On May 22, 2025, I presented the results of my doctoral research at the 103rd Annual Meeting of the Virginia Academy of Science, held at the University of Virginia in Charlottesville. The title of my work is, “Influence of Microbial Mats on the Sedimentary Dynamics and Stratigraphy of the Aaron Formation, South Fork of Little River, Durham County, North Carolina.” I was able to share new insights into microbially influenced sedimentary processes preserved within siliciclastic successions i.e. layers of sand, mud, and silt laid down over time by wind, water, or ice. These deposits date back to the Precambrian, the longest and earliest chapter in Earth’s history (about 4.6 billion to 541 million years ago), when life was just beginning in the form of simple organisms like bacteria and algae, long before complex plants or animals had evolved.
The Aaron Formation is a rock unit located in North-Central North Carolina that dates to the Neoproterozoic Era, an ancient period in Earth’s history that spanned from about 1,000 to 541 million years ago, long before the first animals appeared. My research focuses on a specific strata within this formation, estimated to be around 578 to 588 million years old. The rocks here are made up of very fine, thinly layered siltstone, a type of sedimentary rock formed from compacted mud. What makes this formation especially fascinating is the presence of Vermiforma antiqua, a rare fossil thought to represent one of the earliest signs of life. My research investigates how ancient microbial mats influenced primary sediment deposition, bedform development, and the stratigraphic expression of microbial textures across several meters of exposed section. Utilizing petrographic analysis, grain size analysis, and microfacies examination of thin sections, I identified sedimentary textures such as wrinkle structures, microlamination, cohesive mat-bound intervals, and discontinuous grain fabric features consistent with microbial mat-ground interactions. Fine-grained matrix material (0.106–0.316 mm) deposited above coarser detrital substrates reflects microbially mediated baffling and trapping. Additional evidence includes reworked mat chips, mat fragment laminations, and mechanically disrupted boundaries indicative of episodic flow regimes and microbial colonization during early diagenesis.
These observations suggest that the Aaron Formation was deposited in a low-energy, tidally influenced marine setting characterized by intermittent energy fluctuations conducive to microbial stabilization of the sediment–water interface. The recurrence of mat-induced sedimentary features, associated with biologically originated macrofossils, enhances our ability to recognize microbially induced sedimentary structures (MISS) and discriminate them from purely physicochemical sedimentary structures in ancient strata.
From a stratigraphic perspective, this work improves the interpretation of shallow marine facies associations and aids in identifying depositional signatures linked to microbial surface processes. Differentiating MISS from physically formed structures is crucial for accurately reconstructing paleoenvironmental conditions and refining depositional models for Precambrian sedimentary basins.
I entered the Ocean & Earth Sciences doctoral program at 鶹AV in Fall 2023, after completing an Master of Science degree in Geoscience at Eberhard Karls University Tübingen in Germany. My decision to pursue doctoral research at 鶹AV was driven by the opportunity to work under the mentorship of Dr. Nora Noffke, an internationally recognized expert in sedimentary structures and microbial mat sedimentology. Her foundational work on the sedimentological significance of microbial mat shaped the scientific framework that underpins my research. Looking ahead, I plan to expand this study to include sequence stratigraphic correlations and basin-scale facies mapping, integrating GIS and photogrammetric datasets to improve spatial resolution of microbial sedimentary patterns. I also aim to investigate how machine-learning techniques can assist in classifying mat-induced fabrics in petrographic thin sections and digital outcrop models, offering new tools for quantitative sedimentary analysis.
Beyond academic implications, this work contributes to applied sedimentology by offering refined criteria for recognizing biogenic sedimentary structures in subsurface core analysis, an essential aspect of reservoir characterization, environmental geology, and sequence modeling. By enhancing our ability to interpret early diagenetic features within fine-grained clastic systems, this research provides a framework for understanding microbial sediment interactions across deep time and their relevance in stratigraphic record interpretation.