Introduction: Thorium and rare-earth metals have come into strategic importance in this country in the last few years with the potential use of thorium in the production of atomic power and the development of new uses for the rare earths in the aircraft industry.

From introduction: This bibliography is an annotated list of selected reports that were publicly available as of May 31, 1956, pertaining to the uranium content and/or radioactivity of igneous and metamorphic rocks and minerals in the United States.

From introduction: This report details the reconnaissance for uraniferous lignites in North Dakota, South Dakota, Montana, and Wyoming during 1948 and 1949.

From foreword: This report is a statement of progress during a six-month period on investigations of radioactive materials in the United States.

From introduction: This report describes the general geologic setting, the occurrences of uranium or radioactivity in the Fall Creek, Idaho area and adjacent areas, the probable nature of the mineralization and origin of the deposits, and the estimated reserves of uranium-bearing rock.

From abstract: The Legin group area comprises five privately owned claims, nine Government claims, and some public land. The area is in parts of secs. 28 and 29, T. 43 N., R. 19 W., New Mexico principal meridian, San Miguel County, Colo. It is about 45 miles from the Government mill at Monticello, Utah, and 50 miles from the Vanadium Corporation of America mill at Naturita, Colo. The Legin group area has yielded a total production of more than 18,000 short tons of carnotite ore that averaged 0.32 percent U30 and 2.5 percent V 205 . Most of this production was accomplished during the years from 1935 to 1944, and from 1949 to October 1951.

From introduction: The purpose of this paper is to summarize and review some of the recent mineralogic information relevant to uranium-bearing veins in the United States, as well as to describe some of the reported mineralogic associations and the modes of occurrence of the uranium minerals in vein deposits.

From abstract: Uranium minerals were discovered in the Pumpkin Buttes area, Campbell and Johnson Counties by the U. S. Geological Survey in October 1951. From June to November 1952, an area of about 750 square miles was examined for uranium deposits, and 211 localities with abnormally high radioactivity were found; uranium minerals are visible at 121 of these localities.

A report about a previously published semiquantitative spectrographic method that was modified by applying microphotometric scanning of the spectrograms in such a way that the operator was free to do other work during a large part of the scanning time.

Report discussing an investigation of the stratigraphy of the Phosphoria formation in Montana. The investigation took from 1949 to 1950, and this report includes about half of the data collected. Analytical data and abstracts of several locations' stratigraphic sections are included.

Abstract: "A procedure for the determination of thorium in the concentration range of 0.2 to 10 parts per million ThO2 in felsic or mafic rocks. Thorium is extracted by mesityl oxide and purified by iodate precipitation from nitric acid medium containing tartaric acid and hydrogen peroxide. The thorium is determined spectrophotometrically with thoron from meso-tartaric acid medium."

Report discussing an investigation of radioactivity in part of Clear Creek County, Front Range, Colorado. The methods and results of the reconnaissance are included. Veins containing chalcopyrite were found to be the best source of radioactivity in the region.

From Abstract: "A routine method is given for the determination of potassium and sodium in siliceous, argillaceous, and phosphatic rocks using the Beckman flame photometer 10300."

Abstract: "The mineral bayleyite was first described in 1951 from a mine in Yavapai County, Ariz. This report describes bayleyite from the Hideout No. 1 mine, San Juan County, Utah, together with its associated minerals and mineralogic properties."

A report about a comparison of the uranium content of plants and soils as prospecting guides for uranium made for areas of known mineralization in Fall River County, South Dakota.

Report discussing the exploration of the Upper group area in San Miguel County, Colorado, and the investigation of carnotite ores produced from this area.

The following report covers a reconnaissance for new discoveries of radioactive lignite deposits in the Green River Basin and Uinta Basin of Wyoming and Utah where similar discoveries to previous studies in North Dakota, South Dakota, Montana, and Wyoming were made. Additionally, there were new prospects examined, as well as reconnaissance for uranium deposits.

A report about uranium content of water from various rocks in certain states in the United States. It attempts to locate areas in which large amounts of uranium in the water will reflect the presence of nearby uranium accumulations.

Report discussing the geology and uraniferous carbonaceous rocks found in the Bear River of the Fall Creek area of Bonneville County, Idaho. The report provides information regarding the geology of the area, uranium occurrences, distribution of uranium and other elements in carbonaceous materials, origin of uranium occurrences, core drilling results, and inferred reserves.

Report providing a bibliography and index map for thorium occurrences and rare-earth deposits throughout the United States. The introduction contains information on these deposits' uses, the industry surrounding these deposits and its problems, and ore deposits.

A report about uranium on the Colorado Plateau which is related to coalified wood, crude oil, carbonaceous shale, and carbonaceous matter of unknown origin.

Report discussing the U.S. Geological Survey's investigation of the stratigraphy of the Phosphoria formation in Montana. This contains the second half of data collected during the investigation, which took place from 1949 to 1950.

The following report covers the Petrographic study of Early Cretaceous age sandstone beds in the Fall River formation and the Fuson-Lakota formations, as well as Late Jurassic age beds in the underlying Unkpapa and Morrison formations along the western side of the Black Hills.

A report about the Lemhi Pass area in the Beaverhead Mountains, Lemhi County, Idaho, and Beaverhead County, Montana, which was undertaken to determine the area as a potential source of thorium.