Of volcanic origin and Mesozoic in age, it is located on the oldest part of the Pacific Plate and rises up to 2 km (1.2 mi) (Darwin Rise) above the surrounding ocean floor and is covered with several layers of thick sedimentary sequences that differ from those of other plateaux in the North Pacific.
[4] In the Cretaceous, they formed large tropical islands located closer to the Equator that began to sink in the late Mesozoic.
[5] The MPM formed in the Early Cretaceous (at c. 110 Ma) over a hotspot that uplifted the ocean floor of the still young Pacific Plate.
Reefs developed on the subsiding islands and renewed volcanism in the Late Cretaceous helped maintain some of eastern islands but inevitably the guyots sank to their present depth.
[8] The western half of the Easter hotspot chain, a lineament that includes the Line Islands and Tuamotu archipelago, begins near the eastern part of the MPM.