Collected from within stratigraphic Unit 5, which consists of 2 m of massive loess. Discontinuous, 1- to 5-cm thick deposit of fine white ash, approximately 0.5 m above tephra sample 96TOK1-21. Characterized by platey, tricuspate bubble-wall shards. Most of the platey glass fragments in this tephra are less than 100 microns across, although a few are up to 150 microns.
Stratigraphy, major oxide geochemistry, and 40Ar/39Ar geochronology of a tephra section near Tok, Alaska
|StationID||Latitude||Longitude||Geologist||DateVisited||Age Info||Volcano||Eruption||Location Description||Text Description||Sample ID||Sample Type 1||Sample Type 2||Final Unit||Material||Coeff||SiO2||TiO2||Al2O3||FeOT||MnO||MgO||CaO||Na2O||K2O||P2O5||Total-majors||REF majors||METH majors||Fe2O3/Fe203T orig||FeO/FeOT orig||Volatiles csv||METH volatiles||Cs||Rb||Ba||Sr||La||Ce||Pr||Nd||Sm||Eu||Gd||Tb||Dy||Ho||Er||Tm||Yb||Lu||Y||Zr||Nb||Hf||Ta||Pb||Th||U||Sc||V||Cr||Fe||Co||Ni||Cu||Zn||Ga||Mo||As||Na||K||Ref trace1||METH trace1||Rb||Ba||Sr||La||Ce||Nd||Sm||Eu||Gd||Dy||Er||Yb||Lu||Y||Zr||Nb||Pb||Th||U||Sc||Ti||V||Cr||Ni||Cu||Zn||Ga||Ref trace2||METH trace2||Light csv||Halogen csv||other major csv||other lile csv||other ree csv||other hfse csv||other hpe csv||other tm csv||other misc csv|
|96TOK1||63.198||-142.178||Schaefer, J. R. G.||0000-00-00||124000 ± 10000 known unit; 10271; Age is approximate. Revised glass fission-track age with re-calibration reported in Preece and others (2011); four Old Crow Tephra sample glass fission-track ages (UT1434, UT613, UT501, UT613).||Road-cut at mile 1284.6 of the Alaska Highway, southeast of Tok, Alaska. Approximately 17 miles east of Tetlin Junction and 100 miles north of Wrangell volcanic field. Twelve-m-thick section that exposes interbedded sands, silt and tephra that were deposited against a southeasterly sloping, highly weathered intrusive rock. The section is divided into six units based on lithology. Ten tephra samples were taken; however, approximately one m below tephra 96TOK1-9, there are wispy layers of several multiple-banded tephras that were very thin and discontinuous and not detailed in Schaefer (2002). Datum not specified, assumed to be NAD83.||Collected from within stratigraphic Unit 5, which consists of 2 m of massive loess. Discontinuous, 1- to 5-cm thick deposit of fine white ash, approximately 0.5 m above tephra sample 96TOK1-21. Characterized by platey, tricuspate bubble-wall shards. Most of the platey glass fragments in this tephra are less than 100 microns across, although a few are up to 150 microns.||96TOK1-22||Tephra Fall||Cumulate||Glass||75.33||0.4||12.87||0.32||1.48||3.66||3.81||Reported standard deviation of zero. 100||3668||EMP||1.84||Cl=0.3||EMP|
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