  We study the cross-correlation between 212 MgII quasar absorption systems and
\~20,000 Luminous Red Galaxies (LRGs) selected from the Sloan Digital Sky
Survey Data Release 1 in the redshift range 0.4<z<0.8. The MgII systems were
selected to have 2796 & 2803 rest-frame equivalent widths >=1.0 Angstrom and
identifications confirmed by the FeII 2600 or MgI 2852 lines. Over comoving
scales 0.05--13 h^-1 Mpc, the MgII--LRG cross-correlation has an amplitude
0.69+/-0.09 times that of the LRG--LRG auto-correlation. Since LRGs have
halo-masses greater than 3.5 x 10^12 solar masses for M_R<-21, this relative
amplitude implies that the absorber host-galaxies have halo-masses greater than
2--8 x 10^11 Msun. For 10^13 Msun LRGs, the absorber host-galaxies have
halo-masses 0.5--2.5 x 10^12 Msun. Our results appear consistent with those of
Steidel et al. (1994) who found that MgII absorbers with W_r>=0.3 Angstrom are
associated with ~0.7 L^*_B galaxies.
