  We analyze Spitzer IRS spectra of 110 B-, A-, F-, and G-type stars with
optically thin infrared excess in the Scorpius-Centaurus (ScoCen) OB
association. The age of these stars ranges from 11-17 Myr. We fit the infrared
excesses observed in these sources by Spitzer IRS and Spitzer MIPS to simple
dust models according to Mie theory. We find that nearly all the objects in our
study can be fit by one or two belts of dust. Dust around lower mass stars
appears to be closer in than around higher mass stars, particularly for the
warm dust component in the two-belt systems, suggesting mass-dependent
evolution of debris disks around young stars. For those objects with stellar
companions, all dust distances are consistent with trunction of the debris disk
by the binary companion. The gaps between several of the two-belt systems can
place limits on the planets that might lie between the belts, potentially
constraining the mass and locations of planets that may be forming around these
stars.
