  We study the migration of solid bodies in turbulent protoplanetary accretion
discs by means of global MHD simulations. The bodies range in size from 5
centimetres up to 1 metre, and so include objects whose migration is expected
to be the most rapid due to gas drag interaction with the disc. As they drift
inward through the disc, some of them are trapped in regions where gas pressure
maxima are created by long lived anticyclonic vortices. This accumulation is
very efficient, locally increasing the dust--to--gas ratio by a factor > 100 in
some cases. We discuss the possible implications of this result for theories of
planet formation.
