Crimean speleothems reveal 50,000 years of climate variability and contrasting controls across the Black Sea region

The northern Black Sea region lies at the intersection of North Atlantic, Mediterranean, and continental Eurasian climate systems, making it highly sensitive to shifts in atmospheric circulation. However, high-resolution archives of hydroclimate and atmospheric dynamics under past boundary conditions are scarce in this region. Here we present a nearly continuous, multi-proxy (δ 18 O, δ 13 C, trace elements) record from two Crimean stalagmites (northern Black Sea region) spanning 52.3–2.6 ka BP, providing new insights into hydroclimate variability along the northern Black Sea margin. The Crimean δ 18 O record is dominated by an orbital-scale, temperature-controlled signal, in contrast to speleothem records from the southern Black Sea margin (e.g., Sofular Cave). This contrast is most pronounced during Marine Isotope Stage 3 (MIS 3), when Crimean δ 18 O values exceed those at Sofular by up to ∼5‰, whereas the gradient gradually diminishes through the deglaciation into the Holocene. These observations indicate fundamentally different controls on precipitation isotopes across the Black Sea basin under the glacial boundary conditions, with temperature-dominated, North Atlantic–driven variability in the north and hydrologic-state control associated with lake–sea transitions in the south. Complementary δ 13 C and trace-element records from Crimea document coherent millennial-scale responses to Greenland Stadials and Heinrich events, reflecting enhanced prior calcite precipitation and reduced soil respiration under cold, dry stadial conditions. Together, these results demonstrate the persistent influence of North Atlantic (westerly) on northern Black Sea hydroclimate across glacial–interglacial transitions and establish the region as a reference for understanding mid-latitude continental climate sensitivity to large-scale atmospheric reorganization.