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Abundance observations indicate the presence of rapid-neutron capture (i.e.,r-process) elements in old Galactic halo and globular cluster stars. Theseobservations demonstrate that the earliest generations of stars in the Galaxy,responsible for neutron-capture synthesis and the progenitors of the halostars, were rapidly evolving. Abundance comparisons among several halo starsshow that the heaviest neutron-capture elements (including Ba and heavier) areconsistent with a scaled solar system r-process abundance distribution, whilethe lighter such elements do not conform to the solar pattern. Thesecomparisons suggest two r-process sites or at least two different sets ofastrophysical conditions. The large star-to-star scatter observed in theneutron-capture/iron ratios at low metallicities -- which disappears withincreasing [Fe/H] -- suggests an early, chemically unmixed and inhomogeneousGalaxy. The stellar abundances indicate a change from the r-process to the slowneutron capture (i.e., s-) process at higher metallicities in the Galaxy. Thedetection of thorium in halo and globular cluster stars offers a promising,independent age-dating technique that can put lower limits on the age of theGalaxy.Comment: 6 pages, 3 figures; To appear in the proceedings of the 20th Texas  Symposium on Relativistic Astrophysics, J. C. Wheeler & H. Martel (eds.

The early formation, evolution and age of the neutron-capture elements in the early Galaxy