Adjective
accretional (not comparable)
Of, pertaining to, or formed by accretion
In this respect, Ganymede is different from Callisto, which apparently failed to melt and differentiate early due to loss of the accretional heat during its slower formation. Source: Internet
This relatively fast formation prevented the escape of accretional heat, which may have led to ice melt and differentiation : the separation of the rocks and ice. Source: Internet