[2][5] The seamount is elongate in shape, aligned northwest-southeast (the same direction as the chain), and has a gentle slope and a large, flat top.

A prominent south-trending ridge extends about 50 km (31 mi) from the summit area in the direction of Kimmei Seamount, to the southeast.

However, a thick carbonate cap, similar to the one covering Detroit Seamount, makes it difficult to find the exact eruptive centers.

[2] The top 57 m (187 ft) of sediment included fossil-rich calcarenite and calcium-rich mudstone and siltstone, indicating a shallow-water setting at the time of deposition.

This age range fits well with a radiometric analysis (48.1 Ma) reported for a dredged rock from Koko Seamount from the 1973 expedition.

[2] There was a large amount of variation in the density, structure, porosity, and grain size of the recovered volcanic rock, varying widely with depth.

[2] Dredged carbonate samples from the top of the seamount contained porites and several other corals, covered by coralline algae at shallow to medium depth.