Department of Earth &Environmental Sciences, University of Michigan, 2534 C.C. Little Building, 1100 North University Avenue, Ann Arbor, Michigan 48109, USA.
Department of Geological Sciences, University of Florida, 241 Williamson Hall, PO Box 112120, Gainesville, Florida 32611, USA.
Nat Commun. 2016 Jul 5;7:12079. doi: 10.1038/ncomms12079.
The cause of the end-Cretaceous (KPg) mass extinction is still debated due to difficulty separating the influences of two closely timed potential causal events: eruption of the Deccan Traps volcanic province and impact of the Chicxulub meteorite. Here we combine published extinction patterns with a new clumped isotope temperature record from a hiatus-free, expanded KPg boundary section from Seymour Island, Antarctica. We document a 7.8±3.3 °C warming synchronous with the onset of Deccan Traps volcanism and a second, smaller warming at the time of meteorite impact. Local warming may have been amplified due to simultaneous disappearance of continental or sea ice. Intra-shell variability indicates a possible reduction in seasonality after Deccan eruptions began, continuing through the meteorite event. Species extinction at Seymour Island occurred in two pulses that coincide with the two observed warming events, directly linking the end-Cretaceous extinction at this site to both volcanic and meteorite events via climate change.
白垩纪末期(KPg)大灭绝的原因仍存在争议,这是由于难以将两个时间上紧密相关的潜在因果事件的影响区分开来:德干暗色岩火山省的喷发和希克苏鲁伯陨石的撞击。在这里,我们结合已发表的灭绝模式和来自南极洲西摩岛一个无间断扩展 KPg 边界剖面的新的凝聚同位素温度记录。我们记录了与德干暗色岩火山活动同时发生的 7.8±3.3°C 的升温,以及陨石撞击时的第二次较小升温。由于大陆冰或海冰的同时消失,局部变暖可能会加剧。壳内的可变性表明,德干喷发开始后,季节性可能会减弱,这种情况一直持续到陨石事件。西摩岛上的物种灭绝发生了两次脉冲,与两次观察到的变暖事件同时发生,这直接将该地点的白垩纪末期灭绝与火山和陨石事件通过气候变化联系起来。