Abstract The Black Sea experienced multiple episodes of connection with both the Mediterranean and Caspian seas during the Quaternary. Global sea-level variation has been proposed as the main driver of changes in Mediterranean-Black Sea connectivity, while positive water budgets drove Caspian overspill. We present a new, two proxy, low-resolution record from the Black Sea that allows reconstruction of connectivity history from 430 to 50 ka: dinoflagellate cysts (dinocysts) provide direct evidence for properties of surface waters and strontium isotopes constrain the source(s) of water entering the basin. Dinocysts and 87Sr/86Sr suggest that the Black Sea was isolated from the Mediterranean during global sea-level lowstands associated with glacials MIS 4, 8 and 10. Both proxies also strongly suggest that marine (Mediterranean) water flowed into the Black Sea during the eustatic highstands associated with peak interglacials during MIS 5 and 9. However, while the contribution of marine waters during MIS 5e was similar to the present day, lower 87Sr/86Sr during MIS 9 suggests lower than present input. Connectivity during MIS 11, MIS 7 and MIS 6 is more enigmatic. Lower 87Sr/86Sr than those of the isolated Black Sea and dinocyst assemblages dominated by species of Paratethyan lineage are compatible with input from the Caspian Sea. Dinocyst taxa recovered in MIS 11 can be found in both the Caspian Sea and the Black Sea today. All four interglacials studied contain different dinocyst assemblages, suggesting that different conditions may have prevailed during each warm period. However, high-resolution studies are needed to confirm this observation. Further work on the same sequence could be valuable in elucidating the connectivity history of the Black Sea over the glacial-interglacial cycles of the late Quaternary.

中文翻译：

---

自 430 ka 以来气候驱动的黑海连通性变化：测试双重孢粉学和地球化学方法

摘要 黑海在第四纪经历了多次与地中海和里海的联系。全球海平面变化被认为是地中海 - 黑海连通性变化的主要驱动因素，而正的水预算导致里海溢出。我们提出了一个来自黑海的新的、两个代理的、低分辨率记录，可以重建 430 到 50 ka 的连通性历史：甲藻囊肿（甲藻）为地表水的特性提供了直接证据，锶同位素限制了来源进入盆地的水。Dinocysts 和 87Sr/86Sr 表明，在与 MIS 4、8 和 10 冰川相关的全球海平面低位期间，黑海与地中海隔离。这两个代表还强烈表明，海洋（地中海）水在与 MIS 5 和 9 期间间冰期峰值相关的浮海高位期间流入黑海。 然而，虽然 MIS 5e 期间海水的贡献与今天相似，但 87Sr 较低MIS 9 期间的 /86Sr 表明低于当前输入。MIS 11、MIS 7 和 MIS 6 期间的连接更加神秘。比孤立的黑海低的 87Sr/86Sr 和由 Paratethyan 谱系物种主导的双胞囊组合与来自里海的输入相容。今天在里海和黑海都可以找到在 MIS 11 中恢复的 Dinocyst 分类群。研究的所有四个间冰期都包含不同的双胞胎组合，这表明在每个温暖时期可能存在不同的条件。然而，需要高分辨率研究来证实这一观察结果。对同一序列的进一步研究对于阐明黑海在晚第四纪冰期-间冰期循环中的连通性历史可能很有价值。