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This report describes the results of geologic mapping and sample analysis from the Richardson district, east-central Alaska.
Tags: Age Dates,
Ar-Ar,
Big Delta Quadrangle,
CIPW Norms,
Fluid Inclusion, All tags...
Geobarometry,
Geochemical Data,
Geochronology,
Geothermometry,
Major Oxides,
Microprobe Analysis,
Modal Analysis,
Richardson Mining District,
Trace Elements,
geoscientificInformation, Fewer tags
This map is the result of field investigations by DGGS in 1997 and 1998. This geologic map and report supersede the previously released Public Data File 99-24B, Preliminary interpretive bedrock geologic map of the Healy A-6 Quadrangle, southcentral Alaska. The current map has been updated to include mapping of areas adjacent to the Healy A-6 Quadrangle, newly interpreted bedrock units based on newly acquired analytical, paleontologic, and Ar40/Ar39 data. Ages for the rock units were modified. Field investigations were part of a two-year mapping program to provide geologic ground truth for airborne geophysical surveys flown by DGGS in the Chulitna region of southcentral Alaska during 1996.
Tags: 40Ar/39Ar,
Alaska, State of,
Ar-Ar,
Bedrock,
Chulitna, All tags...
Geology,
Gold,
Healy Quadrangle,
Major Oxides,
Mining,
Plutons,
STATEMAP Project,
Southcentral Alaska,
geoscientificInformation, Fewer tags
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
This map is the result of field investigations by DGGS in 1997 and 1998. This geologic map and report supersede the previously released Public Data File 99-24B, Preliminary interpretive bedrock geologic map of the Healy A-6 Quadrangle, southcentral Alaska. The current map has been updated to include mapping of areas adjacent to the Healy A-6 Quadrangle, newly interpreted bedrock units based on newly acquired analytical, paleontologic, and Ar40/Ar39 data. Ages for the rock units were modified. Field investigations were part of a two-year mapping program to provide geologic ground truth for airborne geophysical surveys flown by DGGS in the Chulitna region of southcentral Alaska during 1996.
Tags: 40Ar/39Ar,
Alaska, State of,
Ar-Ar,
Bedrock,
Chulitna, All tags...
Geology,
Gold,
Healy Quadrangle,
Major Oxides,
Mining,
Plutons,
STATEMAP Project,
Southcentral Alaska,
geoscientificInformation, Fewer tags
40Ar/39Ar data from seven plutonic samples and one metamorphic sample collected during mineral assessment studies in 1991 show that various rock units in the Selawik Hills plutonic complex were emplaced in the order syenite/monzonite (nonfoliated, 106.6 ± 0.8 Ma; foliated, 101.7 ± 0.7 Ma; both on hornblende), followed by nepheline syenite (103.7 ± 0.8 Ma on hornblende) and then quartz monzonite (100.4 ± 3.7 Ma on biotite). 40Ar/39Ar data from Granite Mountain hornblendes yielded ages slightly older, but overlapping, those from Selawik Hills. In this suite, the silica-undersaturated phase appears to be younger (105.7 ±0.8 Ma) than the silica-saturated phase(s) (106.8 ± 0.8 Ma and 107.1 ± 0.8 Ma).
Tags: 40Ar/39Ar,
Age Dates,
Analytical Results,
Ar-Ar,
Candle Quadrangle, All tags...
Geochronology,
Granite,
Granite Mountain,
Hornblende,
Igneous Rocks,
Plutonic Rocks,
Selawik Quadrangle, Fewer tags
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
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