We present the first strontium isotope data of Cretaceous marine invertebrates from north-eastern Russia and the Magellan Seamounts. These provide evidence of a late Turonian age (91.2–90.4 Ma) for the upper part of the Penzhinskaya Formation (Koryak Upland) and a late Coniacian date (90.4–86.4 Ma) for the cephalopod-bearing deposits of the Magellan Seamounts. In addition, they yield information on seasonal variations in the ⁸⁷Sr/⁸⁶Sr ratio in marginal marine environments during the late Turonian. These data raise doubts about a previously postulated hiatus spanning the Turonian–Santonian interval. Our results reveal a close temporal correlation between Sr-isotope excursions and the major Oceanic Anoxic Events (OAEs), which suggests a causal link. However, the link between the late Santonian–early Campanian Sr-isotope minimum and Oceanic Anoxic Event 3 (OAE-3) has yet to be fully resolved and requires additional evidence.

我们提供了来自俄罗斯东北部和麦哲伦海山的白垩纪海洋无脊椎动物的第一个锶同位素数据。这些提供了 Penzhinskaya 组（Koryak 高地）上部的晚 Turonian 年龄（91.2-90.4 Ma）和麦哲伦海山的头足类沉积物晚 Coniacian 日期（90.4-86.4 Ma）的证据。此外，它们还提供有关⁸⁷ Sr/ ^{86季节变化的信息}土伦晚期边缘海洋环境中的 Sr 比率。这些数据对之前假设的跨越 Turonian-Santonian 区间的中断提出了质疑。我们的结果揭示了 Sr 同位素偏移与主要海洋缺氧事件 (OAE) 之间的密切时间相关性，这表明存在因果关系。然而，晚桑托世-早坎帕世 Sr 同位素最小值与海洋缺氧事件 3 (OAE-3) 之间的联系尚未完全解决，需要更多证据。