Title: Exploring the sedimentary, pedogenic, and hydrologic factors that control the occurrence and role of bioturbation in soil formation and horizonation in continental deposits: An integrative approach
Abstract:Interpretation of paleosols involves deciphering the complex interplay between multiple biotic and abiotic processes. Previous ichnological research has shown that trace fossils, which record biotic i...Interpretation of paleosols involves deciphering the complex interplay between multiple biotic and abiotic processes. Previous ichnological research has shown that trace fossils, which record biotic influences on pedogenesis, are particularly useful for reconstructing physicochemical conditions during soil formation, which, in turn, can yield important data about paleoenvironment, paleohydrology, and paleoclimate. Our goal is to integrate ichnology with the substantial body of research that exists in the areas of sedimentology and pedology to present an integrative framework with which to interpret paleosols in the continental rock record. Tiering of traces is particularly prominent in terrestrial settings because the vertical distribution of soil biota is controlled largely by the groundwater profile. Interpretations of trace fossils are therefore facilitated by assigning traces to one of four moisture regimes: epiterraphilic, terraphilic, hygrophilic, and hydrophilic. The balance between deposition and pedogenesis is expressed by the paleosol profile, which can range from simple to compound, composite, or cumulative. The combination of sedimentation and pedogenesis, including groundwater-influenced bioturbation, can act to enhance or destroy horizonation within soils; these processes ultimately determine the paleosol characteristics that are preserved in the stratigraphic record. We illustrate our conceptual model with examples of multiple paleosol types that contain evidence of varying amounts of bioturbation attributable to crayfish.Read More