The research reported herein includes unpublished iodine and uranium data on a group of United States Geological Survey standards and on a group of ultrabasic rocks. Data are also included for the major rock types, deep sea sediments, and for graphite and troilite inclusions in iron meteorites. Tellurium data for the troilite are also reported. Appendix I is a literature article (Bennett and Manuel, 1967a) on Canyon Diablo Graphite. Appendix II is a literature article (Bennett and Manuel, 1967b) on deep sea sediments. The results of this study show that most of the earlier estimates of the crustal abundance of iodine are uniformly too high, except for deep sea sediments. The results also indicate that the apparent atomic dispersion theory of iodine was in fact due to rather uniform iodine contamination. The iodine and uranium abundances from this study are used together with terrestrial xenon abundance data recently redetermined by Mr. R. A. Canalas in this laboratory to show that the I¹²⁹-Xe¹²⁹ formation interval of the earth is similar to that of stony meteorites --Abstract, page ii
