Perturbations of the global carbon cycle across the Cretaceous–Palaeogene boundary

Abstract Two hyperthermal events with different carbon cycle perturbations occurred across the Cretaceous-Palaeogene (K-Pg) boundary, i.e., the late Maastrichtian Warming Event (LMWE) and the early Danian Dan-C2 event. However, the roles played by Deccan volcanism and orbital forcing in these two hyperthermals are still debated. Here, we obtain a new terrestrial δ¹³Ccarb record in the Nanxiong Basin (southeastern China) and compare it with marine records. The results show that both the LMWE and Dan-C2 event can be well distinguished in the terrestrial record and that the Dan-C2 event is characterized by a typical hyperthermal event; however, the specificity of the context under which this event occurred has resulted in inconsistencies in the marine records. In addition, the δ¹³C excursion during the LMWE was more muted and prolonged than that during the Dan-C2 event, and the short-eccentricity cycle disappeared in the marine record during the LMWE, indicating that Deccan volcanism perturbed the carbon cycle during the LMWE, while the Dan-C2 event was less influenced by volcanic perturbation.