  We report the detection of a complex of narrow X-ray absorption features from
the low-mass X-ray binary GX13+1 during 3 XMM-Newton observations in 2000 March
and April. The features are consistent with being due to resonant scattering of
the K_alpha and K_beta lines of He- and H-like iron (Fe xxv and Fe xxvi) and
H-like calcium (Ca xx) K_alpha. Only the Fe xxvi K_alpha line has been
previously observed from GX13+1. Due to the closeness in energy the Fe xxv and
Fe xxvi K_beta features may also be ascribed to Nixxvii and Nixxviii K_alpha,
respectively. We also find evidence for the presence of a deep (tau~0.2) Fe xxv
absorption edge at 8.83 keV. The equivalent widths of the lines do not show any
obvious variation on a timescale of a few days suggesting that the absorbing
material is a stable feature of the system and present during a range of
orbital phases.
