Different types of mineral deposits, principally silicas, oxalates and carbonates, have been observed at many rock art sites throughout the world. Such mineral deposits are often layered and can be dated because they contain a great variety of datable materials. Recent technological advances have expanded the analysis of such components related to rock art. This paper looks at several theoretical and technical notions that enable the dating of silica skin accretions associated with rock art in the Canadian Shield. The dating of these accretions gives the age of certain rock art sites because the rock may have been covered with layers of silica before and after the creation of paintings and engravings. Certain characteristics of silica films can thus reflect the temporal framework and also the climatic conditions present when they were formed. They are thus a source of geological, archaeological and paleoenvironmental information.