Stable isotope ratios (δ¹⁸О and δ²H) were analyzed at the stable isotope laboratory of the Faculty of Geography in the Lomonosov Moscow State University (headed by Prof. Yu. Vasil'chuk) using a Finnigan Delta‐V Plus mass spectrometer applying equilibration techniques. International standards (V ‑ SMOW, GRESP, SLAP) were used for calibration.The values are presented in δ‐notation in per mil (‰) relative to the Vienna Standard Mean Ocean Water (VSMOW) expressed in per mil (‰). Analytical precision was ±0.1‰ for δ¹⁸О and±0.8‰ for δ²H.