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66th Annual Meeting Meteoritical Society
July 28 - August 1, 2003, Munster, Germany
Meteoritics and Planetary Science 38 (Supplement), A28.
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AQUEOUS ALTERATION AND HEATING EVENTS OF ANOMALOUS CM CHONDRITES
M.A. Ivanova, M.A. Nazarov, L.A. Taylor, T.K. Mayeda, and R.N. Clayton.
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PDF 18 Kb
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Unusual carbonaceous chondrites from the desert of Oman, Dhofar 225 (Dh-225) and Dhofar 735 (Dh-735), have similarities to the Antarctic metamorphosed carbonaceous chondrites (MCC) B-7904 (CM), Y-82162 (CI), and Y-86720 (CM). Dh-225 and Dh-735's very different post-accretional histories - including aqueous alteration and heating events - have not affected their oxygen isotopic systematics.
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66th Annual Meeting Meteoritical Society
July 28 - August 1, 2003, Munster, Germany
Meteoritics and Planetary Science 38 (Supplement), A30.
66th Annual Meeting Meteoritical Society
July 28 - August 1, 2003, Munster, Germany
Meteoritics and Planetary Science 38 (Supplement), A32.
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34th Lunar and Planetary Science Conference
2003, March 17-21, Houston, Texas, USA
#1236 CD-ROM
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THE KAIDUN METEORITE: WHERE DID IT COME FROM?
A.Ivanov and М. Zolensky
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PDF 19.5 Kb
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The Kaidun meteorite, which fell on 3.12.1980 at lat. 15° N, long. 48.3° E, holds a special place in the world meteorite collection. Kaidun is characterized by an unprecedentedly wide variety of meteorite material in its makeup. The high degree of variability in this meteorite's material is evidenced by the richness of its mineral composition - nearly 60 minerals and mineral phases have been identified in Kaidun, including several never before found in nature, such as florenskiite FeTiP, the first known phosphide of a lithophilic element.
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34th Lunar and Planetary Science Conference
2003, March 17-21, Houston, Texas, USA
#1757 CD-ROM
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PETROLOGY AND OXYGEN ISOTOPIC COMPOSITIONS OF ANOMALOUS ACHONDRITE NWA
011.
Promprated, L. A. Taylor, Mahesh Anand, D. Rumble III, E. V. Korochantseva, M. A. Ivanova, C. A.
Lorentz, and M. A. Nazarov
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PDF 230 Kb
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Northwest Africa (NWA) 011 is a
single stone of 40 g and has been discovered in the
Moroccan Sahara desert in 1999 [1]. This pyroxene-plagioclase
meteorite was classified as noncumulate
eucrite, on the basis of petrography and geochemistry
[1]. However, certain characteristics of this meteorite
such as the high Fe/Mn values in pyroxene (~65) and
particularly the bulk-rock oxygen isotopic
compositions (d
18О = +2.54, d
17О= -0,48) are not of
typical eucrites and may suggest a new type of basaltic
meteorite [2]. In an attempt to resolve this issue, we
have investigated mineral chemistry and oxygen
isotopic compositions on portions of NWA 011.
Trace-element chemistry and Ar-Ar age is presented in
a companion paper [3].
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34th Lunar and Planetary Science Conference
2003, March 17-21, Houston, Texas, USA
#1575 CD-ROM
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MAJOR AND TRACE ELEMENT CHEMISTRY AND 36Ar - 40Ar AGE OF THE NWA 011 ACHONDRITE.
E.V. Korotchantseva, M.A. Ivanova, C.A. Lorenz, A.I. Bouikine, M. Trieloff, M.A. Nazarov, P.
Promprated, M. Anand, and L.A. Taylor
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PDF 76 Kb
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In this paper, we report new data on major- and
trace-element compositions of this unique meteorite, in
addition to the first results of 36Ar/40Ar dating. The
mineralogy and petrology are reported in a companion
paper [4]. These studies present new evidence showing
that NWA 011 is significantly different from HED
meteorites.
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34th Lunar and Planetary Science Conference
2003, March 17-21, Houston, Texas, USA
#1211 CD-ROM
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NWA 1235: A PHLOGOPITE-BEARING ENSTATITE METEORITE
C. Lorenz, G. Kurat, F. Brandstatter and M. A. Nazarov
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PDF 101 Kb
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NWA 1235 (found in 2000) is a patchily weathered (W2-W3) enstatite rock weighing 80 g. No chondrules or relics thereof are present. It has a coarse-grained hypidiomorphic texture, which is, however, finer relative to that of aubrites. Mineral chemistry and metal-silicate relationships suggest that the rock was formed from an enstatite meteorite source under more oxidized conditions than other enstatite meteorites. A unique features of the meteorite are the unusual composition of troilite and exotic sulfides, presence of a wide set of microinclusions in enstatite and the occurrence of fluorphlogopite.
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34th Lunar and Planetary Science Conference
2003, March 17-21, Houston, Texas, USA
#1226 CD-ROM
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SAYH AL UHAYMIR 085, CV3 CHONDRITE: MINERALOGICAL LINKS WITH CK CHONDRITES
Marina A. Ivanova, Michail A. Nazarov, Robert N. Clayton, Toshiko K. Mayeda, and Lawrence A. Taylor
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PDF 1.6 Kb
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Sayh al Uhaymir 085 is similar to CV3 carbona-ceous
chondrites of the oxidized subgroup, and it has
some peculiarities and characteristics of CK chondrites.
We report on the petrography, mineral chemistry, and
oxygen isotopic compositions of Sayh al Uhaymir 085,
and discuss its peculiarities and origin.
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Meteoritics and Planetary Sciences
(2002) 37, 10, 1337-1345.
THE FIRST KNOWN NATURAL OCCURRENCE OF CaAl2O4, IN A Ca-Al-RICH INCLUSION FROM THE CH CHONDRITE NWA 470
Marina A. Ivanova, Michail I. Petaev, Glenn J. MacPherson, Michail A.Nazarov, Lawrence A. Taylor, and John A. Wood.
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Natural calcium monoaluminate, CaAl2O4, has been found in a grossite-rich Ca-Al-rich inclusion from the CH chondrite NWA 470. The calcium monoaluminate occurs as colorless ~10 mm subhedral grains intergrown with grossite, perovskite, and melilite. Nebular condensation is the most likely origin for the precursor materials of this CAI, but calculations suggest that dust/gas ratios substantially enhanced over solar are required to stabilize CaAl2O4.
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34th Lunar and Planetary Science Conference
2003, March 17-21, Houston, Texas, USA
#1285 CD-ROM
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DHOFAR 304, 305, 306 AND 307: NEW LUNAR HIGHLAND METEORITES FROM OMAN
Svetlana I. Demidova, Mikhail A. Nazarov, Lawrence A. Taylor, and Allan Patchen
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PDF 121 Kb
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Several lunar highland meteorites
were found in the Dhofar region of Oman. Here we
report the first data on the petrography and mineralogy
of four new lunar stones, Dhofar 304, 305, 306 and
307. Dh-304 was found close to Dh-025 and 301,
whereas Dh-305, 306 and 307 were recovered nearby
Dh-081, 280, 302 and 303. The new meteorites are
moderately weathered, impact-melt breccias. No
KREEP or mare components are present in the rocks.
Dh-304 may be paired with Dh-025 and 301. Dh-305,
306, and 307 are probably paired with Dh-302 and
303, but Dh-302 and 305 could represent different
meteorite falls. However, these meteorites are definitely
not related to Dh 081 and 280.
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