Collected from within the top 1 meter of Unit 6, which consists of organic-rich, black-gray silt. Within the silt are 1- to 3-cm-thick, organic-rich bands and fine laminations of silt and tephra. This sample occurs as concentrated ash layers within 0.2- to 1-mm thick laminations of silt and tephra. Highly vesicular pumice with an average grain size of 200 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||627500 ± 47700 40Ar/39Ar; 3668; Age is approximate. Several runs of single-step laser fusion 40Ar/39Ar dating of multiple grains of low K hornblede in tephra sample.||-625550--||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 the top 1 meter of Unit 6, which consists of organic-rich, black-gray silt. Within the silt are 1- to 3-cm-thick, organic-rich bands and fine laminations of silt and tephra. This sample occurs as concentrated ash layers within 0.2- to 1-mm thick laminations of silt and tephra. Highly vesicular pumice with an average grain size of 200 microns.||96TOK1-13||Tephra Fall||Cumulate||Glass||75.87||0.21||13.6||0.34||1.57||4||3.19||Reported standard deviation of zero. 100||3668||EMP||1.19||Cl=0.04||EMP|
This website is supported by the U.S. Geological Survey under Cooperative Agreement Grant G22AC00137
Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.