A catalog compiling the parameters of 346 open clusters , including their metallicities , positions , ages , and velocities has been composed .
The elements of the Galactic orbits for 272 of the clusters have been calculated .
Spectroscopic determinations of the relative abundances , [ el/Fe ] , for 14 elements synthesized in various nuclear processes averaged over data from 109 publications are presented for 90 clusters .
The compiled data indicate that the relative abundances of primary \alpha -elements ( oxygen and magnesium ) exhibit different dependences on metallicity , age , Galactocentric distance , and the elements of the Galactic orbits in clusters with high , elongated orbits satisfying the criterion ( Z ^ { 2 } _ { max } +4 e ^ { 2 } ) ^ { 1 / 2 } > 0.40 and in field stars of the Galactic thin disk ( Z _ { max } is the maximum distance of the orbit from the Galactic plane in kiloparsec and e is the eccentricity of the Galactic orbit ) .
Since no systematic effects distorting the relative abundances of the studied elements in these clusters have been found , these difference suggest real differences between clusters with high , elongated orbits and field stars .
In particular , this supports the earlier conclusion , based on an analysis of the elements of the Galactic orbits , that some clusters formed as a result of interactions between high-velocity , metal-poor clouds and the interstellar medium of the Galactic thin disk .
On average , clusterswith high , elongated orbits and metallicities { [ Fe / H ] } < -0.1 display lower relative abundances of the primary á elements than do field stars .
The low [ O , Mg/Fe ] ratios of these clusters can be understood if the high-velocity clouds that gave rise to them were formed of interstellar material from regions where the star-formation rate and/or the masses of Type II supernovae were lower than near the Galactic plane .
It is also shown that , on average , the relative abundances of the primary á elements are higher in relatively metal-rich clusters with high , elongated orbits than in field stars .
This can be understood if clusters with { [ Fe / H ] } > -0.1 formed as a result of interactions between metal-rich clouds with intermediate velocities and the interstellar medium of the Galactic disk ; such clouds could form from returning gas in a so-called “ Galactic fountain ” .