As a continuation of our previous work , which concerned the radial abundance distribution in the galactic disc over the distances 4–10 kpc this paper presents the first results on the metallicicty in the outer disc ( R _ { G } > 10 kpc ) .
Based on high-resolution spectra obtained for 19 distant Cepheids we sampled galactocentric distances from 10 to 12 kpc .
Combined with the results of our previous work on the inner and middle parts of the galactic disc , the present data enable one to study the structure of the radial abundance distribution over a large baseline .
In particular , we find indications of a discontinuity in the radial abundance distribution for iron as well as a number of the other elements .
The discontinuity is seen at a galactocentric distance R _ { G } = 10 kpc .
This finding supports the results reported earlier by Twarog et al .
( [ 1997 ] ) .