40Ar/39Ar data from rocks collected in the 2015 Wrangellia mineral assessment project area, Mount Hayes A-5, Mount Hayes B-6, and Talkeetna Mountains D-2 quadrangles, Alaska

This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) Wrangellia Mineral Assessment project, part of a multi-year effort focusing on improving the publicly available geoscientific information for the western Wrangellia terrane. The samples described in this report were selected and analyzed to improve our understanding of the geology and structural history of the Wrangellia Mineral Assessment project area. A metagabbro rock sample returned a Late Triassic crystallization age consistent with regional ages for Nikolai Greenstone-related magmatism; however, the two amphibole separates ages do not overlap,...

Tags: 40Ar/39Ar, Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, All tags... Ar-Ar, Basalt, Bedrock, Bedrock Geology, Copper, Crystals, Geochronology, Geologic, Geology, Greenstone, Hayes, Hornblende, Igneous, Igneous Rocks, Interpretation, Lab Methods, Methods, Mica, Mineral Composition, Mineral Resources, Mineralogy, Minerals, Mount Hayes Quadrangle, Muscovite, Plutonic Rocks, Porphyry, Resources, Rocks, Sample Location, Strategic Minerals, Strategic and Critical Minerals Assessment Project, Stratigraphy, Structural Geology, Talkeetna, Talkeetna Mountains, Talkeetna Mountains Quadrangle, Thrust, Volcanic Rocks, geoscientificInformation, Fewer tags

Top Mesozoic unconformity subcrop map, Cook Inlet basin, Alaska

This map shows the subcrop pattern of the Mesozoic rock units present at the top Mesozoic unconformity (also commonly referred to as the base Tertiary unconformity) in Cook Inlet basin, Alaska. The subcrop is projected onto the top Mesozoic unconformity depth surface of Cook Inlet basin, Alaska, published by Shellenbaum and others (2010). Publicly available geologic and geophysical data from multiple sources were collected, interpreted, and integrated into the subcrop map. Formation picks at the top Mesozoic unconformity were determined for 109 wells. Mesozoic horizons from two regional marine two-dimensional (2-D) seismic datasets (approximately 3,300 miles) were interpreted. Eight map units were established for...

Tags: Anchorage, Anchorage Quadrangle, Bedrock Geologic Map, Bedrock Geology, Bibliography, All tags... Biostratigraphy, Cook Inlet, Cook Inlet Basin, Core Logs, Correlation, Depth Interpretation, Drill Logs, Drilling, Energy, Energy Resources, Folds, Forearc Basin, Geologic, Geologic Map, Geology, Geophysical Logs, Geophysics, Gis, Homer, Hydrocarbon, Hydrocarbon Potential, Igneous Rocks, Iliamna Quadrangle, Iniskin Bay, Inoceramus, Interpretation, Kenai, Kenai Peninsula, Kenai Quadrangle, Lake Clark Quadrangle, Matanuska River, Matanuska Valley, Metamorphic Rocks, Mount Katmai Quadrangle, Oil Basins, Oil and Gas, Oil and Gas Basin, Palmer, Palynology, Petroleum, Petroleum Basin Study, Port Graham, Reservoir, Resources, Rock Units, Saddle Mountain, Sedimentary Rocks, Seismic Interpretation, Seldovia, Seward, Seward Quadrangle, Source Rock, Southcentral Alaska, Stratigraphy, Strike-Slip, Structural Geology, Structure, Structure Contours, Structure Map, Subsurface, Surface, Susitna River, Talkeetna Mountains Quadrangle, Talkeetna Quadrangle, Thrust, Tuxedni Bay, Tyonek, Tyonek Quadrangle, Unconformity, Volcanic Rocks, Wasilla, Well Logs, geoscientificInformation, Fewer tags

Active and potentially active faults in or near the Alaska Highway corridor, Dot Lake to Tetlin Junction, Alaska

In 2005, the Alaska Division of Geological & Geophysical Surveys initiated a multi-year geologic field study focused on a corridor centered along the Alaska Highway between Delta Junction and the Canada border. The purpose of this project is to provide geologic information relevant to a proposed Alaska-Canada natural gas pipeline and other future development in the corridor. The scope of this project includes identification of active faults and characterization of seismic hazards. During the 2008 field season the active fault studies were focused on the central part of the corridor between Dot Lake and Tetlin Junction. Field studies included helicopter and fixed-wing air reconnaissance augmented by interpretation...

Tags: Active Fault, Alaska Highway Corridor, C14, Dot Lake, Earthquake, All tags... Faulting, Faults, Gasline, Geologic Hazards, Proposed Natural Gas Pipeline, Robertson River, Strike-Slip, Structural Geology, Structure, Tanacross, Tanacross Quadrangle, Taylor Highway, Tectonics, Tetlin, Thrust, Tok, Tok River, Transportation Corridor, geoscientificInformation, Fewer tags

Active and potentially active faults in or near the Alaska Highway corridor, Delta Junction to Dot Lake, Alaska

During the 2006 and 2007 field seasons, geologic features indicative of possible youthful surface faulting in or near the Alaska Highway corridor between Delta Junction and Dot Lake were identified by helicopter and fixed-wing air reconnaissance, augmented by interpretation of stereo air photos, remotely sensed images, and aeromagnetic and electromagnetic (EM) datanction to the eastern boundary of the Mt. Hayes Quadrangle. The largest of these faults is the previously unrecognized Dot "T" Johnson fault, a major west-trending, south-dipping thrust fault bordering the northern margin of the Alaska Range along the south side of the Tanana River valley. Two other faults identified as active in this study, the Canteen...

Tags: Alaska Highway Corridor, Alaska Pipeline, Big Delta, Big Delta Quadrangle, C14, All tags... Delta Junction, Delta River, Dot Lake, Faulting, Faults, Geologic Hazards, Mount Hayes Quadrangle, Strike-Slip, Structural Geology, Structure, Tanana River, Thrust, Transportation Corridor, Fewer tags