Geodynamics and Paleogeography of the Northwestern Pacific Continental Margin in the Late Cretaceous

摘要

The deep-sea drilling at the Emperor Seamounts during ODP Leg 197 of the D/V JOIDES Resolution confirmed the previous suggestion that the Hawaiian hotspol was situated at substantially higher latitudes in the Campanian than nowadays and then migrated southward during the Late Cretaceous and Early Paleogene. The paleolatitude of Campanian volcanics from the Detroit Seamount (approximately 40° N) determined by three independent methods virtually coincides with the paleolatitudes of the coeval accreted island-arc terranes of the Koryak-Kamchatka fold zone. This makes necessary to compare available data on lithology and deposition settings of concurrent sediments associated with oceanic volcanics of the intraplate (Emperor Seamounts) and subduction-related (fold zone) types that likely formed at similar latitudes. The remarkable differences . between them lead to the conclusion that the Koryak-Kamchatka island-arc terranes were situated in the Late Cretaceous at significantly higher latitudes.