A datum on 14C age of molluscan shells of the Holocene marine terrace deposits at Emi coast in Kamogawa City, Chiba Prefecture

In connection with the survey on the littoral alteration in the Kamogawa seashore, the author got an opportunity to observe the gravel stratum containing molluscan shells in scattered state at Emi coast. The results of 14C age determination of the shells and of the identification of the shells are described. The results of 14C age determination are 5,060 +- 130 y.B.P. for Mytilus corsucus and 5,980 +- 150 y.B.P. for Batillus cornutus, etc. In the marine terrace in Emi coast, any topographical irregularity is not observed. The height is 19m near hills, and 11m at the end close to the coast. It is a topographic plane with only about 8m height difference in the distance of 0.4km. It is considered therefore that at the time of formation of the terrace deposit, the beachline had been at the present height of 19m. (J.P.N.)