Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch (or, in chronostratigraphy: the fifth of six stages in the Upper Cretaceous series). The Campanian spans the time from 83.6 ± 0.7 Ma to 72.1 ± 0.6 Ma (million years ago). It is preceded by the Santonian and it is followed by the Maastrichtian.
Wōdejebato
Volcanism at Wōdejebato appears to have occurred during two phases over a timespan of about 20 million years. The first phase took place during the Cenomanian (100.5 – 93.9 million years ago); it was characterized by explosive eruptions and may be the source of 93.9–96.3 million year old volcanic debris found in the surroundings of Wōdejebato. The second phase occurred during the Campanian between 78.4 and 85 million years ago during chron 33R; it appears to be part of a volcanic event that affected a number of other islands and seamounts in the Marshall Islands and at Wōdejebato lasted for at least four million years. The second stage appears to have been a secondary volcanic episode. Volcanic rocks sampled at Wōdejebato all belong to the second stage, probably due to sampling bias as the samples all come from the summit region. Tectonic evidence indicates that Pikinni formed at the same time as Wōdejebato, while the northern parasitic cone may be less than 80 million years old. An earlier proposal by Schlanger "et al." 1987 envisaged Eocene (56 – 33.9 million years ago) eruptions at Wōdejebato but today the older ages are considered to be correct.