Relevance. Environmental pollution by mining wastes is one of the most urgent environmental problems. Aim. To determine the degree of soil pollution in the residential areas of Eastern Transbaikalia. Objects. Total soil pollution according to the Saet formula (Zc) was studied in 30 settlements of Eastern Transbaikalia, including 14 settlements related to mining. Methods. In order to determine the degree of soil contamination, the settlements were grouped: settlements at gold ore, molybdenum lead-zinc and rare-metal deposits, as well as settlements not related to mining. The factual material was obtained during the research under the basic projects of the Institute of Natural Resources, Ecology and Cryology of the Siberian Branch of the Russian Academy of Sciences from 2000 to 2022. In addition, published data and materials of the territorial geological funds (Chita) were used. The X-ray fluorescence method was used to determine the concentrations of chemical elements in analytical laboratories of the Geological Institute of SB RAS (Ulan-Ude), ISP-MS of ZAO "SGS Vostok Limited" (Chita). Results. Among the considered groups of settlements the following indicators of total soil contamination degree (Zc) were established: mining settlements of lead-zinc deposits – 68.87; gold deposits – 30.67; molybdenum deposits – 32.25; rare-metal deposits – 0.03; settlements not related to mining activity – 0.32. According to the total degree of soil contamination Zс, the settlements of lead-zinc deposits correspond to extremely hazardous, molybdenum deposits – hazardous; gold deposits – moderately hazardous; the settlements of rare-metal deposits and the ones not related to mining activities – low levels of pollution.

The Amazarkanskoye deposit is confined to the intersection node of the northeastern fault zone with tectonic dislocations of sublatitudinal, northwestern and submeridional directions. The Severnaya and Shirotnaya ore zones with vein-embedded stockwork-type mineralization are distinguished. Carbon-bearing sediments are represented by gneisses of the Paleo-Proterozoic Amazar Formation (AR2am), they are gravitated by zones of vein and disseminated mineralization. Gneisses are characterized by elevated gold contents from 0.05 g/t to 2.54 g/t. In terms of the organic carbon content they correspond to high carbonaceous gneisses. Shales of the Amazar Formation correspond to the terrigenous-carbonaceous formation. They were accumulated in shallow epicontinental basins or in the shelf zone in an island-arc environment. The carbon isotopic composition of graphite inclusions in quartz veins indicates its biogenic nature. It was concluded that carbonaceous gneisses of the Amazar Formation were one of the sources of gold ore mineralization.

The paper presents data on the level of contamination of soil cover and technozems approximately the Khapcheranginsky mining and processing plant with 53 chemical elements. For more than 40 years, the enterprise has not been functioning, and processed rocks are stored on the surface, causing powerful technogenic pollution of the area. Reclamation measures have not been carried out, and tailings are not being properly operated. When analyzing the level of pollution in the settlement, it was found that in the technogenic zone the arsenic content exceeded the Threshold Limit Value (TLV) by 130 times (26 times the excess of the Approximate allowable concentrations (AAC), cadmium - 5,7 AAC, copper - 42 TLV, lead - 26,6 TLV (6,6 AAC), antimony - 1,7 TLV, zinc - 81,5 TLV (8,5 AAC). For the residential zone, excess of standard values was noted for the following elements: arsenic - 20-fold excess of TLV (4 AAC), copper - 17 TLV, lead - 3 TLV, antimony - 1.8 TLV, zinc - 14,5 TLV (1,5 AAC)) For the background territory, an excess of Threshold Limit Value (TLV) for arsenic (13-fold) and zinc (4 TLV) was noted, but this is probably due to the natural geochemical features of this region of southern Transbaikalia. The total pollution by the value of the Saeta index (Zc) in the tailings area was 269,6 units, which characterizes the technogenic zone as extremely polluted, the residential zone had a coefficient value of 75,6, and the background zone 27,7, which indicates a high level of soil contamination chemical elements, some of which are highly toxic. The main contribution to the total pollution index, according to the pollution index, belonged to the elements: As, Bi, Cd, Cu, In, Li, Pb, Sb, Sn, W, Zn, the contents of which in the conditions of the technogenic zone of the village of Khapcheranga are many times higher than the standard values. In terms of the geoaccumulation index (Igeo), the most significant toxic elements in the composition of technozems were arsenic and lead. The same elements together with tin had critical values in terms of the soil enrichment factor (EF (Pb) = 68,3, EF (As) = 61,6, EF (Sn) = 32,4), especially in the conditions of the technogenic zone. Thus, in the territory of the village of Khapcheranga and its environs, geochemical anomalies of natural and technogenic origin with an increased content of heavy metals (zinc, antimony, lead, cadmium) and arsenic, which have high carcinogenic activity, leading to teratogenic effects with immunosuppressive properties, were formed with complex exposureY

The analysis of chemical elements distribution in the main components of natural and technological complexes of ore deposits of Eastern Transbaikalia, including their concentrations in productive ore associations and tailing dumps technozems, was performed. As technogenic objects in the current research the territories changed as a result of mining and processing plants activity at the worked out and operating deposits are considered. Potential toxicity of tailing dumps technozems of different types of deposits was calculated. The actual material was obtained during the research on the basic projects of the Institute of Natural Resources, Ecology and Cryology of SB RAS from 2000 to 2018. In addition, published data and materials from the territorial geological funds (Chita) were used. X-ray fluorescent method was used to determine concentrations of chemical elements in the analytical laboratories of the Geological Institute of Siberian Branch of the Russian Academy of Sciences (Ulan-Ude), ICP-MS CJSC "SGS Vostok Limited" (Chita). Among toxic elements of the first grade, increased arsenic concentrations pose a serious hazard. Thus, As concentrations in technozems of Blagodatsky polymetallic deposit are 9078 ppm, Akatuevsky polymetallic deposit - 8 759 ppm, Lubavinsky gold deposit 1 860 ppm. Comparative analysis of concentrations of toxic elements in technozems of tailing dumps with respect to their content in ores in different types of deposits has significant differences. Concentrations of toxic elements in the tailings dumps of gold and molybdenum deposits with respect to their content in the ores are mainly 20-70%, polymetallic locations 0-10%, in rare metal deposits exceeds 100%. These differences are explained by the peculiarities of the mineral composition of ores and technologies of ore processing in mining and processing plants. It has been revealed that polymetallic and tin polymetallic deposits pose the greatest ecological hazard to the natural environment. So, calculation of toxicity of technozems has shown, that among ore deposits of Eastern Transbaikalia, the most ecological danger is characterized by tailing dumps of Blagodatsky (GEr = 74441) and Akatuevsky (GEr = 61803) polymetallic deposits. Among the reviewed deposits, the least environmental hazard is represented by rare metal and tungsten tailings dumps. Thus, toxicity of technozems of Orlovsky deposit is (GEr = 362), Malo-Kulinsky deposit (GEr = 388).

Российская академия наук • Уральское отделение Минералогия техногенеза-2019 ФЕРРИМОЛИБДИТ В ОТВАЛЕ МОЛИБДЕНОВОЙ РУДЫ БУГДАИНСКОГО МЕСТОРОЖДЕНИЯ (ВОСТОЧНОЕ ЗАБАЙКАЛЬЕ) Г. А. Юргенсон 1 , Р. А

Mine water at some mineral deposits in Transbaikalia contains valued metals commercially recoverable from solutions using zeolite rocks. Experimental impregnation of metal-bearing mine water from Sherlovaya Gora and Bom-Gorphon areas with sodium and ammonium kinds of clinoptilolite rocks from shivyrtuin deposit has been carried out. In the laboratory conditions, metals adsorbed by zeolite rocks are extracted by means of displacement by concentrated ammonium salts with further calcinations of the filtrate up to 500 °С. The metal content of the obtained cakes is conditioned by metal concentrations in solutions, by methods of impregnation and by the eluents applied. Saturation of ammonium types of zeolites with mine water solutions from the Sherlovaya Gora lake and further extraction of adsorbed metals by ammonium acetate yields the recovery of lantanoids of 73%. The obtained results, considering multiple recycling of the sorbent, can be used in development of an efficient technology for extraction of rare earth elements from mine solutions.

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.

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.