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

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

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

Core fragment descriptions, Exxon core holes, uplands bordering Yukon Flats basin, east-central Alaska

This Raw Data File provides lithologic descriptions of core fragments recovered from a series of core holes drilled by Exxon (mid-80s) in the uplands bordering the Yukon Flats basin. In addition to descriptions of the material, the tabulated file includes geographic location, core hole numbers, an age estimate, core fragment depth, general lithology, grain size, and facies interpretation. The author examined these core materials in Fairbanks during winter and spring 2002. This work was done in preparation for an assessment carried out by the U.S. Geological Survey of undiscovered, technically recoverable hydrocarbon resources in the Yukon Flats basin.

Tags: Alaska, State of, Beaver Quadrangle, Bedrock, Bedrock Geology, Black River Quadrangle, All tags... Charley River Quadrangle, Circle Quadrangle, Clastics, Clay, Coal, Coleen Quadrangle, Conglomerate, Core Drilling, Drilling, Eagle Quadrangle, Energy, Energy Resources, Exploration, Exploration Well, Facies Analysis, Gas, Gas Basins, Geologic Materials, Geology, Grain Size, Hydrocarbon, Hydrocarbon Potential, Kandik Basin, Livengood Quadrangle, Oil Basins, Oil Development, Oil and Gas, Oil and Gas Basin, Petroleum, Petroleum Basin Study, Resource Assessment, Resource Information, Resources, Sandstone, Sedimentary, Sedimentary Rocks, Shale, Stratigraphy, Yukon Basin, Yukon Flats, Yukon River, 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

Bedrock Core Information System

The Bedrock Core Information System interactive map illustrates important reference information about 1,155 cores in the IGWS bedrock core archive at a glance, including the spatial location, IGWS reference number, total depth below the land surface captured by the core, top bedrock unit penetrated and depth to the top of that unit, and bottom bedrock unit penetrated and depth to the bottom of that unit.

Categories: Web Site; Tags: Bedrock geology, Drill cores, Indiana (IN), Stratigraphic geology, ndc_collection