Реферат |
The article provides a detailed description of Fe-Ti mineralization in the layered (differentiated) bodies of the Misaelga complex (Southern Ural). Various morphogenetic types of iron and titanium oxides are described: segregation ‘drop’, monomineral precipitates of ilmenite, magnetite, and various ilmenitemagnetite intergrowths and decay structures. The chemical composition of magnetite (in wt.%): TiO2 (from 0.13 to 14.27), Al2O3 (from 0.51 to 21.36), Cr2O3 (from 0.48 to 24.07), MgO (from 0.11 to 6.41), MnO (from 0.05 to 1.0), V2O5 (from 0.23 to 1.16), ZnO (from 0.8 to 5.78), NiO (from 0.13 to 0.73), SiO2 (from 0.52 to 2.75), CaO (0.51) and ilmenite: Cr2O3 (from 0.13 to 1.27), MgO (from 0.27 to 5.5), MnO (from 0.14 to 3.51), V2O5 (from 0.14 to 0.37), Al2O3 (3.0) and NiO (1.4). It is shown that chromium and magnesium in magnetite and ilmenite are present only in the minerals of the picrite horizon, where transitional magnetite → chrommagnetite and ilmenite → picroilmenite varieties are formed as a result of heterovalent isomorphism. Based on the calculation of crystallization temperatures, it was found that segregation of the ore melt occurred at T above ~ 1200 °C; the crystallization temperature of ilmenite–magnetite intergrowths was 712–745 °С, and the decay temperature of the solid solution varied within 588–766 °С. It is concluded that the segregation and gravitational deposition of ore minerals are not antagonistic but are realized at certain stages of the evolution of the melt. Moreover, the mechanisms of localization of the ore substance in a limited volume are governed by the physicochemical parameters and thermobaric conditions of the environment of mineral formation during ore genesis existing in a particular volume of the melt during its crystallization. |
Библиографический список |
1. Smirnov V. I. (Ed.). Ore deposits in the USSR. 2nd revised and enlarged edition. Moscow : Nedra, 1978. Vol. 2. 399 p. 2. Alekseev A. A., Alerseeva G. V. Kusinsko-Kopansky (South Ural) intrusive complex – a fragment of a large Plutonian stratification. Transactions (Doklady) of the USSR Academy of Sciences. Earth Science Sections. 1992. Vol. 232, No. 1. pp. 133–136. 3. Alekseev A. A., Alekseeva G. V., Kovalev S. G. Stratified intrusions on the western shoulder of the Urals. Ufa : Gilem, 2000. 188 p. 4. Kholodnov V. V., Bocharnikova T. D., Shagalov E. S. Composition, age and genesis of magnetite–ilmenite ore of the Middle-Riphean stratified Medvedev Massif (Kusinsko-Kopansky complex in the Southern Ural). Lirosfera. 2012. No. 5. pp. 145–165. 5. Alekseev A. A., Alekseeva G. V., Kovalev S. G. Differentiated intrusions on the western shoulder of the Urals. Ufa : Gilem, 2003. 171 p. 6. Kovalev S. G. Differentiated diabase–picrite rock units on the western shoulder of the South Ural. Ufa, 1996. 99 p. 7. Ernst R. E., Pease V., Puchkov V. N., Kozlov V. I., Sergeeva N. et al. Geochemical characterization of Precambrian magmatic suites of the Southeastern margin of the East European Craton, Southern Urals, Russia. Geological Information Summaries. Ufa, 2006. No. 5. pp. 119–161. 8. Kovalev S. G., Puchkov V. N., Kovalev S. S., Vysotsky S. I. Minerals of the Fe–Ni–Co–Cu–S System in Picrite Intrusions of the Southern Urals: Signatures of Liquation and Differentiation of the Sulfide Melt. Doklady Earth Sciences. 2020. Vol. 492, Iss. 1. P. 311–316. 9. Akio Tsusue. The distribution of manganese and iron between ilmenite and granitic magma in the Ôsumi Peninsula, Japan. Contributions to Mineralogy and Petrology. 1973. Vol. 40, Iss. 4. pp. 305–314. 10. Kretz R. Transfer and exchange equilibria in a portion of the pyroxene quadrilateral as deduced from natural and experimental data. Geochimica et Cosmochimica Acta. 1982. Vol. 46, Iss. 3. pp. 411–422. 11. Saxena S. K., Bhattacharji S., Annersten H., Stephansson O. Energetics of Geological Processes. New York : Springer, 1977. 476 p. 12. Wells P. R. A. Pyroxene Thermometry in Simple and Complex Systems. Contributions to Mineralogy and Petrology. 1977. Vol. 62, Iss. 2. pp. 129–139. 13. Wood B. J., Shohei Banno. Garnet-Orthopyroxene and Orthopyroxene-Clinopyroxene Relationships in Simple and Complex Systems. Contributions to Mineralogy and Petrology. 1973. Vol. 42, Iss. 2. pp. 109–124. 14. Loucks R. R. A precise olivine-augite Mg-Fe-exchange geothermometer. Contributions to Mineralogy and Petrology. 1996. Vol. 125, Iss. 2-3. pp. 140–150. 15. Ariskin A. A., Barmina G. S. COMAGMAT: Development of a Magma Crystallization Model and Its Petrological Applications. Geochemistry International. 2004. Vol. 42. Suppl. 1. pp. 1–157. 16. Nathan H. D., Vankirk C. K . A Model of Magmatic Crystallization. Journal of Petrology. 1978. Vol. 19. pp. 66–94. 17. My ers J., Eugster H. P. The system Fe-Si-O: Oxygen buffer calibrations to 1,500K. Contributions to Mineralogy and Petrology. 1983. Vol. 82. pp. 75–90. 18. Berman R. G. Internally-Consistent Thermodynamic Data for Minerals in the System Na2О-K2О-CaOMgO-FeO-Fe2О3-A12О3-SiO2-TiO2-H2О-CO2. Journal of Petrology. 1988. Vol. 29, Iss. 2. pp. 445–522. 19. Huebner J. S., Sato M. The oxygen fugacity-temperature relationships of manganese oxide and nickel oxide buffers. The American Mineralogist. 1970. Vol. 55. pp. 934–952. 20. Lepage L. D. ILMAT: an Excel worksheet for ilmenite–magnetite geothermometry and geobarometry. Computers & Geosciences. 2003. Vol. 29, No. 5. pp. 673–678. 21. Lindsley D. H., Spencer K. J. Fe-Ti oxide geothermometry: Reducing analyses of coexisting Ti-magnetite (Mt) and ilmenite (Ilm). EOS: Transactions, American Geophysical Union. 1982. Vol. 63, No. 18. pp. 471. 22. Zhong-Jie Bai, Hong Zhong, Naldrett A. J., Wei-Guang Zhu, Gui-Wen Xu. Whole-Rock and Mineral Composition Constraints on the Genesis of the Giant Hongge Fe-Ti-V Oxide Deposit in the Emeishan Large Igneous Province, Southwest China. Economic Geology. 2012. Vol. 107, No. 3. pp. 507–524. 23. Kwan-Nang Pang, Mei-Fu Zhou, Lindsley D., Donggao Zhao, Malpas J. Origin of Fe–Ti Oxide Ores in Mafic Intrusions: Evidence from th e Panzhihua Intrusion, SW China. Journal of Petrology. 2008. Vol. 49, Iss. 2. pp. 295–313. 24. Zhong-Jie Bai, Hong Zhong, Wei-Guang Zhu, Wen-Jun Hu, Cai-Jie Chen. The genesis of the newly discovered giant Wuben magmatic Fe–Ti oxide deposit in the Emeishan Large Igneous Province: a product of the late-stage redistribution and sorting of crystal slurries. Mineralium Deposita. 2019. Vol. 54, Iss. 1. pp. 31–46. 25. Zhong-Jie Bai, Hong Zhong, Rui-Zhong Hu, Wei-Guang Zhu, Wen-Jun Hu. Composition of the Chilled Marginal Rocks of the Panzhihua Layered Intrusion, Emeishan Large Igneous Province, SW China: Implications for Parental Magma Compositions, Sulfide Saturation History and Fe–Ti Oxide Mineralization. Journal of Petrology. 2019. Vol. 60, No. 3. pp. 619–648. 26. Charlier B., Grove T. L. Experiments on liquid immiscibility along tholeiitic liquid lines of descent. Contributions to Mineralogy and Petrology. 2012. Vol. 164, Iss. 1. pp. 27–44. 27. Jakobsen J. K., Veksler I. V., Tegner C., Brooks C. K. Crystallization of the Skaergaard Intrusion from an Emulsion of Immiscible Iron- and Silica-rich Liquids: Evidence from Melt Inclusions in Plagioclase. Journal of Petrology. 2011. Vol. 52, No. 2. pp. 345–373. 28. Coint N., Keiding J. K., Ihlen P. M. Evi dence for Silic ate–Liquid I mmiscibility in Monzonites and Petrogenesis of Associated Fe–Ti–P-rich rocks: Example from the Raftsund Intrusion, Lofoten, Northern Norway. Journal of Petrology. 2020. Vol. 61, No. 4. DOI: 10.1093/petrology/egaa045 29. Lindsley D. H., Epler N. Do Fe-Ti-oxide magmas exist? Probably not! American Mineralogist. 2017. Vol. 102, Iss. 11. pp. 2157–2169. 30. Kholodnov V. V., Shagalov E. S., Bocharnikova T. D., Konovalova E. V. Composition and conditions of ilmenite and titanomagnetite ore formation in two-pyroxene gabbro of Medvedevskoe deposit (Southern Urals). II. Staging of ore genesis as a result of evolution of ore-bearing melt. Litosfera. 2016. No. 2. pp. 48–69. 31. Sharkov E. V., Shistyakov A. V., Shchiptsov V. V., Bogina M. M. Nature of Fe–Ti oxide mineralization in Yelets Ozero syenite–gabbro intrusive (North Karelia, Russia): Structural and textural evidence. Basic Problems in the Science on Endogenous Ore Deposits—New Horizons : Proceedings of the All-Russian Conference in Commemoration of the 120th Anniversary of the Outstanding Russian Scientist, Academician A. G. Betekhtin. Moscow : IGEM RAN, 2017. pp. 361–367. 32. Sharkov E. V., Chistyakov A. V., Shchiptsov V. V., Bogina M. M., Frolov P. V. Origin of Fe–Ti Oxide Mineralization in the Middle Paleoproterozoic Elet’ozero Syenite–Gabbro Intrusive Complex (Northern Karelia, Russia). Geology of Ore Deposits. 2018. Vol. 60, No. 2. pp. 172–200. 33. Neradovskiy Yu. N., Groshev N. Yu., Voytekhovskiy Yu. L., Borozdina S. V., Savchenko E. E. Minerals of platinum, palladium, argentum and goldof the Por’yerechensky titan-bearing complex (Kola peninsula). Vestnik Kolskogo nauchnogo tsentra RAN. 2017. Vol. 9, No. 3. pp. 71–87. |