Geology Reference
In-Depth Information
ungrouped chondrite
12.8 g
Found December 23, 2004
2.5 × 2.0 × 1.0 cm
Weathering = C
content than has been established for the H chondrites (<17 mol%).
These samples, as well as others from the higher Feo end of ordinary
chondrites, suggest that ordinary chondrite-like material might be pre-
sent in the asteroid belt and be part of a wider compositional group that
is poorly represented in our collections.
,0
LAP 04757
,6
1cm
1. 6
H chondrites
L chondrites
LL chondrites
Burnwell
EET 96031
LAP 04757
LAP 04757
1. 4
1. 2
1. 0
0.8
0.6
Burnwell
(Russell et al. 1998)
0.4
1mm
12
14
16
18
20
22 24
Fa (mol%)
26
28
30
32
34
Plate 10
MiNERALogy
SigNiFiCANCE
The meteorite consists of abundant chondrules set in a
metal- and sulfide-bearing matrix. olivine is homoge-
neous at Fa
13
and pyroxene exhibits a small range at
Fs
13-16
. Shock effects are present, including metal-sulfide
melting at grain boundaries.
overall, bulk trace element abundances and bulk oxygen
isotopic analysis suggest a common origin for the low-
Feo chondrites Burnwell, EET 96010, and LAP 04757
and the H chondrites (right, [35]). These three samples
could represent extreme members of a redox process
where a limiting nebular oxidizing agent, probably ice,
reacted with material containing slightly higher amounts
of metal than typically seen in the H chondrites (left, [35]).
References [35, 36]
