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The presence and absence of different
isotopically anomalous phases in the primitive
interplanetary dust particle Tiberius
Floss C., Stadermann F. J., and Wopenka B. (2006)
Lunar Planet. Sci. XXXVII, Abstract #1290.
ABSTRACT
Interplanetary dust particles (IDPs) sample material
preserved from the earliest formation of the solar system.
Recent work shows the existence of a subgroup of IDPs
characterized as isotopically primitive. These IDPs have
anomalous bulk N isotopic compositions and contain abundant
circumstellar and interstellar phases. We have been
examining one such IDP, nicknamed Tiberius (u44-m1-5), that
was originally studied with the Washington University ims3f
ion microprobe. Those measurements showed Tiberius to be a
fairly typical chondritic IDP with normal H and C isotopic
compositions, and a bulk 15N enrichment of 53 +/-
6 permil. Significant portions of Tiberius were not consumed
by the ims3f measurements, allowing NanoSIMS measurements to
be made on this particle. Isotopic imaging of C and O led to
the discovery of the first observed presolar grains of
corundum and SiC in an IDP. Here we report on the results of
additional C, N and O isotopic imaging measurements of this
particle.
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