Using Carbon Isotope Equilibrium to Screen Pedogenic Carbonate Oxygen Isotopes: Implications for Paleoaltimetry and Paleotectonic Studies

Figure 4

Individual soil pit δ¹³C_org depth profiles of five Guvo Soil Series soils. Differences in surface δ¹³C_org and δ¹³C_org at depth reflect differences in the overlying vegetation, but each of the five profiles becomes asymptotic below ~20 cm in the profile, so δ¹³C_carb values from pedogenic carbonates collected below those depths should be in isotopic equilibrium with their coexisting soil organic matter’s δ¹³C_org value.