Home – Home – Jornals – Russian Geology and Geophysics 2018 number Неопубликованное

More than 30 years have passed since the current Working Stratigraphic Framework for the Kuril Islands was approved. Over this period, extensive age data (from diatom analysis, K-Ar dating, and other methods) have been obtained for the rocks composing the islands of the Greater Kuril Ridge, through both regional geological mapping and targeted research projects. In addition, the upper boundary of the Neogene was revised in 2011. Consequently, to synthesize these data, it became necessary to draw up an updated Neogene-Quaternary stratigraphic framework and a correlative intraregional chart for the magmatic rocks of the Greater Kuril Ridge. Based on comprehensive diatom biostratigraphy, radioisotope dating, and geological correlation of volcanic complexes, the following have been developed: (1) a new Unified Stratigraphic Framework for the Neogene-Quaternary deposits, and (2) a new intraregional correlation chart for the magmatic assemblages. The diatom and radioisotope data confirmed the absence of a stratified Paleogene–Early Miocene "Green Tuff Complex" previously recognized by researchers at the base of the exposed section of the Greater Kuril Ridge. Diatom analysis of the oldest stratigraphic subdivisions (the Rybakovsky Volcanic Complex and the Shumnovskaya Formation) of the Greater Kuril Ridge – specifically, the identification of the Thalassionema schraderi and Neodenticula kamtschatica diatom zones – indicates that the rocks composing the islands of the Greater Kuril Ridge began to form in the Tortonian (Late Miocene).