A report about minerals fuels and geologies located in parts of the Routt and Moffat counties, Colorado.

This report studies the geology of mineral deposits in Mount Harris, Pilot Knob, Elkhead Creek, and Daton Peek quadrangles in northwestern Colorado.

From abstract: The Little Cone quadrangle includes an area of about 59 square miles in eastern San Miguel County in southwestern Colorado. The quadrangle contains features characteristic of both the Colorado Plateaus physiographic province and the San Juan Mountains, and it has been affected by geologic events and processes of two different geologic environments.

From abstract: The largest single metal-mining operation in the history of mining in Colorado has been developed at Climax, as a result of the increased use of molybdenum in the steel and other industries. Production of molybdenum at Climax was notable for a short period during the World War; it ceased from April 1919 to August 1924 but since then has shown a steady increase. In 1930 from 1,000 to 1,200 tons of ore was milled daily, using only one unit of the 2,000-ton mill. The mine has a reserve of broken ore sufficient to furnish 2,000 tons daily for 3 years and is being developed to continue to furnish this and a still further increased output as the use of the metal may warrant.

From introduction: The greatest known potential oil resource in the world occurs in the oil shale of the Green River formation, and the richest and thickest deposits occur within the area of this report. The purpose of this investigation was to obtain data on the stratigraphic distribution and areal extent of the oil-shale beds and to estimate the potential oil resources in the area.

A report about the known facts about the minerals that make up the rocks, soils, and ore deposits of Colorado.

"A summary of the first 100 years of published knowledge, including the chief occurrences of 445 mineral species."

A report about the geology, composition, and stratigraphic nomenclature of the thirtynine mile volcanic field in central Colorado.

A report about the lithologic units within a red-bed sequence that help to interpret the history and structure of the Woody Creek quadrangle, west-central Colorado.

A report about mapping in the northern and central parts of the Piceance Creek basin of northwestern Colorado where several relatively thin dominantly marlstone units tongue northward into the Eocene Uinta Formation.

From abstract: Deposits of oxidized zinc ore are widely distributed in the western part of Colorado in the Rocky Mountains west of the Front Range and in the uplifted plateaus that border the main area of the Colorado Plateau. The principal production and reserves are restricted to several mining districts--Leadville. Aspen, Monarch, Spring Creek. Horseshoe, Tomichi, Tincup, and Rico--in all of which limestone and dolomites of Paleozoic age are the main host rocks. One deposit, that of the Sedalia mine near Salida has produced commercial quantities of oxidized zinc-copper ore from noncarbonate host rocks, but other known deposits in noncarbonate rocks are mostly low grade.

This report describes the stratigraphy of Pleistocene and Recent deposits in the Denver area, Colorado that was conducted intermittently between 1948-52.

A report about superficial deposits in the Louisville quadrangle, Colorado. They indicate early Pleistocene valley incisions bellow pediments and late Pleistocene valley filling and upland eolian deposition.

This report analyzes surficial deposits in the Louisville quadrangle, Colorado, that are divided into three main groups--pre-Wisconsin, Wisconsin, and Recent.

The following report presents a regional study of the extent, thickness, lithology, stratigraphic relations, age, depositional environment, and tectonic history of thick sulfate deposits and associated salts of sodium and potassium.

A report about the Coughs Creek Tongue which is a sequence of light-gray marlstone, locally containing beds of sandstone and siltstone, in the upper part of the Green River Formation.

From abstract: Thorium has been found since 1949 in at least 33 deposits in an area 6 miles wide and 20 miles long in the Powderhorn district, Gunnison County, Colo. The district is underlain largely by pre-Jurassic metamorphic and igneous rocks, most of which, if not all, are pre-Cambrian in age. These rocks are overlain by sandstone of the Morrison formation of Jurassic age, and by volcanic rocks of the Alboroto group and the Hinsdale formation of Miocene and of Pliocene(?) age, respectively.

The following report presents a preliminary account of the geology and economic aspects of the uranium deposits in the Eureka Gulch area.

The following report was prepared in cooperation with the Colorado State Geological Survey Board and the Colorado Metal Mining Fund Board. This report concerns work done partly on behalf of the U.S. Atomic Energy Commission and is published with the permission of the Commission.

A report about the Sugar Loaf and St. Kevin mining districts located in Colorado. Most of the bedrock consists of pre-Cambian schist, gneiss, granite, and pegmatite.

From abstract: The fluorspar deposits in the Northgate district, Jackson County, Colo., are among the largest in Western United States. The mines were operated intermittently during the 1920's and again during World War II, but production during these early periods of operation was not large. Mining was begun on a larger scale in 1951, and the district has assumed a prominent position among the fluorspar producers in the United States. Within the Northgate district, Precambrian metamorphic and igneous rocks crop out largely in the Medicine Bow Mountains, and later sedimentary rocks underlie North Park and fill old stream valleys in the mountains.

From introduction: The study of the Crystal Mountain district, Larimer County, Colo., is but one phase of this post-World War II pegmatite program, in part carried out by the Geological Survey on behalf of the Division of Raw Materials of the Atomic Energy Commission.

Abstract: "The Precambrian rocks of Colorado consist of a metaphoric complex more than 1,700 million years in age, three groups of igneous rocks about 1,700, 1,400, and 1,000 million years in age, here designated informal age groups, and two areally restricted units of sedimentary rocks, one between 1,400 and 1,700 million years in age and one between 950 and 1,400 million years. A systematic nomenclature for many of the rocks does not exist, but the present state of knowledge will permit establishment of a comprehensive nomenclature. Numerous formal names that have been applied to elements of the Precambrian assemblage are appraised and classified in a table, and eight names are abandoned."