The U.S. Geological Survey has recently measured and sampled the Phosphoria formation at many localities in Idaho and other western states. These data will not be fully synthesized for many years, but segments of the data, accompanied by little or no interpretation, are published as preliminary reports as they are assembled. This report, which contains abstracts of the sections measured in southeastern Idaho (fig. 1), is one of this series and is the fourth report of data gathered in Idaho; it includes about half of the data gathered in Idaho in 1949. The field and laboratory procedures adopted in these investigations are described rather fully in a previous report (McKelvey and others, 1953a).
Many people have taken part in this investigation, which was organized and supervised by V. E. McKelvey. F. J. Anderson, D. F. Davidson, R. S. Jones, R. A. Smart, R. G. Waring, and J. D. Weiser participated in the description of strata and the collection of samples referred to in this report. T. K. Rigby assisted in the preparation of trenches and the collection, crushing, and splitting of samples in the field. The laboratory preparation of samples for chemical analysis was done in Denver, Colo., under the direction of W. P. Huleatt.
