Exhumed Paleosols and Associated Modern Till Soils in Western Illinois

Abstract

Exhumed paleosols and modern soils formed in Illinoian and/or Kansan till occur in a complex pattern in many places on the sides of incised valleys in predominantly loess covered regions in western Illinois and adjacent states. The paleosols studied in western Illinois are thicker, finer textured, grayer and more poorly drained, and more impermeable than the modern soils formed during late Pleistocene and Recent weathering. However, the paleosols and modern soils do not differ greatly in chemical properties.The presence of highly contrasting paleosols and modern till soils on the same slope not only cause problems in soil mapping, but because of side‐hill seepage, and the fine texture and poor physical condition of the paleosols, difficult problems in soil management also exist. The use of soil complexes, undifferentiated units, or the inclusion of strongly contrasting soils in given mapping units is necessary to show these soil conditions on many slopes.

Estudo pedológico de perfis de solos do grande grupo rubrozem da bacia de Curitiba-PR

“…A variação na distribuição dos teores de areia ao longo do perfil e frequentemente inferida como uma indicação da falta de uniformidade do mate rial de origem (COMISSÃO DE SOLOS, 1958, 1962MILLET & DREW, 1963;ROWLES, 1969;BUSHUE et al, 1970).…”