Filters: Tags: igneous (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 Wypych, Alicja Layer, P.W. Freeman, L.K. Benowitz, J.A. Gillis, R.J. More... Tag Types Theme (16) Place (16) Tag Schemes Alaska Division of Geological & Geophysical Surveys (16) ISO 19115 Topic Category (16) View Results as: JSON ATOM CSV

Major-oxide and trace-element geochemical data from rocks collected in 2010 in the Tyonek Quadrangle, Alaska 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 Preliminary bedrock geologic map data for the eastern Bonnifield mining district, Fairbanks and Healy quadrangles, Alaska Mineral Resources Section personnel from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a geologic field survey, including mapping and sampling, in the eastern part of the Bonnifield mining district in the Fairbanks A-1 and A-2 and the Healy D-1 and D-2 quadrangles, Alaska, from June 16 through July 18, 2008. The fieldwork provides basic information critical to building an understanding of Alaska's geology and is part of an integrated program of airborne geophysical surveys followed by geologic mapping. Specifically, this work provides geologic context for geophysical surveys conducted in 2006. Interpretation and synthesis of this data has been presented in professional and trade meetings.... Tags: Alaska Range, Bedrock, Chute Creek, Dry Creek, Dry Creek prospect, All tags... Fairbanks Quadrangle, Geologic, Geology, Glory Creek, Glory Creek prospect, Healy Quadrangle, Igneous, Igneous Rocks, Kansas Creek, Minerals, Red Mountain Creek, Rocks, Rogers Creek, STATEMAP Project, Sedimentary Rocks, Sheep Creek, Slide Creek, Snow Mountain Gulch, WTF (Western Tundra Flats) prospect, Wood River, geoscientificInformation, Fewer tags Geology of Kasatochi volcano, Aleutian Islands, Alaska Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The... Tags: Active Volcanoes, Age Dates, Aleutian Arc, Aleutian Islands, Alluvial Deposits, All tags... Analyses, Analyses and Sampling, Basalt, Bedrock, Bedrock Geology, Caldera, Chemistry, Colluvium, Erosion, Fan, Geochemical Data, Geochemistry, Geochronology, Geologic, Geologic Hazards, Geologic Map, Geological Process, Geology, Geomorphology, Hazards, Historic Eruption, Igneous, Kasatochi, Lava Flow, Mineralogy, Petrographic, Petrography, Petrology, Pumice, Pyroclastics, Rockfall, Rocks, Sample Location, Slope Instability, Slump, Soils, Surface, Surficial, Talus, Tephra, Topography, Ultramafic, Uplift, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Rocks, Volcaniclastics, Volcanoes, Volcanology, geoscientificInformation, Fewer tags Zircon U-Pb and 40Ar/39Ar results from dikes collected within the Bruin Bay fault zone, lower Cook Inlet 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 Major-oxide and trace-element geochemistry of mafic rocks in the Carboniferous Lisburne Group, Ivishak River area, northeastern Brooks Range, Alaska 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 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 Zircon U-Pb and 40Ar/39Ar results from dikes collected within the Bruin Bay fault zone, lower Cook Inlet This data release presents 40Ar/39Ar step-heating geochronology results from rocks collected roughly 7 km southwest of Contact Point, Iliamna B-3 Quadrangle. Samples obtained from a felsic dike intruding the principal Bruin Bay fault plane near Contact Point produced biotite and plagioclase 40Ar/39Ar ages of 36.5 +/- 0.8 Ma and 31.5+/-0.7 Ma, respectively. The age dates inform stratigraphic, structural, and geochronologic studies along the western margin of lower Cook Inlet basin. The accompanying report also presents zircon U-Pb LA-ICP-MS geochronology results for dikes near Ursus Head. 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, Plagioclase, Rocks, Sample Location, Stratigraphy, Structural Geology, Structure, Tectonics, U-Pb, Uranium, Ursus Head, Volcanic, Volcanic Rocks, Zircon, geoscientificInformation, Fewer tags Major-oxide and trace-element geochemical data from rocks collected in 2015 in lower Cook Inlet, Iniskin - Tuxedni region, Alaska The Iniskin-Tuxedni Bay area contains excellent exposures of nearly all of the lower Cook Inlet Mesozoic succession, including most of the stratigraphic sections that define the interval and the petroleum source rocks that comprise the basin. An underdeveloped understanding of the Mesozoic petroleum system has led the Alaska Department of Natural Resources' Division of Geological & Geophysical Surveys and Division of Oil and Gas, and the U.S. Geological Survey to collaborate on a multi-year project that includes two major mapping campaigns. Geologic mapping between Chinitna Bay and the Johnson River during the 2015 field season encompassed volcanic arc rocks northwest of the Bruin Bay fault system, and Mesozoic... Tags: Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, Chemistry, All tags... Chitina, Cook Inlet, Geochemical Data, Geochemistry, Geology, Igneous, Igneous Rocks, Iliamna, Kenai, Lab Methods, Magmatic Arc, Major Oxides, Minor Oxides, STATEMAP Project, Sample Location, Trace Elements, Volcanic, Volcanic Arc, Volcanic Rocks, geoscientificInformation, Fewer tags Geologic map of Mount Chiginagak volcano, Alaska Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south-southwest of King Salmon, Alaska. This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks. The eruptive products of Chiginagak volcano record a history of chiefly andesite lava flows and associated block-and-ash flows. The oldest lavas exposed are Pleistocene in age and are found everywhere around the edifice except in the northeast sector, where Holocene lava flows dominate the landscape. Holocene activity has covered the northeast flank with rubbly-topped andesite lava flows that extend as far as 4.6 km from their source vent at the summit... Tags: Alaska Peninsula, Aleutian Range, Analyses, Chiginagak, Gas, All tags... Geochemistry, Geochronology, Geologic, Geology, Hazards, Igneous, Lahar, Mount Chiginagak, Neoglacial, Pumice, Rocks, Sediment, Sulfur, Surface, Surficial, Tephra, Ugashik Quadrangle, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Gas, Volcanic Rocks, Volcaniclastic Deposits, Volcaniclastics, Volcanoes, Volcanology, Water, geoscientificInformation, Fewer tags Major-oxide, minor-oxide, and trace-element geochemical data from rocks collected in 2008 in the eastern Bonnifield mining district, Fairbanks and Healy quadrangles, Alaska Mineral-resources personnel from the Alaska Division of Geological & Geophysical Surveys carried out a geological field survey, including mapping and sampling, in the eastern part of the Bonnifield mining district in the Fairbanks A-1 and A-2, and the Healy D-1 and D-2 quadrangles, Alaska, from June 16 through July 18, 2008. The fieldwork provides basic information critical to building an understanding of Alaska's geology and is part of an integrated program of airborne geophysical surveys followed by geological mapping. Specifically, this work provides geologic context for geophysical surveys conducted in 2006. To represent a typical lithology, igneous or possible meta-igneous samples were collected and analyzed... Tags: Alaska Range, Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, All tags... Bedrock, Bedrock Geology, Chemistry, Chute Creek, Dry Creek, Fairbanks Quadrangle, Geochemical Data, Geochemical Surveys, Geochemistry, Geologic, Geology, Healy Quadrangle, Igneous, Igneous Rocks, Kansas Creek, Lab Methods, Metamorphic Rocks, Methods, Mineral Assessment, Mineralogy, Minerals, Red Mountain Creek, Resource Assessment, Resource Information, Resources, Rocks, Rogers Creek, STATEMAP Project, Sample Location, Sheep Creek, 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 ages of rocks collected from the Passage Canal area, Seward D-7 Quadrangle, Alaska This report presents 40Ar/39Ar step-heating geochronology results from a single outcrop of a mineralized near-trench intrusion exposed in a road cut near Whittier, Alaska. The outcrop is the best road-accessible occurrence of a Tertiary near-trench pluton in the region and is commonly visited by field trips, yet no prior geochronological data from this outcrop have been published. Two chronologically distinct intrusive bodies, the Paleogene Sanak-Baranof belt and the Eshamy-suite, are documented in the upper Cook Inlet area. Geochronological analysis of the two samples described in this report confirms that the Whittier road-cut intrusion and veins are coeval (53.0 +/- 0.3 Ma and 50.9 +/- 0.2 Ma, respectively) with... Tags: 40Ar/39Ar, Age Dates, Analyses, Analyses and Sampling, Analytical Lab Results, All tags... Analytical Results, Ar-Ar, Bedrock, Bedrock Geology, Geochronology, Geologic, Geology, Igneous, Igneous Rocks, Isotopes, Lab Methods, Methods, Mineralogy, Rocks, Sample Location, Seward Quadrangle, Volcanic Arc, Volcanic Rocks, Whittier, geoscientificInformation, Fewer tags Major-oxide and trace-element geochemical data from rocks collected near Panorama Mountain, Mile 104 Seward Highway, Crow Pass, and Whittier, Alaska In conjunction with hosting field trips for the Association of American State Geologists 2016 annual meeting in Girdwood, Alaska, Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected rock samples and obtained geochemical analysis from several readily accessible, but relatively unstudied outcrops. Samples were collected from Turnagain Arm (mile 104 Seward Highway), Whittier, Crow Pass, and Panorama Mountain (roughly mile 217 Parks Highway). Mineralized samples from veins and veinlets in granitic rocks from the Crow Pass and Whittier sites contain anomalous levels of gold ranging from 0.129 to 0.650 parts per million (ppm). Although none of the samples are from areas open to mineral entry, geochemical... Tags: Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, Base Metals, All tags... Bedrock, Bedrock Geology, Chemistry, Economic Geology, Exploration, Geochemical Data, Geochemical Surveys, Geochemistry, Geologic, Geologic Map, Geology, Gold, Gold Prospect, Heavy Metals, Igneous, Igneous Rocks, Lab Methods, Magmatic Arc, Major Oxides, Metallogenesis, Metals, Mineral Assessment, Mineral Deposit, Mineral Development, Mineral Localities, Mineral Prospect, Mineral Resources, Mineralogy, Minerals, Mining, Minor Oxides, Ore Deposit, Ores, Petrology, Plutonic, Plutonic Hosted, Plutonic Rocks, Plutons, Precious Metals, Resource Assessment, Resource Information, Resources, Sample Location, Southcentral Alaska, Trace Elements, Trace Geochemical, Trace Metals, Whittier, geoscientificInformation, Fewer tags Geologic map of Mount Chiginagak volcano, Alaska Mount Chiginagak is a hydrothermally active volcano on the Alaska Peninsula, approximately 170 km south-southwest of King Salmon, Alaska. This small stratovolcano, approximately 8 km in diameter, has erupted through Tertiary to Permian sedimentary and igneous rocks. The eruptive products of Chiginagak volcano record a history of chiefly andesite lava flows and associated block-and-ash flows. The oldest lavas exposed are Pleistocene in age and are found everywhere around the edifice except in the northeast sector, where Holocene lava flows dominate the landscape. Holocene activity has covered the northeast flank with rubbly-topped andesite lava flows that extend as far as 4.6 km from their source vent at the summit... Tags: Alaska Peninsula, Aleutian Range, Analyses, Chiginagak, Gas, All tags... GeMS NCGMP09, Geochemistry, Geochronology, Geologic, Geology, Hazards, Igneous, Lahar, Mount Chiginagak, Neoglacial, Pumice, Rocks, Sediment, Sulfur, Surface, Surficial, Tephra, Ugashik Quadrangle, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Gas, Volcanic Rocks, Volcaniclastic Deposits, Volcaniclastics, Volcanoes, Volcanology, Water, geoscientificInformation, Fewer tags Geology of Kasatochi volcano, Aleutian Islands, Alaska Kasatochi is a small, isolated island volcano in the center of the Aleutian Island chain. It consists of a roughly circular cone approximately 3 km in diameter with a lake-filled central crater that is 1.2 km in diameter and extends from the highest point on the island to sea level. The oldest unit recognized is a thick series of mid-Pleistocene glaciovolcanic deposits consisting of autobrecciated lava, lahars, and volumetrically minor lava masses that we believe to have been emplaced underneath a regional ice cap. This unit is unconformably overlain by several massive Holocene lavas, above which lies a thick sequence of latest-Holocene pyroclastic deposits likely deposited during the crater-forming eruption. The... Tags: Active Volcanoes, Age Dates, Aleutian Arc, Aleutian Islands, Alluvial Deposits, All tags... Analyses, Analyses and Sampling, Basalt, Bedrock, Bedrock Geology, Caldera, Chemistry, Colluvium, Erosion, Fan, Geochemical Data, Geochemistry, Geochronology, Geologic, Geologic Hazards, Geologic Map, Geological Process, Geology, Geomorphology, Hazards, Historic Eruption, Igneous, Kasatochi, Lava Flow, Mineralogy, Petrographic, Petrography, Petrology, Pumice, Pyroclastics, Rockfall, Rocks, Sample Location, Slope Instability, Slump, Soils, Surface, Surficial, Talus, Tephra, Topography, Ultramafic, Uplift, Volcanic, Volcanic Ash, Volcanic Eruption, Volcanic Rocks, Volcaniclastics, Volcanoes, Volcanology, geoscientificInformation, Fewer tags Major-oxide and trace-element geochemical data from rocks collected near Panorama Mountain, Mile 104 Seward Highway, Crow Pass, and Whittier, Alaska In conjunction with hosting field trips for the Association of American State Geologists 2016 annual meeting in Girdwood, Alaska, Alaska Division of Geological & Geophysical Surveys (DGGS) staff collected rock samples and obtained geochemical analysis from several readily accessible, but relatively unstudied outcrops. Samples were collected from Turnagain Arm (mile 104 Seward Highway), Whittier, Crow Pass, and Panorama Mountain (roughly mile 217 Parks Highway). Mineralized samples from veins and veinlets in granitic rocks from the Crow Pass and Whittier sites contain anomalous levels of gold ranging from 0.129 to 0.650 parts per million (ppm). Although none of the samples are from areas open to mineral entry, geochemical... Tags: Analyses, Analyses and Sampling, Analytical Lab Results, Analytical Results, Base Metals, All tags... Bedrock, Bedrock Geology, Chemistry, Economic Geology, Exploration, Geochemical Data, Geochemical Surveys, Geochemistry, Geologic, Geologic Map, Geology, Gold, Gold Prospect, Heavy Metals, Igneous, Igneous Rocks, Lab Methods, Magmatic Arc, Major Oxides, Metallogenesis, Metals, Mineral Assessment, Mineral Deposit, Mineral Development, Mineral Localities, Mineral Prospect, Mineral Resources, Mineralogy, Minerals, Mining, Minor Oxides, Ore Deposit, Ores, Petrology, Plutonic, Plutonic Hosted, Plutonic Rocks, Plutons, Precious Metals, Resource Assessment, Resource Information, Resources, Sample Location, Southcentral Alaska, Trace Elements, Trace Geochemical, Trace Metals, Whittier, geoscientificInformation, Fewer tags