This is a photo-geologic map of the Skull Mountain Quadrangle at the Nevada Test Site.

Geologic map of the Topopah Spring Southwest quadrangle, Nevada with notations for specific topographic features and profile views. Scale 1:24,000.

Introduction: The chemical character of ground water depends to a large degree upon the character of the rock formations through which the water moves. The composition of the water is the result of several solutional and decompositional processes.

From introduction: A rapid appraisal of the carnotite resources of the Salt Wash sandstone member of the Morrison formation in the Carrizo Mountains area was undertaken by the U. S. Geological Survey late in 1951 in connection with its current project of geologic mapping of the area. Though brief and preliminary, this report provides a summary of production trends and estimated reserves in the area and indicates as far as possible the total potential of the area as a source of uranium. This information may be helpful in planning new milling facilities or other measures to encourage a higher rate of production.

Abstract: Uranium occurs in the North Park(?) formation of Pliocene(?) age in the Miller Hill area, about 25 miles south of Rawlins, Carbon County, Wyo. As much as 0. 5 percent uranium is contained in grab samples, but only about 1000 tons of rock are known to contain as much as 0. 03 percent uranium. Beds of brecciated, silicified limestone 3 to 10 feet thick contain the principal concentrations of uranium. Lesser concentrations are found in calcareous sandstone and quartzite. Uranophane, Ca(UOz)2SizO 7 . 6HZO, the principal uranium'mineral, has been deposited in vugs, as fracture and surface coatings, and as a disseminated constituent of the rock. Uranium also occurs in quantities too small to be megascopically visible in dark-colored chalcedony, lime stone, sandstone, and quartzite beds.

Abstract: Uranium-bearing copper deposits occur in steeply dipping beds of the Sangre de Cristo formation of Pennsylvanian and Permian age south of Coyote, Mora County, N. Mex. Mapping and sampling of these deposits indicate that they occur in lenticular carbonaceous zones in shales and arkosic sandstones. Samples from these zones contain as much as 0.067 percent uranium and average 3 percent copper. Metatyuyamunite is disseminated in some of the arkosic sandstone beds, and uraninite was identified in some of the copper sulfide nodules occurring in the shale. In polished section these sulfide nodules were found to be composed principally of chalcocite with some bornite and covellite, as well as pyrite and malachite. Most of the samples were collected near the surface from the weathered zone. The copper and uranium were probably deposited with the sediments and concentrated into zones during compaction and lithification. Carbonaceous material in the Sangre de Cristo formation provided the environment that precipitated uranium and copper from mineral-charged connate waters forced from the clayey sediments.

From introduction: This report details the results of a 256-pound high explosive cratering experiment at the Chariot test site 110 miles north of the Arctic Circle.

From abstract: Approximately fifty radioactive deposits and nearly fifty properties not abnormally radioactive were examined during a geologic reconnaissance for radioactive minerals in Idaho, Washington, and western Montana during the period July 1952 -- June 1955. The most important uranium deposits are in or near granitic to quartz monzonitic intrusions of probable Cretaceous age in central and northern Idaho, westernmost Montana, and northeastern Washington.

The Topopah Spring and Timber Mountain 15-minute quadrangles comprising about 500 square miles in southern Nye County, Nev., are bounded by longitudes 116°15' W. and 116°30' W. and by latitudes 36°45' N. and 37°15' N. (fig. 1) The quadrangles are mostly within the Nevada Test Site and are approximately 90 miles northwest of Las Vegas (fig. 1). Lathrop Wells, the nearest town, is about 10 miles south of the southern boundary of the Topopah Spring quadrangle.

From introduction: This report summarizes the location, gross geologic features, and natural resources of the major sedimentary basins in the United States, excluding Alaska and Hawaii.

Abstract: Two uranium-bearing minerals, uranothorianite and thorite (?), were found in the stream gravels of the main branch of the South Fork of Quartz Creek, a tributary of the Kiwalik River. Although the bedrock source of the minerals was not located, the radioactive material was traced in slope wash well above the stream gravel. A detailed investigation of the area with more sensitive counters might reveal the source of the minerals and localities where the minerals are sufficiently concentrated to be minable.

From abstract: This paper is primarily a progress report on studies designed to accumulate geologic data that will aid in our understanding of the localization and the genesis of uranium deposits in the Dripping Springs quartzite.

From foreword: The six papers included in this report were prepared in an attempt to summarize briefly, and make available to the public, part of the information concerning uranium deposits that is in unpublished reports of work done by the U. S. Geological Survey under the auspices of the Manhattan Engineer District, and later, the U. S. Atomic Energy Commission.

From introduction: Geophysical surveys have been made in the Uravan area, in southwest Colorado, with the aim of providing information on regional geology, especially on those aspects that may not be apparent from surface evidence alone. Aeromagnetic surveys were made in 1952, and regional gravity surveys were made during the summers of 1953 and 1954. Figure 1 shows the area covered. Information on surface geology was obtained from publications, from geologists working on the Colorado Plateau, and from personal observations.

From abstract: Two hundred and seventy-one prospect pits, mine dumps, or mine workings within the Sugar Loaf-St. Kevin mining districts and vicinity, were tested for radioactivity by the U. S. Geological Survey in 1951 during six weeks of investigation on behalf of the Division of Raw Materials of the U. S. Atomic Energy Commission. One hundred and twenty-two weak radioactivity anomalies were found in the St. Kevin district and vicinity, and eight slight anomalies were noted in"-the Sugar Loaf district, which adjoins the St. Kevin district on the south, Most of the radioactivity anomalies were found in igneous and metamorphic rocks of pre=Cambrian age, but some were found in metalliferous veins of Tertiary age.

Report discussing the stratigraphy of uraniferous rocks discovered near Tordilla Hill in Karnes County, Texas. The report contains sections on the stratigraphy of the area, the structure, uranium minerals, descriptions of individual prospects, and a summary.

Report discussing the coarsely crystalline autunite in granitic rock near Mt. Spokane, Washington. "This report is an abstract of a paper with the same title that is planned for publication in the American Mineralogist."

The following report covers investigations on sedimentary rocks of Middle Pennsylvanian age in northeastern Oklahoma, southeastern Kansas, and western Missouri. Distribution of uranium and other trace elements in these rocks was studied during 1955 and 1956.

Report describing a fluorimetric procedure for determining about 10^-8 percent uranium with 500-ml water samples.

From Abstract: "The equation of the standard curve used in the colorimetric determination of trace amounts of metals by means of dithizone extraction is developed, and a further expression is derived which defines the slope of the standard curve."

A report about uranium in Colorado which oxidize to yield U(VI) before reacting significantly with other mineral constituents.

The following report describes findings from a reconnaissance mission in Alabama, Georgia, and North Carolina on radioactive trace elements in a variety of rocks.

Report discussing information produced from aeromagnetic and regional surveys conducted in the Uravan area of Colorado. This was part of a regional geology study of the Colorado Plateau.

A report about the U. S. Geological Survey's program about uranium investigations and geologic mapping in the Monument Valley area, Arizona. A resource appraisal of the area was an inherent part of the program, and is detailed in this report.