  We present a 1.3 mm continuum survey of protoplanetary disks in the 2-3 Myr
old cluster, IC348, with the Submillimeter Array. We observed 85 young stellar
objects and detected 10 with 1.3 mm fluxes greater than 2 mJy. The brightest
source is a young embedded protostar driving a molecular outflow. The other 9
detections are dusty disks around optically visible stars. Our millimeter flux
measurements translate into total disk masses ranging from 2 to 6 Jupiter
masses. Each detected disk has strong mid-infrared emission in excess of the
stellar photosphere and has Halpha equivalent widths larger than the average in
the cluster and indicative of ongoing gas accretion. The disk mass
distribution, however, is shifted by about a factor of 20 to lower masses,
compared to that in the ~1 Myr old Taurus and Ophiuchus regions. These
observations reveal the rapid decline in the number of small dust grains in
disks with time, and probably their concomitant growth beyond millimeter sizes.
Moreover, if IC348 is to form planets in the same proportion as detected in the
field, these faint millimeter detections may represent the best candidates in
the cluster to study the progression from planetesimals to planets.
