gee, i really made it to move my mac os x time machine archives from its current hard disk to a bigger one!

this was more difficult than this generally is already due to the backups being made remotely, to a so-called sparse bundle disk image.

the trick is to mount that very disk image by double-clicking, dragging the mounted partition to the source input field in disk utility (ie. not opening the disk image itself!) and restoring it to the new, formatted drive.