Limestones and carbonates forming a platform accumulated on Wōdejebato, with drill cores showing total thicknesses of -. Compositionally, it consists mainly of sandy carbonates that are often leached and cemented by calcitic material. These deposits eventually covered the entire upper area of the volcanic high and formed the inner ridge. Variations in sea level occasionally led to parts of the platform either emerging above sea level or submerging, leading to erosion that generated the outer ridge and to the development of characteristic sequences within the deposits.