Two other southwestern Pacific plateaus, Manihiki and Hikurangi, now separated from the OJP by Cretaceous oceanic basins, are of similar age and composition and probably formed as a single plateau and a contiguous large igneous province together with the OJP.

[2] The OJP basaltic basement is four tholeiitic magma series called the Kwaimbaita, Kroenke, Singgalo, and Wairahito.

The extant seamounts of the Louisville Ridge started to form 70 Ma and have a different isotopic composition, and therefore a shift in intensity and magma supply in the plume must have occurred before that.

[10] The early, short-duration eruptions of OJP were thought to coincide with the global Early Aptian oceanic anoxic event (known as OAE1a or the Selli Event, 125.0–124.6 Ma) that led to the deposition of black shales during the interval 124–122 Ma.

[1] There are still unresolved dates by two other research groups that are 4 Ma older so the potential association is not totally eliminated,[11] but all OJP lavas are normally magnetized so are presumably dated after the Cretaceous Normal Superchron (C34, CNS) began at 120.964 Ma[12] Additionally, isotopic records of seawater in sediments have been associated with the 90 Ma OJP submarine eruptions.