ABUNDANCES IN METAL-RICH STARS - DETAILED ABUNDANCE ANALYSIS OF 47 G-DWARF AND K-DWARF STARS WITH [ME H]GREATER-THAN-0.10 DEX/

We have derived elemental abundances of O, Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, Co, Ni as well as for a number of s-elements for 47 G and K d warf, with [Me/H]> 0.1 dex. The selection of stars was based on their kinematics as well as on their uvby - beta photometry. One sample of s tars on rather eccentric orbits traces the chemical evolution interior to the solar orbit and another, on circular orbits, the evolution aro und the solar orbit. A few Extreme Population I stars were included in the latter sample. The stars have -0.1 dex < [Fe/H] < 0.92 dex. The s pectroscopic [Fe/H] correlate well with the [Me/H] derived from uvby - beta photometry. We find that the elemental abundances of Mg, Al, Si, Ca, Ti, Cr and Ni all follow [Fe/H]. Our data put further constraints on models of galactic chemical evolution, in particular of Cr, Mn and Co which have not previously been studied for dwarf stars with [Me/H] > 0.1 dex. The increase in [Na/Fe] and [Al/Fe] as a function of [Fe/H ] found previously by Edvardsson et al. (1993a) has been confirmed for [Na/Fe]. This upturning relation, and the scatter around it, are show n not to be due to a mixture of populations with different mean distan ces to the galactic centre. We do not confirm the same trend for alumi nium, which is somewhat surprising since both these elements are thoug ht to be produced in the same environments in the pre-supernova stars. Nor have we been able to trace any tendency for relative abundances o f O, Si, and Ti relative to Fe to vary, with the stellar velocities, i .e. the stars present mean distance to the galactic centre. These resu lts imply that there is no significant difference in the chemical evol ution of the different stellar populations for stars with [Me/H]> 0.1 dex. We find that [O/Fe] continue to decline with increasing [Fe/H] an d that oxygen and europium correlate well. However [Si/Fe] and [Ca/Fe] seem to stay constant. A real (''cosmic'') scatter in [Ti/Fe] at give n [Fe/H] is suggested as well as a decreasing abundance of the s-eleme nts relative to iron for the most metal-rich dwarf stars. We discuss o ur results in the context of recent models of galactic chemical evolut ion. In our sample we have included a few very metal rich stars, somet imes called SMR (super metal rich) stars. We find these stars to be am ong the most iron-rich in our sample but far from as metal-rich as ind icated by their photometric metallicities. SMR stars on highly eccentr ic orbits, alleged to trace the evolution of the chemical evolution in the galactic Bulge, have previously been found overabundant in O, Mg and Si. We have included three such stars from the study by Barbuy & G renon (1990). We find them to be less metal rich and the other element al abundances remain puzzling. Detailed spectroscopic abundance analys es of K dwarf stars are rare. Our study includes 5 K dwarf stars and h as revealed what appears to be a striking example of overionization. T he overionization is especially prominent for Ca, Cr and Fe. The origi n of this apparent overionization is not clear and we discuss differen t explanations in some detail.