Is there a large database that contains, for many stars, their estimated metallicities as well as their redshifts (or, equivalently, distances from us) and masses? What I'm trying to do is estimate the chemical abundances at different ages of the universe. If I have the metallicity of a star at a given redshift, then I know both its age and its metallicity (and a rough estimate of the proportion of non-H/He elements). Then, if I have this data for varying "weighted metallicities" (metallicity by percentage * mass) for many different redshifts/ages, I can estimate the proportion of elements at varying ages. Thanks.