The Rotation of the Pacific Plate Induced by the Ontong Java Large Igneous Province

The eruption of large igneous provinces usually has major geodynamic in fluence sonoverriding plates.Seamount chains indicate that the drifting direction of the Pacific Plate changed by~80°in the Early Cretaceous when the Ontong Java Plateau formed.This,however,is not fully consistent with the magnetic anomalies.Here we show that there is an angle of~25°between the magnetic anomaly lines M_(0)and 34 of both the Japanese and the Hawaiian lineations,suggesting that the orientations of both spreading ridges changed by roughly the same angle towards the same direction.The configurations of the Shatsky Rise,the Papanin Ridge and the Osbourn Trough suggest that the eruption of the Ontong Java plume head uplifted the southeastern corner of the Pacific Plate,and pushed its east part northward by~700 km within 2 Ma.Meanwhile,the west part of the Pacific Plate was subducting southwestward underneath the eastern Asian Continent.These two forces together rotated the Pacific Plate anticlockwisely by ca 50°.Consequently,the drifting direction of the Pacific Plate also changed from southwestward to northwestward,which plausibly explains the ca 80°bending of the Shatsky Rise and the Papanin Ridge.The ridge between the Pacific and the Izanagi/Kula plates was pointed towards the~300°orientation,whereas the Pacific Plate was subducting towards the~250°orientation before~125 Ma,and towards~280°afterward.