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SAMPLE INFO : S8513F
Sample ID:S8513F
Station ID:S8513
Latitude:61.6
Longitude:-147.8
Datum:NAD83
Sample Type 1:Tephra Fall
Text Description:
Pale-white tephra couplet that occurs approximately 150 cm below the surface. The 150 cm above the tephra is a massive, mottled loess with numerous peat beds intercalated. Below this loess is 4 cm of alternating peat, tephra, peat. The one-cm-thick peat directly overlying the tephra couplet provided a radiocarbon date of 1910+/-200 yBP. This peat has a sharp underlying contact with the two-cm-thick pale-white couplet below it, which overlies another one-cm-thick peat radiocarbon dated at 2410+/-220 yBP. Directly below this peat is a 4-cm-thick mixture of peat and pale-white tephra that was too thin and mixed to be sampled properly. This mixture has a sharp contact with the underlying ice-contact stratified drift.

References:
Holocene tephrochronology of the Matanuska Valley, Alaska

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedAge InfoVolcanoEruptionLocation DescriptionText DescriptionSample IDSample Type 1Sample Type 2Geologic UnitMaterialCoeffSiO2TiO2Al2O3FeOTMnOMgOCaONa2OK2OP2O5Total-majorsREF majorsMETH majorsFe2O3/Fe203T origFeO/FeOT origVolatiles csvMETH volatilesCsRbBaSrLaCePrNdSmEuGdTbDyHoErTmYbLuYZrNbHfTaPbThUScVCrFeCoNiCuZnGaMoAsNaKRef trace1METH trace1RbBaSrLaCeNdSmEuGdDyErYbLuYZrNbPbThUScTiVCrNiCuZnGaRef trace2METH trace2Light csvHalogen csvother major csvother lile csvother ree csvother hfse csvother hpe csvother tm csvother misc csv
S851361.6-147.8Fontana, M. R.< 2410 ± 220 14C; 8881; Radiocarbon date on peat (S8513FPB) that is ~157 cm below surface and directly underlying this tephra, providing a maximum limiting age.Matanuska Glacier overlook and campsite at mile 101 of the Glenn Highway, Alaska. Naturally exposed cliff 40 m above the Matanuska River, approximately 4 km from the 1988 terminus of the glacier. Exposure consists of more than 1.5 m of loess, tephra, and peat sharply contacting the underlying ice-contact stratified drift. Two tephra recorded in the stratigraphy at this location, one which was a couplet and was analyzed, the other which was not sampled. See Fontana (1988) for detailed stratigraphy. Coordinates provided as degrees/minutes and converted to decimal degrees; datum not provided, assumed to be NAD83. Pale-white tephra couplet that occurs approximately 150 cm below the surface. The 150 cm above the tephra is a massive, mottled loess with numerous peat beds intercalated. Below this loess is 4 cm of alternating peat, tephra, peat. The one-cm-thick peat directly overlying the tephra couplet provided a radiocarbon date of 1910+/-200 yBP. This peat has a sharp underlying contact with the two-cm-thick pale-white couplet below it, which overlies another one-cm-thick peat radiocarbon dated at 2410+/-220 yBP. Directly below this peat is a 4-cm-thick mixture of peat and pale-white tephra that was too thin and mixed to be sampled properly. This mixture has a sharp contact with the underlying ice-contact stratified drift. S8513FTephra FallCumulateGlass 75.54 0.35 13.05 1.48 0.44 1.58 4.38 3.03 8881EMP1.48Cl=0.15EMP

SAMPLE LOCATION

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