Bazman has no recorded historical eruptions but fumarolic activity has been reported, as well as ongoing surface deformation. Bazman is considered to be occasionally smoking. Hot springs containing iron and sulfur are other signs of ongoing volcanism; Bazman has been considered a potential site for development of geothermal energy, with a surface area of . In 1960, Bazman together with Taftan was considered a volcano with sporadic historic activity, while a different report in 1975 considered the volcano extinct. Potassium-argon dating of basalts from the volcano has yielded ages of 4.6 and 0.6 million years ago. These dates were obtained on the monogenetic cones; zircons directly from Bazman rocks are dated 7.5 ± 0.1 and 5.9 ± 0.2 million years ago by uranium-lead dating, along with other ages of 8-6 million years ago from other zircons around Bazman. A third date is of 11.7 million years ago. Another report in 1981 suggested that isotopic ages also indicate historic activity. Latest research indicates that the main Bazman volcano formed between 1.4 and 0.63 million years ago, with a preceding stage of regional volcanism between 8.6 and 4.1 million years ago. Later ignimbritic volcanism took place between 590,000 and 470,000 years ago; the final volcanic activity around the summit of the volcano continued until less than 41,000 years ago.