THE LATE GOLOVNINO TRANSGRESSION OF THE MIDDLE PLEISTOCENE IN THE KUNASHIR ISLAND (KURIL ISLANDS)

Abstract

Lithology and facial characteristics of the upper part of the Golovnino Formation in the Kunashir Island (Kuril Islands) are investigated. The distinguished interlayers of volcanic ash may be used as the age and correlation markers. The results of diatom and spore-pollen analyses suggest the middle Pleistocene (Mindel-Riss Interglacial) age of the studied sediments. Two transgressive-regressive cycles of the respective sedimentation period correspond in time to the O-isotope stages 11-9. The elucidated paleogeographic environments indicate that the sea level was 20-25 m higher than now during the first transgressive phase and 5 m higher during the second. The regressive phases are marked by the tuff accumulation and a stratigraphic hiatus. In the middle Pleistocene, the estimated rate of tectonic uprising of the Kunashir Island was 0.28 mm/year. The middle Pleistocene paleogeographic events in the island are correlated with those in Japan, the Chukchi Peninsula, and Alaska.