How Erosion Affects Carbon Isotopic Trends: The Late Permian McKittrick Limestone (2024)

Our ability to predict the nature of future climate change depends on our understanding of the carbon cycle. Much of this understanding comes from studies of ancient carbon cycles, which can be studied through tools such as isotopic data recorded in rocks. These tools assume that observable trends accurately reflect changes through time. However, sediment-to-rock forming processes and erosion can violate this assumption. In this project we consider the impact of relatively small-scale (<1 meter) erosion on documented carbon isotopic trends of the Late Permian McKittrick limestone located in McKittrick Canyon in the Guadalupe Mountains National Park, Texas. We identified an ancient submarine channel in the McKittrick Limestone that forms the basis of this study. By measuring and collecting samples from two sections within the outcrop, we were able to document how erosion impacted the carbon isotopic signal.