Nearly 30 mg of sediment was sampled with steps of 1 cm through the core depth for element content analyses. The sediment was compressed into tablets of 5 mm in diameter and 0.13 g×cm^−2 in the surface density following the methods of Phedorin et al. (2007). The concentrations of elements were measured using the method of X-ray fluorescence analysis using synchrotron radiation at the collective station VEPP 3 (Institute of Nuclear Physics, Novosibirsk, Russia) following the method of Piminov et al. (2016). The concentration of Rb and Ti in the sediment is used as an indicator of terrigenous material accumulation in the sediments and V content as proxy of the redox condition at the bottom (Bodin et al., 2007; Colman et al., 1995; Goldberg et al., 2007). Ratio Y/Rb is used as indicator of volcanic material input (Gorbarenko et al., 2014).