or pond banks. Soils of this group have been 
designated as Pergelic Cryaquolls. This classifica- 
tion recognizes the distribution of finely divided 
organic materials and dark coloration through- 
out much of these shallow profiles as well as 
their wetness. Like most other soil types of the 
area, they are alkaline with pH’s generally greater 
than 7.0. They have relatively low moisture con- 
tents—the August mean is near 150% (odb). Much 
of this moisture is retained in capillary pores (as 
opposed to free-draining voids in the fibrous 
organic horizons of the soils just described). 
Hydraulic conductivity values are close to K = 
7.0 cm hr! in the upper 10 cm of the profile 
and reflect the somewhat looser, occasionally 
granular, texture of this horizon. Below 10 cm, 
values drop to K= 1.2 cmhr'!. 
As will be noted in the profile below, these 
soils often display a thin (1 cm or less), oxidized 
band immediately above an equally thin zone of 
nodular carbonates somewhere in the near sur- 
face horizons. Such features indicate aerobic 
conditions during the summer months with pre- 
cipitation of carbonates and oxidation of iron. 
The following profile is representative of soil 
unit No. 2. 
Soil type: Pergelic Cryaquoll 
Terrain-relief 
element: 
Units 1 through 6, espe- 
cially low-center polygons 
(No. 3) and steep eroding 
stream or pond banks 
(No. 6). 
Portion of element: Rims and high-center poly- 
gons. 
Vegetation: Dryas integrifolia; Salix 
spp.; Papaver sp., and acro- 
carpous mosses. 
Slope: 0-10% 
Depth in cm: 
0-5 Dark brown (7.5 YR 3/2) to very 
dark greyish brown (10 YR = 3/2) 
organic loamy fine sand and silt; 
many uncoated quartz grains; or- 
ganic matter medium to coarse 
fibrous; roots abundant; boundary 
abrupt, smooth. 
57 
5-8 Yellowish red (5 YR 5/6) organic 
silt loam; quartz grains heavily coat- 
ed with iron; massive; roots com- 
mon; free nodular carbonates near 
lower boundary; boundary abrupt, 
irregular. 
8-20 Very dark brown (10 YR 2/2) to 
very dark greyish brown (10 YR 
3/2) organic loam or loamy fine 
sand; fiber content 40-50%; breaks 
down easily; massive to coarse, 
weak platy structure; boundary 
abrupt, smooth. 
20-38 Very dark brown (10 YR 2/2) to 
very dark greyish brown (10 YR 
3/2) loamy fine sand; finely divided 
organic matter < 5%. Massive to 
weak, coarse platy structure; fine 
gravel skeleton (1-2 cm) and >2% 
of volume; stem fragments; bound- 
ary clear, smooth. 
38-50 Very dark brown (10 YR 2/2) to 
dark yellowish brown (10 YR 4/4) 
loam or silt loam; may have an 
organic component; massive, or 
strong, coarse platy structure; 
numerous pebbles; frost. 
The soils designated unit 1 on Plate | are 
among the more interesting, from the standpoint 
of soil genesis, but least extensive soils in the 
map area. Deeply thawed and well-drained, they 
are developed in sands and gravels on the top 
and flanks of pingos and sand and gravel ridges 
which may be associated with pingos. The 
ground surface frequently has a lag gravel and/or 
a hummocky microrelief (where slope angles 
approach 10% or more). The lag fragments 
display carbonate encrustations on their lower 
surface. 
These soils have many characteristics com- 
mon to the Pergelic Cryaquolls just described. 
They probably represent the fullest expression 
of the regional climate in the well-drained envi- 
ronment. The following, somewhat abbreviated 
profile is representative of this soil. 
Soil type: Calcic Pergelic Cryoboroll 
Pingos and related sand 
and gravel ridges. 
Terrain-relief 
element: 
