NASA Technical Reports Server (NTRS) 20000034770: Workshop on Extraterrestrial Materials from Cold and Hot Deserts

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WORKSHOP ON
EXTRATERRESTRIAL MA_RIALS
FROM COLD AND HOT DESERTS
P
II|
July 6-8,1999
Kwa-Maritane, Pilanesberg, South Africa
LPI Contribution No. 997

WORKSHOP ON
EXTRATERRESTRIAL MATERIALS
FROM COLD AND HOT DESERTS
July 6-8, 1999
Kwa-Maritane, Pilanesberg, South Africa
Edited by
Ludolf Schultz, Ian A. Franchi, Arch M. Reid, and Michael E. Zolensky
Sponsored by
Lunar and Planetary Institute
Max-Planck-Institut fur Chemie
University of the Witwatersrand
Lunar and Planetary Institute 3600 Bay Area Boulevard Houston TX 77058-1113
LPI Contribution No. 997
Compiled in 2000 by
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Schultz L.; Franchi I., Reid A., and _Z01e_nskyM., eds. (2000) Workshop_on_ Extraterrestrial Materials from Cold
and Hot Deserts. LPI Contribution No. 997, Lunar and Planetary Institute, Houston. 99 pp.
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LPI Contribution No. 997 iii
INTRODUCTION
Since 1969 expeditions from Japan, the United States, and European countries have recovered more than
20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4(D0--6(g)0
distinct falls, more than all non-Antarctic meteorite falls and finds combined.
Recently many meteorite specimens of a new "population" have become available: meteorites from hot
deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in
Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain
relatively high meteorite concentrations. For example, the 1985 Catalogue of Meteorites of the British
Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries
have been published in MetBase 4.0.
Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology
and Antarctic meteorites, and the differences between Antarctic meteorites and modem falls. In 1995, a
workshop addressed differences between meteorites from Antarctica, hot deserts, and modern falls, and the
implications of possible different parent populations, infall rates, and weathering processes.
Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around
the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of
probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 inJohannesburg,
South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned
prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar
regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from
Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering processes,
(2) terrestrial ages, (3) investigations of "unusual" meteorites, and (4) collection and curation.
Fig. 1. Meteorite finds in the Sahara. Cluster in Algeria belongs to Fig. 2. Meteorite finds of the USA show acluster in dry areas
the Acfer and Tanesrouf finds, those in Libya to Hammadah al of Texas and New Mexico.
Hamra and Dar alGani.
Fig. 3. Numerous meteorite finds show up atthe Nullarbor desert in Fig. 4. The many Antarctic meteorites are found on Blue
Australia. lcefieids located along the Transantarctic Mountains and at the
Yamato Mountains.
2 22_
LPI Contribution No. 997 v
CONTENTS
Program ................................................................................................................................................. ix
Summary of Previous Workshop ......................................................................................................... 1
Workshop Summary ............................................................................................................................. 3
Collections, Collecting Areas, and Pairing Problems ................................................................. 3
Weathering Effects ...................................................................................................................... 4
Terrestrial Age Determinations ................................................................................................... 5
Interplanetary Dust Particles .................................................................................................... ,..5
Noble Gases and Cosmic-Ray Effects ........................................................................................ 6
Repositories of Desert Meteorites ........................................................................................................ 7
Acknowledgments ........................... ;...................................................................................................... 9
Abstracts .............................................................................................................................................. 11
The Natural Thermoluminescence Survey of Antarctic Meteorites: Ordinary
Chondrites at the Grosvenor Mountains, MacAlpine Hills, Pecora Escarpment and
Queen Alexandra Range, and New Data for Elephant Moraine Ice Fields
P. H. Benoit and D. W. G. Sears ................................................................................... 11
Meteorites from the Nullarbor, Australia: An Update
A. W. R. Bevan, P. A. Bland, and A. J. T. Jull ............................................................... 15
Ice Flow as the Principal Sink for Antarctic Meteorites
P. A. Bland, A. J. T. JulI, A. W. R. Bevan, T. B. Smith, F. J. Berry,
and C. T. PiIlinger ......................................................................................................... 17
Pairing among EET87503 Group Howardites and Polymict Eucrites
P. C. Buchanan, D. J. Lindstrom, and D. W. MittIefehldt. ............................................ 21
Chemical Alteration of Hot Desert Meteorites: The Case of Shergottite
Dar al Gani 476
G. Crozaz and M. Wadhwa ........................................................................................... 25
vi Deserts II Workshop
Chemical Compositions of Large Interplanetary Dust Particles from the Stratosphere
and Small Antarctic Micrometeorites: Evidence for Element Loss and Addition in the
Antarctic Micrometeorites
G. J. Flynn, S. R. Sutton, and W. Klrck ......................................................................... 28
The Influence of Terrestrial Weathering on Implanted Solar Gases in Lunar Meteorites
I. Franchi, A. B. Verchovslcy, and C. T. Pillinger ......................................................... 33
Meteorites from Cold and Hot Deserts: How Many, How Big, and What Sort
M. M. Grad)'. ................................................................................................................. 36
Using 14Cand 14C-_°Be for Terrestrial Ages of Desert Meteorites
J. T. JuIl, P. A. Bland, S. E. Klandrud, L. R. McHargue, A. W. R. Bevan,
D. A. Kring, and F. Wlotzka .......................................................................................... 41
The Gold Basin Strewn Field, Mojave Desert, and its Survival from the
Late Pleistocene to the Present
D. A. Kring, A. J. T. JuIl, and P. A. Bland .................................................................... 44
Thermally Mobile Trace Elements in Carbonaceous Chondrites from
Cold and Hot Deserts
M. E. Lipschutz .............................................................................................................. 46
Historical Notes on Three Exceptional Meteorites of Southern Africa: The Cape of
Good Hope, Gibeon, and Hoba
U. B. Marvin .................................................................................................................. 48
Saharan Meteorites with Short or Complex Exposure Ages
S. MercheI, M. Altmaier, T. Faestermann, U. Herpers, K. Knie, G. Korschinek,
P. W. Kubik, S. Neumann, R. Michel, and M. Suter ...................................................... 53
Cosmogenic and Trapped Gas Components in the Martian Meteorite
Dar al Gani 476 from Hot Desert ......
S. V. S. Murty and R. K. Mohapatra .................................... ............................. 'i........... 57
Thermal Effects on Mineralogy, Noble Gas Composition, and Carbonaceous
Material in CM Chondrites
T. Nakamura, T. Kitajima, and N. Takaoka ................................................................... 61
TerreStrial Ages of Antarctic Meteorites Up Date 1999 ....
K. Nishiizumi, M. W. Caffee, and K. C. WeIten ................................................... ......,._ 64
Type I Cosmic Spheres: Key to a Major but Poorly Sampled Asteroid Population?
L. E. Nyquist .................................................................................................................. 65
LPI Contribution No. 997 vii
Do Weathering Effects Influence Cosmic Ray Exposure Ages of
Enstatite Chondrites?
A. Patzer and L. Schultz ................................................................................................ 67
Solar-Cosmic-Ray-Produced Nuclides in Extraterrestrial Matter
R. C. Reedy .................................................................................................................... 69
Noble Gases in 15 Meteorites from the Sahara: Eucrites, Ureilites,
and Ordinary Chondrites
P. Scherer, M. Piitsch, and L. Schultz ........................................................................... 72
Deflation and Meteorite Exposure on Playa Lakes in the Southwestern United States:
Unpaired Meteorites at Lucerne Dry Lake, California
R. S. Verish, A. E. Rubin, C. B. Moore, and R. A. Oriti ................................................ 74
Iron Meteorites from Antarctica: More Specimens, Still 40% Ungrouped
J. T. Wasson .................................................................................................................. 76
The Libyan Meteorite Population
D. Weber, J. ZipfeI, and A. Bischoff. ............................................................................. 81
Degree of Weathering of H-Chondrites from Frontier Mountain, Antarctica
K. C. WeIten and K. Nishiizumi ..................................................................................... 83
Cosmogenic Radionuclides in Hot Desert Chondrites with Low 14CActivities:
A Progress Report
K. C. Welten, K. Nishiizumi, and M. W. Caffee ............................................................. 88
Noble Gases in Desert Meteorites: Howardites, Unequilibrated Chondrites,
Regolith Breccias and an LL7
R. Wieler, H. Baur, H. Busemann, V. S. Heber, and I. Leya ......................................... 90
Identical Origin for Halide and Sulfate Efflorescences on Meteorite Finds and
Sulfate Veins in Orgueil
M. E. ZoIensky ............................................................................................................... 95
List of Workshop Participants ........................................................................................................... 97