  We present the first large sample of accurate iron abundances and
temperatures for clusters at redshifts greater than 0.14. We find that the Fe
abundance shows little or no evolution out to redshift 0.3. This and the early
formation epoch of elliptical galaxies in clusters indicate that most of the
enrichment of the intracluster medium occurred at redshifts greater than 1. If
clusters represent fair samples of the universe, then global metal production
is 2-5 times greater than is inferred from recent studies of galaxies at low
and high redshifts.
