[2] From analysis of seismic reflection survey data and core material recovered by drillings at Site 432, the shipboard party of Deep Sea Drilling Project (DSDP) Leg 55 proposed that Nintoku Seamount was in an intermediate atoll stage (no lagoon but fringing reefs and banks and extensive carbonate bank interiors) before subsidence removed the island below the wave base.

[2] Nintoku Seamount apparently remained at or above sea level long enough to be almost completely devastated by subaerial erosion and wave action.

Reefs were not indicated in the seismic studies, but fragmented pieces of coral were recovered and documented, showing a shallow-water sediment-rich condition.

Poorly recovered and preserved sedimentary deposits indicated a shallow-reef bed typical of terraced flanking reefs and banks, as well as volcanic sand.

First, drilling at the nearby site 432 had hit reasonably unaltered and unchanged basalt with good remnant magnetic properties, key to finding the latitude of origin; but insufficient sampling caused a lack of data, and determining the age accurately was not possible.

Hence, deeper drilling was promised to achieve that goal, providing a time-averaged (as the seamount is in the center of the chain) movement ratio.

[2] Second, a survey of the region showed a rock structure suitable for deep drilling, and nearby sites met low levels of sedimentary cover.

Thirdly, the composition of previously drilled volcanic rock seemed to match the volcano's "average" type, erupted during the post-shield stage of it life.

[4] It was established that Nintoku Seamount's sedimentary cap consists of sandstone and siltstone containing well-rounded to subrounded basalt blocks, volcanic ash, fossil fragments of mollusks, benthic foraminifers, bryozoans, and coralline red algae.

[4] There is evidence suggesting that the eruption rates must have been lower at the period during which the two flows were deposited, which is consistent with the model of Hawaiian volcanic growth, which increases in activity slowly over time before ceasing altogether.

Although some of the rocks needed a more complex and thorough analysis, most samples yielded data suitable to make a preliminary determination of magnetic inclinations.