The history of paleoenvironmental change and its cyclic change during the Common Era in the Lake Hiruga, Fukui Prefecture, central Japan

Koji Seto, Shimane University, EsReC, Matsue, Japan, Sena Irisawa, Shimane University, Geoscience, Matsue, Japan, Junko Kitagawa, Fukui Pref. Satoyama-Satoumi Res. Inst., Wakasa, Japan, Kota Katsuki, Shimane University, Matsue, Japan and Kazuyoshi Yamada, Mus. of Nat. and Envir. History, Shizuoka, Shizuoka, Japan