Particle size, and the mineral and chemical compositions of oozy muds from Crimean salt lakes and the Dead Sea are presented. Muds can be characterized based on the composition of their salts as carbonate, sulphate or chloride types. Fe–V–Mn–Pb–Y–Mn association in the mud of lakes in the south part of the Kerch Peninsula originates from the weathered iron ores, which supply sedimentary material to the lake basin. Elevated concentrations of Rb, Cu, Zn, Mo, Ni, U in the mud of the Dead Sea are most likely due to the deep metalliferous calcium chloride brines supplying the Dead Sea. In general, muds of Crimean lakes are characterized by a higher content of sulphur than those of the Dead Sea. Size distributions of oozy mud are controlled by the distance from the shore, beach sediments particle size distributions, protection of mud by the overlying layer of brine, position in the section, influence of anthropogenic factors. Brines from the Dead Sea and those from Crimean lakes are chemically distinct, reflecting t