Evolution tracks of 40 individual particles in overall metallicity (left panel) and O/Fe ratio (right panel). Particles were selected randomly between 3r_vir and 4r_vir with a radial peculiar velocity exceeding 100 km/s (outflowing) and a final metal mass exceeding m_Z/m_H = 10⁻⁴. The black lines show the medians of 1000 randomly selected particles, each for three different radial ranges. The line colour indicates the temperature of the particle at the given scale factor.