  We studied the relationship between the average stellar abundance of several
elements and the orbital evolution of stars in the neighbourhood of the Sun,
using both observational data for 325 late-type dwarfs in a volume-complete
sample and simulations of the orbital diffusion. Metallicities, ages, and
initial position and velocities for the simulated stars are sampled from
empirical distributions of these quantities in the Milky Way. We found that
that there is a relationship between the average stellar abundance of Fe, Na,
Si, Ca, Ni, and Ba and the mean orbital radius of stars currently passing
through the solar neighbourhood. The greater the difference between the mean
orbital radius and the solar Galactocentric distance, the more deficient the
star is, on average, in these chemical species. The stars that take a longer
time to come from their birthplaces to arrive in the present solar
neighbourhood are more likely to be more metal-poor than those that were born
here. This result is a direct, independent indication that a tightly defined
Galactic age-metallicity relation exists.
