High resolution spectroscopic follow-up of the most metal-poor
  candidates from SkyMapper DR1.1
  We present chemical abundances for 21 elements (from Li to Eu) in 150
metal-poor Galactic stars spanning $-$4.1 $<$ [Fe/H] $<$ $-$2.1. The targets
were selected from the SkyMapper survey and include 90 objects with [Fe/H]
$\le$ $-$3 of which some 15 have [Fe/H] $\le$ $-$3.5. When combining the sample
with our previous studies, we find that the metallicity distribution function
has a power-law slope of $\Delta$(log N)/$\Delta$[Fe/H] = 1.51 $\pm$ 0.01 dex
per dex over the range $-$4 $\le$ [Fe/H] $\le$ $-$3. With only seven
carbon-enhanced metal-poor stars in the sample, we again find that the
selection of metal-poor stars based on SkyMapper filters is biased against
highly carbon rich stars for [Fe/H] $>$ $-$3.5. Of the 20 objects for which we
could measure nitrogen, 11 are nitrogen-enhanced metal-poor stars. Within our
sample, the high NEMP fraction (55\% $\pm$ 21\%) is compatible with the upper
range of predicted values (between 12\% and 35\%). The chemical abundance
ratios [X/Fe] versus [Fe/H] exhibit similar trends to previous studies of
metal-poor stars and Galactic chemical evolution models. We report the
discovery of nine new r-I stars, four new r-II stars, one of which is the most
metal-poor known, nine low-$\alpha$ stars with [$\alpha$/Fe] $\le$ 0.15 as well
as one unusual star with [Zn/Fe] = +1.4 and [Sr/Fe] = +1.2 but with normal
[Ba/Fe]. Finally, we combine our sample with literature data to provide the
most extensive view of the early chemical enrichment of the Milky Way Galaxy.
