40Ar/39Ar data, Seward Peninsula, Alaska
공공데이터포털
This Alaska Division of Geological & Geophysical Surveys (DGGS) Raw Data File presents 40Ar/39Ar age dating results for a volcanic whole-rock sample, selected minerals from various metamorphic rocks and igneous dikes, and white mica from both metamorphic- and hydrothermal-mineralization-related veins encountered on the southern Seward Peninsula, as well as select minerals from one plutonic rock from Cape Denbeigh, eastern Norton Sound, Alaska. Cooling ages on glaucophane, barroisite, amphibole, paragonite, and biotite from metamorphic rocks range from 84 Ma to 209 Ma. The cooling age of white mica in a possible fault zone is 144 Ma. Cooling ages on late-stage metamorphic minerals (winchite and white mica) from veins cutting foliation in metamorphic rocks range from 117 Ma to 139 Ma. Cooling ages on white mica and adularia from hydrothermal mineralization-related veins range from 105 to 131 Ma. The cooling age for one highly alkalic dike is 107 Ma. Cooling ages for younger mafic dikes range from 80 Ma to 84 Ma. The preferred age on a whole-rock sample of basalt is 0.780 +/- 0.011 Ma. Closure and cooling ages on the Cape Denbeigh granite (hornblende, K-feldspar) are 119 Ma and 113 Ma, respectively.