Geology Reference
In-Depth Information
Ungrouped chondrite
113.692 g
Found January 15, 1996
5.5 × 4.0 × 3.5 cm
Weathering = B/C
diversity of materials outside the established groups. Chondrites that have
been ungrouped in the past have eventually led to the establishment of
robust groups (like Renazzo [CR], Karoonda [CK], and Rumuruti [R]
chondrites). Ungrouped chondrites constantly push the boundaries of
classification and keep our classification schemes in check.
14
Cl
12
10
CM
EH
8
CV
CO
6
CK
4
LEW
2
OC
EL
0
6
8 0 2 4 6 8 0 2 4 6 8
Al/Mn (atom ratio)
Fe
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-2.5
LEW85332
high-FeO
low-FeO
-3.0
-3.5
0
5
10
15
20
25
Fe* (mol%)
30
35
40
45
50
Si
Mg
Plate 16
MiNERALogy
SigNiFiCANCE
LEW 85332 shows an aggregate of small granular or por-
phyritic olivine chondrules (most <0.5 mm, but can be up
to 1.2 mm across), chondrule fragments, and irregular
granular masses set in a translucent yellow-brown matrix.
Minor amounts of nickel-iron and sulfide are present as
small grains in the matrix and on chondrule rims. olivine
shows a wide composition range, Fa
1-20
, mean Fa
9
; and
less abundant pyroxene has composition range Fs
1-16
.
The bulk composition is clearly outside of established
chondrite groups (top, [96]), and additional studies
revealed some of the first evidence for a link between
oxygen isotopic variation and Feo content in silicates
(left, [98]). in addition, it contains a hydrated matrix that
illustrates its presence in carbonaceous chondrite groups
other than CR or CM (right, [97]).
References [95-98]
