Cross sections of deposited layers from the divertor of the Joint European Torus (JET) have been investigated, microscopically and by ion microbeam analysis. The thickness of these layers on the studied samples varies between about 50 mu m and 800 mu m depending on the exposure time and poloidal location of the sample. For most of the thicker layers a laminar structure is observed. In some locations changes, such as gaps, are also observed along the laminar structure as well as more complex structures. The possibility to use the layers as historical reference was also investigated.