Holocene temperature variability in the Black Sea region recorded by speleothem fluid inclusions from Sofular Cave in northern Türkiye

Quantitative paleotemperature reconstructions of the Holocene are crucial for understanding the evolution of the climate system in response to various natural and anthropogenic forcings and shed further light on the so-called “Holocene temperature conundrum” (Liu et al., 2014). In the eastern Mediterranean – Black Sea (EMBS) region, records of Holocene temperature variations in continental interiors are predominately based on palynological reconstructions, specifically, pollen records from lake and peat sediments (e.g., Davis et al., 2003). However, vegetation was severely compromised by human activities since the mid-Holocene period and possibly even earlier (e.g., Fyfe et al., 2018) causing uncertainties regarding the general temperature development over the course of the Holocene. In contrast to these biological paleoclimate archives, quantitative paleotemperature reconstructions can be provided by speleothem fluid inclusions (e.g., Affolter et al., 2019; Bernal-Wormull et al., 2025). Speleothems from Sofular Cave in northern Türkiye are known to be highly sensitive to climatic shifts on orbital to decadal timescales (Fleitmann et al., 2009; Held et al., 2024, 2025), making them an excellent archive for recording Holocene low-amplitude climate change.

Temperature estimates based on fluid inclusion isotope analysis average 11.7 ± 2.6°C for the mid- to late-Holocene period, which is almost identical with the modern cave air temperature of 11.8 ± 0.2°C. Overall, temperatures decrease by approximately 1.5°C from the mid- to late-Holocene (~7 ka – 3 ka BP), most likely related to orbital forcing and altering atmospheric circulation patterns in the EMBS region. The Sofular speleothem record also captures distinct temperature minima associated with the 4.2 ka event and the Little Ice Age. Both time intervals are characterized by a cooling of around 1-3°C within decades, although they differ in hydrological conditions, exhibiting wetter conditions during the 4.2 ka event and a dry period during the Little Ice Age in the Black Sea region.

 

References

Affolter et al., 2019: Central Europe temperature constrained by speleothem fluid inclusion water isotopes over the past 14,000 years, Science Advances, 5.

Bernal-Wormull et al., 2025: Temperature variability in southern Europe over the past 16,500 years constrained by speleothem fluid inclusion water isotopes, Climate of the Past, 21, 1235-1261.

Davis et al., 2003: The temperature of Europe during the Holocene reconstructed from pollen data, Quaternary Science Reviews, 22, 1701-1716.

Fleitmann et al., 2009: Timing and climatic impact of Greenland interstadials recorded in stalagmites from northern Turkey, Geophysical Research Letters, 36 (19), L19707.

Fyfe et al., 2018: Trajectories of change in Mediterranean Holocene vegetation through classification of pollen data, Vegetation History and Archaeobotany, 27, 351-364.

Held et al., 2025: Hydrological variability in the Black Sea region during the last 670,000 years recorded in multi-proxy speleothem records from northern Türkiye, Quaternary Science Reviews, 367, 109534.

Held et al., 2024: Dansgaard-Oeschger cycles of the penultimate and last glacial period recorded in stalagmites from Türkiye, Nature communications, 15(1), 1183.

Liu et al., 2014: The Holocene temperature conundrum, Proceedings of the National Academy of Sciences, 111(34), E3501-E3505.