Abstract The end-Triassic mass extinction coincided with the eruption of the Central Atlantic Magmatic Province, a large igneous province responsible for the massive atmospheric input of potentially climate-altering volatile compounds that is associated with a sharp rise in atmospheric CO2. The extinction mechanism is debated, but both short-term cooling (~10s of years) related to sulfur aerosols and longer-term warming (10,000 yrs) related to CO2 emissions—essentially opposite hypotheses—are suggested triggers. Until now, no temperature records spanning this crucial interval were available to provide a baseline or to differentiate between hypothesized mechanisms. Here, we use clumped-isotope paleothermometry of shallow marine microbialites coupled with climate modeling to reconstruct ocean temperature at the extinction horizon. We find mild to warm ocean temperatures during the extinction event and evidence for repeated temperature swings of ~16 °C, which we interpret as a signature of strong seasonality. These results constitute the oldest non-biomineralized marine seasonal temperature record. We resolve no apparent evidence for short-term cooling or initial warming across the 1-80kyr of the extinction event our record captures, implying that the initial onset of the biodiversity crisis may necessitate another mechanism.

中文翻译：

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温度在三叠纪末大灭绝开始中的作用

摘要 三叠纪末大灭绝与中大西洋岩浆省的喷发同时发生，这是一个大型火成岩省，负责大量大气输入潜在改变气候的挥发性化合物，这些化合物与大气 CO2 的急剧上升有关。灭绝机制存在争议，但与硫气溶胶相关的短期冷却（约 10 年）和与 CO2 排放相关的长期变暖（10,000 年）——基本上与假设相反——都是建议的触发因素。到目前为止，还没有跨越这个关键间隔的温度记录可用于提供基线或区分假设机制。在这里，我们使用浅层海洋微生物的团块同位素古温度测量法结合气候模型来重建灭绝地层的海洋温度。我们发现灭绝事件期间海洋温度从温和到温暖，并且有证据表明温度反复波动约 16 °C，我们将其解释为强烈季节性的特征。这些结果构成了最古老的非生物矿化海洋季节性温度记录。在我们的记录所记录的灭绝事件的 1-80kyr 范围内，我们没有解决短期冷却或初始变暖的明显证据，这意味着生物多样性危机的最初爆发可能需要另一种机制。