Lots of Yamato Shijimi(Corbicula japonica)
Just below the surface is a layer of sand that was added to the lakebed during the land reclamation process.
Beneath that, there is a thick layer of clay, with a concentration of Yamato shijimi clams found within the top 60 cm.
The layer, including areas without shells, is thought to represent the period from when Lake Hachirogata was formed (around 2,000 years ago) up until before land reclamation.
The underground layers in Ogata Village are generally in this condition over a wide area.
[Block Sample]
Although it appears that only Yamato shijimi clams (Corbicula japonica) are present, this layer also contains very small gastropods, such as the Kawaguchi tsubo ( Iravadia elegantula : a species of snail).
