Geology Reference
In-Depth Information
Table 10.1.
Number of Antarctic Meteorites by Type
(Expanded Classification)
Type
Table 10.1.
(Continued)
Type
Number
Number
LL5
2616
Acapulcoite
15
LL6
1305
Acapulcoite/Lodranite
5
LL7
4
Achondrite ungrouped
12
Lodranite
6
Angrite
2
Lunar
24
Aubrite
40
Mesosiderite
37
Brachinite
4
Nakhlite
4
C2 ungrouped
6
Pallasite
26
C3 ungrouped
1
R chondrite
27
CB
12
Shergottite
10
CH
6
ALH 84001
1
Chondrite ungrouped
3
Ureilite
65
CH3
3
Winonaite
1
CK4
23
CK5
65
The U.S. Antarctic meteorite program has, as of this
publication, retrieved 20,327 individual specimens col-
lected from 50 formally named field sites (Tables 10.1, 10.2,
and 10.3) on the East Antarctic Plateau adjacent to the
Transantarctic Mountains. A few glaciological and geo-
graphically distinct field sites were grouped together during
the early days of naming field areas that might today have
been split due to the large numbers of meteorites found in
these areas. The Grosvenor Mountains (GRO) meteorites,
for example, actually represent meteorites from individual
icefields such as Otway Massif, Mt. Cecily, Mt. Bumstead,
Mt. Raymond, Mt. Block, Block Peak, and Mauger
Nunataks. The Japanese, Chinese, South Koreans and a
number of European countries also have programs that
send meteorite hunters to the ice. The EUROMET program
recovered more than 250 meteorites from the Frontier
Mountains in 1991 and ~200 meteorites from the Allan
Hills region in 1988 [e.g.,
Delisle and Sievers
, 1991;
Delisle
et al
., 1993]. The Japanese Antarctic collection, housed at
the National Institute of Polar Research, consists of
~17,000 meteorites (as of 2006; a 2012 expedition added
more), though only 25% have been classified [
Kojima
, 2006;
Yamaguchi et al.
, 2012]. The Chinese Antarctic program
(CHINARE) has about 10,000 meteorites [
Liu et al
., 2004].
Of the 20,327 meteorites retrieved from the Antarctic
by the U.S. program to date, 18,926 have been classified as
of this publication (~93%). The U.S. efforts have focused
on systematic characterization and classification of all
meteorites, while other programs concentrate their efforts
on the most scientifically interesting meteorites. Both
approaches yield similar insights into early solar system
processes. We focus on the U.S. collection, which has the
unique distinction of being a statistically significant, well-
characterized population, allowing comparison with sim-
ilarly sized populations of meteorites observed to fall and
non-Antarctic finds.
We classify the U.S. Antarctic meteorite collection into
~40 general types (i.e., all L chondrites are counted as the
CK6
8
CM1 and CM1/2
33
CM2
270
CO3
209
CR1
2
CR2
72
CR3
1
CV3
87
Diogenite
67
En chondrite ungrouped
8
EH impact melt
4
EH3
53
EH4
16
EH5
4
EH6
1
EL3
20
EL4
4
EL5
1
EL6
17
Eucrite
3
Eucrite (brecciated)
117
Eucrite (unbrecciated)
34
FCr (chondrite)
4
H impact melt
12
H3
60
H4
324
H5
3249
H6
2301
Howardite
93
Irons
111
Kakangari-like
1
L impact melt
13
L metal
4
L3
246
L4
322
L5
2986
L6
3748
L7
4
LL impact melt
6
LL3
36
LL4
57
