  We report abundances of elements from $_{26}$Fe to $_{40}$Zr in the cosmic
radiation measured by the SuperTIGER (Trans-Iron Galactic Element Recorder)
instrument during 55 days of exposure on a long-duration balloon flight over
Antarctica. These observations resolve elemental abundances in this charge
range with single-element resolution and good statistics.
  These results support a model of cosmic-ray origin in which the source
material consists of a mixture of 19$^{+11}_{-6}$\% material from massive stars
and $\sim$81\% normal interstellar medium (ISM) material with solar system
abundances. The results also show a preferential acceleration of refractory
elements (found in interstellar dust grains) by a factor of $\sim$4 over
volatile elements (found in interstellar gas) ordered by atomic mass (A). Both
the refractory and volatile elements show a mass-dependent enhancement with
similar slopes.
