Cenozoic igneous activity in northern China as a mechanism for Late Oligocene climate warming.

Continental rifting is often associated with important magmatism, which significantly influences the Earth's climate. In this study, we use comprehensive 3D seismic and borehole datasets from Northern China to document magma intrusion and associated hydrothermal vent complexes (HTVCs) during the Cenozoic. The aim is to understand their impact on Late Oligocene-Early Miocene climate. Both Mesozoic and Cenozoic magma intrusions occurred in the Bohai Bay Basin, Northern China, while Cenozoic magmatism in the Bohai Bay Basin occurred during Late-Oligocene to Early-Miocene, when the final stage of rifting occurred in the region. Methane produced by Cenozoic magma in the Boxing Sag alone is estimated to be 27.2-820 Gt, which accounts for approximately 3-5% of the total methane produced in Northern China (1760-21,100 Gt). Our study suggests that warm climate during late Oligocene was potentially influenced by intensive rifting related sill emplacements in basins such as the Bohai Bay Basin. Giving the extensively developed Cenozoic magmatic intrusions in the Bohai Bay Basin, our results suggest that, similarly to the Paleocene-Eocene thermal maximum (PETM), igneous activity during Late-Oligocene might played a significant role in driving the Late Oligocene Warming event.