北陸地域にみられるビーチロックについて

抄録

Beachrocks were found at two localities in the Hokuriku region, Central Japan. One beachrock locality is Oniu on the Echizen coastal area, Fukui City, Fukui Prefecture. Another beachrock locality is Awazu-cho, Suzu City in the northeasthern part of the Noto Peninsula. The beachrock is composed of granule, sand-size particles and shells. It can be stated that the beachrock corresponds with the intertidal beachrock reported by TAKENAGA (1965). The ¹⁴C age of the beachrock, collected at the sea level altitude of 1.2m in the Echizen coastal ares is 3, 950±80 y.B.P. The ¹⁴C age shows that this beachrock could be formed during the Jomon-transgression. Furthermore, the locality of the beachrock in Suzu City may be regarded as the northernmost position of such rock in Japan.