  A correlation between the metallicity, [M/H], and rest-frame MgII equivalent
width, EW, is found from 49 DLAs and strong sub-DLAs drawn from the literature
over the redshift range 0.2<z_abs<2.6. The correlation is significant at 4.2
sigma and improves to 4.7 sigma when the mild evolution of [M/H] with redshift
is taken into account. Even when including only the 26 DLAs (i.e. excluding
sub-DLAs) which have Zn metallicities and EW>0.7A, the correlation remains at
>3 sigma significance. Since the MgII2796 transition is predominantly saturated
in DLAs (which always have EW greater than 0.3A), EW is far more sensitive to
the kinematic spread of the metal velocity components across the absorption
profile than it is to [M/H]. Thus, the observed [M/H]--EW correlation points to
a strong link between the absorber metallicity and the mechanism for producing
and dispersing the velocity components. We also note that approximately half of
the 13 known molecular hydrogen absorbers have very high EW and very broad
velocity structures which show characteristics usually associated with
outflows. Follow-up ultraviolet- and blue-sensitive high-resolution spectra of
high-EW systems, initially identified in low-resolution spectra, may therefore
yield a large number of new H_2 discoveries.
