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Mineral-resources geologists from the Alaska Division of Geological & Geophysical Surveys (DGGS) carried out a helicopter-supported geological and geochemical resource assessment project in the Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles from July 29 through August 16, 2013. The objectives of this assessment were to improve the publicly-available geological, geophysical, and geochemical data in the area of known occurrences in the Mount Hayes Quadrangle, and to extend this coverage and any gained insight westward into the less-explored extension of the Wrangellia terrane. This program of stream-sediment, pan-concentrate, and rock sampling was conducted as part of the State's Strategic Minerals...
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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...
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This report provides a digital version of the Geologic map of theStillwater Complex, Montana originally published by N. Page andW. Nokleberg (1974). Paper copies of the four geologic mapsheets from the original report were scanned and initiallyattributed by Optronics Specialty Company (Northridge, CA) andremitted to the U.S. Geological Survey for further attributionand publication of the geospatial digital files. The resultingdigital geologic dataset can be queried in a geographicinformation system (GIS) in many ways to produce a variety ofgeological maps.
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Naturally occurring asbestos (NOA) develops in predictable geologic settings worldwide. Various geologic units throughout Alaska include rock types that could potentially host naturally occurring asbestos minerals. This report and digital data release show geologic map units throughout Alaska rated according to their interpreted potential to host NOA. To summarize locations of known asbestos occurrences, we searched the U.S. Geological Survey's (USGS's) Alaska Resource Data File (http://ardf.wr.usgs.gov) and Mineral Resource Data System (http://mrdata.usgs.gov/mineral-resources/mrds-ak.html) for references to asbestos in Alaska and compiled the resulting 62 documented asbestos occurrences. To better predict additional...
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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...
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Late Triassic mafic to ultramafic intrusions in the Wrangellia terrane are host to magmatic sulfide nickel-copper-cobalt and platinum-group element (PGE) mineralization. DGGS's mineral-resources group carried out a geologic mapping project in the eastern Denali Highway region between Watana Creek and Paxson from July 29 through August 7, 2015. This project is part of a multi-year effort focusing on improving the publicly available geological and geochemical data and assessing the mineral potential of the less-explored extension of the western Wrangellia terrane; other data resulting from this project include geophysical surveys and several geochemical datasets. This program of geologic mapping and rock sampling...
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The State of Alaska's Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project, is designed to evaluate Alaska's statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data throughout Alaska. In 2014 and 2015 DGGS also collected and geochemically analyzed 114 rock samples from mafic and ultramafic rocks to evaluate the Tonsina area's potential for platinum-group elements, nickel, and chromium; analytical results are presented in this report.


    map background search result map search result map Geologic map of the Stillwater Complex, Montana: a digital database Geology of Kasatochi volcano, Aleutian Islands, Alaska Geology of Kasatochi volcano, Aleutian Islands, Alaska Major-oxide, minor-oxide, and trace-element geochemical data from rocks and stream sediments in the Wrangellia mineral assessment area, Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles, Alaska Major-oxide and trace-element geochemical data from rocks collected in 2015 in the Wrangellia mineral assessment area, Alaska Geochemical analyses of rock samples from the Tonsina area, Valdez Quadrangle, Alaska Preliminary evaluation of bedrock potential for naturally occurring asbestos in Alaska Geology of Kasatochi volcano, Aleutian Islands, Alaska Geology of Kasatochi volcano, Aleutian Islands, Alaska Geologic map of the Stillwater Complex, Montana: a digital database Major-oxide and trace-element geochemical data from rocks collected in 2015 in the Wrangellia mineral assessment area, Alaska Major-oxide, minor-oxide, and trace-element geochemical data from rocks and stream sediments in the Wrangellia mineral assessment area, Gulkana, Healy, Mount Hayes, and Talkeetna Mountains quadrangles, Alaska Preliminary evaluation of bedrock potential for naturally occurring asbestos in Alaska