Genesis of Buried Paleosols and Soils in Holocene and Late Pleistocene Tills, Bugaboo Glacier Area, British Columbia, Canada

Abstract

Morphological, chemical, and mineralogical properties of three well-dated buried paleosols within Bugaboo Glacier lateral moraines suggest a complex history of Holocene pedogenesis in which soil development was intermittently interrupted by periods of glacial advance and slope instability. Multiple, buried horizons and cumulic horizons of the paleosols probably resulted from local colluviation, disturbance during accretion of overlying tills, and/or frost activity. Comparison of buried paleosols with otherwise similar nearby surface soils suggests diagenetic processes have altered reversible properties (pH, organic matter, and pyrophosphate-extractable forms of iron and aluminum) but not metastable soil properties (horizon sequence, color, texture, clay mineralogy, and dithionite- and oxalateextractable forms of iron and aluminum).

Despite these complicating factors, a chronosequence of 17 well-dated buried and surface soils indicates that relative development generally increases in older soils. Bwj and Bw, Bw and Bfj, Bf (Bsj and probably Bs), and Bs horizons have formed within approximately 120 to 350, 1000, 6800, 10,000 yr, respectively.