(Table S1) Marine Os isotope record across the Cretaceous-Tertiary boundary@en

Continental flood basalt (CFB) volcanism is hypothesized to have played a causative role in global climate change and mass extinctions. Uncertainties associated with radiometric dating preclude a clear chronological assessment of the environmental consequences of CFB volcanism. Our results document a 25% decline in the marine 187Os/188Os record that predates the Cretaceous-Tertiary boundary (KTB) and coincides with late Maastrichtian warming. We argue that this decline provides a chemostratigraphic marker of Deccan volcanism and thus constitutes compelling evidence that the main environmental consequence of Deccan volcanism was a transient global warming event of 3° to 5°C that is fully resolved from the KTB mass extinction.大陆溢流玄武岩（Continental flood basalt, CFB）火山活动被假说为全球气候变化与生物大灭绝的成因之一。放射性同位素测年相关的不确定性，使得学界难以对大陆溢流玄武岩火山活动的环境效应开展清晰的年代学评估。本研究结果显示，海洋187Os/188Os同位素记录在白垩纪-古近纪界线（Cretaceous-Tertiary boundary, KTB）之前出现了25%的下降，且与晚马斯特里赫特期变暖事件相吻合。我们认为，该同位素下降可作为德干火山活动（Deccan volcanism）的化学地层标志，由此提供了强有力的证据：德干火山活动的主要环境效应是一场幅度为3℃至5℃的短暂全球变暖事件，该事件与白垩纪-古近纪界线生物大灭绝事件完全区分开来。