Eccentricity and Obliquity Forcing of Late Cretaceous to Paleocene Climate Changes

The late Cretaceous to Paleocene is one of the typical ‘greenhouse’ intervals of geological history. Therefore, reconstructing paleoclimate changes during the late Cretaceous–Paleocene and understanding its forcing mechanisms are of great significance for evaluating the response of the Earth system to future greenhouse climates. Although significant progress has been made in the study of paleoclimate in the late Cretaceous–Paleocene, spatial and temporal gaps still exist, limiting our understanding. To address this issue, this study compiles high-resolution globally distributed paleoclimatic records from the GZ-X501 section (Gonjo Basin, Southeast Tibet), well SK-1n (Songliao Basin, NE China), the Sigou section (Shanyang Basin, Shaanxi, China), the Datang section (Nanxiong Basin, South China), well 6305/8-2 (Norwegian Sea Basin), the Zumaia section (Basque-Cantabrian Basin, Spain), the Contessa Highway section (Umbria-Marche Basin, Italy), IODP Site U1403 (Newfoundland margin), ODP Sites 1209 and 1210 (equatorial Pacific), ODP Site 1262 (South Atlantic), and the Espírito Santo Basin (subtropical SW Atlantic). These records are analyzed to investigate the role of astronomical forcing in controlling global climate variability. The results indicate that late Cretaceous to Paleocene global climate was paced by eccentricity and obliquity cycles. The strength of the obliquity signal does not show a clear correlation with latitude but correlates with temperature changes: higher temperatures correspond to weaker obliquity signals. This is hypothesized to result from a reduced meridional temperature gradient during warmer periods, which may diminish the effectiveness of obliquity in pacing climate via its control on meridional insolation gradients.