Description, Sampling, and Analysis of Cryosols - Cryopedology - page 22

Chapter 3
Description, Sampling, and Analysis
of Cryosols

3.1 Describing Cryosols

Because of the underlying permafrost and cryoturbation, the approach for describing
and sampling cryosols is different from that used for soils lacking permafrost.
Schoeneberger et al. ( 2012 ) prepared a fi eld topic for describing and sampling soils.
Guidelines for describing and sampling soils in Antarctica are given by Bockheim
et al. for Antarctic soils ( http://erth.waikato.ac.nz/antpas/pdf/Soil_Description_
Manual- Draft_1.pdf ) .
The key attributes to be recorded for cryosols are given in Table 3.1 . Properties
that are somewhat unique to cryosols that should be described include patterned
ground, cryoturbation features, the depth to the top and bottom of each horizon (for
broken horizons), cryostructures, and the depth to and nature of permafrost.
Patterned ground is discussed in more detail in Chap. 4 . Cryoturbation is the domi-
nant soil-forming process in cryosols (Chap. 5 ). A sketch illustrating the kinds of
features that are indicative of cryoturbation is given in Fig. 3.1 . Cryostructures are
a key property of cryosols. Figure 3.2 illustrates several of the more important of
these cryogenic structures. These are discussed further in Chap. 5 .
A sketch and/or Polaroid image of the soil profi le is important especially for
cryoturbated soils with broken and irregular horizons (Fig. 3.3 ). By using two
extendable measuring tapes, the horizons can be shown on a grid for later weighting
to estimate overall horizon thicknesses.
The pedon concept is important in describing, sampling, and classifying cryo-
sols. A pedon is considered to be the smallest volume of soil for descriptive and
sampling purposes. The minimum horizontal area is set a 1 m 2 but it ranges to 10 m 2 ,
depending on the variability of the soil. Figure 3.4a shows that the pedon selected
encompasses the entire unsorted circle unit. In the case of large patterned ground
units, such as low-centered polygons, two pedons are selected, one in the center of
the polygon and the other in the contraction fi ssure (Fig. 3.4b ).