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Cook Inlet has been recognized as the second-largest petroleum province in Alaska, second only to the North Slope. The south-central Tyonek Quadrangle is an area of significant geologic interest because it is the only location in Cook Inlet where the entire producing stratigraphy of the basin is exposed on the surface. Additionally, this area encompasses the structural boundary between the forearc basin and its sediment source rocks. To better understand the petroleum system and the geologic relationships between the exhumed arc intrusive rocks and adjacent Cenozoic stratigraphy of the Cook Inlet forearc basin, during the summer of 2010 the Alaska Division of Geological & Geophysical Surveys conducted a federally-funded...
Tags: Alaska Range,
Analyses,
Analyses and Sampling,
Analytical Lab Results,
Analytical Results, All tags...
Bedrock,
Bedrock Geology,
Chemistry,
Cook Inlet,
Cook Inlet Basin,
Exploration,
Geochemical Data,
Geochemical Surveys,
Geochemistry,
Geology,
Igneous,
Igneous Rocks,
Lab Methods,
Magmatic Arc,
Major Oxides,
Minor Oxides,
Neacola Mountains,
Petrology,
Resources,
Rocks,
STATEMAP Project,
Sample Location,
Tordrillo Mountains,
Trace Elements,
Trace Geochemical,
Tyonek,
Tyonek Quadrangle,
Volcanic,
Volcanic Arc,
Volcanic Rocks,
geoscientificInformation, Fewer tags
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A physiographically prominent, approximately 40 square km plateau lies roughly 20 km east of Mount Spurr volcano, northwestern Cook Inlet region, Alaska, and comprises the preserved remnant of a volcaniclastic succession, designated in this study as map unit Qvc. Although this readily mappable package of volcaniclastic rocks has been recognized in numerous studies during the past five decades, uncertainties regarding its age and origin have persisted. We describe the general characteristics of the volcaniclastic plateau, provide new age constraints for deposits, present lithofacies descriptions and interpretations of the volcaniclastic strata, and synthesize our observations and lithofacies analysis to propose an...
Tags: Age Dates,
Alluvial,
Alluvial Deposits,
Bedrock,
Bedrock Geology, All tags...
Capps Glacier,
Debris Flow,
Debris Flow Deposit,
Depositional Environment,
Depositional Environments,
Detrital Zircon,
Facies Analysis,
Geochronology,
Geological Process,
Geology,
Lahar,
Lahar Runout Flow,
Liquefaction,
Mount Spurr,
Paleoenvironment,
Paleogeography,
STATEMAP Project,
Sediment Transport,
Sedimentary,
Sedimentary Rocks,
Sedimentation,
Sedimentology,
Tyonek Quadrangle,
U-Pb,
Volcaniclastics,
geoscientificInformation, Fewer tags
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This data release presents zircon U-Pb LA-ICP-MS geochronology from igneous rocks exposed in a coastal exposure at Ursus Head, Iliamna C-2 Quadrangle. Sills and dikes exposed in a coastal exposure at Ursus Head are deformed within the Bruin Bay fault zone. Common dikes intruding late Triassic Kamishak Formation strata composing the hanging-wall of the Bruin Bay fault are cut by numerous small-scale, low-angle, bedding-parallel, and high angle contractional faults. Sample 09MAW006A collected from one of many dikes deformed in the fault zone produced a uni-modal distribution of zircon ages of with a weighted mean of 206.92 +/-0.96 (2 sigma, n=47) and an MSWD of 1.1. Sample 09BG020C collected from a sill of more mafic...
Tags: 40Ar/39Ar,
Age Dates,
Analyses,
Analyses and Sampling,
Analytical Lab Results, All tags...
Analytical Results,
Ar-Ar,
Bedrock,
Bedrock Geology,
Contact Point,
Cook Inlet,
Cook Inlet Basin,
Fault Displacement,
Geochronology,
Geologic,
Geology,
Igneous,
Iliamna Quadrangle,
Isotopes,
Lab Methods,
Lead,
Methods,
Naknek,
Plagioclase,
Rocks,
Sample Location,
Stratigraphy,
Structural Geology,
Structure,
Tectonics,
U-Pb,
Uranium,
Ursus Head,
Volcanic,
Volcanic Rocks,
Zircon,
geoscientificInformation, Fewer tags
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The Alaska Division of Geological & Geophysical Surveys, in collaboration with the University of Alaska Fairbanks, collected mafic rocks in the Ivishak River area of the northeastern Brooks Range during summer 2009 for geochemical sampling. The sampled rocks, including lava flows, sills, and limy volcaniclastic strata, crop out within the carbonate-platform succession of the Carboniferous Lisburne Group. Refer to Herriott and others (2011) for additional information regarding the geologic and geographic context of these samples, preliminary implications of the geochemical data presented here, and a summary of known mafic rock occurrences in the Arctic Alaska terrane. The analytical data tables associated with this...
Tags: Analyses and Sampling,
Brooks Range,
Geochemical Data,
Geochemistry,
Igneous, All tags...
Igneous Rocks,
Ivishak River,
Major Oxides,
Sagavanirktok Quadrangle,
Trace Elements,
geoscientificInformation, Fewer tags
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The 1:63,360 Kavik River geologic map area consists of ~620 square miles and ties together previous DGGS mapping in the Sadlerochit and Shublik Mountains area of the western Arctic National Wildlife Refuge (ANWR) on the east and the structurally complex foothills and mountain front near the Kemik gas accumulation on the west. The map area exposes a unique intersection of North Slope stratigraphy where all three major depositional megasequences are mappable in close association (Ellesmerian, Beaufortian, and Brookian).
Tags: Arctic National Wildlife Refuge,
Canning River,
Fin Creek,
Geologic,
Geologic Map, All tags...
Geology,
Juniper Creek,
Kavik River,
Mount Michelson Quadrangle,
North Slope,
North Slope Basin,
Oil and Gas Basin,
Rock Units,
STATEMAP Project,
Sedimentary,
Sedimentary Rocks,
Sedimentation,
Sedimentology,
Seismic Profile,
Structural Geology,
Structure,
Structure Map,
geoscientificInformation, Fewer tags
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