Carbon isotope data of terrestrial organic matter (δ13CTOM) obtained in Hokkaido, northern Japan, from the marine Cretaceous Yezo Group along the northwestern Pacifi c margin elucidated a detailed chemostratigraphy for the Turonian Stage in this region of East Asia. Chemostratigraphic intra-basin correlation reveals three positive δ13CTOM events in the Middle-Upper Turonian of the Yezo Group. δ13CTOM fl uctuations in these events show similar patterns in the Yezo Group, indicating that terrestrial organic matter is mixed suffi ciently before deposition in the Yezo Basin. These δ13CTOM events are correlated with previously documented δ13Ccarbonate events in Europe (the Lulworth-Round Down, Glynde-Pewsey, and Late Turonian Events) based on global biostratigraphy. Our chemostrati graphic correlations strengthen the use of these δ13C events for global correlation of the Turonian marine successions. In addition, global correlation of Turonian marine and terrestrial δ13C events identifi es changes in isotopic difference between δ13CTOM and δ13Ccarbonate (ΔTOM-carbonate), which are interpreted to refl ect changes in atmospheric pCO2 levels, and climate-driven stresses of humidity and soil processes. In earlier stages of Turonian, ΔTOM-carbonate values are increased. Elevated atmospheric pCO2, and increased humidity and soil processes in enhanced greenhouse conditions during mid-Turonian, are interpreted to enlarge ΔTOM-carbonate values. In later stages of Turonian, ΔTOM-carbonate values are at a constant level, and the loweringof atmospheric pCO2 or decrease of climate stress related to the diverse paleoclimatic cooling is interpreted to have restored the ocean-atmosphere δ13C trends.
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