Geology Reference
In-Depth Information
Table 10.2.
Number of objects recovered by year.
Year
Stones
Meteorites
Terrestrial*
1976
11
11
0
1977
302
300
2
1978
308
305
3
1979
75
73
2
1980
102
100
2
1981
317
315
2
1982
108
108
0
1983
289
281
8
1984
274
272
2
1985
366
360
6
1986
590
558
32
1987
685
670
15
1988
910
876
34
1989
0
0
0
1990
1,100
1,098
2
1991
601
600
1
1992
255
254
1
1993
853
840
13
1994
608
596
12
1995
238
235
3
1996
394
388
6
1997
1,091
1,086
5
1998
192
190
2
1999
1,041
1,031
10
2000
759
756
3*
2001
336
335
1
2002
924
885
39*
2003
1,355
1,353
2*
2004
1,231
1,228
3*
2005
236
233
5
2006
854
842
13
2007
710
700
10
2008
521
519
2
2009
1,021
1,014
8
2010
§
1,234
1,237
4
2011
§
302
302
0
2012
§
394
393
1
Total recovered
20,580
20,327
254
Total classified
18,926
% Terrestrial
1.23
*
Terrestrial number also includes tiny pieces of fusion crust.
§
Samples from these seasons are still being characterized as of November 2013,
so additional terrestrial material may be identified among the collection.
same type, for example, as are all martian meteorites; the
number of meteorites of each type can be seen in the
expanded classification in Table 10.1). While the vast
majority (~90%) of Antarctic meteorites collected each
year are ordinary chondrites, each year a few meteorites
are found that are enigmatic, either exhibiting properties
outside the range previously defined for a given group of
meteorites or necessitating the formation of an entirely
new group of meteorites. These meteorites represent
pieces of the cosmochemical puzzle that challenge our
understanding of how our solar system formed and
evolved. As examples, the first of the newly defined CH
chondrites (ALH 85085; Plate 24) was recovered in
Antarctica [
Weisberg and Righter
, 2014 (this volume)]
and the acapulcoite-lodranite clan [
Mittlefehldt and
McCoy
, 2014 (this volume)] was only represented by the
type meteorites prior to the Antarctic program. Many
anomalous, poorly understood meteorites remain in the
collection awaiting future recoveries, technological inno-
vations, or paradigm shifts to fully understand their
