  We present a study of the Ca II K and IR-triplet lines in a sample of
Classical T Tauri stars in the Chamaeleon I star-forming region. We study
X-shooter spectra of the stars in the sample and find that in some of these
stars the Ca II lines are much weaker than expected from their H line fluxes
and mass accretion rate. Since the Ca II K lines have characteristic
magnetospheric accretion line profiles and the magnetospheric flows feed
directly from the inner disk, we interpret the Ca deficit in terms of depletion
due to processes happening in the disk. To test this hypothesis, we define a
coarse depletion indicator using the flux of the Ca II K line and show that it
correlates with disk properties. In particular, using indicators extracted from
Spitzer/IRS spectra, we obtain that all the transitional and pre-transitional
disks of the sample show depletion, consistent with trapping of refractories in
pressure bumps created by planets and/or in the planets themselves. We find
full disks with Ca depletion in the sample that also show indications of
advanced dust evolution. We apply magnetospheric accretion models to fit the
Balmer and Ca II line fluxes of a star showing clear Ca depletion and derive a
Ca abundance in its inner disk of about 17% solar.
