About 7,000 years ago, at Newberry's Northwest Rift Zone, lava fountains erupted from a fissure with a length of , yielding basaltic and andesitic lava flows. Strombolian eruptions (which eject incandescent cinder, lapilli, and lava bombs) produced tephra that formed Lava Butte, a cinder cone near Newberry with a height of , a base diameter of , and a crater depth of . With a lopsided shape where the northeastern rim is taller than the southwestern counterpart, this cinder cone sits south of Bend.