Koko crater, rising above the eastern coast of Oahu, is one a group of tuff cones and satellitic vents of late-Pleistocene to possible Holocene age on the eastern flank of the massive Koolau shield volcano. This elongated shield volcano of Pliocene-Pleistocene age forms much of the eastern half of Oahu. Koko crater is part of the Honolulu Series, a group of tuff cones, cinder cones, and spatter cones, many with associated lava flows.

Photo by Lee Siebert, 1997 (Smithsonian Institution).

This image is made available under the Public Domain Dedication CC0 license, but proper attribution is appreciated.

Koolau