Properties and classification of some desert soils in coarse-textured glacial drift in the Arctic and Antarctic

Abstract

Polar Desert soils in the Arctic (66° and 74°N latitude) are contrasted with Cold Desert soils in the Antarctic (77°S). The soils are derived from sandy-skeletal glacial drift and have not been influenced by cryoturbation. Pedogenic horizons are limited to a desert pavement (designated D) and to a weak B horizon in the oldest soils of both groups. Solum thickness increases with age in the two soil groups; however, because of a slightly greater amount of soil moisture, the increase in solum thickness is greater for Polar Desert soils. Soils of both groups often contain “dry” permafrost. The Polar Desert soils at 74°N and most of the Cold Desert soils are neutral to mildly alkaline and the Polar Desert soils at 66°N are strongly to medium acid. Although soluble salts increase with age in soils of both groups, the increase is more marked in the more arid Cold Desert soils. Results from this study and a survey of the literature show that sodium is the prevalent cation in water extracts of Cold Desert soils and in Polar Desert soils above ca. 80°N. Chloride is the major anion in Cold Desert soils in the McMurdo Sound vicinity and in noncalcareous Polar Desert soils. Ion ratios indicate that salts in these soils are contributed by marine aerosols. The soils examined contain less than 5% clay-size (< 2 μm) material. Mica, vermiculite and kaolinite are the predominant phyllosilicate minerals in the clay fractions of Polar Desert soils, and mica, vermiculite and montmorillonite are most abundant in Cold Desert soils. A scheme contrasting clay-mineral alteration in soils of the two groups is provided. In the Canadian system, the Cold Desert soils are Static Cryosols, and the Polar Desert soils are either. Static Cryosols or Dystric Brunisols. In the U.S. system, the soils are Pergelic Cryorthents. Suggestions are given to modify the U.S. system so as to better distinguish polar soils.