7 oie pen ect tek 33 of radionuclides moving through the soil. This is certainly true for cs t37 and sr??, which were abundant compared to other radionuclides in the leachates. It also was demonstrated by comparing the gamma-ray spectra of depth increments that there is a more rapid movement of cst?? than of other gamma-emitters present. It should be recalled that the exchange capacity of these soils originates from the organic content, which, as is obvious from the photographs of the core sections and Table III, is far higher in the old than in the young soil. There is thus more opportunity for exchange and retention of radionuclides in old soil. Mechanical mixing, due mainly to the activity of land crabs, plays an important role in redistribution in the surface layers. This effect is obvious in areas where there has been active burrowing, and is probably occurring to a small extent throughout densely vegetated areas as is indicated by the presence of ce t44_py 144 and But?? in the litter. These radionuclides could only have come directly from the soil by upward mixing since they were not found in the vegetation which contributed significantly to the litter. CONCLUSIONS Different plant and soil environments on single islets have a different vertical distribution pattern of radionuclides u, from the same fallout material. The vertical distribution of pay ga x0 i oye