From introduction: To improve understanding of uranium mineralization of the Todilto Limestone of Late Jurassic age in the Grants district, New Mexico, the mines active in 1957 were reviewed to determine the major types of deposits. A representative example of each type was selected and mapped in great detail to establish a prototype. It was hoped that the analysis of prototypes might shed considerable light on the mineralization process and aid evaluation of other deposits by offering a standard of comparison.

Although uranium gas first discovered in the Carrizo Mountains area in 1918, the ores were not developed until 1942. They have, however, been mined continuously since that time. Formations in the area range from the Pernian Cutler through the Cretaceous Mancos shale, and all are intruded by a dioritic laccolith and its related dikes. The older structures, which include the Defiance Uplift, the San Juan Basin, and the Four Corners Platform are somewhat disrupted by the effects of the intrusion. A number of mines are described and mineralogical and geochemical studies made are outlined. The primary uranium mineral is unknown, but the chief uranium ore-mineral is the secondary mineral, tyuyamunite. It is concluded that there is at least minor structural control of the ore bodies along sedimentary trends and joints, and that all ore bodies of 500 tons or more are on the Defiance monocline or its extensions. The uranium may have been syngenetic in the sediments, and redistributed by solutions or, more likely, that it rose vertically in hydrothermal solutions from the local intrusive bodies.

From Purpose, Scope, and Methods: The objective of this study was an evaluation of resources of the Carrizo Mountains area. Four factors: distribution of ore bodies, relation of uranium to the host rock, relation of ore to structure, and circumstances that might precipitate uranium were studied in search of data bearing on manner of distribution of ore, the time and causes of deposition, and the probable source of the uranium-bearing solutions.

Abstract: Ten days were spent during June 1955, examining the sedimentary rocks along the San Juan and Colorado Rivers between Mexican Hat, Utah, and Lee's Ferry, Arizona. The most favorable area for uranium deposits occurs in the Shinarump member of the Chinle formation between Clay Hills Crossing and Spencer Camp along the San Juan River. Mineralization is spotty and deposits are small and almost all below ore-grade. Only one small mine, the Whirlwind, is currently producing ore. Gray-green alteration of the underlying Moenkopi is moderately developed in the vicinity of the Whirlwind mine; elsewhere alteration is weakly developed.

Introduction: The Ambrosia Lake area includes all of T. 14 N., R. 10 W., and portions of adjacent townships in McKinley County, approximately 20 miles north of Grants, New Mexico (fig. 1). Uranium was discovered in April, 1955, and extensive exploration drilling followed.

From introduction: This is one of a series of three reports on airborne radioactivity surveys in the United States. The reports contain the 185 airborne anomaly maps issued by the U. S. Atomic Energy Commission as a result of the AEC's aerial surveying program conducted from March 1952 to June 1956; two ground reconnaissance maps of Utah also are included. Most of the reconnaissance was done in the western United States.

Report documenting work to map in detail the Roy Mesa and Enos Johnson claim areas so that ore guides could be determined and the areas could be evaluated for drilling and to complete a general reconnasaince of the favorable Mesozoic.

The US Atomic Energy Commission conducted a drilling program in McKinley County, New Mexico, from August 19, 1953, through April 19, 1954, to explore the Jurassic Todilto limestone for uranium occurrences on the eastern, northeastern, northern and northwestern sides of Haystack Butte

Discussing a reconnaissance, in the uppermost Cretaceous and early tertiary rocks of the eastern San Juan Basin, New Mexico, for uranium

Describing and comparing the uranium deposits in the Morrison formation, except those of the Ambrosia Lake locality.

Results of a survey in the southwest segment of the Zuni Uplift sedimentary formations. It includes an overview of physical geography in the area, as well as economic geography, including mineral deposits.

Report presenting the results of a survey in the southwest segment of the Zuni Uplift sedimentary formations. The report includes figures and plates that provide an overview of physical geography in the area, as well as economic geography, including mineral deposits.