OVERVIEW OF FINDINGS FROM A DECADE OF RESEARCH EXAMINING THE HOLOCENE SOD TABLES IN THE WHITE RIVER BADLANDS

In the Badlands, the sod tables remaining from incision of Holocene pediments are perforated with pseudokarst. Observation of these voids triggered our scrutiny of sod tables. Initially, we surveyed the relief of sod tables from the adjacent washes in an attempt to group sod tables into geomorphic clusters, as river terraces are often categorized. This effort was stymied by the rugged topography, so we commenced study of paleosols within the sod tables, with hopes of identifying marker beds to allow correlation. To date, however, no paleosol has proven useful as a marker bed. Meanwhile, we have collected 25 radiocarbon dates from paleosols, which offer the opportunity for inferences concerning geomorphic processes during the past 3,600 years. The dates cluster during intervals of fan stability and pedogenesis, including ~900, 1100-1300, 1700-1900, 2300-2400, and ~3600 radiocarbon years bp. These intervals of soil development on alluvial-colluvial silts compare well with those reported for eolian deposits within the same region. The age of the uppermost paleosol also provides a maximum age for onset of the incision that dissected the pediments into sod tables. Furthermore, with initiation of the incision known, minimum erosion rates of down-cutting equal 0.8 cm/yr, while rates of lateral retreat of arroyo walls equal 2-5 cm/yr, or more, during the last millennium. In addition to examining these paleosols, we have developed a classification for pseudokarst throughout the region, as well as postulating upon the hydrologic conditions contributing to such morphogenesis. Lastly, we have refined a host of pedagogical approaches to undergraduate research that have involved about four dozen undergraduates logging one thousand field days, who we collectively call the Badlands Working Group at Slippery Rock University of Pennsylvania. We employ a peer-mentoring model, where alumni return to guide novices. Interdisciplinary inquiry is another hallmark, including an amalgam of art and science. Our 2008 expedition yielded an art gallery exhibition entitled Where Art Meets Science: Synergy on the Landscape, which received highly favorable reviews. We intend to continue this inquiry to explain Holocene landscape evolution, while preparing materials that better convey the story of the Badlands to the general public.