A broadleaf tree of buried forest found on the river bed of the Iwaki is aged 2480±85 years B. P. (N-1958). First, the forest was growing in back-swamps region. At the above age, the area was covered by sand about 6m thick, and the forest was buried. Then, the area was changed to natural levee region. In the recent several years, the forest reappeared due to the lowering of river bed.
