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New 1:24,000-scale geologic mapping in the Storm King Mountain7.5' quadrangle, in support of the USGS Western Colorado I-70Corridor Cooperative Geologic Mapping Project, provides new dataon the structure on the south margin of the White River upliftand the Grand Hogback and on the nature, history, anddistribution of surficial geologic units.Rocks ranging from Holocene to Proterozoic in age are shown onthe map. The Canyon Creek Conglomerate, a unit presently knownto only occur in this quadrangle, is interpreted to have beendeposited in a very steep sided local basin formed bydissolution of Pennsylvanian evaporite late in Tertiary time.At the top of the Late Cretaceous Williams Fork Formation is aunit of sandstone,...
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During 2009, the Alaska Division of Geological & Geophysical Surveys continued a program, begun in 2006, of reconnaissance mapping of surficial geology in the proposed natural-gas pipeline corridor through the upper Tanana River valley. The study area is a 12-mi-wide (19.3-km-wide) area that straddles the Alaska Highway from the western boundaries of the Tanacross B-3 and A-3 quadrangles near Tetlin Junction eastward to the eastern boundaries of the Nabesna D-1 and C-1 quadrangles along the Canada border. Mapping during 2008-2009 in the Tanacross and Nabesna quadrangles linked with the mapping completed in the Tanacross, Big Delta and Mt. Hayes quadrangles in 2006-2008. Surficial geology was initially mapped in...
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Temporal and spatial sources of silica for chert remain poorly constrained. Modern sources to the worlds oceans include silica in rivers > aeolian (dust) deposition > sea floor vents and submarine weathering. However, changes in aridity and dust flux during the Phanerozoic may explain variations in the ocean silica cycle and times and places of chert formation. The chemistry of fine quartz dust (FQD) provides a chemical mechanism for the transformation of FQD to polymorphs of silica in chert; FQD is readily dissolved, then reprecipitated as Opal-A by either biotic or abiotic processes. An unequivocal relation between increases in dust flux and biogenic opal-A in the western Pacific Ocean during the past 200 kyr...
Channel- and lens-shaped deposits of non-eolian red sandstone are enclosed within the eolian Leche-e Member of the Page Sandstone in south-central Utah. Detailed analysis of lithology and geometry, and regional correlation of the red sandstone deposits suggests that the channel-shaped scours and in-filling deposits were formed by ephemeral stream processes, in contrast to earlier interpretations that suggested a marine estuarine origin. We hypothesize that ephemeral streams transporting volcanic debris flowed toward the north and northeast along the western edge of the Page erg. Local avulsion, possibly caused by eolian damming of an adjacent drainage, led to stream flow into low areas of the Page erg. Entrainment...
Channel- and lens-shaped deposits of non-eolian red sandstone are enclosed within the eolian Leche-e Member of the Page Sandstone in south-central Utah. Detailed analysis of lithology and geometry, and regional correlation of the red sandstone deposits suggests that the channel-shaped scours and in-filling deposits were formed by ephemeral stream processes, in contrast to earlier interpretations that suggested a marine estuarine origin. We hypothesize that ephemeral streams transporting volcanic debris flowed toward the north and northeast along the western edge of the Page erg. Local avulsion, possibly caused by eolian damming of an adjacent drainage, led to stream flow into low areas of the Page erg. Entrainment...
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This data file presents 40Ar/39Ar step-heating geochronology results for a granite sample from the Livengood mining district. The Livengood area is a historically productive placer mining area approximately 80 road miles north of Fairbanks, Alaska. This data is a component of a geologic map and accompanying report that synthesizes recently collected and previously published agency and industry geologic data in a 1:50,000-scale comprehensive geologic map to build a better understanding of the geology and mineral-resource potential of the Livengood area.
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The Weldona 7.5' quadrangle is located on the semiarid plains of northeastern Colorado, along the South Platte River corridor where the river has incised into Upper Cretaceous Pierre Shale. The Pierre Shale is largely covered by surficial deposits that formed from alluvial, eolian, and hillslope processes operating in concert with environmental changes from the Pleistocene to the present. The South Platte River, originating high in the Colorado Rocky Mountains, has played a major role in shaping surficial geology in the map area, which is several tens of kilometers downstream from where headwater tributaries join the river. Recurrent glaciation (and deglaciation) of basin headwaters has affected river discharge...
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Great thicknesses of eolian dune deposits of early Oligocene age crop out in the Chuska Mountains of northwestern New Mexico-Arizona (as much as 535 m thick) and in the Mogollon-Datil volcanic field of western New Mexico-Arizona (as much as 300 m thick). 40Ar/39Ar ages of intercalated volcanic rocks indicate eolian deposition in these areas was approximately synchronous, with eolian accumulation beginning regionally at ca. 33.5 Ma and ending at ca. 27 Ma. Probable eolian sandstone of Oligocene age 483 m thick is also present in the subsurface of the Albuquerque Basin of the Rio Grande rift. The beginning of eolian deposition on the Colorado Plateau corresponds closely to the beginning of eolian (loessic) deposition...
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Alaska Division of Geological & Geophysical Surveys (DGGS) has conducted 1:63,360-scale geologic mapping of the Sagavanirktok B-1 Quadrangle (640 square km´┐Żequivalent to four 7.5 minute quadrangles). This mapping project reinterprets micropaleontologic correlations for 17 Sagavanirktok Quadrangle wells, and reprocesses data from the one publicly-available seismic line. Surface geologic mapping, subsurface-to-surface stratigraphic age control, and seismic framework are required to reliably decipher the complex geology of this key area of the Brooks Range. Outcrops within the Sagavanirktok B-1 Quadrangle are the closest surface expressions of Prudhoe Bay source and reservoir rocks. This study yields critical petroleum-related...
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This map illustrates potential near-surface sources of geologic materials that may be useful for construction and other purposes. Field observations indicate that each geologic unit (for example, flood-plain alluvium) has a definite composition or range of composition. Therefore, the presence of material type is interpreted from the distribution of geologic units (Newberry and others, 1996 - PDF96-16). Assignment of Unified Soil Classes (Wagner, 1957) is based on visual observation and interpretation of the likely distribution of the materials; no grain-size analyses were performed. Descriptions of unconsolidated deposits are modified from Pewe and Bel (1975a-d) and Pewe and Bell (1976). This map is generalized...
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The Fort Morgan 7.5' quadrangle is located on the semiarid plains of northeastern Colorado, along the South Platte River corridor where the river has incised into Upper Cretaceous Pierre Shale. The Pierre Shale is largely covered by surficial deposits that formed from alluvial, eolian, and hillslope processes operating in concert with environmental changes from the late Pliocene to the present. The South Platte River, originating high in the Colorado Rocky Mountains, has played a major role in shaping surficial geology in the map area, which is several tens of kilometers downstream from where headwater tributaries join the river. Recurrent glaciation (and deglaciation) of basin headwaters has affected river discharge...
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This map is a compilation of previously unpublished and published data, as well as from updated field mapping. This publication offers a 1:125,000-scale map sheet accompanied by a booklet containing a summary of the geology, a colored terrane map, map unit descriptions, a summary table listing selected mineral deposits and energy resources, references, and a correlation of map units. The text (in the report) describes the geology and resource potential of a highly mineralized region centered in the Farewell silver-lead-zinc district southeast of McGrath. Potentially important coal resources flanking the Alaska Range are also described in the map area.
Trends in snow acidity reflect the balance between strong acid inputs and reactions with neutralizing materials. Carbonate dust can be an important contributor of buffering capacity to snow; however, its concentration in snow is difficult to quantify because it dissolves rapidly in snowmelt. In snow with neutral or acidic pH, most calcite would dissolve during sample melting if snow samples were processed using standard techniques. Here a method is described for separating particulate carbonate matter from snow. Snow samples were melted in solutions close to saturation with calcite, decreasing the dissolution rate by a factor of 100?200 compared with natural melting of snow. Particulate matter larger than 0.45 ?m...
Diatom assemblages in sediments from two subalpine lakes in the Uinta Mountains, Utah, show asynchronous changes that are related to both anthropogenic and natural inputs of dust. These lakes are downwind of sources of atmospheric inputs originating from mining, industrial, urban, agricultural and natural sources that are distributed within tens to hundreds of kilometers west and south of the Uinta Mountains. Sediment cores were retrieved from Marshall and Hidden lakes to determine the impacts of atmospheric pollution, especially metals. Paleolimnological techniques, including elemental analyses and 210Pb and 239+240Pu dating, indicate that both lakes began receiving eolian inputs from anthropogenic sources in the...
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This 1:50,000 scale geologic map describes the distribution of unconsolidated deposits, identifies local geologic hazards, and provides information about the depositional environment and basic engineering properties of common surficial-geologic materials in and around Shaktoolik, Alaska. Map units are the result of combined field observations and aerial imagery interpretation. A suite of local ground observations were collected over a two-week period in July 2011 by a helicopter-supported team of DGGS geologists and collaborators. Field investigations included soil test pits, sample collection, soil and rock description, oblique aerial photography, and documentation of landscape morphology.
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This geologic map and report depicts portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles. The Livengood area is a historically productive placer mining area approximately 80 road miles north of Fairbanks, Alaska. This report synthesizes recently collected and previously published agency and industry geologic data in a 1:50,000-scale comprehensive geologic map to build a better understanding of the geology and mineral-resource potential of the Livengood area. It expands and updates the Alaska Division of Geological & Geophysical Surveys (DGGS) Preliminary Interpretive Report (PIR) 2004-3 with the addition of new DGGS mapping and drillhole data from ITH, and integrates previously published DGGS surficial...
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This preliminary geologic map of the Fairbanks mining district was mapped at 1:63,360 scale. The report describes the geologic setting, structural geology, earthquake potential, economic geology and the description of bedrock units.


map background search result map search result map The Chuska erg: Paleogeomorphic and paleoclimatic implications of an Oligocene sand sea on the Colorado Plateau Geologic map of the Storm King Mountain quadrangle, GarfieldCounty, Colorado Data release for the geologic map of the Weldona 7.5' quadrangle, Morgan County, Colorado Data release for the geologic map of the Fort Morgan 7.5' quadrangle, Morgan County, Colorado Preliminary Geologic Map of the Fairbanks Mining District, Alaska Preliminary Derivative Geologic Materials Map of the Fairbanks Mining District, Alaska Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska Engineering-geologic map of the Alaska Highway corridor, Tetlin Junction to Canada border, Alaska Surficial geology of the Dalton Highway (Itkillik-Sagavanirktok rivers) area, southern Arctic foothills, Alaska Geologic Map of the Eastern Half of the McGrath Quadrangle, Alaska Reconnaissance surficial-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district, Alaska Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district, Alaska Surficial geologic map of the Shaktoolik area, Norton Bay Quadrangle, Alaska USGS 1:24000-scale Quadrangle for Eolian, TX 1961 The chemistry of eolian quartz dust and the origin of chert Geologic map of the Storm King Mountain quadrangle, GarfieldCounty, Colorado Data release for the geologic map of the Weldona 7.5' quadrangle, Morgan County, Colorado Data release for the geologic map of the Fort Morgan 7.5' quadrangle, Morgan County, Colorado USGS 1:24000-scale Quadrangle for Eolian, TX 1961 Reconnaissance surficial-geologic map of the Sagavanirktok B-1 Quadrangle, eastern North Slope, Alaska Geologic map of portions of the Livengood B-3, B-4, C-3, and C-4 quadrangles, Tolovana mining district, Alaska Geologic map of the Dalton Highway (Atigun Gorge to Slope Mountain) area, southern Arctic Foothills, Alaska Surficial geology of the Dalton Highway (Itkillik-Sagavanirktok rivers) area, southern Arctic foothills, Alaska Surficial geologic map of the Shaktoolik area, Norton Bay Quadrangle, Alaska The Chuska erg: Paleogeomorphic and paleoclimatic implications of an Oligocene sand sea on the Colorado Plateau Preliminary Geologic Map of the Fairbanks Mining District, Alaska Preliminary Derivative Geologic Materials Map of the Fairbanks Mining District, Alaska Geologic Map of the Eastern Half of the McGrath Quadrangle, Alaska Engineering-geologic map of the Alaska Highway corridor, Tetlin Junction to Canada border, Alaska The chemistry of eolian quartz dust and the origin of chert