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Nomenclature of Precambrian Rocks in Colorado

Description: 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 estab… more
Date: 1977
Creator: Tweto, Ogden
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Pegmatites of the Crystal Mountain District, Larimer County, Colorado

Description: 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.
Date: April 1952
Creator: Thurston, William R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Oxidized Zinc Deposits of the United States: Part 3. Colorado

Description: 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 Seda… more
Date: 1964
Creator: Heyl, Allen V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Geology and Fluorspar Deposits, Northgate District, Colorado

Description: 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 … more
Date: 1960
Creator: Steven, Thomas August
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Areal Geology of the Little Cone Quadrangle, Colorado

Description: 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.
Date: 1960
Creator: Bush, Alfred Lerner; Marsh, Owen Thayer & Taylor, Richard B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Thorium and Rare-Earth Minerals in Powderhorn District, Gunnison County, Colorado

Description: 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.
Date: 1956
Creator: Olson, J. C. & Wallace, S. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Climax Molybdenum Deposit, Colorado

Description: 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 rese… more
Date: 1933
Creator: Butler, B. S. & Vanderwilt, J. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tertiary Geology and Oil-Shale Resources of the Piceance Creek Basin, Between the Colorado and White Rivers, Northwestern Colorado

Description: 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.
Date: 1961
Creator: Donnell, John R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Sugar Loaf and St. Kevin Mining Districts, Lake County, Colorado

Description: 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.
Date: 1955
Creator: Singewald, Q. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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