Integrated ichnological-sedimentological facies models: mixed-influence delta deposits

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This 5-year project explores the complexities of  trace fossil assemblages that are preserved in ancient deposits of deltas.  The study of trace fossils is referred to as "Ichnology".The deltaic intervals selected for study show either a mixture of river and wave influences, or a mixture of river and tide influences preserved in the structures of the rocks. It is hypothesized that these intermediate delta types (as opposed to river-, wave-, or tide-dominated expressions) possess unique trace fossil characteristics. Such characteristics include trace fossil diversity, burrowing intensity, types of interpreted animal behaviours, uniformity of burrow distribution, and size ranges of the biogenic structures.The case studies chosen for this project will be compared to previously assessed successions that reflect end-member states.  The integration of the physical sedimentary features with the observed trace fossil characteristics will enhance our ability to identify similar deposits elsewhere, and will provide a continuum of delta types to assist in the development of more broadly applicable depositional models. Additional case studies will explore the concept of delta asymmetry; a situation where mixed river-wave influenced deltas may be characterized by preferential river deposition on the downdrift side of the delta lobe. Asymmetric deltas yield unique successions and have, historically, been difficult to identify in the rock record.  The case studies evaluated in this project will attempt to erect criteria to enhance our ability to recognize these complex successions.