The volcano is of Pliocene age and was active between 4 million years ago and 70,000 years ago; radiometric dating has yielded ages of 3.97 million years for rocks at the base of Mount Rittmann and 240,000 ± 200,000, 170,000 ± 20,000 and 70,000 ± 20,000 years ago for lava flows. The caldera appears to be younger than the volcanic rocks at Pilot Glacier. It was possibly formed by a Plinian eruption. Tephra deposits at Outback Nunataks, Eemian-age tephras at Talos Dome in East Antarctica and dust bands found in blue-ice areas of Frontier Mountain and Lichen Hill in Victoria Land may originate from Mount Rittmann. The eruption history of the volcano is poorly known due to the scarcity of outcrops.