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The soil temperature of
the perennially frozen peat layers was found
to be 0° C .
This agrees with the results of soil temperatures taken
in northern Manitoba under similar conditions .
Ice Content : Mesisols have developed in a wet environment and thus, in
the perennially frozen state,
they are always associated with high
amounts of ice .
The ice is generally found to be in the form of
segregated ice crystals, vein ice, and small ice lenses (see Plate 4A) .
These soils, in areas of widespread permafrost, are sometimes associated
with pure ice bodies in the form of ice layers or ice wedges .
The ice content usually ranges between 60 percent and 80 percent
on a volume basis in Mesisols associated with peat plateaus and
palsas (Figures 5 and 6) . On the other hand, some peatlands around
the Wrigley area (site T29B)
are higher in ice and a layer or layers
of pure ice are found (Figure 6) . Mesisols associated with peat
polygons are higher in ice content than those associated with palsas
and peat plateaus . Here, large amounts of ice are found in the form
of active and buried ice wedges (Figure 5 and Plates 2B and 3B) .
The underlying fine-textured till material usually has
the same
amount of ice as the frozen peat layer (Figure 6, T29B) . The ice here,
however, is mainly of the thicker ice lens and vein ice types (see
Plate 4B) . This is reflected in the doming of these perennially
frozen areas .
The cross-section shows that the doming is mainly
the result of the more extensive ice
lens and vein ice formation in
the underlying mineral material and to a lesser extent to the high
ice content frozen peat whose ice is mainly in the form of ice