Rare earth elements are actively used in industry, but the study of their distribution in natural waters in the Obi River basin remains insufficient for water management, geoecological and geological exploration. The least studied levels of rare earth elements content in underground and surface water bodies, which led to the purpose of the work – assessment of the total level of rare earth elements content in river, marsh and underground waters in the basin of the Oba River on the sections of its upper (From the origins of Chulyshman and Katuni in Mountain Altai to the mouth of the River Tom) And the middle current (from the mouth of Tomi, including the catchment of this river, to the mouth of the river Irtysh). The results of the research include a synthesis and analysis of rare earth elements in underground (deposits of Neogen-Quaternary, Paleogenic and Paleozoic age), river (large, medium and small rivers) and marsh (marshes of lowland, transition and upper types) waters in the basin of the Obi River on the sections of its upper and middle current. It has been shown that the highest average concentrations of rare earth elements are characteristic of the underground waters of Paleozoic sediments within the Altae-Sayan hydrogeological fold zone, but comparable levels of content are generally characteristic of the underground waters of quaternary sediments, river waters throughout the studied territory and waters of lowland and transition marshes of lowland areas. The minimum content of rare-earth elements is noted for underground waters of paleogenic deposits, which does not exclude the possibility of isolation of mineral phases approximately represented by phosphates of rare-earth elements.

Pasechnik Elena Yurievna, Candidate of Science (Geology and Mineralogy), Associate Professor, Tomsk Polytechnic University, 30, Lenin av., Tomsk, 634050, Russian Federation, e-mail: paseyu@yandex.ru 

Savichev Oleg Gennadievich, Doctor of Science (Geography), Professor, Tomsk Polytechnic University, 30, Lenin av., Tomsk, 634050, Russian Federation, e-mail: OSavichev@mail.ru 

Domarenko Victor Alekseevich, Candidate of Science (Geology and Mineralogy), Associate Professor, Tomsk Polytechnic University, 30, Lenin av., Tomsk, 634050, Russian Federation, e-mail: domarenkova@tpu.ru 

Vladimirova Olga Nikolaevna, Postgraduate, Tomsk Polytechnic University, 30, Lenin av., Tomsk, 634050, Russian Federation, e-mail: onv-2018@yandex.ru

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