Geology Reference
In-Depth Information
Lunar anorthositic
regolith breccia
31.39 g
Found January 18, 1982
3.0 × 2.5 × 3.0 cm
Weathering = A/B
Anorthositic portions of the Moon are found in the lunar highlands, or
the rough mountainous regions between the smoother mare. These are
some of the oldest portions of the Moon but were only sampled extensively
by a few of the
Apollo
missions. Additional samples of the highlands can
provide better and more comprehensive understanding of the geologic
history of this fundamental province on the Moon.
Oliv. Pyr.
Impact melt
Granulitic
Pristine
90
A
K
80
H
O
C
N
J
D
B
70
L
Ferroan
anorthosites
I
60
F
50
85
90
95
Avg. Ca/(Co+Na+K)1n plagioclase
Plate 64
MiNERALogy
SigNiFiCANCE
ALH A81005 is a polymict regolith breccia that contains
clasts of low Ti mare basalt, high Ti mare basalt, granu-
litic breccia, cumulate breccia, impact melt, anorthosite,
norite, and troctolite. it also contains many soil compo-
nents (regolith breccia and agglutinate), and mineral and
glass fragments.
ALH A81005 was the first recognized lunar meteorite. it
contains clasts that bridge the gap between the magnesium
suite samples (MgS) and ferroan anorthosites (FAN),
illustrating that lunar meteorites provide information that
complements the
Apollo
and
Luna
collections (left, [487]).
References [436-489]
