Quantitative and Nuanced Approaches Elucidate Carbon Isotope Records

Earth scientists have leveraged carbon isotope records to interpret Earth history and establish chronostratigraphic frameworks for decades (e.g., Halverson et al., 2005, https://doi.org/10.1130/b25630.1; Kaufman & Knoll, 1995, https://doi.org/10.1016/0301-9268(94)00070-8; Knoll et al., 1986, https://doi.org/10.1038/321832a0; Saltzman & Thomas, 2012, https://doi.org/10.1016/b978-0-444-59425-9.00011-1; Scholle & Arthur, 1980, https://doi.org/10.1306/2f91892d-16ce-11d7-8645000102c1865d). Increasingly detailed and nuanced approaches have been applied to understanding carbon isotope records in light of local- and regional-scale processes that complicate interpretations. The recent work of Gazdewich et al. (2024, https://doi.org/10.1029/2023gc011376) is a prescient example, in which they conduct a series of analyses to constrain the influence of authigenic carbonate burial on the global carbon isotope mass balance during the Late Devonian. Here, I briefly review some recent developments in quantitative approaches to understanding carbon isotope values measured from carbonate rocks (δ¹³C_carb), with a focus on comparisons of measured δ¹³C_carb values, models for understanding what controls δ¹³C_carb values, and correlation tools for aligning δ¹³C_carb stratigraphies. These new approaches are elucidating carbon isotope records across Earth history and may prove to be transformative for our understanding of the global carbon cycle.