Speleothem Records from the Eastern Part of Europe and Turkey-Discussion on Stable Oxygen and Carbon Isotopes

The region comprising of East Central Europe, South East Europe and Turkey contributed to the SISAL (Speleothem Isotopes Synthesis and AnaLysis) global database with stable carbon and oxygen isotope time-series from 18 speleothems from 14 caves. The currently available oldest record from the studied region is the ABA-2 flowstone record (Abaliget Cave; Hungary) reaching back to MIS 6. The temporal distribution of the compiled 18 records from the region points out a similar to 20 kyr-long period, centering around 100 ka BP, lacking speleothem stable isotope data. The regional subset of SISAL_v1 records displays a continuous coverage for the past similar to 90 kyr for both delta C-13 and delta O-18, with a mean temporal resolution of similar to 12 yr for the Holocene, and >50 yr for the pre-Holocene period. The highest temporal resolution both for the Holocene and the pre-Holocene was achieved in the So-1 record (Sofular Cave; Turkey). The relationship between modern day precipitation delta O-18 (amount weighted annual and winter season mean values; 1961-2017) and climatological parameters was evaluated. The strong positive correlation found in East Central Europe reinforces the link between modern day precipitation delta O-18, temperature and large-scale circulation (North Atlantic Oscillation) expected to be preserved in the speleothem delta O-18 record; while a negative relationship was documented between precipitation amount and oxygen isotope compositions in South East Europe. Variations of delta C-13 values are primarily interpreted as reflecting dry/wet periods across the region. Elevation gradients from three non-overlapping periods of the last similar to 5 kyr indicated elevation gradients around -0.26 parts per thousand per 100 m(-1) for calcite delta O-18.