Conventional ¹⁴C dating was done in Radiocarbon Laboratories: Geological Institute, Russian Academy of Sciences (Lab ID - GIN - Head L.Sulerzhitsky), in the Dating Laboratory Helsinki University (Lab ID - Hel - Head H.Jungner), Lomonosov Moscow State University (Lab ID - MSU - Heads P.Kaplin and O.Parunin) and in Geographical Research Institute, St. Petersburg State University (lab ID - LU - Head Kh. Arslanov).Calibrated ages were determined as yr BP using Oxcal 4.2 based on the IntCal13 dataset.