The main idea of the presented data was to reveal the micromorphological structure, mineral and chemical compositions of the unique soils, which have been covered with waste mining and processing production of sulfide-tungsten deposits of Transbaikalia for a long time. In comparison with natural alluvial swamp soils, these buried soils are characterized by the increase in content of (i) ferrous neoplasma and (ii) weathered grains of mica and feldspar, and (iii) the density of microaggregates along with the proportions of potentially dangerous chemical elements represented by heavy metals. The technogenic nature of pollution in these soils is confirmed by the accumulation of the following potentially hazardous chemical elements—Cd, Zn, F, Mo, Cu, Ni, As, Co, Pb namely in the upper organogenic horizons. It was revealed that the intensity of soil contamination is affected by the duration of storage of ore dressing waste, composition and level content of toxic elements in it.