as sea cliffs or wave cut terraces have been found; at one site there is a terrace about wide, surmounted by a high cliff. Pinnacles and depressions dot the surface platform. The surface of the platform consists of limestone that is partially covered by pelagic sediments; underwater cameras have shown the presence of rock slabs covered by ferromanganese crusts. The guyot rises from a seafloor of Jurassic age (201.3 ± 0.2 – ca. 145 million years ago) that might be as much as 154 million years old. Terrestrial organic material on the seafloor around Resolution Guyot originated from when it was still an island, and carbonate sediments swept away from the guyot collected on the surrounding seafloor. Regional setting The Pacific Ocean seafloor contains many guyots formed during the Mesozoic era (251.902 ± 0.3 – 66 million years ago) in unusually shallow seas. These submarine mountains are characterized by a flat top and usually the presence of carbonate platforms that rose above the sea surface during the middle Cretaceous (ca. 145 – 66 million years ago). While there are some differences to present-day reef systems, many of these seamounts were formerly atolls, which still exist. These structures formed as volcanoes in the Mesozoic ocean. Fringing reefs may have developed on the volcanoes, which then became barrier reefs as the volcano subsided and turned into an atoll, and which surround a lagoon or a tidal flat. The crust underneath these seamounts tends to subside as it cools, and thus the islands and seamounts sink. Continued subsidence balanced by upward growth of the reefs led to the formation of thick carbonate platforms. Sometimes volcanic activity continued even after the formation of the atoll or atoll-like structure, and during episodes where the platforms rose above sea level erosional features such as channels and blue holes developed. The formation of many seamounts has been explained by the hotspot theory, which suggests that the chains of volcanoes become progressively older along the length of the chain, with an erupting volcano only at one end of the system. Resolution lies on a volcano on the lithosphere heated from below; as the plate shifts it is moved away from the heat source and volcanic activity ceases, producing a chain of volcanoes that get progressively older away from those currently active. Potential hotspots involved in the formation of Resolution Guyot are the Easter, Marquesas, Society and in some