EAR-PF:Stratigraphic paleobiology in continental settings: Developing a sequence-stratigraphic framework of fossil preservation in continental deposits through model building and

Loughney Katharine M, Ann Arbor MI

Investigators

Abstract

Dr. Katharine Loughney has been awarded an NSF Postdoctoral Fellowship to investigate large-scale controls on fossil preservation at the University of Georgia under the mentorship of Dr. Steven Holland. Many factors contribute to the preservation of fossils, including the habitats in which plants and animals lived, and the geologic processes that control the burial of their remains. In marine environments, water depth is a major control on habitat, sedimentation, and animal abundance, and the rock and fossil records of marine systems can therefore be studied in relation to their mutual drivers. On land, tectonics, climate, elevation, and stream processes are important controls on the spatial distribution of habitats and the burial of organisms. The interaction of these controls is complex and has not been as extensively studied as those in the marine realm. The goal of this project is to study the preservation of fossils in relation to the controls on habitat and burial in terrestrial environments. Through modeling fossil accumulation under varying tectonic and climatic states to predict the occurrence of fossils in sedimentary basin fill, and by testing these predictions in the field, the large-scale drivers of preservation can be better constrained. The outcomes of this project will enhance understanding of how tectonics, climate, and sedimentation processes control fossil preservation and will allow the occurrence of fossil-bearing strata to be predicted. This project will involve undergraduate students in field and laboratory work, while project findings will be incorporated into field-based paleontology courses to contribute to the training and education of graduate students. Additionally, the project will be the basis for public museum displays. Accommodation and sedimentation are the two main stratigraphic controls on the distribution of sedimentary facies, which can be evaluated using sequence stratigraphy. Stratigraphic paleobiology integrates the fossil record with sequence-stratigraphic architecture, revealing the predictable occurrence of fossiliferous facies. The goal of the proposed research is to apply the principles of sequence stratigraphy to understand the distribution of fossiliferous facies in relation to the history of accommodation and sedimentation in continental extensional-basin sequences. Extensional basins are important repositories of the continental fossil record, and their tectonic and facies evolution is predictable and well characterized. Dr. Loughney will: 1) develop a conceptual model of fossil accumulation in alluvial systems tracts that incorporates the intra- and extrabasinal controls on sedimentation in extensional continental basins, and 2) test the model with field work in the Miocene Stewart Valley Group of Nevada. Characterizing the facies relationships and stratigraphic occurrence of fossil localities through the Stewart Valley Group will test the predictions of the model and demonstrate how fossil preservation changes through the history of accommodation and sedimentation in the basin. This research will enable patterns of evolution and extinction in continental plants and animals to be integrated with stratigraphy and preservation across basins. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.