From Abstract: "This bulletin is a summary of present knowledge of the adsorbent or bleaching clays-their distribution, field and laboratory identification, physical and chemical properties, uses, quality, and value. Problems in the drying, treating with acids, and washing are discussed, and methods of testing and rating decolorizing efficiency are described."

This report describes results of a field study in the Shafter mining district and conclusions presented are drawn from field studies along with office studies.

From abstract: Perry and Lewis Counties, east of the Tennessee River, in west-middle Tennessee, are underlain by nearly flat-lying rocks of Paleozoic age, with Mississippian cherty limestones forming the greater part of the surface of the western Highland Rim Plateau ridges. Near the summits of the ridges there is a fairly definite horizon in the chert that contains manganese and iron oxides in varying degrees of concentration. Weathering of the mineralized chert has produced widespread float on the hill slopes and in the beds of small spring branches, and the presence of this float, some of it rich enough for metallurgical manganese ore, has encouraged a search for promising deposits in place. In the present study 52 localities where the mineralized beds crop out or have been prospected were examined.

From Introduction: "The recent large increase in gold production from the Alma district has greatly stimulated interest in territory immediately to the east, where many small gold-bearing veins have been discovered. Consequently, as a cooperative project of the United States Geological Survey and the State of Colorado, 7 weeks in 1938 were devoted to renaissance work to determine the origin of the placer gold and the possibilities for discovering valuable lode deposits either near the surface or at depth."