BP (Morlan, 1980), prevailing cold temperatures allowed permafrost to aggrade
through the glaciolacustrine sediments and form segregated ice lenses.
Active layers between 60 and 100 cm develop over permafrost that aggrades
upward with sedimentation and vegetation succession (Morse et al.
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In deeper lakes (> 2 m), a thaw bulb may develop in the underlying permafrost, but upon drainage, permafrost aggrades
into the sediments, and the ice-wedge network is reestablished.
Second, as peat accumulates, permafrost aggrades
from below, drawing water to the plane of freezing (Zoltai and