the age of Bovedy is 16 Brander, J., and Wadge, G., Nature, 244,496-498 (1973). currently under investigation in the hope that it will provide a 17 Johnston, G. L .. in Geodynamics of Iceland and the North Atlantic area (edit. by Kristjansson, L.), 49-62 (Reidel, Dordrecht 1974). younger limit to the time of differentiation of the parent of its 18 Serson, P. H., Hannaford, W., and Haines, G. V., Science, 162, 355-357 (1968). 19 Sigurdswn, H., Rit. visindafjelags islendinga, 38, 162-179 (1967).
    [Show full text]
  • Meteorite Collections: Catalog
    Meteorite Collections: Catalog Institute of Meteoritics Department of Earth and Planetary Sciences University of New Mexico July 25, 2011 Institute of Meteoritics Meteorite Collection The IOM meteorite collection includes samples from approximately 600 different meteorites, representative of most meteorite types. The last printed copy of the collection's Catalog was published in 1990. We will no longer publish a printed catalog, but instead have produced this web-based Online Catalog, which presents the current catalog in searchable and downloadable forms. The database will be updated periodically. The date on the front page of this version of the catalog is the date that it was downloaded from the worldwide web. The catalog website is: Although we have made every effort to avoid inaccuracies, the database may still contain errors. Please contact the collection's Curator, Dr. Rhian Jones, ([email protected]) if you have any questions or comments. Cover photos: Top left: Thin section photomicrograph of the martian shergottite, Zagami (crossed nicols). Brightly colored crystals are pyroxene; black material is maskelynite (a form of plagioclase feldspar that has been rendered amorphous by high shock pressures). Photo is 1.5 mm across. (Photo by R. Jones.) Top right: The Pasamonte, New Mexico, eucrite (basalt). This individual stone is covered with shiny black fusion crust that formed as the stone fell through the earth's atmosphere. Photo is 8 cm across. (Photo by K. Nicols.) Bottom left: The Dora, New Mexico, pallasite. Orange crystals of olivine are set in a matrix of iron, nickel metal. Photo is 10 cm across. (Photo by K.
    [Show full text]
  • Extra-Terrestrial Igneous Granites and Related Rocks: a Review of Their Occurrence and Petrogenesis
    This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Lithos 153 (2012) 3–24 Contents lists available at SciVerse ScienceDirect Lithos journal homepage: www.elsevier.com/locate/lithos Extra-terrestrial igneous granites and related rocks: A review of their occurrence and petrogenesis Bernard Bonin ⁎ UMR8148 ‘IDES’, CNRS, Département des Sciences de la Terre, Université de Paris-Sud, F-91405 ORSAY CEDEX, France article info abstract Article history: The telluric planets and the asteroid belt display the same internal structure with a metallic inner core and a Received 4 November 2011 silicate outer shell. Experimental data and petrological evidence in silicate systems show that granite can be Accepted 4 April 2012 produced by extreme igneous differentiation through various types of igneous processes. Available online 14 April 2012 On Moon, 4.4–3.9 Ga granite clasts display dry mineral assemblages. They correspond to at least 8 discrete intru- sive events. Large K/Ca enrichment and low REE abundances in granite relative to KREEP are consistent with sil- Keywords: icate liquid immiscibility, a process observed in melt inclusions within olivine of lunar basalts and in lunar Planetary granites fi A-type meteorites.
    [Show full text]
  • Late Accretion and Lithification of Chondritic Parent Bodies: Mg Isotope Studies on Fragments from Primitive Chondrites and Chondritic Breccias
    Meteoritics & Planetary Science 42, Nr 7/8, 1291–1308 (2007) Abstract available online at http://meteoritics.org Late accretion and lithification of chondritic parent bodies: Mg isotope studies on fragments from primitive chondrites and chondritic breccias Anna K. SOKOL1, 3*, Addi BISCHOFF1, Kuljeet K. MARHAS2, Klaus MEZGER3, and Ernst ZINNER2 1Institut für Planetologie, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany 2McDonnell Center for the Space Sciences and Physics Department, Washington University, One Brookings Drive, Saint Louis, Missouri 63130, USA 3Institut für Mineralogie, Corrensstr. 24, 48149 Münster, Germany *Corresponding author. E-mail: [email protected] (Received 16 October 2006; revision accepted 25 July 2007) Abstract–Recent results of isotopic dating studies (182Hf-182W, 26Al-26Mg) and the increasing number of observed igneous and metamorphosed fragments in (primitive) chondrites provide strong evidence that accretion of differentiated planetesimals predates that of primitive chondrite parent bodies. The primitive chondrites Adrar 003 and Acfer 094 contain some unusual fragments that seem to have undergone recrystallization. Magnesium isotope analyses reveal no detectable radiogenic 26Mg in any of the studied fragments. The possibility that evidence for 26Al was destroyed by parent body metamorphism after formation is not likely because several other constituents of these chondrites do not show any metamorphic features. Since final accretion of a planetesimal must have occurred after formation of its youngest components, formation of these parent bodies must thus have been relatively late (i.e., after most 26Al had decayed). Al-Mg isotope data for some igneous-textured clasts (granitoids and andesitic fragments) within the two chondrite regolith breccias Adzhi-Bogdo and Study Butte reveal also no evidence for radiogenic 26Mg.
    [Show full text]
  • The Origin of Chondrules and Chondrites: Debris from Lowâ•'Velocity Impacts Between Molten Planetesimals?
    Meteoritics & Planetary Science 47, Nr 12, 2170–2192 (2012) doi: 10.1111/maps.12002 The origin of chondrules and chondrites: Debris from low-velocity impacts between molten planetesimals? Ian S. SANDERS1,* and Edward R. D. SCOTT2 1Department of Geology, Trinity College, Dublin 2, Ireland 2Hawai’i Institute of Geophysics and Planetology, University of Hawai’i at Manoa, Honolulu, Hawai’i 96822, USA *Corresponding author. E-mail: [email protected] (Received 11 June 2012; revision accepted 17 September 2012) Abstract–We investigate the hypothesis that many chondrules are frozen droplets of spray from impact plumes launched when thin-shelled, largely molten planetesimals collided at low speed during accretion. This scenario, here dubbed ‘‘splashing,’’ stems from evidence that such planetesimals, intensely heated by 26Al, were abundant in the protoplanetary disk when chondrules were being formed approximately 2 Myr after calcium-aluminum-rich inclusions (CAIs), and that chondrites, far from sampling the earliest planetesimals, are made from material that accreted later, when 26Al could no longer induce melting. We show how ‘‘splashing’’ is reconcilable with many features of chondrules, including their ages, chemistry, peak temperatures, abundances, sizes, cooling rates, indented shapes, ‘‘relict’’ grains, igneous rims, and metal blebs, and is also reconcilable with features that challenge the conventional view that chondrules are flash-melted dust-clumps, particularly the high concentrations of Na and FeO in chondrules, but also including chondrule diversity, large phenocrysts, macrochondrules, scarcity of dust-clumps, and heating. We speculate that type I (FeO-poor) chondrules come from planetesimals that accreted early in the reduced, partially condensed, hot inner nebula, and that type II (FeO-rich) chondrules come from planetesimals that accreted in a later, or more distal, cool nebular setting where incorporation of water-ice with high D17O aided oxidation during heating.
    [Show full text]
  • Abstracts 5002-5050.Fm
    Meteoritics & Planetary Science 38, Nr 7, Supplement, A9–A153 (2003) http://meteoritics.org Abstracts POTENTIAL NEW IMPACT SITES IN PATAGONIA, ARGENTINA, SPIN DYNAMICS OF TERRESTRIAL PLANETS FROM EARTH- SOUTH AMERICA BASED RSDI M. C. L. Rocca. Mendoza 2779–16A, Ciudad de Buenos Aires, Argentina, I. V. Holin. Space Research Institute, Moscow, Russia. E-mail: (1428DKU). E-mail: [email protected] [email protected] Introduction: The southern part of Argentina has a total surface of Introduction: Despite wide Earth-based observations and many 786,112 km2. It is composed of five provinces: Neuquen, Rio Negro, Chubut, spacecraft missions, much remains unknown in spin dynamics of terrestrial Santa Cruz, and Tierra del Fuego. So far, no impact sites have been reported planets and related issues. Through accurate measurement of spin vectors and in this region. As part of an ongoing project to discover meteorite impact their variations with time, we may look deeply into planetary interiors. It has sites, this area was investigated through examination of 76 color LANDSAT not been possible to do so with known Earth-based techniques and spacecraft satellite images (1:250,000; resolution = 250 m) at the Instituto Geografico missions have been the only way to obtain such data. The upcoming Militar (IGM) (Military Geographic Institute) of Buenos Aires. When a Messenger (USA) and BepiColombo (Europe, Japan) orbiting and orbiting/ potential candidate was found, a more detailed study of images was done. landing missions should give obliquity and librations of Mercury closely LANDSAT color images at the scale of 1:100,000 and aerial photographs at related with its internal constitution [1].
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE ALEXANDER M. RUZICKA February 11, 2021 Education Ph.D. 1996 Planetary Sciences, University of Arizona. Tucson, AZ M.S. 1988 Earth and Space Sciences, SUNY Stony Brook, NY B.S. 1982 Geology, University of Minnesota, Minneapolis, MN B.S. 1982 Geophysics, University of Minnesota, Minneapolis, MN Employment • Professor, Portland State University, Department of Geology, 2016-current • Associate Professor, Portland State University, Department of Geology, 2012-2016 • Assistant Professor, Portland State University, Department of Geology, 2006-2012 • Research Assistant Professor, Portland State University, Department of Geology, 2001- 2006 • Assistant Professor, Portland State University, Department of Geology, 2000 • Instructor, Portland Community College, Portland, 1999-2002 • Postdoctoral Research Fellow, University of Tennessee, Knoxville, 1996-1999 • Graduate Research Associate, University of Arizona, Tucson, 1991-1996 • Graduate Research Assistant, University of Arizona, Tucson, 1986-1991 • Graduate Teaching Assistant, University of Arizona, Tucson, 1987 • Graduate Research Assistant, SUNY Stony Brook, 1982-1985 Dissertation Petrologic-kinetic studies of meteorites, 1996, Advisor William V. Boynton. Refereed Publications Ruzicka A.M., J.M. Friedrich, M.L. Hutson, J.W. Strasser, R.J. Macke, M.L. Rivers, R.C. Greenwood, K. Ziegler and R.N. Pugh (2020) Shock compaction heating and collisional processes in the production of type 3 ordinary chondrites: Lessons from the (nearly) unique L3 chondrite melt breccia Northwest Africa 8709. Meteorit. Planet. Sci. 55, 1418- 1438. https://doi.org/10.1111/maps.13567 Hugo R.C., A.M. Ruzicka and A.E. Rubin (2020) Mesoscale and microscale shock effects in the LL6 (S4) chondrites Saint-Severin and Elbert: A tale of two breccias. Meteorit. Planet.
    [Show full text]
  • Simultaneous Accretion of Differentiated Or Metamorphosed Asteroidal Clasts and Chondrules
    Simultaneous accretion of differentiated or metamorphosed asteroidal clasts and chondrules Anna K. SOKOL 1,3 , Addi BISCHOFF 1, Kuljeet K. MARHAS 2, Klaus MEZGER 3, and Ernst ZINNER 2 1Institut für Planetologie, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany 2McDonnell Center for the Space Sciences and Physics Department, Washington University, One Brookings Drive, St. Louis, MO 63130, U.S.A 3Institut für Mineralogie, Corrensstr. 24, 48149 Münster, Germany submitted to: Meteoritics & Planetary Science (October, 2006) 1 Abstract Recent results of isotopic dating studies ( 182 Hf-182 W, 26 Al-26 Mg) and the increasing number of observed igneous and metamorphosed fragments in (primitive) chondrites provide strong evidence that accretion of differentiated planetesimals pre-dates that of primitive chondrite parent bodies. Some very primitive chondrites (Adrar 003, Acfer 094), contain unusual fragments, that seem to have undergone high-grade thermal metamorphism; some clasts have igneous textures (granitoid and andesitic fragments in the ordinary chondrite breccias Adzhi-Bogdo and Study Butte). All these fragments indicate mixing of achondritic fragments and chondritic components. Here, we present Al- Mg isotopic data for several of these fragments. No clear evidence of radiogenic 26 Mg could be found in any of the studied fragments and 2 σ upper limits for 26 Al/ 27 Al range from 5.6 x10 -7 to 2.4 x 10 -5. The possibility that evidence for 26 Al was destroyed by parent-body metamorphism after formation is not likely, because these fragments and several other constituents of these primitive chondrites do not show any metamorphic features. Since final accretion of a planetesimal must have occurred after formation of its youngest components, formation of these parent bodies must thus have been relatively late (i.e.
    [Show full text]
  • Nature and Origins of Meteoritic Breccias 679
    Bischoff et al.: Nature and Origins of Meteoritic Breccias 679 Nature and Origins of Meteoritic Breccias Addi Bischoff Westfälische Wilhelms-Universität Münster Edward R. D. Scott University of Hawai‘i Knut Metzler Westfälische Wilhelms-Universität Münster Cyrena A. Goodrich University of Hawai‘i Meteorite breccias provide information about impact processes on planetary bodies, their collisional evolution, and their structure. Fragmental and regolith breccias are abundant in both differentiated and chondritic meteorite groups and together with rarer impact-melt rocks pro- vide constraints on cratering events and catastrophic impacts on asteroids. These breccias also constrain the stratigraphy of differentiated and chondritic asteroids and the relative abundance of different rock types among projectiles. Accretional chondritic breccias formed at low impact speeds (typically tens or hundreds of meters per second), while other breccias reflect hyper- velocity impacts at higher speeds (~5 km/s) after asteroidal orbits were dynamically excited. Iron and stony-iron meteorite breccias only formed, when their parent bodies were partly molten. Polymict fragmental breccias and regolith breccias in some meteorite groups contain unique types of clasts that do not occur as individual meteorites in our collections. For example, ureilite breccias contain feldspathic clasts from the ureilite parent body as well as carbonaceous chon- dritic projectile material. Such clasts provide new rock types from both unsampled parent bod- ies and unsampled parts of known parent bodies. We review breccias in all types of asteroidal meteorites and focus on the formation of regolith breccias and the role of catastrophic impacts on asteroids. 1. GENERAL INTRODUCTION shock waves during collisional processes. Partsch (1843) and von Reichenbach (1860) described “polymict breccias” 1.1.
    [Show full text]