Properties and classification of cold desert soils from Antarctica

Eight pedons representing three climatic zones and parent materials ranging from Holocene to Pliocene were characterized from the Dry Valleys region of Antarctica. All of the soils contain abundant water-soluble salts, including NaCl in coastal regions, NaNO3 along the polar plateau, and Na2SO4 in intermediate areas. The salts originate primarily from atmospheric deposition and accumulate linearly with time. Based on a comparison of salt input by precipitation and the salt content of the profiles, minimal leaching of salts has occurred during the past 3 million yr in soils along the polar plateau. Chemical weathering generally is restricted to oxidation of Fe-bearing minerals and some clay authigenesis. Some of the soils contain ice-cemented permafrost; however, many of the older soils with <5% moisture content have dry permafrost. Although the soils bear many features of Aridisols, they fail to meet the requirements of an aridic soil moisture regime because of the very cold temperatures. They could be classified as Cryids if the Aridisols suborder were expanded to include soils with temperatures that never exceed 5 or 8 degrees C. In the proposed Gelisols order for permafrost-affected soils, the soils are classified as Natric, Glacic, and Typic Anhyturbels (evidence of cryoturbation) and Salic and Petrosalic Anhyhaplels (no cryoturbation).