Metal enrichment of the Sextans-like model galaxy, h177, from 190 to 430 Myr. The surface density of gas is color-coded in blue. After each supernova explosion, shown in yellow and red for Pop III and Pop II stars, respectively, yields were ejected, using the SPH kernel scheme. The metallicity of gas, color-coded in orange, was determined by the amount of Fe received from the supernovae ejecta. The star formation density threshold ρ_SFR, c was set to 1 and 5 atom cm⁻³ in the top and bottom panels, respectively.