We present a model to explain the wide range of abundances for heavy r -process elements ( mass number A > 130 ) at low [ Fe/H ] .
This model requires rapid star formation and/or an initial population of supermassive stars in the earliest condensed clots of matter to provide a prompt or initial Fe inventory .
Subsequent Fe and r -process enrichment was provided by two types of supernovae : one producing heavy r -elements with no Fe on a rather short timescale and the other producing light r -elements ( A \leq 130 ) with Fe on a much longer timescale .