Whereas the southern half of San Cristóbal Island began forming by a shield volcano about 2.4 million years ago, the northeast section including Punta Pitt is geologically very young. The last eruptions may have occurred a few centuries ago. As lava seeped from a line of volcanic fissures, the hot magma met the cold seawater and exploded into clouds of ash and dust. As these particles landed, they compacted into a volcanic tuff cone. Because the resulting rock is soft and porous, it is easily eroded by the elements. The results are dramatic beige cliffs with irregular ridges that glow in the sunshine.
