Time evolution of the surface metal abundance profiles by number of hydrogen (or helium) according to the depth in the star for the DA model 3 (top panel) and the DB model 5 (bottom panel) for accretion rates listed Table 2. From bottom to top there are chronological times (t = 10⁶ s, t = 10⁸ s, and t = 5 × 10⁹ s for the DA model, and t = 10⁸ s, t = 10⁹ s, t = 10¹⁰ s, and t = 10¹² s for the DB model). The dashed lines represent the behaviour with only gravitational settling taken into account, and the solid lines represent the behaviour with both fingering convection and gravitational settling. For the DB model profiles are identical because fingering convection does not develop.