Geological Structure of the Submarine Vityaz Ridge within the Seismic Gap Area (Pacific Slope of the Kurile Island Arc)

摘要

Results of geological research conducted by the Pacific Oceanological Institute of the Far East Division of the Russian Academy of Sciences and the Institute of Oceanology of the Russian Academy of Sciences on the submarine Vityaz Ridge during Cruise 37 of RN Akademik M.A. Lavrentyev in 2005 are discussed. Various rocks constituting the basement and sedimentary cover of the ridge were dredged in three areas of the ridge. Based on isotope geochronology, petrogeochemical, petrographic, and paleontological data and comparison with similar rocks available from the adjacent land and Sea of Okhotsk, they are subdivided into several age complexes. Late Cretaceous, Eocene, Late Oligocene, Miocene, and Pliocene–Pleistocene complexes are defined among the igneous rocks, while volcanogenic–sedimentary rocks are united into Late Cretaceous–Early Paleocene (late Campanian– Danian), undivided Paleogene (Paleocene–Eocene?), Oligocene–early Miocene, and Pliocene–Pleistocene complexes. The obtained data on the age and formation settings of the defined complexes made it possible to reconstruct the geological evolution of the central Pacific slope of the Kurile island arc.