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Environmental Geochemical Studies of Selected Mineral Deposits in Wrangell-St. Elias National Park and Preserve, Alaska

Description: From abstract: Environmental geochemical investigations took place in Wrangell-St. Elias National Park and Preserve (WRST), Alaska, between 1994 and 1997. Areas studied include the historic Kennecott stratabound copper mines and mill area; the historic mines and mill in the Bremner district, where gold was produced from polymetallic veins; the sporadically active gold placer mines at Gold Hill; the undisturbed, unmined porphyry copper-molybdenum deposits at Orange Hill and Bond Creek; and the historic mines and mill at Nabesna, where gold-bearing iron skarn deposits were exploited. The cooperative study between the U.S. Geological Survey and the National Park Service focused on identifying and characterizing geochemical signatures associated with these mineralized areas. Sample media included surface water, bedload sediment, rock, mine waste, and mill tailings samples.
Date: 2000
Creator: Eppinger, Robert G.; Briggs, Paul H.; Rosenkrans, Danny S. & Ballestrazze, Vanessa
Partner: UNT Libraries Government Documents Department

Mafic and Ultramafic Xenoliths from Volcanic Rocks of the Western United States

Description: From abstract: Mafic and ultramafic xenoliths in the Western United States are present in volcanic rocks ranging from lamprophyric to dacitic in composition and are found in every major tectonic province from the Coast ranges from California to the Great Plains. Xenoliths from 68 localities are described here, but new localities are being discovered, and much remain to be learned about their distribution with respect to the tectonic and geophysical framework of the Western United States.
Date: 1988
Creator: Wilshire, Howard Gordon; Meyer, C. E.; Nakata, John K.; Calk, L. C.; Shervais, John W.; Nielson, J. E. et al.
Location Info:
Partner: UNT Libraries Government Documents Department

Quaternary Movement Along the La Jencia Fault, Central New Mexico

Description: From abstract: The La Jencia fault is a recently reactivated late Cenozoic basin margin structure of major proportions that forms the western margin of the Rio Grande rift, which borders the eastern sides of the northern Magdalena Mountains and the southern Bear Mountains in central New Mexico. Stratigraphic throw on the fault has not been determined, but Precambrian rocks of the Magdalena Mountains are uplifted a minimum of 800 m (meters) above the adjacent basin floor, below which lie a thick section of upper Cenozoic basin-fill deposits. Most of the implied displacement is probably Neogene in age.
Date: 1988
Creator: Machette, Michael N.
Partner: UNT Libraries Government Documents Department

Deposits of Pre-1980 Pyroclastic Flows and Lahars from Mount St. Helens Volcano, Washington

Description: From introduction: This report describes the character, origin, age, and extent of deposits of pyroclastic flows and lahars that were formed at Mount St. Helens before 1980, and their stratigraphic relations to other rocks and deposits of volcanic and glacial origin.
Date: 1987
Creator: Crandell, Dwight Raymond
Partner: UNT Libraries Government Documents Department

Runoff Characteristics and Washoff Loads from Rainfall-Simulation Experiments on a Street Surface and a Native Pasture in the Denver Metropolitan Area, Colorado

Description: Abstract: Rainfall simulation studies were conducted in conjunction with the Denver Regional Urban Runoff Program to: (1) Compare runoff quantity and quality from two different intensities of rainfall on impervious plots having identical antecedent conditions, (2) document a first flush of constituent loads in runoff from 1,000-square-foot streetsurface plots, (3) compare runoff characteristics from a street surface subjected to simulated rainfall with those from a 69-acre urban basin of mixed land use subjected to natural rainfall, (4) perform statistical analysis of constituent loads in the runoff with several independent variables, and (5) compare the quantity and quality of runoff from 400-square-foot plots of native grasses used for pasture and subjected to simulated rainfall with that from a 405-acre basin covered with native grasses used for pasture and sub-jected to natural rainfall. The rainfall simulations conducted on the street surface showed that higher intensity simulated rainfall produced a higher percentage of runoff than lower intensity rainfall. A first flush of constituent loads occurred for most constituents in the runoff from most rainfall simulations on the street surface; however, a first flush did not occur in the runoff from simulated rainfall on the pasture. The event mean concentrations of constituents in the runoff from simulated storms on the street surface were generally much smaller than the event mean concentrations of constituents in the runoff from an adjacent urban basin. Analysis of the data from the rainfall simulations on a street surface indicates that intensity of rainfall and total rainfall are important variables determining constituent loads. The design of the experiment was such that intensity of rainfall and total rainfall were highly correlated, thus precluding the development of useful regression equations to predict washoff loads. The quality of runoff from the simulated rainfall on the pasture was influenced by the disturbed perimeters of ...
Date: 1987
Creator: Mustard, Martha H.; Ellis, Sherman R. & Gibbs, Johnnie W.
Partner: UNT Libraries Government Documents Department

Some Middle Cenomanian (Upper Cretaceous) Acanthoceratid Ammonites from the Western Interior of the United States

Description: Abstract: The ammonite family Acanthoceratidae de Grossouvre is represented in the Western Interior region by many genera. Species and subspecies of Calycoceras, Acanthoceras, Cunningtoniceras, Plesiacanthoceras, and Protacanthoceras are important guide fossils to narrow zones of middle Cenomanian age in southeastern Montana, northeastern Wyoming, western South Dakota, and central Kansas. In this region, the ammonite zonation through most of the middle Cenomanian seems to be, from oldest to youngest, a zone of Acanthoceras muldoonense Cobban and Scott, a zone of Acanthoceras bellense Adkins and Calycoceras leonense (Adkins), a zone of Cunningtoniceras amphibolum (Morrow) with subzones of C. amphibolum amphibolum and C. amphibolum fallense (n. subsp.), and a zone of Plesiacanthoceras wyomingense (Reagan). In this report, Acanthoceras muldoonense, A. bellense, and Calycoceras leonense are described from the northern part of the Western Interior for the first time. Cunningtoniceras amphibolum, originally assigned to Acanthoceras, is described in more detail and divided into the nominate subspecies and the new subspecies C. amphibolum fallense. The earliest whorls of Plesiacanthoceras wyomingense, previously unknown, are described as well as all the later growth stages. The small genus, Protacanthoceras, is represented by several new species and one new subspecies. Protacanthoceras fisheri is found in the zone of Acanthoceras bellense, P. vetula occurs in the subzone of Cunningtoniceras amphibolum amphibolum, and P. hosei hosei and P. hosei sheridanense are found in the subzone of C. amphibolum fallense. Protacanthoceras alzadense is associated with Plesiacanthoceras wyomingense.
Date: 1987
Creator: Cobban, William Aubrey
Partner: UNT Libraries Government Documents Department

A Descriptive Catalog of Selected Aerial Photographs of Geologic Features in the United States

Description: From introduction: The U.S. Geological Survey has selected and assembled sets of photographs that illustrate numerous types of geologic features in the United States. This catalog lists these special sets of photographs that are available for purchase and describes the features illustrated. One reduced photograph from each set is shown on the back pages of this catalog to assist the purchaser in his selection.
Date: 1968
Creator: Geological Survey (U.S.)
Partner: UNT Libraries Government Documents Department

Geologic Studies, Project Gnome, Eddy County, New Mexico

Description: From abstract: For Project Gnome, part of the Plowshare Program to develop peaceful uses for nuclear energy, a nuclear device was detonated December 10, 1961, underground in rack salt of the Permian Salado Formation southeast of Carlsbad, New Mexico. The Geological Survey's investigations on behalf of the U.S. Atomic Energy Commission provided basic geologic and geophysical information needed to define preshot and postshot geologic and hydrologic conditions at and near the site. This report describes the geology of the site, some physical and chemical properties of the rocks, and the known effects of the nuclear detonation on the rocks of the site.
Date: 1968
Creator: Gard, Leonard Meade, Jr.
Partner: UNT Libraries Government Documents Department

Stratigraphy of Outcropping Permian Rocks in Parts of Northeastern Arizona and Adjacent Areas

Description: From introduction: In the spring and early summer of 1950 the writers undertook an investigation of the outcropping Permian rocks in northeastern Arizona, northwestern New Mexico, and parts of southern Utah. This work had as its specific objective the establishing of correlations of Permian rocks in the Zuni uplift, Defiance uplift, and Monument Valley upwarp. The determination of these relations, it is believed, will be of aid in the current activities of the Geological Survey in the Navajo Reservation which have as objectives the investigation of the mineral fuels and water resources of the area.
Date: 1961
Creator: Read, C. B. & Wanek, Alexander A.
Partner: UNT Libraries Government Documents Department

Geology of the southern Guadalupe Mountains, Texas

Description: From Abstract: "This report deals with an area of 425 square miles in the western part of Texas, immediately south of the New Mexico line. The report describes the geology of the area, that is, the nature of its rocks, tectonics, and surface features, and the evidence that they give as to the evolution of the area through geologic time. Incidental reference is made to the geology of surrounding regions in order to place the area in its environment."
Date: 1948
Creator: King, Philip B.
Partner: UNT Libraries Government Documents Department

Shorter Contributions to General Geology, 1936

Description: From abstract: This report describes four species of Ostreidae from the Upper Cretaceous of the Gulf region. The zones that the species characterize lie either in the upper part of the Austin chalk or in beds of upper Austin age.
Date: 1940
Creator: Loughlin, G. F.
Partner: UNT Libraries Government Documents Department

The Flora of the New Albany Shale: Part 1. Diichnia Kentuckiensis, a New Representative of the Calamopityeae

Description: Abstract: A new genus of the Cycadofilicales, Diichnia, is described from the New Albany shale, of late Devonian age, in central Kentucky. The one known species, which is based on stem material showing internal structure, belongs in the family Calamopityeae. Foundation for the generic segregation is seen in the double leaf truce of the genotype, D. kentuckiensis, in contrast with the originally single trace in other known representatives of the family.
Date: 1936
Creator: Read, Charles B.
Partner: UNT Libraries Government Documents Department

Pre-Cambrian Rocks of the Lake Superior Region: A Review of Newly Discovered Geologic Features, with a Revised Geologic Map

Description: From abstract: Detailed knowledge of the geology of the pre-Cambrian rocks of the Lake Superior region has been greatly augmented since the publication of Monograph 52 by the United States Geological Survey in 1911. The authors have attempted in the present report to assemble as much of this new information as possible, and to give the reader a birdseye view of the geology as seen in the light of all studies made there up to the present time. Detailed descriptions are not presented, and the emphasis is placed upon the major problems of correlation. A revised map of the region, with cross sections, accompanies the report, bringing up to date a knowledge of the areal geology of the region, which otherwise could be gained only by consulting some 150 maps contained in almost as many separate local reports, many of which are unpublished.
Date: 1935
Creator: Leith, C. K.; Lund, Richard Jacob & Leith, Andrew
Partner: UNT Libraries Government Documents Department

Miocene Foraminifera of the Coastal Plain of the Eastern United States

Description: From introduction: In the following report the species of Foraminifera found in the Miocene of the Coastal Plain region of the eastern United States from Florida to Maryland are described and recorded. Numerous papers have been published on this region, some of which, however, are largely lists. Where the original material on which a paper was based has not been available for the present study, the records have been omitted, as it is very difficult to place the species in their proper position without seeing the actual specimens.
Date: 1933
Creator: Cushman, Joseph A. & Cahill, Edgar D.
Partner: UNT Libraries Government Documents Department

Origin of the Anhydrite Cap Rock of American Salt Domes

Description: From abstract: The thesis of this paper is that the anhydrite cap rock of salt domes originated by the residual accumulation and consolidation, on top of a salt stock, of sedimentary anhydrite freed from the salt by solution of the top of the stock. This hypothesis is compared with that of origin from a bed of sedimentary anhydrite supposed to have overlain the salt of the salt stock in depth and to have been forced up on top of the stock as it rose. The strongest basis for the hypothesis of residual accumulation is the presence, between the anhydrite cap rock and the top of the salt stock on many salt domes, of a flat solution surface, the "salt table," decapitating anhydrite-bearing folds in the salt. The paper considers other general geologic evidence and internal petrographic evidence with a view to ascertaining to what extent they confirm or at least fit this interpretation.
Date: 1933
Creator: Goldman, Marcus I.
Partner: UNT Libraries Government Documents Department

Gold Quartz Veins of the Alleghany District, California

Description: From Outline of the Report: The Alleghany district, in the southern part of Sierra County, Calif., has long been famous for the high-grade gold ore of its quartz veins. The oldest rocks of the district (pp. 6-17) are of sedimentary and volcanic origin and correspond to part of the Calaveras formation as mapped in the Colfax and Downieville folios of the Geologic Atlas of the United States. These rocks are divided into five formations, of which three-the Blue Canyon, Relief, and Cape Horn formations follow the definitions laid down by Lindgren in the Colfax folio, and two-the Tightner and Kanaka formations-are new units required by the more detailed nature of the present study. It is thought possible that a conglomerate which forms the basal part of the Kanaka formation is of glacial origin. Intrusions of gabbro and more basic rocks, the latter now completely serpentinized, crop out over nearly half the area in which pre-Tertiary rocks are exposed. Small granitic dikes of later age than the basic intrusives are found in the western part of the district. Overlying and largely concealing the older rocks are auriferous gravel of Eocene and Miocene age, andesitic breccia of probable Miocen age, basalt flows of probable Pleistocene age, and minor amounts of Pleistocene and Recent gravel.
Date: 1932
Creator: Ferguson, Henry G. & Gannett, Roger W.
Partner: UNT Libraries Government Documents Department

Geology of the Big Snowy Mountains, Montana

Description: From introduction: The main purpose of the field investigations on which this paper is based was to determine the structure of the mountains. The geologic formations were therefore studied, and sufficient data were obtained to construct a combined areal and structural map.
Date: 1931
Creator: Reeves, Frank
Partner: UNT Libraries Government Documents Department

Glaciation in Alaska

Description: From introduction: The history of glaciation in Alaska offers a fascinating field for study. Because of the remarkable development and easy accessibility of valley and piedmont glaciers in the coastal mountains, Alaska has long been popularly conceived as a land of ice and snow, a concept that is only slowly being corrected. To the student of glaciation, however, Alaska affords a unique opportunity to observe the formation, movement, and dissipation of the many living glaciers, to examine the results of glacial erosion on a gigantic scale, and to discover and work out the sequence of Pleistocene events as shown by the topographic forms in both glaciated and unglaciated areas and by the deposits left by ice and water during earlier stages of glaciation.
Date: 1931
Creator: Capps, Stephen R.
Partner: UNT Libraries Government Documents Department