Report issued by the U.S. Bureau of Mines on two samples of crude oil collected from the Greasewood Flat area of northwestern Colorado. These samples were analyzed for many characteristics, and an approximate summary of those characteristics are presented. The report contains two tables of data.

Report issued by the Bureau of Mines over exploration of the lead and zinc deposits of the Madonna Mine. Descriptions of the deposits are presented. This report includes tables, maps, and illustrations.

From introduction: This report summarizes some of the results of U. S. Geological Survey investigations in the Club Mesa area and presents a compilation of available geologic data that would be helpful in future exploration. Detailed geologic logs of U. S. Geological Survey holes drilled in the Club Mesa area on public land that is no longer withdrawn from mineral entry are on open file for public inspection in the U. S. Geological Survey office, Grand Junction, Colorado.

From introduction: The present report summarizes the indicated and inferred reserves which have been found to date by the drilling in Club Mesa, Montrose County of New Mexico, and includes an estimate of the potential reserves predicted for the area. It also includes a statement of plans for additional drilling. A final report will be prepared on the completion of the drilling planned for 1951.

From purpose of study: The Vallecito Conglomerate of the Needle Mountains area in southwestern Colorado was studied to evaluate the uranium potential of the unit and to test the applicability of the uraniferous Precambrian pebble-conglomerate exploration model in this area. The main thrust of this project is the Vallecito Conglomerate, but the Uncompahgre Formation, which is also in the Needle Mountains area has basal conglomerate that was investigated in a reconnaissance mode. Five specific objectives have been formulated to meet the overall purpose of this project, and these include: a) Determine the uranium distribution in the Vallecito Conglomerate and the basal conglomerate of the Uncompahgre Formation. b) Evaluate the uranium resources of the area to the degree possible utilizing available information and personal field investigations. c) Test the validity of application of the Precambrian quartz-pebble conglomerate model to this area. d) Recommend detailed studies and delineate drilling sites in the area to further evaluate the uranium resources if warranted. e) Recommend additional geologic, geophysical and geochemical studies which would bear directly on evaluation of uranium resources of the Precambrian pebble conglomerates in the Needle Mountains area.

This report provides uranium and other elemental data resulting from the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Cortez quadrangle, Colorado/Utah.

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.

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

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.

Report summarizing the results of geological exploration of the Atkinson Mesa area of Montrose County, Colorado and contains a brief description of the area's geology and ore deposits.

Report discussing the regional geology, geomorphology, structure, mineral deposits, and details of the sedimentary and igneous rocks of the Placerville Quadrangle in Colorado.

A report about how the U. S. Geological Survey explored the Atkinson Mesa area for uranium and vanadium bearing deposits from July 2, 1951, to June 18, 1953, with 397 diamond drill holes that totaled 261,251 feet.

The following report covers a reconnaissance resource appraisal in pre-Morrison formations, particularly the Shinarump conglomerate, on the Colorado Plateu and adjoining regions during December of 1951. This report is preliminary in nature and the ideas are presented as a hypothesis to be tested by future work.

Report discussing the possible existence of pegmatites containing beryllium deposits in the granite stock in the vicinity of Mount Antero and White Mountain, Chaffee County, Colorado.

Report discussing the results of a six-week geological investigation of 271 prospect pits, mine dumps, and mine workings in the Sugar Loaf -St. Kevin mining districts of Lake County, Colorado during 1951. The objective of the investigation was to determine the presence of radioactive materials.

From introduction: This report describes work done in the Sterling, Colorado, National Topographic Map Series (NTMS) quadrangle (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

This report examines the region of the Piceance Creek basin in Colorado so that the United States Bureau of Mines may develop plans for an underground oil-shale research facility in the center of the basin. It includes maps, charts, and graphs.

This report investigates the effects of the sewage-sludge recycling site and a landfill site on the ground-water system of Denver. It includes several maps.

A report regarding factual data obtained during an examination of the copper King Shaft, Black Hawk Claim no. 1, Larimer County, Colorado. This report is designed to provide the owners with the factual data obtained from their property in accordance with the Agreement for Mineral Exploration with them.

A computer analysis of NURE-HSSR data.

A preliminary reserve statement, regarding Reserve Blocks B and C, located in the Legin group Area, in San Miguel County, Colorado.

The following slides document black sand deposits that were analyzed in the parent report, Radioactive Titaniferous Heavy Mineral Placers in the San Juan Basin, New Mexico and Colorado.

Report documenting the results of chemical analysis for 1518 water and 1604 sediment samples in the Durango quadrangle, Colorado. It includes an overview of the area, methods, data analysis, and evaluation.