The Cretaceous submarine Ontong Java Plateau, in the western Pacific Ocean, is the most voluminous of the world's large igneous provinces (LIPs), and represents the largest known magmatic event on Earth. LIPs are the products of basaltic volcanism on a scale and at an effusion rate not seen on Earth at the present time, and their formation may have had significant effects on the Earth's climate and biosphere. The currently favoured explanation for LIP formation is the rapid decompression and melting of anomalously hot mantle in the heads of newly ascended mantle plumes. This volume summarizes the results of research aimed principally at testing the plume-head hypothesis for the formation of the Ontong Java Plateau, and presents the results of integrated studies following recent basement drilling on the plateau by the Ocean Drilling Program. Nineteen papers cover topics as diverse as petrology, geochemistry, tectonics, volcanology, palaeomagnetism and biostratigraphy.