  We report the abundances of C, Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni,
Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Sm in 25 solar-type stars in the solar
neighbourhood, and their correlations with ages, kinematics, and orbital
parameters. The spectroscopic analysis, based high resolution and high S/N
ratio data, was differential to the Sun and applied to atomic line EWs and to C
and C2 spectral synthesis. We performed a statistical study using a tree
clustering analysis, searching for groups of stars sharing similar abundance
patterns. We derived Teff, log(g), and [Fe/H] with errors of 30 K, 0.13 dex,
and 0.05 dex, respectively. The average error in [X/Fe] is 0.06 dex. Ages were
derived from theoretical HR diagrams and memberships in kinematical moving
groups. We identified four stellar groups: with over-solar abundances (<[X/H]>
= +0.26 dex), under-solar abundances (<[X/H]> = -0.24 dex), and intermediate
values (<[X/H]> = -0.06 and +0.06 dex) but with distinct chemical patterns.
Stars sharing solar metallicity, age, and Galactic orbit possibly have
non-solar abundance, an effect either of chemical heterogeneity in their natal
clouds or migration. A trend of [Cu/Fe] with [Ba/Fe] seems to exist, in
agreement with previous claims in the literature, and maybe also of [Sm/Fe]
with [Ba/Fe]. No such correlation involving C, Na, Mn, and Zn is observed.
[Mg/Fe], [Sc/Fe], and [Ti/Fe] increase with age. [Mn/Fe] and [Cu/Fe] first
increase towards younger stars up to the solar age, and then decrease, a result
we interpret as possibly related to time-varying yields of SN Ia and the weak
s-process. [Sr/Fe], [Y/Fe], [Sr/Mg], [Y/Mg], [Sr/Zn], and [Y/Zn] linearly
increase towards younger stars. [Zr/Fe], [Ce/Fe], [Nd/Fe], [Ba/Mg], [Ba/Zn],
and [Sr,Y,Ba/Sm] increase but only for stars younger than the Sun. The steepest
negative age relation is due to [Ba/Fe], but only for stars younger than the
Sun.
