Geology Reference
In-Depth Information
K chondrite
23.13 g
Found December 9, 1987
3.0 × 2.5 × 2.0 cm
Weathering = B
K chondrites are a small group of samples that share some common char-
acteristics, such as reduced silicate mineralogy, and bulk compositions
that fall outside of established chondrite groups. For this reason they have
been grouped together with the prospect of establishing a new group of
meteorite with some common features.
17
Cl
CM
10
EH
CV
R
CO
CK
5
Kakangari
CR
LEW87232
L
2
H
LL
EL
1
7
10
20
30
Al/Mn (atom ratio)
4
2
LEW 87 Matrix
LEW 87232
Lea Co. 002
Kakangari
0
WhoIe Rock
TF
Kakangari
LEW 87232
Lea Co. 002
-2
Kakangari Matrix
Chondrules
LEW 87232
Lea Co. 002
Matrix
Kakangari
LEW 87232
CR
Kakangarl
-4
CV
-6
-2
0
2
4
δ
18
O (‰)
6
8
10
Plate 37
MiNERALogy
SigNiFiCANCE
LEW 87232 shows numerous chondrules (up to 1.8 mm
across), chondrule fragments, and mineral grains in a
translucent brown matrix. Chondrules are mainly gran-
ular or porphyritic olivine ((Fa
0.6-2
, mean Fa
1.0
) and oliv-
ine-pyroxene (Fs
0.5-9
). Minor amounts of nickel-iron and
a little sulfide are present as small grains in matrix or on
chondrule rims. The matrix appears to consist largely of
phyllosilicates.
More detailed studies of LEW 87232 have identified
some subtle differences from the other members of the
trio (left and right, [249]). Whether LEW 87232 and the
others will remain grouped after more extensive studies is
not clear. However, the unique features of these samples
nonetheless illustrate the diversity of materials in the
meteorite collections, diversity that may have gone unrec-
ognized without the collection of large numbers of sam-
ples from Antarctica.
References [245-249]
