Soil Development as an Indication of Relative Age of Quaternary Deposits, Baffin Island, N.W.T., Canada

Abstract

Soils can aid in subdivision and correlation of Quaternary deposits in eastern Baffin Island. The most useful data consist of horizon thicknesses and the intensity of oxidation in horizons beneath the A horizon. For Polar Desert soils formed from tills under a sparse lichen cover, the following trends are noted: soils ca. 200 yr old exhibit very subtle Cox horizons no more than 5 cm thick; those ca. 700 yr old have subtle Cox colors, with a maximum thickness of 30 cm; soils considered to have formed since late Wisconsin (ca. 10,000 yr) have weak cambic B horizons that are less than 9 cm thick; and well-expressed cambic B horizons, up to 24 cm thick, characterize early Wisconsin tills (ca. 100,000 yr old). Under a full vegetation cover, Arctic Brown soils form from marine deltaic deposits along the coast. Compared to the above Polar Desert soils, mostly located inland, the horizons in the Arctic Brown soils are thicker, some are more intensely oxidized, and development rates are perhaps ten times more rapid. In contrast to the success in using field soil data for age differentiation, laboratory data on particle-size distribution, organic matter, and pH were not consistently useful. Both the oldest Polar Desert soils and the Arctic Brown soils are Inceptisols, and for till sequences the progression is no soil (0 yr) → Pergelic Cryopsamments or Cryorthents (200 yr) → weak Pergelic Cryochrepts (10,000 yr) → strong Pergelic Cryochrepts (100,000 yr).