View article

The response of the Pacific plate to oceanic island and seamount loads has been used to estimate the distribution of ridge crest and off-ridge volcanism on the plate since the late Jurassic. The most extensive event, forming the Hess rise, Line Islands ridge, Necker ridge, and Robbie ridge, occurred on the Pacific/Farallon and Pacific/Phoenix ridge crests during the interval 90–120 Myr BP (Barremian to Turonian). This event, which extended over a much larger area than comparable volcanism on the continents, is one of the largest to be documented in the geological record.