Perhaps the Key to unlocking the CV
parent body and other failed planets, this meteorite is
one of the most important new finds if this century.
After the fall of Allende, many questions were answered
about CV meteorite origin, but many more remained. NWA
2651 and its pairings are offering a whole new outlook
on the nature of this and other failed planets. You need
not look far to find numerous abstracts from major
universities and institutions, here are a couple:
Northern Arizona University – This
material is fully authenticated.
Description and classification (
T. Bunch and J. Wittke
, NAU ), results from one thin section (2.4 cm
2 ): mostly recrystallized into fine-grained (<0.5 mm,
avg. = 0.185 mm) polygonal and subhedral grains with the
exception of several medium to large (1.2 –3.0 mm)
orthopyroxene grains that contaiin very small olivine
(<0.1 mm) inclusions. Very homogeneous assemblage,
olivine and orthopyroxene analyses are within the
precision of the electron microprobe (± 0.15 mol %).
Olivine, Fa 18.9 (FeO/MnO = 38.1 g/g); orthopyroxene, Fs
16.8 Wo 2.9 (FeO/MnO = 20.0 g/g); plagioclase, An 15.1
Or 4.7 ; metal (only taenite found), Ni = 18.9 wt. %;
chromite (only one grain found), cr# = 84.5; FeS , Ni =
1.42 wt. % and Co = 0.28 wt. %, minor merrillite. Oxygen
isotope replicate analyses (D. Rumble, CIW ) of
acid washed, bulk sample by lased fluorination gave d 17
O = 3.23 and 2.98, d 18 O = 5.03 and 4.37 and D 17 O =
0.614 and 0.708. Formerly classified as an H7.
Weathering grade, W2/3 with staining; shoc k
level, S1.
There are several unusual primitive
achondrites that apparently are not related to the
lodranite-acapulcoite or brachinite parent bodies.
Divnoe and Zag (b) are two FeO-rich achondrites that are
similar to brachinites, but with different oxygen
isotope patterns. NWA 3133/2651 paired specimens were
originally classified as L7 chondrites, but oxygen
isotope analyses show that this meteorite is a primitive
achondrite whose oxygen isotopes plot on the CV3 mixing
line and may represent a melt differentiate of a
moderately large CV3 parent body. NWA 011/2400 is very
different from other primitive achondrites in having FeO/MnO
molecular ratios similar to lunar rocks and oxygen
isotopes consistent with CR carbonaceous chondrites.
Moreover, the texture is consistent with igneous
derivation in contrast with the metamorphic
recrystallized textures of most primitive achondrites.
Like NWA 3133/2651, this meteorite may also be an
igneous melt differentiate of a moderately large CR
carbonaceous chondrite parent body.
