Integrated Ichnological-Sedimentological Facies Models in a Sequence Stratigraphic Framework

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Trace fossils, unlike most other fossils, allow an assessment of how animals interacted with their environment while they were alive. In rocks of shallow-marine origin, they comprise one of the most common biological features, yet are relatively understudied. Nothing is more sensitive to changes in the environment and climate than the animals that inhabit them, and so trace fossils provide an unparalleled opportunity to investigate how their responses have operated and changed through time. Animal behaviours, and their resulting trace fossils, vary in response to changes in salinity, physical energy, sediment size, deposition rate, water turbidity, etc., permitting highly detailed interpretations of the ancient sedimentary and environmental record. Correspondingly, this research proposal outlines seven studies that focus on assessing how animal-sediment relations have operated in ancient delta, shoreface/beach, and estuarine settings (paleoenvironments). These paleoenvironments will be assessed with respect to their responses to sea level change, used to establish systems tracts that are fundamental subdivisions of sequence stratigraphy. These shallow-marine environments commonly respond to a complex interplay of river, wave, storm and tidal processes, and are referred to as mixed-process systems. The studies in this proposal are designed to answer fundamental questions about shallow-marine deposits, how they change along the paleoshoreline (e.g., delta asymmetry, tidally influenced shorefaces), and how they have responded to changing sea level in the past (e.g., accumulation during falling sea level, low sea level, rising sea level, and stable but high sea level). Concomitantly, the studies also provide young scientists the opportunity to acquire much-needed skills in the identification and interpretation of trace fossils and bioturbation (animal-generated) fabrics, and the integration of these data with physical (process-response) sedimentology. Together, these avenues of research yield more accurate interpretations of the origins of ancient sedimentary deposits, enable the spatial mapping of resulting deposits, and provide criteria for recognizing how ancient marginal-marine environments vary along the shoreline and seaward into the basin. The biological and physical characteristics of the these sedimentary successions have a major impact on the distribution and quality of hydrocarbon reservoirs and aquifers.