Basalts were mainly erupted early in the history of the volcano. During the last 100,000 years, the magma chamber became established; this allowed both the differentiation of trachytes and the occurrence of large eruptions. A gap in the rock spectrum (Daly gap) with a scarcity of benmoreite and mugearite has been noted at Mount Melbourne and other volcanoes in the region. There is no agreement on which processes contributed to petrogenesis in the Mount Melbourne volcanic field. The magmatic system that feeds Mount Melbourne appears to have a distinct composition from the one associated with the Mount Melbourne volcanic field.