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George R. Mansfield

Publications and source records attributed to George R. Mansfield.

4 recordsLinked to original sources
USGS1940

Phosphate deposits of the United States

Different types of phosphate deposits and different sources of phosphate in the United States are briefly discussed. In Florida two types of phosphate are now mined, land pebble and hard rock. The principal characteristics of these types of rock are stated and methods of prospecting, mining and recovery briefly outlined. Testimony given before the Congressional Committee to Investigate the Adequacy and Use of Phosphate Resources of the United States, November 28, 1938, at Lakeland, Fla., showed Florida's reserves to be far greater than previously supposed. Similarly at corresponding hearings in Tennessee a few days earlier the reserves of brown phosphate, the only type now mined in that State, were shown to exceed earlier official estimates. Reserves of the Western fields have been raised a little to bring them abreast of current information but no attempt has been made, as in the other States named, to include lower grades of rock than those formerly considered in the estimates. Professor J. Stewart Williams has shown for Utah that such a procedure would tremendously increase these figures . Reserves of the United States as a whole are now considered to exceed ten billion tons, not counting those classed as possible or certain phosphatic limestones mentioned at the hearings of the Congressional Committee. As nearly 2,000,000 acres of public land in the Western States and 66,000 acres in Florida remain to be examined for their phosphate content the stated figure will ultimately be greatly increased. At the present rate of consumption, 3,000,000 tons annually, ten billion tons would last more than 3,000 years.

Colorado, Florida, Idaho, Montana, South Carolina,↗
USGS1937

Role of physical chemistry in stratigraphic problems

Stratigraphy is concerned mainly with the genesis and interpretation of stratified rocks, which include some of wide extent and of great scientific as well as economic interest that are largely of chemical rather than of detrital origin. Chemical agencies have been recognized to some extent in genetic studies of these rocks, but little work has been done approaching in maturity the type of study now given to the genesis of igneous rocks and of ores, in which physical chemistry plays so important a part.A plea is presented to geologists with training in physical chemistry to interest themselves in stratigraphic problems that involve the use of this science. Examples cited are the phosphate beds and bedded cherts of the Phosphoria formation in Idaho and adjacent States and the potash-bearing Salado halite of the Permian basin in New Mexico and Texas. The interplay of ions in the solutions from which these formations were derived must have been controlled by such conditions as temperature, pressure, degree of concentration, and the like. Possibly laboratory study would enable us to reproduce these conditions and results and thus better interpret the geologic history of the times when these formations were built.

Economic Geology↗