46th Lunar and Planetary Science Conference (2015)
1942.pdf
KEEPING UP WITH THE LUNAR METEORITES – 2015. R. L. Korotev1 and A. J. Irving2, 1Department of
Earth & Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, Saint Louis MO
63130; 2Department of Earth & Space Sciences, University of Washington, Seattle, WA 98195; [email protected]
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NWA 8306 (1389 g) [E] appears to be paired with
NWA 7834 and NWA 7948 [1]. NWA 8599 (36.5 g) [J]
is paired with NWA 5744, a granulitic breccia of troctolitic anorthosite composition [8]. We have not yet studied NWA 8651 (598 g) or NWA 8687 (563 g), but from
the descriptions [2] these two stones are probably also
part of the NWA 5744 pair group. (The other three new
stones that we have not yet studied are Mount DeWitt
12007, NWA 8607 and NWA 8609.)
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J
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H
JJ
J
D
D
DDD L
ZZZ
DE
CZZ 22 3
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M D E
CZZ
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EM
#
E
C #22
##333 MLLLLMME
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C
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M
22# 3#3 # 2 LM
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MM L
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L
NNN
N
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N
H
3
Sm / Th
Since our abstract of last year [1], a remarkable 24
new lunar meteorite stones with a total mass of 14.690
kg have been announced in the Meteoritical Bulletin
online database [2] (and we have studied another 10 yet
unnamed stones). We obtained the compositional data
presented here on multiple subsamples of 19 of the
stones by INAA [3]. Unless otherwise noted, all of the
new meteorites are fragmental or regolith breccias.
Abar al’ Uj 012 (123 g) [plot symbol # in Fig. 1] is
the first lunar meteorite from Saudi Arabia [4]. It is a
typical feldspathic lunar meteorite in composition (Fig.
1) and an impact-melt breccia.
Dhofar 1980 (6 stones, 23.5 g total) [1], an impactmelt breccia, is compositionally identical to Dhofar
1627 and was found nearby. Dhofar 1983 (57 g) [2] and
Dhofar 1984 (32.1 g) [3] are likely pairs to Dhofar
1673 [5,6].
2
BAF 1
1
KREEP range
range of mature
soil from Apollo 16
H
H
8455
clan
8
B
B
B
A
B A
A
G
GB
FGG
1 1 GF
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HH
P PP
H
P
Sm (µg/g)
subsamples
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4936
clan
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A16
soil
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1.6
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Sm (µg/g)
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Figure 3. Several feldspathic lunar meteorites have Sm/Th
ratios different from KREEP: troctolitic anorthosite NWA 8599
[J] (and its pair, NWA 5744), NWA 8586 [H], NWA 8673 [N],
and NWA 8701 [P].
8455
8668
unnamed
4936
8181
5
0
1.7
Eu (µg/g)
Figure 2. NWA 8455, 8668, and several yet unnamed meteorites plot with the NWA 4936 clan (4936, 5406, 6221, 6355,
6470, 6570, 6687, 7190, 7986, & 8181) in Fig. 1 but have a
distinctly greater Sm/Eu ratio, one that is similar to mature soil
from Apollo 16 (yellow field).
Most of the new lunar meteorites are from northwestern Africa. Several, on the basis of similar composition and texture, are likely pairs to previously discovered meteorites. NWA 8181 (18.2 g) [A] is the 9th stone
in the NWA 4936 pair group, a group that has a composition similar to Apollo 16 soil (Fig. 2) and a glassy matrix. NWA 8277 (773 g) [D], the most mafic of the
breccias studied here (14.8% FeO), is likely a terrestrial
pair to NWA 7611 and perhaps a launch pair to NWA
4884, QUE 94281, and Yamato 793274/981031 [7].
The remaining new stones appear to represent nine
new meteorites. Small NWA 8182 (15.6 g) [B] is compositionally distinct (Fig. 1). NWA 8222 [C] (208.6 g)
and Oued Awlitis 001 (432.5 g, impact-melt breccia)
[Z] [9] are highly feldspathic, KREEP-poor breccias.
NWA 8455 (2814 g) [F] and NWA 8668 (166 g) [G]
are probably paired with each other. Although they plot
with NWA 8181 and the 11 stones of the NWA 4936
pair group in Fig. 1, they form a different trend in Fig. 2,
one with greater Sm/Eu, and are less glassy. NWA 8586
(704.5 g) [H] is compositionally similar to many other
feldspathic lunar meteorites, except that Sm/Th is low
(Fig. 3). NWA 8641 (5895 g, the largest meteorite studied here) [L] and NWA 8682 (83 g in 7 pieces) [M] are
likely paired. These two along with NWA 8673 (263 g)
[N] and NWA 8701 (72 g) [P] are 2–3 richer in Sm
than most feldspathic lunar meteorites (Fig. 1). The latter two stones (8673 N and 8701 P) are distinct in having Sm/Th less than that of KREEP, suggesting that
KREEP is not the cause of the high Sm compared to
“typical” feldspathic lunar meteorites (Fig. 1). Finally,
46th Lunar and Planetary Science Conference (2015)
1942.pdf
77th Annual Meeting of the Meteoritical Society, #1216. [5] Korotev
R. L. and Irving A. J. (2013) LPSC44, #1405. [6] Hill P. J. A., et al.
(this conf.). [7] Korotev R. L., et al. (2003) Antarctic Meteorite Research 16, 152–175. [8] Kuehner S. M. et al. (2010) LPSC41, #1552.
[9] Wittmann et al. (this conf.). [10] Korotev et al. (this conference).
NWA 8632 (23.8 g) [K] is a new mare basalt; see companion abstract [10].
References: [1] Korotev R. L. and Irving A. J. (2014) LPSC45,
#1405. [2] http://www.lpi.usra.edu/meteor/metbull.php. [3] Korotev
R. L. (2012) M&PS 47, 1365–1402. [4] Mészáros M. et al. (2014)
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OA
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1F
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G
range of mature soils XX
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from Apollo 16
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O
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EX
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Sm (µg/g)
typical feldspathic
lunar meteorites
OO O O
# OOOH
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basaltic
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feldspathic
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X = NWA
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stone means
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Sc (µg/g)
Figure 1. Lunar meteorites from Oman and northwest Africa in Sc-Sm space. New meteorites in color; “old” meteorites in gray.
NWA 8673 (photo courtesy of Greg Hupé)
NWA 8701 (photo courtesy of Stefan Ralew)
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