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Ancient Lavas in Shenandoah National Park Near Luray, Virginia
Abstract: In the Blue Ridge Province of northern Virginia, Maryland, and southern Pennsylvania, Lower Cambrian beds are underlain by a thick sequence of greenstone and interbedded sedimentary rocks known as the Catoctin Formation. An area near Luray, Va., was studied to determine the thickness of the formation, its relationship to overlying and underlying rocks, and the original nature of the lavas from which the Catoctin greenstone was derived. There the Catoctin Formation lies unconformably on granitic rocks. Its basal sedimentary layer ranges from a few inches to 150 feet in thickness and contains pebbles of underlying basement rocks. The erosion surface beneath the Catoctin is irregular, and in several places, hills as much as 1,000 feet high were buried beneath the Catoctin lavas. No important time break is indicated between the deposition of the Catoctin Formation and the overlying Cambrian sediments. The original Catoctin lavas were basaltic and were probably normal plateau basalts. Columnar joints, amygdules, sedimentary dikes, flow breccias, low-dipping primary joints, and other primary structures are well preserved.
Areal Geology of the Little Cone Quadrangle, 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.
Bentonite Deposits of the Northern Black Hills District Wyoming, Montana, and South Dakota
From abstract: The northern Black Hills bentonite mining district includes parts of Crook County, Wyo., Carter County, Mont., and Butte County, S. Dak. Within this district, many beds of bentonite occur interspersed with sedimentary strata of Cretaceous age that have an average total thickness of about 3,000 feet and consist chiefly of marine shale, marl, and argillaceous sandstone. The bentonite beds occur in formations ranging upward from the Newcastle sandstone to the lower part of the Mitten black shale member of the Pierre shale. Tertiary (?) and Quaternary deposits of gravel, sand, and silt are present on extensive terraces, and deposits of such materials also extend along stream courses in all parts of the district.
Beryl-bearing Pegmatites in the Ruby Mountains and Other Areas in Nevada and Northwestern Arizona
From abstract: Pegmatite occurs widely in Nevada and northwestern Arizona, but little mining has been done for such pegmatite minerals as mica, feldspar, beryl, and lepidolite. Reconnaissance for beryl-bearing pegmatite in Nevada and in part of Mohave County, Ariz., and detailed studies in the Dawley Canyon area, Elko County, Nev., have shown that beryl occurs in at least 11 districts in the region. Muscovite has been prospected or mined in the Ruby and Virgin Mountains, Nev., and in Mohave County, Ariz. Feldspar has been mined in the southern part of the region near Kingman, Ariz., and in Clark County, Nev.
Changes in Stratigraphic Nomenclature by the U.S. Geological Survey, 1963
A report that fits in a series of reports that are about changes in stratigraphic nomenclature and that will list publications in which the changes have been describes. It deals with stratigraphy, including those defining changes in stratigraphic nomenclature in reports of the U.S. Geological Survey.
Chromite and Other Mineral Deposits in Serpentine Rocks of the Piedmont Upland, Maryland, Pennsylvania and Delaware
From abstract: The Piedmont Upland in Maryland, Pennsylvania, and Delaware is about 160 miles long and at the most 50 miles wide. Rocks that underlie the province are the Baltimore gneiss of Precambrian age and quartzite, gneiss, schist, marble, phyllite, and greenstone, which make up the Glenarm series of early Paleozoic(?) age. These are intruded by granitic, gabbroic, and ultramafic igneous rocks. Most of the ultramafic rocks, originally peridotite, pyroxenite, and dunite, have been partly or completely altered to serpentine and talc; they are all designated by the general term serpentine. The bodies of serpentine are commonly elongate and conformable with the enclosing rocks.
Construction of Pressure-Temperature Diagrams for Multicomponent Systems After the Method of Schreinemakers--A Geometric Approach
A report about the Schreinemakers method and the creation of pressure temperature diagrams for multicomponent systems.
Copper Mosses as Indicators of Metal Concentrations
A report that analyses samples of copper mosses and their substrates and compares these analyses with those published elsewhere.
Distribution and Thickness of Devonian Rocks in Williston Basin and in Central Montana and North-Central Wyoming
A report which includes 200,000 square miles in the southern part of the Williston basin of North Dakota, South Dakota, and Montana. The Devonian rocks consist mostly of marine carbonate, evaporite, and shale beds.
The Foote Creek and Dutton Creek Formations, Two New Formations in the North Part of the Laramie Basin, Wyoming
A report about two new geologic formations in Wyoming. The Foote Creek Formation consists of beds of fine-grained sandstone with shale, siltstone, and coal beds. The Dutton Creek Formation consists of beds of coarse-grained locally conglomeratic sandstone.
Geologic Reconnaissance of the Antelope-Ashwood Area North-Central Oregon
A report describing the geology of a few counties in Oregon. Strata is exposed that ranges in age from pre-Tertiary to Quaternary.
Geology and Coal Resources of the Salyersville North Quadrangle, Magoffin, Morgan, and Johnson Counties, Kentucky
From introduction: The U.S. Geological Survey has conducted investigations of the geology and coal resources of the area in and adjacent to the Salyers-ville North quadrangle in the Eastern Kentucky coal field (fig. 7). The Salyersville North quadrangle lies between lat. 3745' and 37052'30'' N., and long. 8300' and 83 07'30'' E.; it is a 71/2-minute quadrangle in the southeast quarter of the Dingus 15-minute area which also includes the Dingus, Lenox, and White Oak 7 -minute quadrangles (fig. 8). The present report is the second for the 15-minute Dingus area; a report by Adkison (1957) has been published for the White Oak quadrangle and a third report is in preparation for the Lenox quadrangle. Other published reports for quadrangles in the vicinity are those by Englund (1955) for Cannel City to the west; Bergin (1962) for Seitz to the southwest; and Hauser (1953) for Paintsville to the east.
Geology and Fluorspar Deposits, Northgate District, Colorado
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.
Geology and Mineral Deposits of the Carlile Quadrangle, Crook County, Wyoming
From introduction: Geologic mapping of the Carlile quadrangle, which includes one of several uranium-producing areas in northeastern Wyoming, was undertaken to provide a detailed geologic map that could be used as an aid to further exploration for uranium deposits; to study in detail the known uranium deposits to determine whether or not there are any relations among structure, stratigraphy, lithology, and uranium deposits; and to outline, insofar as possible, areas favorable for more detailed exploration for uranium.
Geology and Mineral Deposits of the St. Regis-Superior Area, Mineral County, Montana
From introduction: The St. Regis-Superior area was studied during the summers of 1953 and 1954 as a part of geologic investigations by the U.S. Geologic Survey in and near the Coeur d'Alene district. The object of the present work was primarily threefold: to ascertain the main structural features in the area, with particular attention to the Osburn fault zone; to investigate the mineral deposits; and to determine the stratigraphic relations of the rocks.
Geology and Uranium Deposits of the Southern Part of the Powder River Basin, Wyoming
A report about the Powder River Basin in northeastern Wyoming which is a physiographic unit bounded on the west by the Bighorn Mountains. There are sedimentary rocks which range in age from Cambrian to Oligocene.
Geology of Franklin, Webster, and Nuckolls Counties, Nebraska
A report about the Geology of three locations in Nebraska. Each location primarily are made up of Shale and chalk of Late Cretaceous age.
Geology of Part of the Craig C-2 Quadrangle and Adjoining Areas, Prince of Wales Island, Southeastern Alaska
From abstract: The area mapped is on the east coast of Prince of Wales Island, southeastern Alaska, about 35 miles northwest of the town of Ketchikan. Deposits of magnetite and copper in the mapped area and on Kasaan Peninsula, which adjoins it on the southeast, have been mined for copper and have produced more than 600,000 tons of ore valued at more than $6 million.
Geology of the Clark Fork Quadrangle Idaho-Montana
A report about the Clark Fork quadrangle which is underlain by more than 38,000 feet of low-grade metasedimentary rocks of the Precambrian Belt series. The quadrangle has both metallic and nonmetallic mineral deposits of considerable value.
Geology of the Duck Creek Pass Quadrangle Montana
A report about the Duck Creek Pass quadrangle which forms a large part of the bedrock of western Montana and adjoins other areas in which geologic studies are already completed or in progress.
Geology of the Jewel Cave Southwest Quadrangle, Custer County, South Dakota
From introduction: This study was part of the U.S. Geological Survey's continuing study of the geology and ore deposits of the southern Black Hills, which was stimulated by the discovery of uranium deposits in sandstone in the area in 1951 (Page and Redden, 1952; Bell and Bales, 1955).
Geology of the Lost Creek Schroeckingerite Deposits Sweetwater County, Wyoming
A report which presents the geologic results of an exploration program in the Lost Creek area by the U.S. Geological Survey in 1951-52 on behalf of the Division of Raw Materials of the U.S. Atomic Energy Commission.
Gold Veins Near Great Falls, Maryland
From abstract: Small deposits of native gold are present along an anastomosing system of quartz veins and shear zones just east of Great Falls, Montgomery County, Md. The deposits were discovered in 1861 and were worked sporadically until 1951, yielding more than 5,000 ounces of gold. The vein system and the principal veins within it strike a few degrees west of north, at an appreciable angle to foliation and fold axial planes in enclosing rocks of the Wissahickon Formation of late Precambrian (?) age. The veins cut granitic rocks of Devonian or pre-Devonian age and may be as young as Triassic. Further development of the deposits is unlikely under present economic conditions because of their generally low gold content and because much of the vein system lies on park property, but study of the Great Falls vein system may be useful in the search for similar deposits elsewhere in the Appalachian Piedmont.
The Helderberg Group and the Position of the Silurian-Devonian Boundary in North America
A paper that reviews the Helderberg Group and its relation to the Silurian-Devotion boundary.
Manganese Deposits in the Drum Mountains, Juab and Millard Counties, Utah
From abstract: The Drum Mountains are in west-central Utah 30 miles northwest of Delta, between the Sevier Desert on the east and Whirlwind Valley on the west. It is a typically barren desert range comprising a westward-tilted structural unit in which is exposed as much as 9,000 feet of quartzite (Cambrian and Precambrian?) and 3,000 feet of carbonate rocks of Cambrian age. These beds, which strike northward and dip west, are cut by myriad east- to northeast trending faults with displacements of a few feet to a few thousand feet. Quartz monzonite dikes, pebble dikes, and vein deposits are present locally along the faults. The Cambrian rocks are overlain unconformably by volcanic rocks of probable Tertiary age.
Minerals of Colorado: A 100-Year Record
A report about the known facts about the minerals that make up the rocks, soils, and ore deposits of Colorado.
Nomenclature and Correlation of Lithologic Subdivisions of the Jefferson and Three Forks Formations of Southern Montana and Northern Wyoming
A report about the Jefferson Formation and the Three Forks Formation. Both of them constitute a sequence of dominantly marine rocks.
Nonopaque Heavy Minerals in Sandstone of Jurassic and Cretaceous Age in the Black Hills Wyoming and South Dakota
A report about sandstone in the black hills of Wyoming and South Dakota. It discusses the nonopaque heavy minerals found within it.
Ordovician Graptolites of the Basin Ranges in California, Nevada, Utah, and Idaho
From introduction: This report presents a summary of the graptolite faunas of the Basin Ranges as known from the collections of the U.S. Geological Survey and the Departments of Geology of the University of California at Los Angeles and Utah State University. The collections were made in the period 1872-1958, but only a very small number of specimens have been described or illustrated in the 80 or so years elapsed.
Oxidized Zinc Deposits of the United States: Part 1. General Geology
From introduction: This report is intended as a descriptive summary. The fieldwork on which it is based was completed in the central Western States in 1952-56, and additional studies were made in the Central and Eastern States before and after the western studies. Research and compilation were completed in 1956-59. Other reports will describe in detail the geology and origin of the oxidized zinc deposits in Colorado, Utah, Nevada, and California. (See also Heyl and Bozion, 1960.)
Oxidized Zinc Deposits of the United States: Part 2. Utah
From introduction: This report is compiled from fieldwork and available published data on the oxidized zinc deposits of Utah. Most of the deposits were examined by the author during the autumns of 1952-55 as part of a general study of oxidized zinc deposits of the Western States. In addition, several deposits were visited by geologists of the U.S. Geological Survey as a part of mineral investigation studies since 1940. In the process of obtaining this information many mining companies and individuals have been consulted.
Oxidized Zinc Deposits of the United States: Part 3. Colorado
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.
Pecos National Monument, New Mexico: Its Geologic Setting
From introduction: The ruins of the pueblos and missions of Pecos lie on the east bank of Glorieta Creek near its junction with the Pecos River at the south end of the Sangre de Cristo Mountains in north-central New Mexico. Here the Pecos River and Glorieta Creek have formed a broad rolling valley in which the red adobe walls of the mission church stand as a striking monument to a historic past.
A Preliminary Report on the Precambrian Iron Deposits Near Atlantic City, Wyoming
A report about 100 square miles of metamorphosed Precambrian sedimentary and volcanic rocks in Wyoming. The district in which they are located is known for its gold, but iron deposits of high economic potential are being developed in the northwest part.
Strategic Graphite, A Survey
From abstract: Strategic graphite consists of certain grades of lump and flake graphite for which the United States is largely or entirely dependent on sources abroad. Lump graphite of high purity, necessary in the manufacture of carbon brushes, is imported from Ceylon, where it occurs in vein deposits. Flake graphite, obtained from deposits consisting of graphite disseminated in schists and other metamorphic rocks, is an essential ingredient of crucibles used in the nonferrous metal industries and in the manufacture of lubricants and packings. High-quality flake graphite for these uses has been obtained mostly from Madagascar since World War I. Some flake graphite of strategic grade has been produced, however, from deposits in Texas, Alabama, and Pennsylvania. The development of the carbon-bonded crucible, which does not require coarse flake, should lessen the competitive advantage of the Madagascar producers of crucible flake.
Surficial Geology of Mount Rainier National Park, Washington
From introduction: Much of the ground surface around Mount Rainier volcano is directly underlain by loose geologic deposits that veneer the hard rock formations. Examples of these deposits are sand and gravel bars along the rivers, ridges of loose rock debris beside the glaciers, and sloping aprons of rock fragments beneath almost every cliff. Even though they are generally thin and inconspicuous when compared with the rock formations, these surficial deposits are clues to geologic events that. have profoundly influenced the shape of the park's landscape. Thus, from the character and extent of glacial deposits one can judge the age and size of former glaciers that carved the cirques and deep canyons of the park; from the mudflows which streamed down nearly every valley one can infer the age and size of huge landslides of the past that helped determine Mount Rainier's present shape; and from the pumice deposits some of the volcano's recent eruptive activity can be reconstructed.
Terrestrial Impact Structures—A Biography 1965-68
A bibliography on impact structures by that supplements the U.S. Geological Survey Bulletin 1220 by citing literature published or reviewed since 1964.
Tertiary Geology and Oil-Shale Resources of the Piceance Creek Basin, Between the Colorado and White Rivers, Northwestern Colorado
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.
Tofty Tin belt, Manley Hot Springs District, Alaska
From abstract: Buried placer deposits in a belt about 8 miles long by 1 mile wide at Tofty, near Manley Hot Springs, Alaska, have yielded a few hundred tons of cassiterite as a byproduct to the recovery of several million dollars in placer gold.
Uranium-bearing Coal in the Great Divide Basin Sweetwater County Wyoming
A report about 24 townships in Wyoming which were geographically mapped. Fourteen of them contain uranium-bearing coal. There are 30 coal beds in these locations and seven of them contain the uranium-bearing coal.
Uranium Content of Ground and Surface Waters in a Part of the Central Great Plains
A report about the uranium content of water from various rock units and geologic terrains. Rocks of uranium might indicate which underground water sources contain uranium.