Vertical distribution of elements in non-polluted estuarine sediments determined by neutron induced prompt gamma-ray and instrumental neutron activation analyses

Neutron induced prompt gamma-ray analysis (PGA) and instrumental neutron ac tivation analysis (INAA) have been applied to the sediments collected from the Yasaka River estuary in Oita Prefecture, Japan. The vertical distributi on of 33 elements in the sediments has been determined and compared with th at in more polluted estuarine sediments. While the S content increased with increasing depth because of a sulphide accumulation under reducing conditi on, the increase in sulphide-forming elements such as Ag. Cd, Co and Zn was not observed in the deeper section of the Yasaka River estuarine sediments .