Section 10 Periglacial-Related Forms

Abstract

The Geounits of this Group are cold climate non-glacial phenomena. The processes are intimately associated with intense frost action. The Units occur in seasonally unfrozen unconsolidated deposits and organic materials. Eleven Units and three Variants are ordered in three Subgroups: Zi Ground ice Units are bodies of massive ice and ice in cavities, voids, or other openings in soil and rock. Zm Cryoturbated materials are irregular structures formed in earth materials by deep frost penetration and freezing and thawing processes (Figs. 84 to 86). Zk Thermokarst terrain is irregular topography resulting from differential thaw settlement or caving of the ground due to melting of ground ice. (Note: Definitions are from National Research Council of Canada Technical Memorandum No. 142, 1988).