  We present the first results of a larger study into the stellar abundances
and chemical trends in long-lived dwarf stars in the solar neighbourhood that
belong to (based on their kinematics) the thin and thick galactic disk,
respectively. We confirm that the trends of alpha-elements in the thin and
thick disk are distinct (this has previously been shown for Mg by Fuhrmann
1998, but e.g. Chen et al. 2000 claimed the trends to follow smoothly upon each
other). We find that the thick disk show the typical signature of contribution
from SN Ia (i.e. the ``knee'') to the enrichment of the interstellar gas out of
which the later generations of thick disk stars formed. The trend starts out as
[Mg/Fe] ~0.35 at [Fe/H] ~ -0.7 and continue on this level with increasing
[Fe/H] until -0.4 dex where a decline in [Mg/Fe] starts and steadily continues
down to 0 dex at solar metallicity. The same is true for the other
alpha-elements (e.g. Si). Using ages from the literature we find that the thick
disk in the mean is older than the thin disk. Combining our results with other
observational facts we suggest that the most likely formation scenario for the
thick disk is, still, a violent merger event. We also suggest that there might
be tentativeevidence for diffusion of orbits in todays thin disk (based on
kinematics in combination with elemental abundances).
