The Preido Hill (PrH) reworked with MacGregor Cabin (MC) tephra. The composition reported was calculated from analyses of eighteen samples: UT1887, UT1893, UA1085, UA1087, UA1088, UA1089, UA1090, UA1091, UA1216, UA1221, UA1222, UA1228, UA1229, UA1230, UA1231, UA1223, UA1075, and UA1076.
An extensive middle to late Pleistocene tephrochronologic record from east-central Alaska
Tephrochronology of middle to late Pleistocene loess in east-central 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|
|Jensen_2008_Chester_Bluff||65.38||-142.66997||Jensen, B. J. L.||Chester Bluff is located in Yukon Charley Rivers National Preserve (YCNP) in east-central Alaska, on the northwest bank of the Yukon River directly upstream from its confluence with the Charley River. It is a terrace comprising a series of individual bluffs dissected by gullies that extend laterally for about 3 km. The south-facing bluffs are dry and substantial excavation (>2m) is needed to reach frozen sediments. Chester Bluff can be broadly differentiated into four units. The base of the bluff is a bedrock terrace exposed up to ~10 m above river level, composed of argillite, part of the Cretaceous Biederman Formation. Deposited on the terrace are 8-10 m of paleo-Yukon River gravel, which are overlain by 5-10 m of sand and silt rhythmites with minor gravel and planar-bedded sand. Up to 40 m of silt, interpreted as loess and interbedded with multiple organic horizons and tephra beds, cap the sequence. Sites A through C were visited in the area and were found to host 19 distinct tephra beds. A near vertical slope at Site A prevented trench completion. Two trenches were excavated on either side of Site A to examine the lateral continuity of tephra beds. Site B was successfully logged from the top of the bluff to the upper-most sand unit associated with the flood deposits. Thick colluvium at Site C prevented completion of the trench at this site. No coordinates provided; location imprecisely georeferenced from Figure 1 in Jensen et al. (2008).||The Preido Hill (PrH) reworked with MacGregor Cabin (MC) tephra. The composition reported was calculated from analyses of eighteen samples: UT1887, UT1893, UA1085, UA1087, UA1088, UA1089, UA1090, UA1091, UA1216, UA1221, UA1222, UA1228, UA1229, UA1230, UA1231, UA1223, UA1075, and UA1076.||Jensen_2008_Chester_Bluff_PrH/MC_mix||Tephra Fall||Cumulate||Glass||75.2||0.11||14.87||0.92||0.07||0.26||1.45||4.38||2.69||6162||EMP||0.92||Cl=0.04; H2O=6.32||EMP|
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