Filters: partyWithName: Alaska Division of Geological & Geophysical Surveys (X) > partyWithName: Benowitz, J.A. (X) > partyWithName: Twelker, Evan (X)

Filters Date Range Past year (0) Past month (0) Past week (0) Past day (0) Custom range... To   Search Contacts Layer, P.W. Wypych, Alicja Tag Types Theme (3) Place (3) Tag Schemes Alaska Division of Geological & Geophysical Surveys (3) ISO 19115 Topic Category (3) View Results as: JSON ATOM CSV

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 40Ar/39Ar data from the Talkeetna Mountains C-4 Quadrangle and adjoining areas, central Alaska This report presents 40Ar/39Ar step-heating geochronology results for igneous and metamorphic rocks from the Alaska Division of Geological & Geophysical Surveys' (DGGS) Talkeetna Mountains C-4 Quadrangle and Adjoining Areas geologic mapping project. Hornblende-bearing gabbro returned a Late Triassic crystallization age consistent with regional results for Nikolai Greenstone-related magmatism. We determined Early Jurassic metamorphic ages for hornblende and sericite from two samples of upper greenschist to amphibolite grade metavolcanic rocks. Our results indicate that a granodiorite pluton intruding Wrangellia in the study area has a Middle Jurassic age consistent with the Talkeetna Arc, indicating that the Wrangellia... Tags: 40Ar/39Ar, Age Dates, Analyses, Analyses and Sampling, Analytical Lab Results, All tags... Analytical Results, Ar-Ar, Bedrock, Bedrock Geology, Geochronology, Geology, Lab Methods, Plutonic Rocks, Plutons, STATEMAP Project, Sample Location, Strategic and Critical Minerals Assessment Project, Talkeetna Mountains Quadrangle, Volcanic, Volcanic Arc, Volcanic Rocks, 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