RELATIVE AGE AND ORIGIN OF SOILS IN EASTERN WRIGHT VALLEY, ANTARCTICA

Soils on moraines deposited by the Wright Lower Glacier were differentiated on the basis of weathering features of surface boulders, soil morphology, and the amount of water-soluble salts. Soils ranked from youngest to oldest include those on Wright Lower, Trilogy, Loop, C, and D end moraines. The following properties increase with soil age: Reciprocal of frequency of upstanding boulders and the percentage of boulders weathered in place on moraine crests; depths of oxidation, ghosts, salt encrustations and slightly coherent consistence and depth to ice cement in soil profiles; electrical conductivity, cations (Na+, Ca2+, Mg2+, K+), and anions (Cl−, SO42−) in 1:5 soil:water extracts from the horizon of maximum salt content; and silt and clay in the B horizon. Soils were ordinated using indices of similarity. Relative ages of soils on Wright Lower, C, and D moraines were estimated on the assumptions that Trilogy and Loop soils are 18,000 and ca. 135,000 years B.P., respectively, and that soluble salts bear a linear relationship to soil age. © 1979 The Williams & Wilkins Co.