Mineralogical and Geochemical Trends Associated with Fragipan Prism Morphology in a Late Wisconsinan Glacial till.

While multiple theories of fragipan genesis have been proposed for discrete parent materials with little agreement in processes, there is general agreement as to common properties and geography.  A morphologic feature common to nearly all fragipans is coarse prismatic structure.  How this structure is derived in the horizon’s genesis is of debate with some believing the process to be relatively quick and others believing it to be a long term pedogenic process. In order to better understand prism genesis, we investigate fragipan prism face and interior mineralogy and geochemistry in a Late Wisconsinan age glacial till of the Volusia series (fine-loamy, mixed, mesic Aeric Fragiaquept). Using major and trace element analysis, petrographic grain analysis of specific particle size fractions and helium pycnometer particle density, we compare and contrast prism face vs. prism interior differences with depth.