Relative Motions Between Oceanic and Continental Plates in the Pacific Basin

A model is presented for the displacement history between western North America, eastern Eurasia, and adjacent oceanic plates (Pacific, Farallon, Izanagi, Kula, and Phoenix) for the past 180 million years. The model is based on the assumption that the hotspots in the Atlantic region have remained fixed relative to the hotspots in the Pacific basin (but not necessarily relative to the spin axis). The model uses a new determination for relative motion between the oceanic plates of the Pacific basin. The results show that in a broad sense the Kula and Izanagi plates moved in a general south to north direction through the Pacific basin, implying rapid subduction beneath Eurasia and right lateral oblique subduction with respect to North America. In contrast, the Farallon plate swept in a general west to east trajectory across the basin and was accompanied by rapid subduction beneath North America. The Kula and Izanagi plates were capable of transporting allochthonous terranes rapidly northward toward the paleopole. The Farallon plate was capable of transporting terranes bearing Tethyan fauna eastward across the Pacific basin and juxtaposing those terranes agains