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SAMPLE INFO : UT491
Sample ID:UT491
Station ID:Dawson_Cut
Latitude:64.9
Longitude:-147.7
Datum:NAD83
Sample Type 1:Tephra Fall
Text Description:
Occus in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. Tripartite character: a basal mafic mineral-rich zone, followed by a vitric layer, which is capped by reworked crystal-rich sands. Preece (1991) reports a 1- to 3-cm-thick white tephra with abundant mafic minerals overlain by reworked ash. Maximum unreworked thickness of 1.5 cm. interbedded with massive tan-colored silt.

References:
Tephrostratigraphy of the late Cenozoic Gold Hill loess, Fairbanks area, Alaska
Tephrochronology of late Cenozoic loess at Fairbanks, central Alaska
Age of Sheep Creek Tephra (Pleistocene) in central Alaska from thermoluminescence dating of bracketing loess
Changing ideas on the identity and stratigraphic significance of the Sheep Creek tephra beds in Alaska and the Yukon Territory, northwestern North America

GEOCHEM DATA
StationIDLatitudeLongitudeGeologistDateVisitedAge InfoVolcanoEruptionLocation DescriptionText DescriptionSample IDSample Type 1Sample Type 2Final 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
Dawson_Cut64.9-147.7Preece, S. J.< 190000 ± 20000 known unit; 4365; This is the maximum age of all Sheep Creek tephra from Westgate and others (2007), who demonstrated that the Sheep Creek tephra is actually made up of several stratigraphic units.Section exposed along the Steese Highway, just outside of Fairbanks, Alaska; location imprecisely georeferenced from Figure 4 in Preece et al. (1999). Occus in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. Tripartite character: a basal mafic mineral-rich zone, followed by a vitric layer, which is capped by reworked crystal-rich sands. Preece (1991) reports a 1- to 3-cm-thick white tephra with abundant mafic minerals overlain by reworked ash. Maximum unreworked thickness of 1.5 cm. interbedded with massive tan-colored silt.UT491Tephra FallCumulateGlass 72.54 0.26 16.37 2.03Reported analytical value of zero. Reported standard deviation value of zero. 0Reported analytical value of zero. Reported standard deviation value of zero. 0 2.57 4.37 1.85 94.7856EMP2.03Cl=0 0.84 39 569 647 9.53 17.9 6.1 1.24 0.43 0.16 0.54 0.09 2.22 0.29 2.46 0.91 3.08 4.17 52 56INAA
Dawson_Cut64.9-147.7Preece, S. J.< 190000 ± 20000 known unit; 4365; This is the maximum age of all Sheep Creek tephra from Westgate and others (2007), who demonstrated that the Sheep Creek tephra is actually made up of several stratigraphic units.Section exposed along the Steese Highway, just outside of Fairbanks, Alaska; location imprecisely georeferenced from Figure 4 in Preece et al. (1999). Occus in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. Tripartite character: a basal mafic mineral-rich zone, followed by a vitric layer, which is capped by reworked crystal-rich sands. Preece (1991) reports a 1- to 3-cm-thick white tephra with abundant mafic minerals overlain by reworked ash. Maximum unreworked thickness of 1.5 cm. interbedded with massive tan-colored silt.UT491Tephra FallCumulateGlass 72.54 0.26 16.37 2.03 2.57 4.37 1.85 2166EMP2.03H2O=5.2EMP

SAMPLE LOCATION

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