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Anomalous nitrogen isotopic compositions in the
stardust-rich Antarctic micrometeorite T98G8: affinities to primitive
CR chondrites and anhydrous IDPs.
Floss C., Stadermann F. J., Yada T., Noguchi T., and
Nakamura T. (2009)
Lunar & Planet. Sci. 40, Abstract #1082.
ABSTRACT
After their initial discoveries in interplanetary dust
particles (IDPs) and primitive meteorites, presolar silicates were also
found in several Antarctic micrometeorites (AMMs). One micrometeorite
in particular, T98G8, exhibits high abundances of silicate stardust
grains and also contains several C-anomalous grains tentatively
identified as SiC; notably eleven distinct presolar grains were found
in a single 20 x 20 µm2 area of this AMM. Nitrogen
isotopic anomalies have been associated with high presolar grain
abundances in some extraterrestrial samples, including the CR
chondrites and IDPs. Here we report on C and N isotopic distributions
in T98G8 and explore the relationship of this micrometeorite to other
extraterrestrial materials.
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