Abstract
Stratigraphic, sequence stratigraphic and sedimentary environment analyses on the late Pleistocene-Holocene sediments of the eastern side of Osaka Bay, central Japan was carried out. The Suminoe cores taken from the Suminoe area on the western side of Osaka plain were used. Sedimentological, tephrochronological, AMS14C dating, paleontological and micro-paleontological methods were applied. We found seven sedimentary units (Sm-7 to Sm-1) and grouped them into two formations. The Uemachi Formation is composed of marine clay deposits (Sm-6) with shore face deposits at the basal part (Sm-7) with fluvial terrace deposits at the top part (Sm-5). The Namba Formation is a Holocene marine sandy shoreface deposit (Sm-3) with fluvial deposits probably of the last glacial period at the basal part (Sm-4) and delta-front deposits at the upper part (Sm-2). We recognized two sedimentary systems, such as bay-delta system (Sm-7 to Sm-6 and Sm-3 to Sm-2) and conglomeratic braided stream system (Sm-5 and Sm-4). Furthermore we grouped these cores into three depositional sequences (DS1 to DS3) since 130 ka.
