Model atmosphere and kinematical analyses of early-type stars from the Edinburgh-Cape Survey

We present high-resolution spectroscopic observations of 21 B-type stars, s elected from the Edinburgh-Cape Blue Object Survey. Model atmosphere analys es confirm that 14 of these stars are young, main-sequence B-type objects w ith Population I chemical compositions. The remaining seven are found to be evolved objects, including subdwarfs, horizontal branch and post-AGB objec ts. A kinematical analysis shows that all 14 young main-sequence stars coul d have formed in the disc and subsequently been ejected into the halo. Thes e results are combined with the analysis of a previous subsample of stars t aken from the Survey. Of the complete sample, 31 have been found to be youn g, main-sequence objects, with formation in the disc, and subsequent ejecti on into the halo, again being found to be a plausible scenario.