Determining geomorphological and land use effects through physico-chemical fingerprinting of soils

The purpose of this project is to develop a framework for quantifying and differentiating the effects of early historic land uses on characteristics of soils formed in loess at two historical archaeology sites in the Midwestern United States: New Philadelphia Historical Landmark (NPHL) in western Illinois and Plum Grove Historical Farmstead (PGHF) in eastern Iowa. The significance of this research to topics such as global climate change, the role of soils in the carbon and nitrogen cycles, the effects of land use on sustainable use of soils, and augmenting the historical record by revealing land use activities for areas that have limited record of past land use are presented in the Introduction. The Introduction also includes reviews of previous geochemical studies and studies of natural and anthropogenic effects on the physical and chemical properties of soils. Research efforts were conducted in three main phases and the results of each phase are presented as individual chapters herein. Phase one focuses on identifying physico-chemical signatures of land use effects on soils at NPHL and determining the minimal resolution required to discriminate these effects to develop a multi-prong methodological framework. Phase two is an exploration of the efficacy of using portable x-ray fluorescence to measure non-pollution level chemical impacts from land use activities in order to refine the methodological framework by targeting soil samples for more costly, higher precision analyses. Phase three is a test of the refined framework to examine land use effects on physico-chemical characteristics of soil at PGHF. In the Summary and Conclusions the physico-chemical results from NPHL and PGHF are compared and contrasted to evaluate the methodological framework and its utility for investigation of land use effects at other Midwestern locations. The final section discusses possible revisions to the approach and outlines opportunities for future investigations.