Koko Guyot (also sometimes known as Kinmei and Koko Seamount) is a 48.1 million year old guyot, a type of underwater volcano with a flat top, which lies near the southern end of the Emperor seamounts, about 200 km (124 mi) north of the "bend" in the volcanic Hawaiian-Emperor seamount chain. Pillow lava has been sampled on the north west flank of Koko Seamount, and the oldest dated lava is 40 million years old. Seismic studies indicate that it is built on a 9 km (6 mi) thick potion of the Pacific Plate. The oldest rock from the north side of Koko Seamount is dated at 52.6 and the south side of Koko at 50.4 million years ago.