Geology and Quaternary environments of the Tategahana Paleolithic site in Nojiri-ko (Lake Nojiri), Nagano, central Japan

Abstract

Excavation of the Tategahana Paleolithic site at Nojiri-ko (Lake Nojiri), central Japan, began in 1962, and the 21st excavation was performed in 2014. The Upper Pleistocene to Holocene fluvio-lacustrin Nojiri-ko Formation is distributed in and around Nojiri-ko. Fossils such as those of Naumann's elephant (Palaeoloxodon naumanni) and Yabe's giant deer (Sinomegaceros yabei), representing the ice age in Japan, have been excavated there in large quantities; at least 46 Naumann's elephants have been found. The fossils have been excavated in strata dating to 37.9–60.4 ka, comparable to MIS 3. Analysis of fossil pollen assemblages indicates that the vegetation at the time was a mixture of coniferous and broad-leaved trees. Bone instruments and spiral flakes made from elephant and deer bones, and stone tools created from stone, not found in the peripheral region, have been excavated from the Nojiri-ko Formation, and concentrated clusters of different types of fossilized elephant bones have been found.The top horizon containing elephant remains is 37.9 ka old, and thus older than MIS 2 (the Last Glacial Maximum), making it unlikely that Naumann's elephant disappeared from Nojiri-ko only because of climatic cooling. Findings strongly suggest that the occurrence of these large mammal fossils is the result of human activity. The Tategahana Paleolithic site provides important insights into the transitional phase from Asian Paleanthropine to Homo sapiens in Japan.