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Hopkm, D. M., 1903, Aspects of the paleogeagraphy
of Beringla during the late PIektocene,
Hopkina, D. M., Matthews, J. V,, Jr., Schweger,
C. E., and Young, S. B., eds., Paleogeography of
Beringia: New York, Academic Press, p. 3-28.
Lachenbruch, A. H., and Brewer, M. C., 1959, Dlssipa-
tion of the temperature effect of drilling a well
in Arctic Alaska: U.S. Geological Survey Bulle-
tin 1083-C, p. 73-109.
khenbruch, A. H., Greene, G. W., and Marshall, B.
V., 1966, Permafrost and the geothermal
regimes, & Wilirnovsky, N. J., and Wolfe, J. N.,
eds., Environment of the Cape Thompson region,
Alaska: U.S. Atomic Energy Commission, Divi-
sion of Teahnical Infor mation Report P NE-481,
p. 149-163.
Lachenbruch, A. H., and Marshall, B. V., 1977, Sub-sea
temperatures and a simple tentative model for
offshore permafrost at Pcudhoe Bay, Alaska:
U.S. Geological Survey Open-File Report 77-395,
54 p.
Lachenbruch, A. B., Sass, J. H., Marsm, B. V., and
Moses, T. B., Jr., 1983, Permafrost, heat flow,
and geothermal regime at Prudhoe Bay, Alaska:
U.S. aeological Survey Open-File Report [in
press].
Cornpdmm of gmhdm stn- from two northern
AZaska &me fields
Ey Jahn P. Q6llonay and Eduard k gasterl
Grain-size parameters were determined for 40
eolian samples collected from two AJaskan dune fields
north of the Arctic Circle (area 3, fig. 5; fig. 10). A
total of 20 samples were collected from the Great
Kobuk Sand Dunes during summer 1981. 'he Great
Kobuk Sand Dunes cornpose one of two active dune
fields located .$I the central Kobuk Valley and cover an
wea of 78 km (Fernald, 1964). The other 20 samples
were collected from a stabilized gleistmene dune field
that covers more then 7,000 km of the National Pe trolwm Reserve In Naska (Carter, 1901). Grain-size
analyses of yamples from this stabilized dune field
have been reported elsewhere (Galloway, 1981).
All samples were analyzed using standard techniques,
as described by Polk (1964). Slew of the
sand fraction was done at 1/20 intervals, and, when
necessary, the fine fraction (material greater than 48,
mud) was analyzed with a hydrophotometer. Only two
of the samples from the active Great Kobuk Sand
Dunes had a mud content greater Vlan 2 percent; the
average mud content was 1.16 percent. None of the
Great Kobm Sand Dunes wmples were analyzed with
the hydrophotometer. The mud content of the samples
from the northern (Pleistocene) dune field ranged from
less than 0.5 to 12.5 percent, and analysis of the fines
with the hydrophotometer was nece-y for samples
with a mud content greater than 2 percent. Because
most of the fines settled out after the first six hydre
hotometer readings (78, fine silt), a llmit of 8.0B
silt/clay boundary) was used in the computer program
4
'physical Geography and Soil Science Labaratory,
University of Amsterdam, The Netherlands.
(Pime and Gd, 1966) for generation of the cumula-
tive curves from which the graphical statistics were
derived (Polk and Ward, 1957). Cumulativefrequency
curves for a coarse- and a fine-grained sample col-
lected from the north end of the Great Kobuk Sand
Dunes were previously published by Fernald (1964, p.
K24).
Figure 10.-lndex map showlng approximate locations
of two major dune fields north of the Arctic Circle,
northern Alaska.
Table 2.--Sumnary - of graphical statfstics
CGraphlcal statistics in 0 (phi) units] I
Mean
graln Sorting Skewness
size
Great Kobuk Sand Dunes I
2.6005, 0.5654, 0 4456,
fine sand rnodera tel y we1 1 synunetrtcal
( 1.8465- sorted (0.8657- (-0.1767-
3.0065) 0.3566) 0.3636)
Northern A1 aska I Pl el stocene) dune f 1 el d I
2.6838. 0.7960, 0.1259,
ffne sand moderately fine
(2.1433- sorted (1.4086- i -0.2922-
3.8706) 0.3858) 0.4937 )