Filters: Tags: Metamorphism (X) > partyWithName: Alaska Division of Geological & Geophysical Surveys (X)

Filters Date Range Past year (0) Past month (0) Past week (0) Past day (0) Custom range... To   Search Contacts Benowitz, J.A. Layer, P.W. State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys Metadata manager Naibert, T.J. More... Tag Types Theme (3) Place (3) Tag Schemes Alaska Division of Geological & Geophysical Surveys (2) None (1) ISO 19115 Topic Category (3) View Results as: JSON ATOM CSV

Geologic map of the Circle mining district, Alaska This report provides detailed (1:63,360-scale) mapping of portions of U.S. Geological Survey Circle B-2 (1955), B-3 (1955), B-4 (1952), C-2 (1955), C-3 (1955), and C-4 (1952) quadrangles. The area is part of the Circle mining district and adjacent to the Fairbanks mining district. 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: Aereal, Aerial Photography, Aeromagnetic Survey, Age Dates, Alaska, State of, All tags... Alluvial Deposits, Alluvium, Amphibolite, Ar-Ar, Bedrock, Bibliography, Birch Creek, C14, Carbonates, Circle Hot Springs, Circle Mining District, Circle Quadrangle, Clastics, Coal, Colluvial Deposits, Colluvium, Conductivity Survey, Conodonts, Crooked Creek, Electromagnetic Survey, Fan, Faulting, Faults, Fluvial, Folding, Fossils, Geologic, Geomorphology, Glacial, Glacial Deposits, Glacial Drift, Granite, Hornblende, Hornfels, Igneous Rocks, K-Ar, Magnetite, Major Oxides, Mammoth Creek, Mastodon Dome, Metamorphic Grade, Metamorphic Minerals, Metamorphism, Mineralogy, Modal Analysis, Petrography, Plutonic, Plutonic Hosted, Porphyry, Precious Metals, Quartz, Regional, Regional Metamorphism, Sample Location, Sandstone, Schist, Sedimentary, Structure, Surficial, Tectonics, Terranes, geoscientificInformation, 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 40Ar/39Ar data from rocks collected in 2013 in the Wrangellia mineral assessment area, Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles, Alaska This DGGS report presents 40Ar/39Ar age dating results from selected mafic to intermediate intrusions encountered during a geological and geochemical resource assessment project in the Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles. Three intrusions returned mid-Cretaceous crystallization ages, while one olivine gabbro returned a Late Triassic crystallization age. Two altered or metamorphosed samples yielded Late Jurassic and Early Cretaceous ages. Analyses were performed by the University of Alaska Fairbanks Geochronology Laboratory, and results were reported by Paul Layer and Jeff Benowitz. Products included in this data release are: a summary of sample collection method; the laboratory report,... Tags: 40Ar/39Ar, Age Dates, Amphitheater Mountains, Analyses, Analyses and Sampling, All tags... Analytical Lab Results, Analytical Results, Ar-Ar, Bedrock, Bedrock Geology, Geochronology, Geology, Gulkana Quadrangle, Healy Quadrangle, Lab Methods, Metamorphism, Mineral Assessment, Mineral Deposit, Mineral Resources, Mount Hayes Quadrangle, Platinum Group Elements, Sample Location, Skarn, Strategic and Critical Minerals Assessment Project, Talkeetna Mountains Quadrangle, geoscientificInformation, Fewer tags