TANAKA Yoshiyuki Kyushu University, Faculty of Literature, Associate Professor, 文学部附属九州文化史研究施設, 助教授 (50128047)
NISHIMURA Yasushi Nara National Cultural Properties Research Institute, Center of Eastern Cultural, 埋蔵文化財センター, 室長 (80000488)
SAWADA Masaaki Nara National Cultural Properties Research Institute, Center of Eastern Cultural, 埋蔵文化財センター, 室長 (20000490)
TANABE Shozo Kyoto University of Art & Design, Professor, 教授
ARAKI Shinsuke Hiraizumi Town Museum, Director, 館長
The major work undertaken in this study was the conducting of a field study in the zone along the southern shore of Takashima. In addition to this methods of conservation treatment of recovered artifacts wave examined in a laboratory. For purpose of comparative research a field study of the Shitadaru offshore seabed site of Ishigaki City in Okinawa Prefecture was also carried out, with the ceramic waves recovered being drawn and catalogued.
As the ground topography of Takashima and the seabed topography form a consecutive relationship, observations were made from the sea to the land, and recorded visually with a TV camera. This was carried out as part of the field survey. Simultaneously a seabed section, namely, the depth and ground stratum under a fixed measuring line were measured continuously while cruising along that line. Based on the results of surface sonar image photographs taken with a side scan sonar of the seabed topography throughout the whole extent of the well known site, dives were made in those areas in which it was thought highly possible that archaeological features and artifacts could be buried. These areas were examined in detail and recorded visually. Centering around Urashimoura, judged as the most likely area in which artifacts could still remain, the area was surveyed carefully, with additional side scan sonar, sub-bottom profiler, and electromagnetic surveys. Furthermore, boring was carried out at 3 of the points at which positive responses were observed, and samples of seabed sediment stratum taken. Substructure data and dating samples were also taken for sub-bottom profiler data analysis.