THE SELENGA ORE DISTRICT OF THE BURYAT REPUBLIC: GEOLOGICAL STRUCTURE, MINERAGENY, GEODYNAMICS, DEVELOPMENT PROSPECTS

Purpose. The studies are aimed at the investigation of geological structure and mineragenetic zonation, description of ore clusters, genetic types of ore deposits and geodynamic conditions of their formation, prediction and prospects of future commercial exploration of the Selenga ore district of the Buryat Republic. Methods. The study employs complex structural-geological and mineragenetic researches including thematic, explorative-surveying and geological-prospecting works carried out earlier. The analysis of the material composition of magmatic rocks and strategic raw material ores is performed by means of modern petrological-geochemical and isotope-geochronological methods using the composition of rare and rare-earth elements, microprobe minerals identification as well as isotope (U-Pb, Sm-Nd, Rb-Sr, Sr-Sr, Ar-Ar, O, C etc.) and lithological-biostratigraphic data. Results. It is found that Upper Paleozoic and Early Mesozoic tectono-magmatic structures are widely developed within the ore district. They are associated with the development of the transregional Upper Paleozoic Selenga-Vitim volcano-plutonic belt of riftogenic type as well as with the formation of the West Transbaikalian Mesozoic zone of riftogeneous (intraplate) magmatism. The main commercially important strategic mineral raw material resources of the Selenga ore district which are located in the ore clusters (the Kunaley, Kizhinga, Cheremshanka-Oshurkovo, Tashir et al.) and beyond their bounds are associated with the Late Paleozoic-Mesozoic magmatic activity. It is found that molybdenum and beryllium are the main ore minerals within the district which determine the mineragenetic features of the investigated ore district. Conclusions. The new material characteristics of the Upper Paleozoic and Mesozoic intraplate magmatic complexes, the associated deposits of strategic mineral raw material (Mo, Be, Ti, quartz, fluorite and apatite raw material) and other promising ore objects of copper, gold, uranium and rare-earth-barium-strontium mineralization are obtained. The geodynamic conditions of their formation and the main age boundaries of the ore-forming processes are revealed. The mining prospects of the Selenga ore district and the involvement of this ore potential in the program of the region's economic modernization are estimated.

geological structure, ore district, strategic raw material, deposits, mineragenetic zoning, development prospects

1. Yanshin A.L. Geologicheskaya karta Yuga Vostochnoi Sibiri i Severnoi chasti MNR. Masshtab 1:1500000 [Geological map of the South of Eastern Siberia and the Northern part of the MPR. Scale 1:1500000]. Leningrad: Kartfabrika Vserossijskogo nauchno-issledovatel'skogo geologicheskogo instituta Publ., 1980. (In Russian).

2. Platov V.S., Savchenko A.A., Ignatov A.M., Gorokhovskii D.V., Shor G.M., Alekseenko V.D., Mukhin V.N., Suslova S.V., Platova E.V., Bol'shakova T.V., Shelomentseva T.I. Gosudarstvennaia geologicheskaia karta Rossiiskoi federatsii. Masshtab 1:1000000 (tret'e pokolenie). Aldano-Zabaikal'skaia seriia. List M-48. Ob"iasnitel'naia zapiska [National geological map of the Russian Federation. 1:1000000 (3rd generation). Aldan-Transbaikalian series. Chart sheet M-48. Ulan-Ude. Explanatory note]. Saint Petersburg: Sankt-Peterburgskaja kartfabrika Vserossijskogo nauchno-issledovatel'skogo geologicheskogo instituta Publ., 2009, 271 p. (In Russian).

3. Gordienko I.V., Bulgatov A.N., Ruzhentsev S.V. Minina O.R., Klimuk V.S., Vetluzhskikh L.I., Nekrasov G.E., Lastochkin N.I., Sitnikova V.S., Metelkin D.V., Goneger T.A., Lepekhina E.N. The Late

4. Riphean-Paleozoic history of the Uda-Vitim island arc system in the Transbaikalian sector of the Paleoasian Ocean. Geologiya i geofizika [Geology and Geophysics], 2010, vol. 51, no. 5, pp. 589–614. (In Russian).

5. Gordienko I.V., Nefed'ev M.A. The Kurba-Eravna ore district of Western Transbaikalia: Geological and geophysical structure, types of ore deposits, predictive assessment, and mineral-resource potential. Geologiya rudnykh mestorozhdenii [Geology of ore deposits], 2015, vol. 57, no. 2, pp. 114–124. (In Russian). https://doi.org/10.7868/S0016777015020021

6. Gordienko I.V., Gorokhovsky D.V., Smirnova O.K., Lantseva V.S., Badmatsyrenova R.A., Orsoev D.A. Dzhida ore district: Geological structure, structural and metallogenic zoning, genetic types of ore deposits, geodynamic conditions of their formation, forecasts, and development prospects. Geologiya rudnykh mestorozhdenii [Geology of ore deposits], 2018, vol. 60, no. 1, pp. 1–36. (In Russian). https://doi.org/10.1134/S1075701518010038

7. Gordienko I.V. Sredne- i verkhnepaleozoiskii vnegeosinklinal'nyi magmatizm Sayano-Baikal'skoi gornoi oblasti [Middle and Upper Paleozoic extrageosynclinal magmatism of the Sayan-Baikal mountain

8. area]. Tektonika Sibiri [Tectonics of Siberia]. Vol. 7. Moscow: Nauka Publ., 1976, pp. 82–90. (In Russian).

9. Gordienko I.V. Paleozoiskii magmatizm i geodinamika Tsentral'no-Aziatskogo skladchatovogo poyasa [Paleozoic magmatism and geodynamics of the Central Asian Fault Belt]. Moscow: Nauka Publ., 1987, 240 p. (In Russian).

10. Gordienko I.V., Kuz'min M.I. Geodynamics and metallogeny of the MongolianTransbaikalian region. Geologiya i geofizika [Russian Geology and Geophysics], 1999, vol. 40, no 11, pp. 1545–1562. (In Russian).

11. Yarmolyuk V.V., Kovalenko V.I., Sal'nikova E.B., Budnikov C.V., Kovach V.P. Tectonic magmatic zoning, sources of igneous rocks and geodynamics of the Early Mesozoic Mongolia–Transbaikal Province. Geotektonika [Geotectonics], 2002, no. 4, pp. 42–63. (In Russian).

12. Yarmolyuk V.V., Kozlovsky A.M., Salnikova E.B., Travin A.V., Kudryashova E.A. Early Mesozoic Rift Magmatism of the Central Mongolia: Geochronological Evidence for Evolution of MongolianTransbaikalian Zoned Igneous Province. Doklady Akademii nauk [Doklady Earth Sciences], 2017, vol. 475, no. 6, pp. 669–675. (In Russian). https://doi.org/10.7868/S086956521724015X

13. Tsygankov A.A., Burmakina G.N., Khubanov V.B., Buyantuev M.D. Geodynamics of Late Paleozoic batholith-forming processes in Western Transbaikalia. Petrologiya [Petrology], 2017, vol. 25, no. 4, pp. 395–418. (In Russian). https://doi.org/10.7868/S0869590317030049

14. Litvinovsky B.A., Yarmolyuk V.V., Vorontsov A.A., Zhuravlev D.Z., Posokhov V.F., Sandimirova G.P., Kuz'min D.V. Late Triassic formation stage of the MongolianTransbaikal alkaline-granitoid province: data of isotope-geochemical studies. Geologiya i Geofizika [Russian Geology and Geophysics], 2001, vol. 42, no. 3, pp. 445–456. (In Russian).

15. Tsygankov A.A., Litvinovsky B.A., Jahn B.M., Reichow M.K., Liu D.Y., Larionov A.N., Presnyakov S.L., Lepekhina Y., Sergeev S.A. Sequence of magmatic events in the Late Paleozoic of Transbaikalia, Russia (U-Pb isotope data). Geologiya i geofizika [Russian Geology and Geophysics], 2010, vol. 51, no. 9, pp. 1249–1276. (In Russian).

16. Jahn B.M., Litvinovsky B.A., Zanvilevich A.N., Reichow M.K. Peralkaline granitoid magmatism in the Mongolian-Transbaikalian Belt: evolution, petrogenesis and tectonic significance. Lithos, 2009, vol. 113, рр. 521–539. https://doi.org/10.1016/j.lithos.2009.06.015

17. Reichow M.K., Litvinovsky B.A., Parrish R.R., Saunders A.D. Multi-stage emplacement of alkaline and peralkaline syenite-granite suites in the Mongolian-Transbaikalian Belt, Russia: Evidence from U-Pb geochronology and whole rock geochemistry. Chemical Geology, 2010, vol. 273 (1–2), рр. 120–135. https://doi.org/10.1016/j.chemgeo.2010.02.017

18. Gordienko I.V., Klimuk B.C. Bimodal volcanism of the Tugnuy riftogenic depression (TransBaikal region). Geologiya i geofizika [Russian Geology and Geophysics], 1995, vol. 36, no. 5, pр. 23–37. (In Russian).

19. Yarmolyuk V.V., Vorontsov A.A., Ivanov V.G., Kovalenko V.I., Baikin D.N., Sandimirova G.P. Epochs of bimodal and alkaline granite magmatism in the western Transbaikal region: Geochronological data on the region of Tugnui depression. Doklady Akdemii nauk [Doklady Earth Sciences], 2000, vol. 373, no. 1, pp. 78–83. (In Russian).

20. Kuz'min M.I., Yarmolyuk V.V. Mantle plumes of Central Asia (Northeast Asia) and their role in forming endogenous deposits. Geologiya i geofizika [Russian Geology and Geophysics], 2014, vol. 55, no. 2, pp. 153–184. (In Russian).

21. Donskaya T.V., Windley B.F., Mazukabzov A.M., Kröner A., Sklyarov E.V., Gladkochub D.P., Ponomarchuk V.A., Badarch G., Reichow M., Hegne E. Age and evolution of late Mesozoic metamorphic core complexes in southern Siberia and northern Mongolia. Journal of the Geological Society, 2008, vol. 165, рр. 405–421. https://doi.org/10.1144/0016-76492006-162

22. Nikiforov A.V., Yarmolyuk V.V., Pokrovskii B.G., Kovalenko V.I., Ivanov V.G., Andreeva I.A., Zhuravlev D.Z., Ripp G.S., Vladykin N.V., Korshunov V.V. Late mesozoic carbonatites of western Transbaikalia: Mineralogical, chemical, and isotopic (O, C, S, and Sr) characteristics and relationships to alkaline magmatism. Petrologiya [Petrology], 2000, vol. 8, no. 3, pp. 278–302. (In Russian).

23. Ripp G.S., Kobylkina O.V., Doroshkevich A.G., Sharakshinov A.O. Pozdnemezozoiskie karbonatity Zapadnogo Zabaikal'ya [Late Mesozoic carbonatites of Western Transbaikalia]. Ulan-Ude: Buryat Scientific Centre of Siberian Department of Russian Academy of Sciences Publ., 2000, 224 p. (In Russian).

24. Baturina E.E., Ripp G.S. Molibdenovye i vol'framovye mestorozhdeniya Zapadnogo Zabaikal'ya (osnovnye cherty metallogenii i geokhimii) [Molybdenum and tungsten deposits of Western Transbaikalia (basic metallogeny and geochemistry features)]. Moscow: Nauka Publ., 1984, 152 p. (In Russian).

25. Ignatovich V.I. Mineral base of molybdenum. Razvedka i okhrana nedr [Prospect and protection of mineral resources], 2007, no. 12, pp. 37–43. (In Russian).

26. Gordienko I.V. Evolution of Paleozoic magmatism and endogenous mineralization of the folded frame of the south of the Siberian platform and the geodynamic conditions of its formation. Tikhookeanskaya geologiya [Russian Journal of Pacific Geology], 1992, vol. 11, no. 4, pp. 101–109. (In Russian).

27. Ignatovich V.I., Fil'ko A.S. Sostoyanie i perspektivy uvelicheniya mineral'no-syr'evoi bazy molibdena i vol'frama v Buryatii [Conditions of increasing the mineral material base of molybdenum and tungsten in Buryatia: state and prospects]. Khimiya, tekhnologiya i prirodnoe syr'e molibdena i vol'frama [Chemistry, technology and natural raw material of molybdenum and tungsten]. Ulan-Ude, 1978, pp. 131–140. (In Russian).

28. Skripkina V.V., Vernik V.L., Reif L.I., Ignatovich V.I., Andreev G.V. A new volcanic structure with molybdenum mineralization in Western Transbaikalia. Doklady Akademii nauk SSSR [Doklady of the USSR Academy of Sciences], 1982, vol. 264, no. 6, pp. 1461–1464. (In Russian).

29. Pokalov V.T., Bolokhontseva S.V., Vasin V.V. The Zharchikha Upper Paleozoic mineral occurrence of molybdenum in the breccia pipe in the caledonides of Western Transbaikalia. Izvestiya akademii nauk SSSR. Seriya geologicheskaya [Proceedings of the USSR Academy of Sciences. Geological series], 1985, no. 7, pp. 99–107. (In Russian).

30. Vernik V.L., Ripp G.S. Zharchikhinskoe molibdenovoe mestorozhdenie [The Zharchikha molybdenum deposit]. Vol. 1, b. 2. Moscow: Geoinformmark Publ., 1995, pp. 176–179. (In Russian).

31. Khubanov V.B., Dugdanova E.E., Tsygankov A.A., Buyantuev M.D. Vozrastnye sootnosheniya shchelochnykh i molibdenitsoderzhashchikh granitoidov Selenginskogo molibdenovorudnogo raiona (Zapadnoe Zabaikal'e) [Age correlations of alkaline and molybdenite-containing granitoids of the Selenga molibdenum-ore district (Western Transbaikalia)]. Materialy III mezhdunarodnoi geologicheskoi konferentsii “Granity i evolyutsiya Zemli” [Proceedings of the 3rd International Geological Conference “Granites and evolution of the Earth”]. Ekaterinburg, 2017, p. 330. (In Russian).

32. Bakhtin V.I., Yalovik G.A., Gusev Yu.P., Ignatovich V.I., Lbov V.A. The main minerals of Buryatia. Razvedka i okhrana nedr [Prospect and protection of mineral resources], 2007, no. 12, pp. 15–21. (In Russian).

33. Gordienko I.V. Composition and age of the Tamir suite of volcanogenic rocks, Western Transbaikalia. Izvestiya akademii nauk SSSR. Seriya geologicheskaya [Proceedings of the USSR Academy of Sciences. Geological series], 1980, no. 7, pp. 84–91. (In Russian).

34. Efimov I.I. The Kudara molybdenum-copper-porphyry ore occurrence. Globus [Globe], 2010, no. 5 (13), pp. 42–46. (In Russian).

35. Ginzburg A.I., Zabolotnaya N.P., Novikova M.I., Gal'chenko V.I. The genetic features of fluorite-phenacite-bertlandite mineralization. Razvedka i okhrana nedr [Prospect and protection of mineral resources], 1969, no. 1, pp. 3–10. (In Russian).

36. Kupriyanova I.I., Shpanov E.P. Berillievye mestorozhdeniya Rossii [Beryllium deposits of Russia]. Moscow: GEOS Publ., 2011, 353 p. (In Russian).

37. Lykhin D.A., Yarmolyuk V.V. Zapadno-Zabaikal'skaya berillievaya provintsiya: mestorozhdeniya, rudonosnyi magmatizm, istochniki veshchestva [West Transbaikalian beryllium province: deposits, ore-bearing magmatism, substance sources]. Moscow: GEOS Publ., 2015, 256 p. (In Russian).

38. Pekhterev S.N., Nechepaev E.V., Artamonova N.A., Vologdin M.A., Dukhovskii A.A., Enikeev F.I., Kozhunova S.V., Krutkina O.N., Stupina T.A., Chetverikov M.E., Shor G.M. Gosudarstvennaya geologicheskaya karta Rossiiskoi Federatsii. Masshtab 1:1000000 (tret'e pokolenie). Seriya Aldano- Zabaikal'skaya. List M-49. Ob"yasnitel'naya [National geological map of the Russian Federation. Scale 1:1 000 000 (3rd generation). Aldan-Transbaikalian series. Chart sheet M-49. Explanatory note]. Saint Petersburg: Sankt-Peterburgskaja kartfabrika Vserossijskogo nauchno-issledovatel'skogo geologicheskogo instituta Publ., 2012, 438 p. (In Russian).

39. Takhanova S.S. The management of mineral resources of Republic of Buryatia. Razvedka i okhrana nedr [Prospect and protection of mineral resources], 2017, no. 9, pp. 3–10. (In Russian).

40. Novikova M.I., Zabolotnaya N.P Beryllium-bearing feldspar metasomatites of Mesozoic activation zones. Sovetskaya geologiya [Soviet geology], 1988, no. 12, pp. 92–100. (In Russian).

41. Badmatsyrenova R.A., Badmatsyrenov M.V. The sources of basic magmatism in Western Transbaikalia in the Late Paleozoic (from geochemical and isotope data). Geologiya i geofizika [Russian Geology and Geophysics], 2011, vol. 52, no. 6, pp. 807–818. (In Russian).

42. Zaitsev S.U. Osnovnye osobennosti lokalizatsii uranovogo orudeneniya v slantsevykh kompleksakh Naranskoi ploshchadi [Main features of uranium mineralization localization in Naran area shale complexes]. Tezisy Tret'ego mezhdunarodnogo simpoziuma “Uran: geologiya, resursy, proizvodstvo” [Abstracts of the 3rd international symposium “Uranium, geology, resources, production”], Moscow: Fedorovsky All-Russian Scientific-Research Institute of Mineral Resources Publ., 2013, p. 54. (In Russian).

43. Bulnaev K.B. Naranskoe mestorozhdenie [The Naran deposit]. Mestorozhdeniya Zabaikal'ya [Deposits of Transbaikalia]. Vol. 1, book 2. Moscow: Geoinformmark Publ., 1995, pp. 197–203. (In Russian).

44. Gordienko I.V. Apatitonosnye diority oshurskogo tipa – novyi geneticheskii tip apatitovykh mestorozhdenii [Apatitebearing diorites of the Oshurkovo type – a new genetic type of apatite deposits]. V chteniya pamyati akademika S.S. Smirnova [V Readings to the memory of the Academician S.S. Smirnov]. Chita: Zabaikal'skii filial geograficheskogo obshchestva Publ., 1970, pp. 135–138. (In Russian).

45. Andreev G.V., Gordienko I.V. Kuznetsov A.N., Kravchenko A.I. Apatitonosnye diority Yugo-Zapadnogo Zabaikal'ya [Apatite-bearing diorites of the South-Western Transbaikalia]. Ulan-Ude: Buryatskoe knizhnoe izdatel'stvo Publ., 1972, 200 p. (In Russian).

46. Tsarev D.I., Batueva A.A. Differentsiatsiya komponentov bazitov pri granitizatsii (na primere Oshurkovskogo apatitovogo mestorozhdeniya, Zapadnoe Zabaikal'e) [Differentiation of the basite components under granitization (on example of the Oshurkovo apatite deposit, Western Transbaikalia]. Novosibirsk: Geo Publ., 2013, 135 p. (In Russian).

47. Ripp G.S., Izbrodin I.A., Doroshkevich A.G., Lastochkin E.I., Rampilov M.O., Burtseva M.V. Oshurkovskii bazitovyi pluton: khronologiya, izotopno-geokhimicheskiei mineralogicheskie osobennosti, usloviya obrazovaniya [Oshurskovo basite pluton: chronology, isotope-geochemical mineralogical features, formation conditions]. Novosibirsk: Geo Publ., 2013, 163 p. (In Russian).

48. Borisov A.P., Gal'chenko V.I., Mironov A.G., Korsunov V.M. Cheremshanka quartzite as a basis for the complex development of ore resources of Buryatia. Gornyi zhurnal [Mining Journal], 1999, no. 3, pp. 1–4. (In Russian).

49. Tsarev D.I., Khrustalev V.K., Gal'chenko V.I., Ayurzhanaeva D.Ts. Geology and genesis of the Cheremshanka silica deposit, Western Transbaikalia, Russia. Geologiya rudnykh mestorozhdenii [Geology of ore deposits], 2007, vol. 49, no. 4, pp. 334–345. (In Russian).

50. Zonenshain L.R., Kuz'min M.I., Natapov L.M. Tektonika litosfernykh plit territorii SSSR [Tectonics of lithospheric plates of the USSR territory]. In 2 books, book 2. Moscow: Nedra Publ., 1990, 334 p. (In Russian).

51. Minina O.R., Doronina N.A., Nekrasov G.E., Vetluzhskikh L.I., Lantseva V.S., Aristov V.A., Naugol'nykh S.V., Kurilenko A.V., Khodyreva E.V. Early Hercynides of the Baikal-Vitim Fold System, Western Transbaikalia. Geotektonika [Geotectonics], 2016, no. 3, pp. 63–84. (In Russian). https://doi.org/10.7868/S0016853X16030073

52. Gordienko I.V., Tsygankov A.A. Magmatism and ore formation in various geodynamic conditions of the Sayan-Baikal Fold Region and adjacent territories. Razvedka i okhrana nedr [Prospect and protection of mineral resources], 2017, no. 9, pp. 36–44. (In Russian).

53. Bakhtin V.I., Yalovik G.A. The mineral resource base of the Buryat Republic: state and development prospects until 2020. Razvedka i okhrana nedr [Prospect and protection of mineral resources], 2007, no. 12, pp. 6–15. (In Russian).

54. Gordienko I.V., Bulgatov A.N., Nefed'ev M.A., Orsoev D.A. Geological and geophysical, forecast-metallogenic researches and exploration prospects of North Baikal ore district mineral resources. Izvestiya Sibirskogo otdeleniya Sektsii nauk o Zemle Rossiiskoi akademii estestvennykh nauk. Geologiya, poiski i razvedka rudnykh mestorozhdenii [Proceedings of the Siberian Department of the Section of Earth Sciences, Russian Academy of Natural Sciences. Geology, Prospecting and Exploration of Ore Deposits], 2014, no. 2 (45), pp. 5–18. (In Russian).

55. Gordienko I.V., Roshchektaev P.A., Gorokhovsky D.V. Oka ore district of the Eastern Sayan: Geology, structuralmetallogenic zonation, genetic types of ore deposits, their geodynamic formation conditions, and development prospects. Geologiya rudnykh mestorozhdenii [Geology of Ore Deposits], 2016, vol. 58, no. 5, pp. 405–429. (In Russian). https://doi.org/10.7868/S001677701605004X

56. Petrov O.V. Mineral'no-syr'evoi potentsial nedr Rossiiskoi Federatsii [Evaluation of raw mineral potential of the Russian Federation subsoil]. Vol. 1. Prognozno-metallogenicheskii analiz [Prognostic-metallogenic analysis]. Saint Petersburg: A.P. Karpinsky Russian Geological Research Institute Publ., 2009, 224 p. (In Russian).