золото-молибденовая руда, технозем, хвостохранилище, химический элемент, подвижная форма, коэффициент биологического поглощения, давендинское месторождение, восточное забайкалье, gold-molybdenum ore, technosoil, tailing, a chemical element, the mobile form, factor of biological absorption, deposit davenda, eastern transbaikalia, Engineering geology. Rock mechanics. Soil mechanics. Underground construction, TA703-712

New data on the mineral and chemical composition of the ore, host rocks and technosoils of tailings gold-molybdenum deposit Davenda are outlined. The mineral composition of the ore (%): quartz (96), molybdenite (1, but on average 0.26), pyrite (7), chalcopyrite (2), sphalerite (0.07), galena (to.1), sulphosalts (0.02), bismuthinite (0.2), scheelite (up to 0.02), tungsten (up to 0.01), bornite (0.03), tetradymite (to 0.001) emplektite (rare occurrences) and gold (up to1817g/t). In the oxidation zone developed various sulfates, including large (up to10 cm) gypsum crystals, chalkanthite, malachite, azurite, brochantite, molybdenite, ferrimolybdite. The contents of the main chemical elements, which compose technosoils of tailing, exeed their clarks. Exceptions are zinc, tin, and yttrium. Especially high concentration factors for arsenic, bismuth and molybdenum, which indicates the imperfection of applied technologies of the ores enrichment. The distribution of chemical elements in the geotechnogenic system: productive mineral complex (ore + host rock)→soil→technosoils →plants. Revealed the share of Mo, Zn, Cu, Pb mobile form, in technosoils. Identified acid-base characteristics of technosoils. It was found that the most important of the mobile forms is a water-acid-ion exchange, to a much lesser extent - organic elements.