14 spies change with increasing depth. In the 0.60 to 0.66-mev photopeak region of the 0 to l-inch increment, the relatively broad peak is a combination of the 0.60-mev photopeak of spt25 and the 0.66-mev peak of Cs 137 -B a L37m - in the l to 2-inch increment the peak becomes sharper and is oriented toward the 0.66-mev photopeak of Cs 137 -B a 137m - At the 9 to 10-inch incre- ment there is almost complete orientation toward the cst 37_ Ba 37m peak, with little spt?5 remaining. 1 . ¢ 2 a In Pig. 6 a comparison is given of the spectrum of the 9 to 10-inch increment (Fig. 5) and the gamma spectra of cst37 and spt?5 spikes. Fig. 7 shows the gamma spectra of increments taken from an undisturbed area in 1958. The first spectrum is from the 0 to 1/4-inch depth and the subsequent spectra are from 1/8~-inch depth increments to a depth of l inch. sht?5, the rare earths, The highest levels of and co°?, which move more slowly than cst?? or sr??, are in the 1/2 to 5/8-inch increments, whereas the est?) which moves most rapidly in this soil type, is in the 3/4 to 7/8-inch increment. Litter and Guano The gamma-ray spectrum of litter, consisting of leaves, twigs and floral parts splattered with tern droppings, collected from old soil in 1961 (Fig. 8) shows the csi3? photopeak to be much higher than the spt?5 peak. skewed to the left, The 1.17 peak of Co 60 is indicating the presence of the 1.12-mev AS