Station: Jensen_2008_Chester_Bluff

Station ID:	Jensen_2008_Chester_Bluff ^[1] ^[2]
Volcano:
Collector:	Jensen, B. J. L.
Date visited:
NAD83 latitude:	65.38
NAD83 longitude:	-142.66997
Default location:	No
Location description:	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).
Station Location:
Samples:	Jensen_2008_Chester_Bluff_Variegated_tephra Jensen_2008_Chester_Bluff_Woodchopper_Creek_tephra Jensen_2008_Chester_Bluff_Old_Crow_tephra Jensen_2008_Chester_Bluff_Biederman_tephra Jensen_2008_Chester_Bluff_Coal_Creek_tephra Jensen_2008_Chester_Bluff_Charley_Village_tephra Jensen_2008_Chester_Bluff_Chester_Bluff_tephra Jensen_2008_Chester_Bluff_Kandik_River_tephra Jensen_2008_Chester_Bluff_Andrew_Creek_tephra Jensen_2008_Chester_Bluff_Ben_Creek_tephra Jensen_2008_Chester_Bluff_Yukon_Tanana_tephra Jensen_2008_Chester_Bluff_Preido_Hill_tephra Jensen_2008_Chester_Bluff_McGregor_Cabin_tephra Jensen_2008_Chester_Bluff_Tom_King_tephra Jensen_2008_Chester_Bluff_Slavens_Roadhouse_tephra Jensen_2008_Chester_Bluff_Beaton_Pup_tephra Jensen_2008_Chester_Bluff_Geophysical_Institute Jensen_2008_Chester_Bluff_Charley_River_tephra Jensen_2008_Chester_Bluff_Biederman_tephra-P1 Jensen_2008_Chester_Bluff_Biederman_tephra-P2 Jensen_2008_Chester_Bluff_Chester_Bluff_tephra-1 Jensen_2008_Chester_Bluff_Chester_Bluff_tephra-2P1 Jensen_2008_Chester_Bluff_Chester_Bluff_tephra-2P2 Jensen_2008_Chester_Bluff_PrH/MC_mix Jensen_2008_Chester_Bluff_Variegated_tephra-P1 Jensen_2008_Chester_Bluff_Variegated_tephra-P2 Jensen_2008_Chester_Bluff_Geophysical_Institute-P1 Jensen_2008_Chester_Bluff_Geophysical_Institute-P2 Jensen_2008_Chester_Bluff_Ben_Creek_tephra-P1 Jensen_2008_Chester_Bluff_Ben_Creek_tephra-P2 Jensen_2008_Chester_Bluff_Yukon_Tanana_tephra-P1 Jensen_2008_Chester_Bluff_Yukon_Tanana_tephra-P2 Jensen_2008_Chester_Bluff_Yukon_Tanana_tephra-P3 UT1871 UT1872 UA1055 UA1077 UA1052 UA1053 UA1054 UA1064 UA1078 UA1092 UA1093 UA1094 UA1095 UT1878 UT1880 UT1889 UA1234 UT1888 UA1080 UT1884 UT1681 UA1079 UA1081 UT1885 UA1082 UA1051 UA1067 UT1874 UT1875 UA1083 UA1209 UT1881 UT1883 UA1084 UA1059 UA1060 UA1068 UA1069 UT1676 UT1876 UA1210 UA1062 UT1877 UT1665 UA1058 UA1073 UA1074 UA1215 UA1220 UA1225 UA1226 UA1227 UA1217 UA1218 UT1887 UA1087 UA1088 UA1089 UA1090 UA1091 UA1216 UA1221 UA1222 UA1228 UA1229 UA1230 UA1231 UA1223 UA1075 UA1076 UA1098 UA1212 UA1213 UA1214 UA1235 UA1086 UA1219 UA1224 UA1232

References Cited

[1] An extensive middle to late Pleistocene tephrochronologic record from east-central Alaska, 2008

Jensen, B.J.L., Froese, D.L., Preece, S.J., Westgate, J.A., and Stachel, Thomas, 2008, An extensive middle to late Pleistocene tephrochronologic record from east-central Alaska: Quaternary Science Reviews, v. 27, p. 411-427, doi:10.1016/j.quascirev.2007.10.010 .

[2] Tephrochronology of middle to late Pleistocene loess in east-central Alaska, 2007

Jensen, B.J.L., 2007, Tephrochronology of Middle to Late Pleistocene Loess in Eastcentral Alaska: University of Alberta M.S. thesis, 120 p.

Alaska Volcano Observatory

Station: Jensen_2008_Chester_Bluff

References Cited

[1] An extensive middle to late Pleistocene tephrochronologic record from east-central Alaska, 2008

[2] Tephrochronology of middle to late Pleistocene loess in east-central Alaska, 2007