|Title||Mineralogy and morphological properties of buried polygenetic paleosols formed in late quaternary sediments on upland landscapes of the central plains, USA|
|Publication Type||Journal Article|
|Year of Publication||2010|
|Authors||Presley, DR, Hartley, PE, Ransom, MD|
|Keywords||Central Plains, Great Plains, Landscapes, Loess, Mineralogy, Paleosols, Quaternary|
East central Kansas is largely comprised of alternating, level beds of Permian shale and limestone of the Central Plains, USA. Polygenetic upland soils of east central Kansas have been formed though multiple and likely different sets of soil forming factors. Upland soils in this region have a complex genesis, often contain one or more paleosols, and form in multiple parent materials including loess, locally reworked loess or colluvium, and residuum. The depth to bedrock rarely exceeds 2 m. Upland hillslope soils commonly contain one or more paleosols, and can be observed on a variety of hillslope positions on the landscape. Generally, the lower paleosols are recognized by strongly expressed structure, thick continuous clay coatings on all faces of peds, and strong reddish color with either 7.5YR or 5YR hues. Soil textures of the paleosols often feel less clayey than the overlying horizons in field determinations. At first, this was attributed to a decrease in clay content, stickiness, and plasticity. However, subsequent laboratory characterization revealed that the clay content was usually highest in the lower paleosol horizons, and that the clay mineralogy of the modern soil was dominated by smectite, while the paleosols contained a mixed suite of minerals. Therefore, the perceived decrease in clay content was caused by a change in clay mineralogy, a feature that can be exploited in future field descriptions in order to more accurately distinguish between stratigraphic units in these thin, welded polygenetic soils. The age of the paleosols sampled in this study were typical for the late Quaternary-aged Severance formation, clustering in two age ranges, which were ≈ 19,000 to 20,000 and ≈ 22,500 to 27,700 uncalibrated 14C yr BP. The results from this study illustrate that although they might be thin, truncated, and welded, late Quaternary-aged loess-derived soils and paleosols occur in regular, predictable patterns on many upland hillslopes in the Bluestem Hills Major Land Resource Area, and this region should be included in future regional investigations of the Central Plains.