The glacier-covered Mount Haddington shield volcano forms the high point of James Ross Island along the Larsen Rift near the northern tip of the Antarctic Peninsula. Effusive eruptions fed large lava deltas with basal hyalocalstite breccias overlain by subaerial lava flows. Well-preserved tuff cones and pyroclastic cones on the eastern flank below the summit icecap were considered to be only a few thousand years old (Smellie et al., 2008).