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SAMPLE INFO : UT734
Sample ID:UT734
Station ID:Sheep_Creek_Valley
Latitude:64.9
Longitude:-147.9
Datum:NAD83
Sample Type 1:Tephra Fall
Text Description:
Occurs in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. 2- to 3-cm-thick white (7.5Y8/1) layer (with a maximum thickness of 6 cm) 1.5 m below the contact of Gold Hill Loess (GHL) and the overlying retransported loess of the late Pleistocene Goldstream Formation. Microfaulted with a tripartite character: a basal dark crystal-rich sand-sized layer, followed by a much finer-grained vitric layer, which is capped by reworked crystal-rich tephra/sands.

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
Late Pliocene Dawson Cut forest bed and new tephrochronological findings in the Gold Hill Loess, east-central 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
Sheep_Creek_Valley64.9-147.9Pewe, T. L.< 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.-188050--From Westgate et al. (2007): Sheep Creek Cut mining exposure, about 15 km northwest of Fairbanks, Alaska. Location imprecisely georeferenced from Figure 4 in Preece et al. (1999).Occurs in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. 2- to 3-cm-thick white (7.5Y8/1) layer (with a maximum thickness of 6 cm) 1.5 m below the contact of Gold Hill Loess (GHL) and the overlying retransported loess of the late Pleistocene Goldstream Formation. Microfaulted with a tripartite character: a basal dark crystal-rich sand-sized layer, followed by a much finer-grained vitric layer, which is capped by reworked crystal-rich tephra/sands.UT734Tephra FallCumulateGlass 72.58 0.24 16.56 2.1Reported analytical value of zero. Reported standard deviation value of zero. 0Reported analytical value of zero. Reported standard deviation value of zero. 0 2.58 3.92 1.84 93.2656EMP2.1Cl=0 0.89 46 716 580 13.07 20.4 8.5 1.79 0.48 0.17 0.69 0.13 2.25 0.3 2.87 1.07 4.1 7.82 62 56INAA
Sheep_Creek_Valley64.9-147.9Pewe, T. L.< 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.-188050--From Westgate et al. (2007): Sheep Creek Cut mining exposure, about 15 km northwest of Fairbanks, Alaska. Location imprecisely georeferenced from Figure 4 in Preece et al. (1999).Occurs in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. 2- to 3-cm-thick white (7.5Y8/1) layer (with a maximum thickness of 6 cm) 1.5 m below the contact of Gold Hill Loess (GHL) and the overlying retransported loess of the late Pleistocene Goldstream Formation. Microfaulted with a tripartite character: a basal dark crystal-rich sand-sized layer, followed by a much finer-grained vitric layer, which is capped by reworked crystal-rich tephra/sands.UT734Tephra FallCumulateGlass 71.73 0.3 16.06 1.84 0.06 0.7 2.69 4.63 1.95 4365EMP1.84H2O=4.01; Cl=0.04EMP
Sheep_Creek_Valley64.9-147.9Pewe, T. L.< 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.-188050--From Westgate et al. (2007): Sheep Creek Cut mining exposure, about 15 km northwest of Fairbanks, Alaska. Location imprecisely georeferenced from Figure 4 in Preece et al. (1999).Occurs in the uppermost part of the Gold Hill Loess, close to the contact with the overlying Goldstream Formation. 2- to 3-cm-thick white (7.5Y8/1) layer (with a maximum thickness of 6 cm) 1.5 m below the contact of Gold Hill Loess (GHL) and the overlying retransported loess of the late Pleistocene Goldstream Formation. Microfaulted with a tripartite character: a basal dark crystal-rich sand-sized layer, followed by a much finer-grained vitric layer, which is capped by reworked crystal-rich tephra/sands.UT734Tephra FallCumulateGlass 72.71 0.24 16.59 2.1 2.58 3.93 1.84 2166EMP2.1H2O=6.7EMP

SAMPLE LOCATION

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