Notes on the Chronology of Japanese Quaternary

Abstract

As the time-stratigraphical units of the Japanese Quaternary, the writer here proposes 12 units in ascending order, namely, 1 (I 1) Akasian, 2 (I 2) Sanukian, 3 (J 1) Makutian, Sematian, Naritian, 4 (J 2) Manzakian, Nisiyagian, 5 (J 3) Iwazikuan, Tatikawian, Ekotian, 6 (K 1) Numian and 7 (K 2) Yurakutyoan., The last two belong to Holocene., The later half of the Akasian perhaps may be regarded to belong to Villafranchian or the Gunz ice age., The Akasi Group represented by Metasequoia and Parastegodon is probably Astian in age., J 3 corresponds generally to Wurm ice age and Iwazikuan carries lithic culture of Aurignacian type., Nisiyagian represented by the namadicus-occidentalis-Sinomegaceroides (Japanese Megacerid ) fauna and characterized by Palaeoloxodon aomoriensis has close relationship with the eminent terrace-making (Du 1-M) happened after the Manzakian cold age., In the South Kwanto, J 1 is the age of transgression, while in the large parts of Japan J 2 and J 3 is known as the land age., Noteworthy is the Ekotian, top of the Japanes Pleistocene, characterized by Larix flora which indicates the climatic condition same as those of the present median high mountainland of Japan about 10002000m high above sea level., Remains of some alpine flora are found from several localities, about 4580m high above sea level., Sanukian, represented by Stegodon orientalis, occupies the lowest part of the Japanese Pleistocene.,