Bibcode
Lindstrom, D. J.; Keller, L. P.; Martinez, R. R.
Bibliographical reference
In Lunar and Planetary Inst., Twenty-Fourth Lunar and Planetary Science Conference. Part 2: G-M p 877-878 (SEE N94-16173 03-91)
Advertised on:
3
1993
Citations
0
Refereed citations
0
Description
Maralinga is an anomalous CK4 carbonaceous chondrite which contains
numerous Ca-, Al-rich inclusions (CAI's) unlike the other members of the
CK group. These CAI's are characterized by abundant green hercynitic
spinel intergrown with plagioclase and high-Ca clinopyroxene, and a
total lack of melilite. Instrumental Neutron Activation Analysis (INAA)
was used to further characterize the meteorite, with special focus on
the CAI's. High sensitivity INAA was done on eight sample disks about
100-150 microns in diameter obtained from a normal 30 micron thin
section with a diamond microcoring device. The CAI's are enriched by
60-70X bulk meteorite values in Zn, suggesting that the substantial
exchange of Fe for Mg that made the spinel in the CAI's hercynitic also
allowed efficient scavenging of Zn from the rest of the meteorite during
parent body thermal metamorphism. Less mobile elements appear to have
maintained their initial heterogeneity.