Geology and U-Pb zircon geochronology and Pb isotope geochemistry of mid-Cretaceous plutonic rocks in the Mount Nansen map area (NTS 115I/3 and part of 115I/2)
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The geology in the Mount Nansen area, of the Dawson Range, comprises a metamorphic basement overlain and intruded by mid and Late Cretaceous magmatic rocks. Mid-Cretaceous epithermal deposits are recognized in the Brown-McDade cluster in the south, and Late Cretaceous porphyry and epithermal occurrences in the centrally located Klaza cluster. Here we report eight new U-Pb zircon crystallization ages, two CA-TIMS and six LA-ICPMS, and Pb isotopic data for igneous feldspar from six samples. A 199.06 ± 0.96 Ma crystallization age demonstrates the host rock to the Brown-McDade deposit is the Late Triassic to Early Jurassic Minto suite. We report crystallization ages of 111 ± 1.8 Ma for the Dickson Hill porphyry, 107.96 ± 0.03 and 107.86 ± 0.03 Ma for the central and border phases of the Bow Creek granite, respectively, and 107.0 ± 0.72, 107.0 ± 0.78 and 107.5 ± 0.67 Ma for equigranular and porphyritic phases of the Dawson Range granodiorite. These ages confirm a mid-Cretaceous Whitehorse suite affinity for these rocks with porphyritic textures suggesting high-level emplacement. Feldspar Pb isotopic data of igneous rocks in the Mount Nansen area become more radiogenic with time and are distinct for Late Triassic to Early Jurassic plutonic rocks versus Cretaceous rocks. Cretaceous feldspar isotopic data broadly overlaps Pb isotopic values of galena from deposits throughout the Dawson Range suggesting coeval magmatic rocks are a significant source of metals.
Zircon U-Pb geochronology and whole rock geochemistry for pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado
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This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data and zircon U-Pb geochronology and trace element concentrations for samples from pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado. Samples were collected in order to constrain the evolution of the pre-ignimbrite magmatic system.
Zircon U-Pb geochronology and whole rock geochemistry for pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado
공공데이터포털
This U.S. Geological Survey (USGS) data release provides whole rock major, minor, and trace element geochemical data and zircon U-Pb geochronology and trace element concentrations for samples from pre-ignimbrite volcanoes within the San Juan locus of the mid-Cenozoic Southern Rocky Mountain volcanic field, Colorado. Samples were collected in order to constrain the evolution of the pre-ignimbrite magmatic system.
U-Pb Isotopic Data and Ages of Detrital Zircon Grains, Whole Rock Major and Trace-element Geochemistry, and Whole Rock Isotopic Data from Selected Rocks from the Western Alaska Range, Medfra area, and Livengood area, Alaska
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This data release contains 3 datasets, U-Pb isotopic data and associated ages of detrital zircon grains for 27 sedimentary rocks, whole rock major and trace-element geochemistry for 15 igneous or phosphatic rock samples, and whole rock Sr, Nd, and Pb isotopic data for 6 igneous rock samples. The samples were collected from multiple localities across Alaska as part of geological mapping and research conducted between 1974 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey.
U-Pb Isotopic Data and Ages of Detrital Zircon Grains, Whole Rock Major and Trace-element Geochemistry, and Whole Rock Isotopic Data from Selected Rocks from the Western Alaska Range, Medfra area, and Livengood area, Alaska
공공데이터포털
This data release contains 3 datasets, U-Pb isotopic data and associated ages of detrital zircon grains for 27 sedimentary rocks, whole rock major and trace-element geochemistry for 15 igneous or phosphatic rock samples, and whole rock Sr, Nd, and Pb isotopic data for 6 igneous rock samples. The samples were collected from multiple localities across Alaska as part of geological mapping and research conducted between 1974 and 2014 and funded by the Mineral Resources Program of the U.S. Geological Survey.