This session is devoted to the description and origin of PGM-bearing assemblages from mafic-ultramafic complexes, as well as from unconventional deposits: sedimentary formations, hydrothermal deposits, river alluvia. The session will include experimental work on PGE-bearing systems, and consequent explanations on the formation of natural deposits. Special attention will be paid to the association of PGM with accessory phases, which are able to accurately constrain the age of metal deposition and the composition and origin of PGE-bearing fluids. Contributions dealing with the distribution of PGE anomalies and deposits in Europe and on the potential of the different terranes and tectonic belts, will also be welcome.