FERROMANGANESE CRUSTS OF MENDELEEV SWELL: THE FEATURES OF COMPOSITION AND FORMATION

The materials for the study are based on the samples obtained during the Russian expedition «Arktika-2012» by dredging the southern part of the Mendeleev Swell. The material composition of ferromanganese crusts was studied, and their age was determined by the technique of excess 230Th. There are three layers diff ering in color and thickness in the section of the crusts. Vernadite, ferroksigit, birnessite, goethite and todorokite have been found among the Mn and Fe minerals. Comparison of the average contents of Mn, Ni, and Co samples with cobalt-rich crusts of the Magellan Mountains indicates their depletion of these elements. At the same time, the maximum content of Co and Ni in the upper crusts is comparable to their content in the crusts of the Atlantic and Indian Oceans. The crusts of the Mendeleev Swell are characterized by a high content of Sc, As, Li, Th and V. Crusts composition is characterized by several major phases: manganese oxides, hydroxides ferrous and non-metallic clay and clastic minerals. Content of identifi ed phases varies from layer to layer. Two main factors dominated in forming crust: deposition of ferromanganese bulk from the water column (with a substantial additional supply of hydrothermal substances in the early stages of their formation) and local impulses of ingress of terrigenous material.

1. Andreyev S. I., Anikeyeva L. I., Kazakova V. E. et al. Kobaltbogatyye rudy Mirovogo okeana. [Cobalt-rich ores of the World Ocean]. St. Petersburg, FGUP VNIIOkeangeologiya, 2002, р. 167. (In Russian).

2. Bazilevskaya E. S., Skolotnev G. S. Zhelezomargantsevyye otlozheniya s khrebta Mendeleyeva (Severnyy Ledovityy okean). [Ferromanganese deposits from the Mendeleev Range (Arctic Ocean)]. Dokl. Akademii nauk, 2015, Vol. 464. no. 6, рр. 708—711. (In Russian).

3. Baturin G. N., Dubinchuk V. T., Ivanov G. I., Sirayev A. I. Osobyy tip zhelezomargantsevogo orudeneniya na dne Arkticheskogo basseyna. [A special type of ferromanganese mineralization at the bottom of the Arctic basin]. Dokl. Akademii nauk, 2014, Vol. 458. no. 4, рр. 436—441. (In Russian).

4. Bogdanova O. Yu. Sravnitelnyy analiz mineralnogo i khimicheskogo sostava zhelezo-margantsevykh gidrotermalno-osadochnykh i sedimentatsionnykh obrazovaniy // Geologiya rifta Tadzhura: nablyudeniya iz podvodnykh apparatov. [Comparative analysis of the mineral and chemical composition of iron-manganese hydrothermal-sedimentary and sedimentary formations // Tadzhur Rift Geology: observations from underwater vehicles], Moscow, Nauka, 1987, рр. 201—206. (In Russian).

5. Bogdanova O. Yu., Gorshkov A. I. Petrografiya i mineralogiya zhelezomargantsevykh rud // Geologiya rifta Tadzhura: nablyudeniya iz podvodnykh apparatov. [Petrography and mineralogy of ferromanganese ores // Geology of Tadzhur rift: observations from underwater vehicles]. Moscow, Nauka, 1987, рр. 194—201. (In Russian).

6. Bogdanova O. Yu., Gorshkov A. I. Mineralogiya nizkotemperaturnykh zhelezistykh i margantsevykh obrazovaniy gidrotermalnogo polya TAG// Gidrotermalnyye obrazovaniya sredinnogo khrebta Atlanticheskogo okeana. [Mineralogy of Low-Temperature Ferrous and Manganese Formations of the Hydrothermal Field of TAG // Hydrothermal Formations of the Middle Ridge of the Atlantic Ocean]. Moscow, Nauka, 1992, рр. 160—172. (In Russian).

7. Dubinin A. V., Uspenskaya T. Yu., Gavrilenko G. M., Rashidov V. A. Geokhimiya i problemy genezisa zhelezomargantsevykh obrazovaniy ostrovnykh dug zapadnoy chasti Tikhogo okeana. [Geochemistry and problems of the genesis of iron-manganese formations of island arcs of the western part of the Pacific Ocean]. Geokhimiya, 2008, no. 12, рр. 1280—1303. (In Russian).

8. Ivanova A. M., Smirnov A. N., Rogov V. S. et al. Shelfovyye zhelezomargantsevyye konkretsii — novyy vid mineralnogo syria arkticheskikh morey Rossii [Offshore ferromanganese concretions - a new type of mineral raw materials in the Arctic seas of Russia]. Miner. resursy Rossii: Ekonomika i upr., 2006, no. 6, рр. 14—19. (In Russian).

9. Kuznetsov V. Yu. Radiokhronologiya chetvertichnykh otlozheniy. [Radio chronology of Quaternary sediments]. St. Petersburg, KOMILFO, 2008, р.312. (In Russian).

10. Melnikov M. E. Mestorozhdeniya kobaltonosnykh margantsevykh korok. [Месторождения кобальтоносных марганцевых корок]. Gelendzhik, FGUGP GNTs «Yuzhmorgeologiya», 2005, рр. 230. (In Russian).

11. Morozov A. F., Petrov O. V., Shokalskiy S. P. et al. Novyye geologicheskiye dannyye. obosnovyvayushchiye kontinentalnuyu prirodu oblasti Tsentralno-Arkticheskikh podnyatiy. [Новые геологические данные, обосновывающие континентальную природу области Центрально-Арктических поднятий]. Region. geologiya i metallogeniya, 2013, no. 53, рр. 34—55. (In Russian).

12. Novikov G. V., Baturin G. N. Sorbtsionnaya aktivnost okeanskikh i morskikh zhelezomargantsevykh konkretsiy i korok razlichnogo khimicheskogo i mineralnogo sostavov. [Sorption activity of ocean and marine ferromanganese nodules and crusts of various chemical and mineral compositions]. Okeanologiya, 1997, Vol. 37, no. 4, рр. 525—531. (In Russian).

13. Novikov G. V., Murdmaa I. O. Ionoobmennyye svoystva okeanskikh zhelezomargantsevykh konkretsiy i vmeshchayushchikh pelagicheskikh osadkov. [Ion-exchange properties of oceanic iron-manganese nodules and enclosing pelagic sediments]. Litologiya i poleznyye iskopayemyye, 2007, no. 2, рр. 153—186. (In Russian).

14. Novikov G. V. Sorbtsionnyye tipy zhelezo-margantsevykh obrazovaniy Mirovogo okeana // Mineralogo-tekhnologicheskaya otsenka mestorozhdeniy poleznykh iskopayemykh i problemy raskrytiya mineralov. [Sorption types of iron-manganese formations of the World Ocean // Mineralogical and technological assessment of mineral deposits and problems of mineral disclosure]. Petrozavodsk, Karel. nauch. tsentr RAN, 2011, рр. 68—82. (In Russian).

15. Platonov M. V.. Tugarova M. A. Petrografiya oblomochnykh i karbonatnykh porod. [Petrography of detrital and carbonate rocks]. Uchebno-metodicheskoye posobiye. St. Petersburg, 2004, р. 72 s. (In Russian).

16. Chukhrov F. V., Gorshkov A. I., Drits V. A. Gipergennyye okisly margantsa. [Manganese hypergenic oxides]. Moscow, Nauka, 1989, р. 208. (In Russian).

17. Bau M., Schmidt K., Koschinsky A. et al. Discriminating between diff erent genetic types of marine ferro-manganese crusts and nodules based on rare earth elements and yttrium // Chemical Geology. — 2014. — 381. — Р. 1—9.

18. Dausmann V., Frank M., Siebert C. et al. The evolution of climatically driven weathering inputs into the western Arctic Ocean since the late Miocene: Radiogenic isotope evidence // Earth and Planetary Science Letters. — 2015. — 419. — Р. 111—124.

19. Hein J. R., Conrad T. A., Frank M. et al. Copper-nickel-rich, amalgamated ferromanganese crust-nodule deposits from Shatsky Rise, NW Pacifi c // Geochem. Geophys. Geosyst. — 2012. — Vol. 13, № 10 (http://www.geomar.de/fi leadmin/personal/fb1/p-oz/mfrank/Hein_et_al_2012.pdf).

20. Hein J. R., Klofas J., Mizell K., Conrad T. A. Rare-Metal-Rich Ferromanganese Mineral Deposits from the Western Arctic Ocean // The 41st Conference of the Underwater Mining Institute. — [S. l.], 2012.

21. Hein J. R., Koschinsky A. Deep-Ocean Ferromanganese Crusts and Nodules // Treatise on Geochemistry. — 2nd ed. — 2014. — P. 273—291.

22. Hein J. R., Mizell K., Koschinsky A., Conrad T. A. Deepocean mineral deposits as a source of critical metals for high- and green-technology applications: Comparison with land-based resources // Ore Geology Rev. — 2013. — P. 1—14.

23. Hein J. R., Schwab W. G., Davis A. S. Cobalt- and platinum-rich ferromanganese crusts and associated substrate rocks from the Marshall islands // Mar. Geol. — 1988. — Vol. 78. — Р. 255—283.

24. Konstantinova N., Cherkashov G., Hein J. R. et al. Ferromanganese Crusts from Mendeleev Ridge, Arctic Ocean // Special Iss. of Ore Geology Rev. — In the press.

25. McLennan S. M. Rare earth elements in sedimentary rocks; infl uence of provenance and sedimentary processes // Rev. Mineral. Geochem. — 1989. — 21. — Р. 169—200.