[Mg/Fe] and [Ca/Fe] abundance ratios as a function of [Fe/H] for the dwarf spheroidal model (h177). The stellar distribution in blue is compared to the Sextans observations, shown as gray points with error bars. For both simulations and observations, we added contours, shown in black and red, respectively, which represent the regions encompassing 30, 60, and 90% of the stars. The observational data are the same as in Fig. 5.