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Twenty-two igneous and metamorphic rock samples were collected in a 20-km-long swath centered on the Alaska Highway between Tetlin Junction, Alaska, and the Canada border. Igneous and metamorphic rock samples were submitted to the Apatite to Zircon, Inc. laboratory (A2Z), where zircon U-Pb age analysis, using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), was performed by Paul O'Sullivan. The 15 felsic plutonic rock samples and one gabbro sample yield Cretaceous zircon U-Pb weighted-mean ages ranging from 95.7 Ma to 106.2 Ma. Zircons from a metadiorite yield a Triassic weighted-mean age of about 241.9 Ma. Metamorphic zircons from two samples with felsic igneous protoliths yield Mississippian...
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This dataset is intended to provide seamless, integrated geologic mapping of the U.S. Intermountain West region as a contribution to The National Geologic Map supported by the National Cooperative Geologic Mapping Program of the U.S. Geological Survey. Surficial and bedrock geology are included in this data release as independent datasets at a variable resolution from 1:50,000 to 1:250,000 scale. No original interpretations are presented in this dataset; rather, all interpretive data are assimilated from referenceable publications. Derivative polygon features created for this dataset demonstrate the distribution of SIGMa-GeMS Geologic Provinces derived from the distribution of map units. Initial contributions to...
The geology of an area of 660 square miles mostly in the northeastern corner of Tennessee and small adjacent areas in Virginia and North Carolina is the subject of this report. The region lies principally in the Unaka province, with extensions northwestward into the Appalachian Valley and southwestward into the Blue Ridge province. The report combines results of surveys made between 1941 and 1953 by the U. S. Geological Survey, the Tennessee Division of Geology, and the Tennessee Valley Authority, and is published in cooperation with the Tennessee Division of Geology. Northeasternmost Tennessee is a region of widespread mineralization and was formerly important for mineral production. Iron, manganese, and bauxite...
Tags: Abingdon, Alluvium, Andesite, Argillite, Arkose, All tags...
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This U.S. Geological Survey (USGS) data release provides monazite and xenotime geochronology from Proterozoic rocks collected from outcrop in central Colorado and whole rock isotope geochemistry, and zircon and monazite geochronology from a Proterozoic rock sampled from a drill core from western Colorado. The drill core sample was collected from the 1 Paradox Valley injection core near Bedrock, CO at a depth of 4,755-4,765 m below the surface. The samples were in order to constrain the age, provenance, metamorphic history, and geochemical character of basement terranes in Colorado.
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Aerial view northwest toward Horn Creek Rapids, river mile 90.9, showing numerous pegmatite and granite dikes in black Vishnu Schist. Inner canyon is 1,300 feet deep here.
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Aerial view south and downriver from river mile 211.9 toward a Precambrian “island” of schist (photographs WM07, WM08, WM09) during the basal Cambrian sea encroachment, right bank of river mile 212.5.
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The Preliminary Interpretive Report 2004-3B, "Bedrock geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska," is the bedrock geologic map of an approximately 123-square-mile area in the central Livengood Quadrangle, Alaska.
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The Fortymile electromagnetic and magnetic airborne geophysical survey data were acquired with a DIGHEM-V Electromagnetic (EM) system and a cesium magnetometer. The EM and magnetic sensors were flown at a height of 30 meters (m). In addition the survey recorded data from radar and laser altimeters, a GPS navigation system, 50/60 Hz monitors and a video camera. Flights were performed with an AS-350-B2 Squirrel helicopter at a mean terrain clearance of 60 m along N-S survey flight lines with a spacing of 400 m. Tie lines were flown perpendicular to the flight lines at intervals of approximately 4,800 m
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This data set contains boundaries and tags for major geologic units in Alaska, Hawaii, Puerto Rico and the U.S. Virgin Islands. In addition to the polygons representing the areal extent of geologic units, it identifies major faults and continental glaciation in Alaska. The data depict the geology of the bedrock that lies at or near the land surface, but not the distribution of surficial materials such as soils, alluvium, and glacial deposits. This map complements the Generalized Geologic Map of the Conterminous United States by Reed and Bush. The data are generalized from a compilation prepared for use in the Geologic Map of North America, published as a paper map by the Geological Society of America and...
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View northwest toward southeast side of Precambrian Zoroaster Granite “island” of Cambrian seaway, onlapped by Cambrian Tapeats Sandstone, from Tonto Trail, south of river mile 85.1.
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Overview This directory was developed to provide discovery information for anyone looking for publicly accessible repositories that house geological materials in the U.S. and Canada. In addition, this resource is intended to be a tool to facilitate a community of practice. The need for the directory was identified during planning for and follow-up from a drill core repository webinar series in Spring 2020 for public repository curators and staff in the U.S. and Canada hosted by the Minnesota Geological Survey and the Minnesota Department of Natural Resources. Additional supporting sponsors included the U.S. Geological Survey National Geological and Geophysical Data Preservation Program and the Association of American...
Categories: Data; Types: Downloadable, Map Service, OGC WFS Layer, OGC WMS Layer, Shapefile; Tags: Alabama, Alaska, Alberta, Arkansas, British Columbia, All tags...
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The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi.org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic...
Categories: Data, Data Release - Revised; Types: ArcGIS REST Map Service, ArcGIS Service Definition, Downloadable, Map Service; Tags: Alabama, Arizona, Arkansas, California, Colorado, All tags...
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We report U-Pb zircon geochronology results for one metavolcanic and one metaplutonic rock sample from the Mount Hayes A-6 Quadrangle of central Alaska. These samples are representative of rock units assigned to the Clearwater terrane of Jones and others (1987), a sequence of greenschist-grade metavolcanic and metasedimentary rocks of poorly constrained age and tectonic origin. Our results indicate a crystallization age of 277.33 +/- 11.84 Ma for a felsic metavolcanic rock, and a 268.05 +/- 11.64 Ma crystallization age for a granitic metaplutonic unit intruding the former.
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Re-analyses of sample pulps and bulk rejects from historic USBM rock and heavy-mineral-concentrate samples were conducted by the Alaska Division of Geological & Geophysical Surveys (DGGS) as part of the State of Alaska's Strategic and Critical Minerals Assessment project, which is designed to evaluate Alaska's potential for these resources. The objective of this resource assessment is to expand the state's geochemical database by obtaining and publishing modern, quantitative geochemical analyses for historic USBM samples, where available. Highlights of this re-analysis project include heavy mineral concentrates with up 7,220 ppm Sn, 5,870 ppm Cr, and 17,000 ppm Mn.
Tags: Aluminum, Antimony, Arsenic, Barium, Basalt, All tags...


map background search result map search result map Generalized Geologic Map of the United States The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States Fortymile mining district electromagnetic and magnetic airborne geophysical survey, data compilation Bedrock geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska Analyses of historic U.S. Bureau of Mines rock and heavy mineral concentrate samples for geochemical trace-element and rare-earth element data--Ray Mountains and Kanuti-Hodzana uplands area, Alaska Zircon U-Pb age data, Alaska Highway Corridor, Tanacross and Nabesna quadrangles, Alaska U-Pb zircon age data from meta-igneous rocks in the Clearwater Mountains, Mount Hayes A-6 Quadrangle, Alaska CM01. View southwest and downriver toward Vishnu Schist CM05. Black river-polished amphibolitic schist EM04. Pegmatite dikes in schist EM13. View northwest toward southeast side of Precambrian Zoroaster Granite “island” of Cambrian seaway EM22. Aerial view northwest toward Horn Creek Rapids EM26. River-polished Vishnu Schist WM02. View west toward granite rocks from Hundred and Ninety Mile canyon WM04. View southeast and downriver toward metamorphic rocks with granitic dikes WM06. Aerial view south and downriver toward a Precambrian “island” of schist Directory of Public Repositories of Geological Materials Data release of monazite and xenotime geochronology for Proterozoic rocks in central Colorado and monazite and zircon geochronology and whole-rock isotope geochemistry fo a Proterozoic drill core sample from western Colorado Seamless Integrated Geologic Map Database of the Intermountain West: Contributions to The National Geologic Map U-Pb zircon age data from meta-igneous rocks in the Clearwater Mountains, Mount Hayes A-6 Quadrangle, Alaska Bedrock geologic map of the Livengood SW C-3 and SE C-4 quadrangles, Tolovana mining district, Alaska Fortymile mining district electromagnetic and magnetic airborne geophysical survey, data compilation Analyses of historic U.S. Bureau of Mines rock and heavy mineral concentrate samples for geochemical trace-element and rare-earth element data--Ray Mountains and Kanuti-Hodzana uplands area, Alaska Zircon U-Pb age data, Alaska Highway Corridor, Tanacross and Nabesna quadrangles, Alaska Seamless Integrated Geologic Map Database of the Intermountain West: Contributions to The National Geologic Map The State Geologic Map Compilation (SGMC) Geodatabase of the Conterminous United States Directory of Public Repositories of Geological Materials Generalized Geologic Map of the United States