Neutron-capture element abundances in the globular cluster M15

High-resolution, high signal-to-noise ratio, blue-violet spectra of three r ed giant branch tip stars in M15 have been obtained with the Keck I High-Re solution Echelle Spectrograph. These spectra have been analyzed to determin e the abundances of several neutron-capture elements, including the radioac tive chronometer element thorium. There are two principal results of this s tudy. First, the abundances of the heavier (Z greater than or equal to 56) elements for each of the three stars is well matched by a scaled solar syst em r-process abundance distribution. Second, a weighted mean-observed Th/Eu ratio for the stars implies an age fbr the neutron-capture material in M15 stars of 14 +/- 3 Gyr, in reasonable agreement with other recent age estim ates for Galactic globular clusters.