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

Figure 5

Plot of the relationship between δ¹³C_carb and δ¹³C_org for samples collected >30 cm below the soil surface. The results from different regions and different climatic regimes all fall along the same regression line and the calculated Δ¹³C values closely matches the theoretical value given in equation (1). While δ¹³C_org actually drives δ¹³C_carb, by convention Δ¹³C is δ¹³C_carb - δ¹³C_org, so that is how the data have been regressed here. The solid black line represents the linear regression, the dashed lines the 95% confidence interval, and the grey lines the 95% prediction confidence interval.