eorcsaee TABLE OF CONTENTS Page INTRODUCTION METHODS OF COLLECTION AND MEASUREMENT RESULTS AND DISCUSSION Depth Gradient of Gamma Spectra 12 Old Soil l2 Litter and Guano 14 Young Soil 18 Depth Gradient of sr?° RADIOAUTOGRAPHS Young Soil 21 25 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