Audit Com) Hasnaa Chennaoui (Initiative for Planetary and Space Sciences in Africa)
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Cross-References ASTEROID IMPACT Definition and Introduction History of Impact Cratering Studies
18 ASTEROID IMPACT Tedesco, E. F., Noah, P. V., Noah, M., and Price, S. D., 2002. The identification and confirmation of impact structures on supplemental IRAS minor planet survey. The Astronomical Earth were developed: (a) crater morphology, (b) geo- 123 – Journal, , 1056 1085. physical anomalies, (c) evidence for shock metamor- Tholen, D. J., and Barucci, M. A., 1989. Asteroid taxonomy. In Binzel, R. P., Gehrels, T., and Matthews, M. S. (eds.), phism, and (d) the presence of meteorites or geochemical Asteroids II. Tucson: University of Arizona Press, pp. 298–315. evidence for traces of the meteoritic projectile – of which Yeomans, D., and Baalke, R., 2009. Near Earth Object Program. only (c) and (d) can provide confirming evidence. Remote Available from World Wide Web: http://neo.jpl.nasa.gov/ sensing, including morphological observations, as well programs. as geophysical studies, cannot provide confirming evi- dence – which requires the study of actual rock samples. Cross-references Impacts influenced the geological and biological evolu- tion of our own planet; the best known example is the link Albedo between the 200-km-diameter Chicxulub impact structure Asteroid Impact Asteroid Impact Mitigation in Mexico and the Cretaceous-Tertiary boundary. Under- Asteroid Impact Prediction standing impact structures, their formation processes, Torino Scale and their consequences should be of interest not only to Earth and planetary scientists, but also to society in general. ASTEROID IMPACT History of impact cratering studies In the geological sciences, it has only recently been recog- Christian Koeberl nized how important the process of impact cratering is on Natural History Museum, Vienna, Austria a planetary scale. -
Physical and Chemical Properties of Matrix in Primitive Chondrites Thesis
Open Research Online The Open University’s repository of research publications and other research outputs Physical and Chemical Properties of Matrix in Primitive Chondrites Thesis How to cite: Vaccaro, Epifanio (2017). Physical and Chemical Properties of Matrix in Primitive Chondrites. PhD thesis The Open University. For guidance on citations see FAQs. c 2016 The Author https://creativecommons.org/licenses/by-nc-nd/4.0/ Version: Version of Record Link(s) to article on publisher’s website: http://dx.doi.org/doi:10.21954/ou.ro.0000cc17 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 Physical and chemical properties of matrix in primitive chondrites SEM element map of QUE 99177 matrix Epifanio Vaccaro (MSc Hons. Geological Sciences, Palermo University) The Open University & Natural History Museum, London Supervisors: Natalie Starkey, Ian Franchi, Sara Russell November 2017 This thesis was submitted to The Open University for the degree of Doctor of Philosophy i Abstract The origin and formation of our Solar System is an open research question, which the scientific community is trying to address. In this work was specifically investigated the fine grained matrix which is a mixture of fine-grained materials composed largely of amorphous silicate and sub-micrometre crystals forsterite and enstatite. This is thought to be the remnants of the dust and gas of the protoplanetary disk that allows us to better understand chemical and physical properties of this precursor material. -
Flooding Induced by Rising Atmospheric Carbon Dioxide 10,11 204,206 87 86 B 207,208Pb Sr/ Sr
Fiscal Year 2020 Annual Report VOL. 30, NO. 10 | OCTOBER 2020 Flooding Induced by Rising Atmospheric Carbon Dioxide 10,11 204,206 87 86 B 207,208Pb Sr/ Sr 234U/ 230 Th Sr-Nd-Hf • Geochronology – U/Th age dating • Geochemical Fingerprinting – Sr-Nd-Hf and Pb isotopes • Environmental Source Tracking – B and Sr isotopes High-Quality Data & Timely Results isobarscience.com Subsidiary of OCTOBER 2020 | VOLUME 30, NUMBER 10 SCIENCE 4 Flooding Induced by Rising Atmospheric Carbon Dioxide GSA TODAY (ISSN 1052-5173 USPS 0456-530) prints news Gregory Retallack et al. and information for more than 22,000 GSA member readers and subscribing libraries, with 11 monthly issues (March- Cover: Mississippi River flooding at West Alton, Missouri, April is a combined issue). GSA TODAY is published by The Geological Society of America® Inc. (GSA) with offices at USA, 1 June 2019 (Scott Olsen, Getty Images, user license 3300 Penrose Place, Boulder, Colorado, USA, and a mail- 2064617248). For the related article, see pages 4–8. ing address of P.O. Box 9140, Boulder, CO 80301-9140, USA. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of race, citizenship, gender, sexual orientation, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. © 2020 The Geological Society of America Inc. All rights reserved. Copyright not claimed on content prepared Special Section: FY2020 Annual Report wholly by U.S. government employees within the scope of their employment. Individual scientists are hereby granted 11 Table of Contents permission, without fees or request to GSA, to use a single figure, table, and/or brief paragraph of text in subsequent work and to make/print unlimited copies of items in GSA TODAY for noncommercial use in classrooms to further education and science. -
Post-Impact Hydrothermal Activity in Meteorite Impact Craters and Potential Opportunities for Life
Bioastronomy 2002: Life Among the Stars IAU Symposium, Vol. 213, 2004 R.P.Norris and F.H.Stootman (eds.) Post-Impact Hydrothermal Activity in Meteorite Impact Craters and Potential Opportunities for Life Christian Koeberl Department of Geological Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria, [email protected] Wolf Uwe Reimold Impact Cratering Research Group, School of Geosciences, University of the Witwatersrand, Johannesburg 2050, South Africa, [email protected] Abstract. Impact craters are prominent landforms on all objects with a solid surface in the solar system. The formation of an impact structure is a high-energy, high-temperature transient event which introduces large amounts of energy into a limited area. This energy can, in part, be expanded on the creation and activation of a hydrothermal system within and even outside of the crater. Depending on the crater size and geology of the target region, this hydrothermal system may persist for extended periods of time. Such impact-induced hydrothermal systems could well have provided conditions supportive of the development of life on the early Earth and it is not unreasonable to assume that similar conditions could have led to life-favoring circumstances on other planets and satellites. 1. Introduction Studies during the last few decades have convinced most workers that the planets formed by collision and hierarchical growth starting from small objects, Le., from dust to planetesimals to planets. All planets and satellites of the solar system that have solid surfaces (e.g., Mercury, Venus, Mars, the asteroids) are covered by craters. Impact cratering has been either the most important, or one of the most important processes that affected the shaping of their surfaces. -
Meteorite Impact Cratering on Earth: Hazards, and Geological and Biological Consequences
C. Koeberl · Meteorite impact cratering on Earth: Hazards, and geological and biological consequences Meteorite impact cratering on Earth: Hazards, and geological and biological consequences Ao. Univ. Prof. Dr. Christian Koeberl [email protected] University of Vienna Department of Geological Science Center for Earth Sciences Althanstrasse 14 1090 Vienna Tel: +43-1-4277-53110; Fax: -1-4277-9534 Impact is a unique, short-time, high-energy geological process. Craters are periods of time, an average cratering rate can be estab- a fundamental and common topographic form on the surfaces of planets, lished). Part of the problem regarding recognition of the satellites, and asteroids. On large planetary bodies, of the size of the Moon remnants of impact events is the fact that terrestrial pro- and larger, craters can form in a variety of processes, including volcanism, cesses (sedimentation, erosion, plate tectonics, etc.) either impact, subsidence, secondary impact, and collapse. The two most im- cover or erase the surface expression of impact structures portant processes are volcanism and impact. On smaller bodies (e. g., of on Earth. Many impact structures are covered by younger the size of minor planets), impact may be the only process that can form craters (as shown, for example, by the numerous craters that pockmark (i. e., post-impact) sediments and are not visible on the the surfaces of asteroids). In the explanation of terrestrial crater-like struc- surface. Others were mostly (or entirely) destroyed by tures, the interpretation as volcanic features and related structures (such erosion. In some cases, ejecta have been found far from as calderas, maars, cinder cones) has traditionally dominated over impact- any possible impact structure. -
Similarities in Element Content Between Comet 67P/Churyumov–Gerasimenko Coma Dust and Selected Meteorite Samples
MNRAS 469, S492–S505 (2017) doi:10.1093/mnras/stx1908 Advance Access publication 2017 August 2 Similarities in element content between comet 67P/Churyumov–Gerasimenko coma dust and selected meteorite samples Oliver J. Stenzel,1‹ Martin Hilchenbach,1 Sihane Merouane,1 John Paquette,1 Kurt Varmuza,2 Cecile´ Engrand,3 Franz Brandstatter,¨ 4 Christian Koeberl,4,5 Ludovic Ferriere,` 4 Peter Filzmoser,2 Sandra Siljestrom¨ 6 and the COSIMA team 1Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37077 Gottingen,¨ Germany 2Vienna University of Technology, Institute of Statistics and Mathematical Methods in Economics, A-1040 Vienna, Austria 3Centre de Sciences Nucleaires´ et de Sciences de la Matiere` – CSNSM, Bat. 104, 91 405 Orsay, France 4Natural History Museum, Burgring 7, A-1010 Vienna, Austria 5Department of Lithospheric Research, University of Vienna, A-1090 Vienna, Austria 6RISE Research Institutes of Sweden, Bioscience and Materials / Chemistry and Materials, Box 5607, 114 86 Stockholm, Sweden Accepted 2017 July 25. Received 2017 June 26; in original form 2017 February 21 ABSTRACT We have analysed the element composition and the context of particles collected within the coma of 67P/Churyumov–Gerasimenko with Rosetta’s COmetary Secondary Ion Mass An- alyzer (COSIMA). A comparison has been made between on board cometary samples and four meteorite samples measured in the laboratory with the COSIMA reference model. Fo- cusing on the rock-forming elements, we have found similarities with chondrite meteorites for some ion count ratios. The composition of 67P/Churyumov–Gerasimenko particles measured by COSIMA shows an enrichment in volatile elements compared to that of the investigated Renazzo (CR2) carbonaceous meteorite sample. -
From the President
Supplement to Meteoritics & Planetary Science, vol. 52, no. 11 The Meteoritical Society Newsletter (November 2017) A report of the business carried out by The Society over the past year, edited by Michael K. Weisberg, Secretary. IN THIS ISSUE From the President Important reminders Annual meetings Please renew your membership before Dec From the Treasurer 15 as the society has to pay the costs of From the Endowment Committee mailing late reminders. Members renewing Publications reports after March 31 incur a $15 surcharge and MAPS GCA risk missing issues of MAPS. You can renew Elements online at From the Nomenclature Committee http://metsoc.meteoriticalsociety.net. From the Membership Committee Nominate your colleagues and students for Awards and honors awards. Nominations for Fellows will be Call for nominations New Fellows to be elected considered this year. Deadlines are in From the Secretary January. See the Awards section for details. Election of new Council Proposals to host the 2022 MetSoc meeting are due in March. Please contact the secretary for procedures. FROM THE PRESIDENT President’s Report membership, and increasingly the commitment of an individual to take ownership of running our Meeting. The annual newsletter provides the President an I can say from experience that this is a somewhat opportunity to reflect on matters of interest to Society daunting task, but for those of us who have done it, it Members. First off I would like to thank Past has been a complete privilege and the memories President Mike Zolensky for all his hard work in generated go far beyond science, but are more akin to keeping the Society moving forward. -
This PDF File Is Subject to the Following Conditions and Restrictions
Geological Society of America 3300 Penrose Place P.O. Box 9140 Boulder, CO 80301 (303) 357-1000 • fax 303-357-1073 www.geosociety.org This PDF file is subject to the following conditions and restrictions: Copyright © 2009, The Geological Society of America, Inc. (GSA). All rights reserved. Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in other subsequent works and to make unlimited copies for noncommercial use in classrooms to further education and science. For any other use, contact Copyright Permissions, GSA, P.O. Box 9140, Boulder, CO 80301-9140, USA, fax 303-357-1073, [email protected]. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. This file may not be posted on the Internet. The Geological Society of America Special Paper 458 2009 Deep drilling in the Chesapeake Bay impact structure—An overview Gregory S. Gohn U.S. Geological Survey, 926A National Center, Reston, Virginia 20192, USA Christian Koeberl Department of Lithospheric Research, University of Vienna, A-1090 Vienna, Austria Kenneth G. Miller Department of Earth & Planetary Sciences, Rutgers University, Piscataway, New Jersey 08854-8066, USA Wolf Uwe Reimold Museum für Naturkunde–Leibniz Institute at Humboldt University Berlin, Invalidenstrasse 43, 10115 Berlin, Germany ABSTRACT The late Eocene Chesapeake Bay impact structure lies buried at moderate depths below Chesapeake Bay and surrounding landmasses in southeastern Virginia, USA. -
Remote Sensing Studies of Impact Craters: How to Be Sure?
C. R. Geoscience 336 (2004) 959–961 Perspective Remote sensing studies of impact craters: how to be sure? Christian Koeberl Department of Geological Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria After previous studies on impact craters in the While the details of the relation of this largest docu- eastern Sahara, particularly in Chad [2,15] and Libya mented impact event in the recent geological history [1], the paper by Paillou et al. [11] provides a good of our planet and the K/T mass extinction are still be- opportunity to discuss some important aspects of ing investigated, it is clear that these studies, over the impact craters. They are a dominant landform on our past 20 years, have finally led to a more general re- Moon, and on other atmosphereless bodies (including alization that impact cratering has been of profound planets and the satellites of planets) in our solar importance for the biological and geological evolution system. On the Earth, impact craters are far less of our planet (e.g., [6,12–14]). obvious, and only about 170 structures have so far This brings us to the topic of how to recognize been confirmed to have been formed by hypervelocity an impact crater. On the Moon and other planetary impact. The diameters of these terrestrial impact bodies that lack an appreciable atmosphere, impact craters range from less than 100 m to about 200 km; craters can commonly be recognized from morpholog- a couple of these structures have originally been even ical characteristics, but on Earth complications arise larger, probably about 250 to 300 km in diameter. -
African Meteorite Impact Craters: Characteristics and Geological Importance
Journal of African Earth Sciences, Vol. 18, No. 4, pp. 263-295, 1994 Pergamon Copyright © 1994 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0899-5362/94 $7.00 + 0.00 0899-5362(94)00044-1 African meteorite impact craters: characteristics and geological importance CHRISTIAN KOEBERLt~ 1Institute of Geochemistry, University of Vienna, Dr.-Karl-Lueger-Ring 1, A-1010 Vienna, Austria. 2Economic Geology Research Unit, Depa~ i.ment of Geology, University of the Witwatemmnd,Johannesburg 2050, South Africa. (Received 26 October 1993 : accepted 12 May 1994) Abslzact - Geologists have realized that impact cratering is the single most important surface-forming and modifying process for the other terrestrial planets and the satellites of all planets. The recognition of impact cratering as an important geological process on earth has been rather slow. However, geologists are now realizing that giant impacts have had a determining influence on the geological and biological evolution of our planet. The study of impact craters allows important conclusions, not only about the origin mid history of our solar system and its planets, but also about a fundamentally important geological process. In addition, impact craters may have a definite economic importance as some craters have been shown to contain important mineral or oil deposits. F'dtesn meteorite impact craters have so far been identified on the African continent:. Amguid (Algeria), Aomunga (Chad), Aouelloul (Mauritania), B.P. (Libya), Bosumtwi (Ghana), Highbury (Zimbabwe), Kalkkop (South Africa), Oasis (Libya), Ouarkziz (Algeria), Roter Kamm (Namibia), Saitpan (South Africa), Talemzane (Algeria), Tenoumer (Mauritania), T'm Bider (Algeria), and V~:lefort (South Africa). -
Supplement to Meteoritics & Planetary Science, Vol. 43, No. 10
Supplement to Meteoritics & Planetary Science, vol. 43, no. 10 The Meteoritical Society Newsletter (October 2008) A report of the business carried out by the society over the past year, edited by Jeff Grossman, Secretary. FROM THE PRESIDENT special workshops on meteorites, development of a new membership initiative, etc. This fund is administered by the endowment President’s Editorial Joseph I. Goldstein committee of the Meteoritical Society and the funds are invested in a conservative manner. You will soon receive a brochure which It has been a pleasure to serve as your president and to work with discusses the endowment fund in more detail. so many of you to improve our society. I have a few months This year we received donations from Gordon McKay’s remaining of my presidency and I am in the process of filling colleagues and friends and a major gift from his wife, Linda Uljon, vacancies on our major committees, my last major task. I want to to set up a permanent endowment fund of over $25,000 to support a thank our officers, members of the council, and committee members Gordon A. McKay award for the best student presentation at a for their hard work. I continue to be impressed by the loyalty of our Meteoritical Society meeting. This addition to our endowment fund members and their willingness to help make our society stronger. will allow us to continuously support this award with a cash prize. Unfortunately, I cannot thank everyone who contributed over the last Special endowment funds such as this or individual gifts will two years for their efforts. -
Geochemistry of Impactites
Geochemistry of Impactites Suevitic polymict breccia from the 1 2 3 Bosumtwi impact crater Christian Koeberl , Philippe Claeys , Lutz Hecht , in Ghana, showing a and Iain McDonald4 variety of rock fragments; the foamy 1811-5209/12/0008-0037$2.50 DOI: 10.2113/gselements.8.1.37 inclusions are impact glass that may carry the geochemical signature eochemical analysis is an essential tool for the confirmation and study of the impactor. Sample is ca 10 cm wide. of impact structures and the characterization of the various rock types Ginvolved (target rocks, impact breccias, melt rocks, etc.). Concentrations and interelement ratios of the platinum-group elements, as well as the proximal ejecta, melt rocks, and osmium and chromium isotope systems, allow quantification of extraterres- pseudotachylitic breccias, the trial components and the identification of impactor types in impact deposits. latter being dikes of melt rock at In addition, chemolithostratigraphy can reveal the possible role of impacts the bottom of an impact structure; we also consider a few examples of in environmental change throughout the geologic record. This article deals distal ejecta. Impact processes predominantly with terrestrial impact structures. produce brecciation, shock meta- morphism, and melting and Keywords: impacts, ejecta, geochemistry, platinum-group elements, vaporization of the target rocks. chromium isotopes The chemical composition of impactites provides important INTRODUCTION information that supplements petrological data. It depends The geochemistry and