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SAMPLE INFO : UT1052
Sample ID:UT1052
Station ID:Ash_Bend
Latitude:63.5
Longitude:-137.267
Datum:NAD83
Sample Type 1:Tephra Fall
Text Description:
Conspicuous, white tephra bed, up to 3 cm thick, near base of silty beds that overly the base of channel cut into the upper glaciofluvial gravels at the head of a gulley located at the downstream end of the section. Trace amounts of a low vesicular glass and bubble-wall shards are present. Dominated by plagioclase and hornblende with lesser amounts of ilmenite and magnetite. Hypersthene is scarce and slightly- to nonpleochroic. Apatite, clinopyroxene and quartz occur in trace quantities. From Preece et al. (2011): pumice, rare blocky shards, and rare bubble-wall shards; in silt of sedimentary fill incised into the Reid glacial drift; 90 cm below Sheep Creek-A (UT1051). Sample collected by B. Alloway, 1990.

References:
Changing ideas on the identity and stratigraphic significance of the Sheep Creek tephra beds in Alaska and the Yukon Territory, northwestern North America
A catalogue of late Cenozoic tephra beds in the Klondike Goldfields and adjacent areas, Yukon Territory
Dating Early and Middle (Reid) Pleistocene glaciations in central Yukon by tephrochronology

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
Ash_Bend63.5-137.267Preece, 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.Ash Bend Section, Stewart River, Yukon Territory, Canada. Type section for the Reid glaciation and early Beringian Bison fossils. Located a few kilometers inside the outer limit of Reid drift, which was deposited during an extensive advance of the Cordilleran Ice Sheet across central Yukon Territory, Canada. The Reid till forms a prominent 10-m-high scarp within a thick, recessive sequence of glaciofluvial gravels at Ash Bend. Coordinates from Preece et al. (2011). Datum not specified, assumed to be NAD83.Conspicuous, white tephra bed, up to 3 cm thick, near base of silty beds that overly the base of channel cut into the upper glaciofluvial gravels at the head of a gulley located at the downstream end of the section. Trace amounts of a low vesicular glass and bubble-wall shards are present. Dominated by plagioclase and hornblende with lesser amounts of ilmenite and magnetite. Hypersthene is scarce and slightly- to nonpleochroic. Apatite, clinopyroxene and quartz occur in trace quantities. From Preece et al. (2011): pumice, rare blocky shards, and rare bubble-wall shards; in silt of sedimentary fill incised into the Reid glacial drift; 90 cm below Sheep Creek-A (UT1051). Sample collected by B. Alloway, 1990.UT1052Tephra FallCumulateGlass 73.26 0.2 15.52 1.35 0.05 0.48 2.21 4.34 2.55 4365EMP1.35Cl=0.03; H2O=3.53EMP
Ash_Bend63.5-137.267Preece, 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.Ash Bend Section, Stewart River, Yukon Territory, Canada. Type section for the Reid glaciation and early Beringian Bison fossils. Located a few kilometers inside the outer limit of Reid drift, which was deposited during an extensive advance of the Cordilleran Ice Sheet across central Yukon Territory, Canada. The Reid till forms a prominent 10-m-high scarp within a thick, recessive sequence of glaciofluvial gravels at Ash Bend. Coordinates from Preece et al. (2011). Datum not specified, assumed to be NAD83.Conspicuous, white tephra bed, up to 3 cm thick, near base of silty beds that overly the base of channel cut into the upper glaciofluvial gravels at the head of a gulley located at the downstream end of the section. Trace amounts of a low vesicular glass and bubble-wall shards are present. Dominated by plagioclase and hornblende with lesser amounts of ilmenite and magnetite. Hypersthene is scarce and slightly- to nonpleochroic. Apatite, clinopyroxene and quartz occur in trace quantities. From Preece et al. (2011): pumice, rare blocky shards, and rare bubble-wall shards; in silt of sedimentary fill incised into the Reid glacial drift; 90 cm below Sheep Creek-A (UT1051). Sample collected by B. Alloway, 1990.UT1052Tephra FallCumulateGlass 73.07 0.18 15.53 1.41 0.08 0.5 2.33 4.31 2.57 10311EMP1.41Cl=0.03; H2O=3.12EMP

SAMPLE LOCATION

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