  Chondrules formed by the melting of dust aggregates in the solar
protoplanetary disk and as such provide unique insights into how solid material
was transported and mixed within the disk. Here we show that chondrules from
enstatite and ordinary chondrites show only small 50Ti variations and scatter
closely around the 50Ti composition of their host chondrites. By contrast,
chondrules from carbonaceous chondrites have highly variable 50Ti compositions,
which, relative to the terrestrial standard, range from the small 50Ti deficits
measured for enstatite and ordinary chondrite chondrules to the large 50Ti
excesses known from Ca-Al-rich inclusions (CAIs). These 50Ti variations can be
attributed to the addition of isotopically heterogeneous CAI-like material to
enstatite and ordinary chondrite-like chondrule precursors. The new Ti isotopic
data demonstrate that isotopic variations among carbonaceous chondrite
chondrules do not require formation over a wide range of orbital distances, but
can instead be fully accounted for by the incorporation of isotopically
anomalous nuggets into chondrule precursors. As such, these data obviate the
need for disk-wide transport of chondrules prior to chondrite parent body
accretion and are consistent with formation of chondrules from a given
chondrite group in localized regions of the disk. Lastly, the ubiquitous
presence of 50Ti-enriched material in carbonaceous chondrites, and the lack of
this material in the non-carbonaceous chondrites support the idea that these
two meteorite groups derive from areas of the disk that remained isolated from
each other through the formation of Jupiter.
