white, ° Re wwe te Seed bbe as . a ee er TABLE OF CONTENTS Page INTRODUCTION L METHODS OF COLLECTION AND MEASUREMENT 4 RESULTS AND DISCUSSION 7 Depth Gradient of Gamma Spectra 12 Old Soil 12 Litter and Guano 14 Young Soil 18 Depth Gradient of sr?° 21 RADIOAUTOGRAPHS 25 Young Soil 25 Undisturbed 25 Eroded 25 Old Soil 28 Horizontal Movement 28 Buried Organic Layers 30 Roots 30 Pumice 31 CONCLUSIONS 33 SUMMARY 35 REFERENCES 37 ty i 4 yk 4 aot »* ”