CONTINENTAL SCIENTIFIC DRILLING OF CRETACEOUS SONGLIAO BASIN: CONTINUOUS HIGH-RESOLUTION TERRESTRIAL ARCHIVES UNDER GREENHOUSE CLIMATE

Today continued anthropogenic CO2 emissions may force the climate to shift to a Cretaceous–like greenhouse climate. Understanding Cretaceous climate from integrated marine and terrestrial records may therefore be helpful for future climate predictions. The Songliao Basin in East Asia is a long-lived lake basin preserving extensive terrestrial sediments in Cretaceous. The Continental Scientific Drilling of Cretaceous Songliao Basin (the SK drilling project) provides a continuous terrestrial record of the whole Cretaceous. Three phases of SK include the SK-1 drilling project (Phase 1, Upper Cretaceous), the SK-2 drilling project (Phase 2, Lower Cretaceous), and the Deep Underground Laboratory project (Phase 3, underground detection and exploration). A multidiscipline research on SK provides important information on the age framework, terrestrial climate change and organic carbon deposition in Cretaceous. Constrained by high quality SIMS U-Pb zircon radiometric ages, magnetostratigraphy, biostratigraphy and cyclostratigraphy, the chronostratigraphic framework of SK provides a basis for correlation between terrestrial records in the Songliao Basin and Cretaceous marine sediments. Multiple paleoclimatic and paleoenvironmental indicators, including sedimentary features, mineralogical and elemental compositions, and stable isotopes, are applied to SK to resolve the terrestrial paleoclimate change. Organic carbon accumulation in the Songliao Basin occurred under bottom water anoxia probably related to sea water incursion, and the higher organic carbon burial rate than marine basins suggests that giant lakes may serve as important sinks of atmospheric CO2.