Geologic map of the Tanana A-1 and A-2 quadrangles, central Alaska

This report provides detailed (1:63,360-scale) mapping of the Tanana A-1 and A-2 quadrangles (500 square miles; equivalent to eight 7.5-minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the south of the Tanana B-1 Quadrangle. This report includes detailed bedrock, surficial, structural, and stratigraphic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the report also includes derivative maps of geologic construction materials and geologic hazards. The Tanana A-1 and A-2 Quadrangles and surrounding area comprise several isolated mountainous ridges in the western Yukon-Tanana Upland...

Tags: 40Ar/39Ar, Aerial Photography, Aeromagnetic Map, Aeromagnetic Survey, Age Dates, All tags... Bibliography, Biostratigraphy, CIPW Norms, Carbonates, Cerium, Clastics, Conductivity Survey, Core Logs, Cultural Resources, Depositional Environment, Diagenesis, Disseminated, Economic Geology, Economic Study, Electromagnetic Survey, Epithermal, Erosion, Faulting, Folding, Fossils, Geologic Map, Geomorphology, Geophysical Map, Glacial, Glacial Processes, Gold, Greenschist, Greisen, Historic Resources, Hot Springs, K-Ar, Lab Methods, Lode, Magnetic Susceptibility, Magnetometer Survey, Major Oxides, Manley Basin, Marine, Measured Stratigraphic Section, Metamorphic Grade, Metamorphism, Mineralogy, Mining, Modal Analysis, Niobium, Ores, Orogeny, Paleobotany, Paleocurrent, Paleoenvironment, Paleontology, Palynology, Petrogenesis, Petrography, Petrology, Placer, Plutonic, Plutonic Hosted, Precious Metals, Production Data, Provenance, Rare Earth Elements, Reconstructions, Regional, Regional Metamorphism, Remote Sensing, Resistivity Survey, Resource Assessment, Sandstone, Sedimentary, Sedimentation, Shale, Silver, Structure, Structure Map, Surficial, Tectonic Map, Tectonics, Terranes, Topographic Map, Turbidites, Type Section, Uplift, Volcanic, Volcanic Hosted, Yukon River, geoscientificInformation, Fewer tags

Interpretive geologic bedrock map of the Tanana B-1 Quadrangle, Central Alaska

This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed bedrock, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.

Tags: Aerial Photography, Aeromagnetic Survey, Age Dates, Amphibolite, Bibliography, All tags... Carbonates, Clastics, Coal, Conductivity Survey, Electromagnetic Survey, Faulting, Folding, Geologic, Geomorphology, Geothermometry, Greenschist, Hornfels, Igneous Rocks, Index Minerals, Isograds, Isotopes, K-Ar, Lode, Magnetic Susceptibility, Metamorphic Grade, Metamorphic Minerals, Metamorphism, Petrography, Plutonic, Plutonic Hosted, Precious Metals, Regional, Regional Metamorphism, Resource Assessment, Rifting, Sample Location, Sandstone, Schist, Sedimentary, Shale, Structure, Tectonics, Terranes, Uplift, Volcanic, Yukon-Tanana Terrane, geoscientificInformation, Fewer tags

Evidence for strain induced graphitization across a ductile fault zone

A suite of slate samples collected along a 2 km transect crossing the Lishan Fault in central Taiwan were evaluated to assess the role of ductile strain energy in natural graphitization at greenschist facies metamorphic conditions. Scanning electron microscope (SEM) imaging documents phyllosilicate and quartz replacement textures consistent cleavage development via dissolution-precipitation processes that increase in intensity from east to west. X-ray diffraction data reveal an east-to-west linear decrease in the full-width-at-half-maximum (FWHM) values of the 004 muscovite peaks and shifts towards higher 2θ (lower d) values. Rietveld refinements required two distinct muscovite populations and muscovite microstrain...

Categories: Data, Data Release - Under Revision; Tags: Electron Microprobe Analysis, Electron Petrography, Energy Resources, Energy Resources, Geochemistry, All tags... Graphitization, Greenschist, Raman Spectroscopy, Slate, Taiwan, Thermal Proxy, USGS Science Data Catalog (SDC), X-ray Diffraction, Fewer tags

Geology of the Grandfather Mountain Window and Vicinity, North Carolina and Tennessee

The Blue Ridge belt in northwestern North Carolina and northeastern Tennessee is composed chiefly of 1,000-million to 1,100-million-year-old metamorphic and plutonic rocks that have been thrust many miles northwestward across unmetamorphosed Cambrian(?) and Cambrian sedimentary rocks of the Unaka belt. The Blue Ridge thrust sheet is rooted on the southeast along the Brevard zone, a zone of strike-slip faulting along which metamorphic and plutonic rocks of the Inner Piedmont belt are juxtaposed with rocks of the Blue Ridge. Near the southeastern edge of the Blue Ridge belt, the Blue Ridge thrust sheet is breached by erosion, and the rocks beneath are exposed in the Grandfather Mountain window, which is 45 miles long...

Tags: Alluvial fan, Alluvium, Amphibolite, Arkose, Ashe, All tags... Avery, Basalt, Beech Granite, Blowing Rock Gneiss, Brown Mountain Granite, Burke, Caldwell, Cambrian, Carter, Chilhowee Group, Cranberry Gneiss, Diabase, Dolomite, Dolostone, Erwin Formation, Gabbro, Gneiss, Grandfather Mountain Formation, Granite, Granodiorite, Gravel, Greenschist, Hampton Formation, Johnson, Limestone, Linville Metadiabase, McDowell, Migmatite, Mineral Resources, Mitchell, Mudstone, Mylonite, North America, North Carolina, Paleozoic, Phyllonite, Proterozoic, Quartz monzonite, Quartzite, Quaternary, Rome Formation, Sandstone, Schist, Shady Dolomite, Shale, Siltstone, Structural Geology, Tennessee, Triassic, Tuff, USGS Science Data Catalog (SDC), Ultramafic intrusive rock, Unicoi Formation, United States, Volcanic ash, Watauga, Wilkes, Wilson Creek Gneiss, bedrock geologic units, building stone resources, copper, core analysis, critical minerals, earth sciences, earth structure, field sampling, folding (geologic), foliation (geologic), fracture (geologic), geologic contacts, geologic history, geologic maps, geologic structure, geology, geoscientificInformation, geospatial datasets, igneous rocks, iron, lead, lineation (geologic), lithostratigraphy, manganese, metallic mineral resources, metamorphic rocks, metamorphism (geological), microscopy, mineral resources, mineralogy, nonmetallic mineral resources, petrography, petrology, plutonic rocks, sedimentary rocks, stratigraphy, structural geology, titanium, unconsolidated deposits, uranium, volcanic rocks, zinc, Fewer tags

Geologic map of the Tanana B-1 quadrangle, central Alaska

This report provides detailed (1:63,360-scale) mapping of the Tanana B-1 Quadrangle (250 square miles; equivalent to four 7.5 minute quadrangles). The area is part of the Manley Hot Springs-Tofty mining districts and adjacent to the Rampart mining district to the north of the Tanana A-1 and A-2 Quadrangles. This report includes detailed geologic, structural, stratigraphic, and geochronologic data. Based on the resulting geologic maps, field investigations, and laboratory materials analyses, the project has also generated derivative maps of geologic construction materials and geologic hazards.

Tags: Aerial Photography, Aeromagnetic Survey, Age Dates, Amphibolite, Ar-Ar, All tags... Bibliography, C14, CIPW Norms, Carbonates, Clastics, Coal, Conductivity Survey, Conodonts, Electromagnetic Survey, Faulting, Faults, Folding, Fossils, Geologic, Geomorphology, Geothermometry, Glacial, Glacial Processes, Greenschist, Igneous Rocks, Index Minerals, Isograds, Isotopes, K-Ar, Lode, Major Oxides, Metamorphic Grade, Metamorphic Minerals, Metamorphism, Modal Analysis, Petrography, Plutonic, Plutonic Hosted, Precious Metals, Reconstructions, Regional, Regional Metamorphism, Resource Assessment, Rifting, Sample Location, Sandstone, Schist, Sedimentary, Shale, Structure, Surficial, Tectonics, Terranes, Type Section, Uplift, Volcanic, Yukon River, geoscientificInformation, Fewer tags

Database for the Geologic Map of the South Boston 30' × 60' Quadrangle, Virginia and North Carolina

The 1:100,000-scale geologic map database of the South Boston 30' × 60' quadrangle, Virginia and North Carolina, provides geologic information for the Piedmont along the I-85 and U.S. Route 58 corridors and in the Roanoke River watershed, which includes the John H. Kerr Reservoir and Lake Gaston. The Raleigh terrane (located on the eastern side of the map) contains Neoproterozoic to early Paleozoic(?) polydeformed, amphibolite-facies gneisses and schists. The Carolina slate belt of the Carolina terrane (located in the central part of the map) contains Neoproterozoic metavolcanic and metasedimentary rocks at greenschist facies. Although locally complicated, the slate-belt structure mapped across the South Boston...

Tags: 30 x 60 minute, Aaron Formation, Aarons Creek, Alkaline basalt, Allen Creek, All tags... Alluvium, Amphibolite, Argillite, Armistead Branch, Ashcake Creek, Augen gneiss, Averett, Bagleys Mills, Banister Lake, Banister River, Barnes Junction, Basalt, Baskerville, Bears Element Creek, Beaver Pond, Beaver Pond Creek, Beech Creek, Bethel Hill, Big Hounds Creek, Big Juniper Creek, Biotite gneiss, Birch Creek, Bishops Corner, Black Walnut Creek, Blackridge, Blackstone Creek, Blanes Millpond, Bluestone Creek, Bluestone Otter Creek, Bluewing Creek, Bowes Branch, Boydton, Bracey, Brodnax, Brunswick County, Buckham Creek, Buckhorn Creek, Buckskin Creek, Buffalo Creek, Buffalo Junction, Buffalo Springs, Buggs Island, Burton Branch, Butcher Creek, Cambrian, Cargills Creek, Carolina slate belt, Carolina terrane, Castle Creek, Castle Heights, Cataclasite, Catawba Creek, Cedar Creek, Cenozoic, Charlotte County, Chase City, Christie, Clarksville, Clarkton, Clays Mill, Clover, Clover Creek, Cluster Springs, Coleman Creek, Colluvium, Conglomerate, Connor Lake, Cotton Creek, Couches Creek, Country Line complex, Cox Creek, Crooked Creek, Crupper Run, Crystal Hill, Cub Creek, Cunningham complex, Dacite, Dan River, Devils Branch, Devonian, Diabase, Difficult Creek, Diorite, Dixon Millpond, Dockery Creek, Drakes Branch, Dryburg, Dudley, Dundas, Ellis Creek, Esnon, Evans Creek, Farmers Branch, Felsic gneiss, Finchley, Finnewood Creek, Finneywood, Flat Creek, Flat Rock Creek, Forksville, Formosa, Fort Mitchell, Gabbro, Gibson Creek, Gilliams Branch, Gneiss, Goodell Creek, Granite, Granitic gneiss, Granodiorite, Granville County, Grassy Creek, Great Creek, Greenschist, Gregory Corner, Hagood Creek, Halifax, Halifax County, Harmony, Hawtree Creek, Hitesburg, Holocene, Horsepen Creek, Horseshoe Lake, Hughs Lake, Hunting Creek, Hyco Formation, Hyco River, Island Creek, Island Creek Reservoir, Jeffress, Johnson Creek, Jurassic, Kenbridge, Kerr Reservoir, Kettle Creek, Kettlesticks Creek, Kits Creek, La Crosse, Lake Gaston, Lake Gordon, Langford Pond, Lawsons Creek, Layton Creek, Lennig, Little Genito Creek, Little Horsepen Creek, Little Johnson Creek, Little Juniper Creek, Little Temble Creek, Long Branch, Lunenburg, Lunenburg County, Lyle Creek, Marengo, Mason Creek, Mayo, Mayo Creek, Mayo Reservoir, Mecklenburg County, Mesozoic, Metabasalt, Metamorphic rock, Metamorphic suite of South Hill, Metasedimentary rock, Metavolcanic rock, Middle Meherrin River, Mikes Creek, Miles Creek, Mill Branch, Milton terrane, Mines Creek, Miocene, Miry Creek, Mississippian, Mitchell Creek, Monzodiorite, Monzonite, Moody Creek, Mossingford, Mount Laurel, Mountain Creek, Mylonite, Nathalie, Nelson, Neogene, Neoproterozoic, North Carolina, North Meherrin River, North View, Nutbush Creek, Nutbush Creek mylonite zone, Omega, Ontario, Ordovician, Orthogneiss, Otter Creek, Paleozoic, Palmer Crossroads, Palmer Springs, Panhandle Creek, Parham Creek, Pennsylvanian, Permian, Person County, Peter Creek, Philbeck Crossroads, Phyllonite, Piney Creek, Piney Grove, Plantersville, Pleistocene, Pliocene, Poplar Creek, Public Fork, Quartz diorite, Quartz monzonite, Quartzite, Quaternary, Rabat, Raleigh terrane, Randolph, Ready Creek, Red Bank, Red Oak, Redlawn, Reedy Creek, Reeses Creek, Rehoboth, Reynolds Creek, Rhyolite, Riverdale, Roanoke Creek, Roanoke River, Rocky Branch, Sand, Sandy Creek, Saxe, Schist, Scotts Crossroad, Scottsburg, Seay Creek, Shiny Rock, Siddon, Siltstone, Silurian, Sinai, Skipwith, Smith Creek, South Boston, South Hill, South Meherrin River, Spanish Grove, Stokes Creek, Stony Creek, Taylors Creek, Temble Creek, Terrace, The Ridge, Tonalite, Triassic, Tungsten, Twittys Creek, USGS Science Data Catalog (SDC), Union Level, Vance County, Vance pluton, Victoria, Virgilina, Virgilina Formation, Virginia, Wallace Branch, Warren County, Wightman, Winn Creek, Wolf Trap Creek, Wylliesburg, abandoned mines and quarries, bedrock geologic units, copper, earth sciences, folding (geologic), foliation (geologic), fracture (geologic), geologic contacts, geologic maps, geologic processes, geologic structure, geologic time periods, geologic time scales, geology, geoscientificInformation, geospatial datasets, information product types, inlandWaters, lithology, maps and atlases, metamorphic rocks, metamorphism (geological), mining and quarrying, place, sedimentary rocks, sedimentation, society, stratum, structural geology, structure, surficial geologic units, unconsolidated deposits, utilitiesCommunication, Fewer tags

40Ar/39Ar data from the Tok River area, Tanacross A-5 and A-6 quadrangles and adjoining areas, eastern Alaska Range

This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) geologic mapping project in the Tanacross A-5 and A-6 quadrangles and adjoining areas. Our results indicate the Hona granodiorite pluton intruded the area in the Late Cretaceous between 76 and 71 Ma. We determined Cretaceous metamorphic ages from 126 to 121 Ma for hornblende, biotite, sericite and muscovite from multiple samples of upper greenschist to amphibolite grade rocks. This is consistent with regional argon results that imply this area is in the upper plate of the Yukon Tanana Terrane (Hansen and Dusel-Bacon, 1998). Basaltic andesite dikes...

Tags: 40Ar/39Ar, Amphibolite, Analyses, Analyses and Sampling, Analytical Lab Results, All tags... Analytical Results, Basalt, Bedrock, Crystals, Exploration, Faulting, Geochronology, Geologic, Geology, Gneiss, Granite, Granodiorite, Greenschist, Hornblende, Igneous, Isotopes, Metamorphic, Metamorphic Rocks, Metamorphism, Methods, Mica, Mineral Composition, Mineral Prospect, Mineralogy, Minerals, Muscovite, Noah Prospect, Plagioclase, Plutonic, Rocks, Sample Location, Sericite, Shalosky Prospect, Tanacross Quadrangle, Tok, Tok Mining District, Tok River, geoscientificInformation, Fewer tags

Evidence for strain induced graphitization across a ductile fault zone (Under Revision)

Note: this data release is currently being revised and is temporarily unavailable. A suite of slate samples collected along a 2 km transect crossing the Lishan Fault in central Taiwan were evaluated to assess the role of ductile strain energy in natural graphitization at greenschist facies metamorphic conditions. Scanning electron microscope (SEM) imaging documents phyllosilicate and quartz replacement textures consistent cleavage development via dissolution-precipitation processes that increase in intensity from east to west. X-ray diffraction data reveal an east-to-west linear decrease in the full-width-at-half-maximum (FWHM) values of the 004 muscovite peaks and shifts towards higher 2θ (lower d) values. Rietveld...

Categories: Data, Data Release - Under Revision; Tags: Electron Microprobe Analysis, Electron Petrography, Energy Resources, Energy Resources, Geochemistry, All tags... Graphitization, Greenschist, Raman Spectroscopy, Slate, Taiwan, Thermal Proxy, USGS Science Data Catalog (SDC), X-ray Diffraction, Fewer tags