Вестник МГТУ. 2019, Т. 22, № 1.

Вестник МГТУ. 2019. Т. 22, № 1. С. 36-47. DOI: 10.21443/1560-9278-2019-22-1-36-47 Table. Results of heavy concentrate analyses Таблица. Результаты анализа шлиховых проб Sample No. Sample type Primary characteristics of sample Task Sample weight Heavy fraction weight Mineral content Left river bed Alluvial-fluvial 175 kg, washed to gray sand, sieved Diamond, accessories, gold, zircon, rutile, ilmenite 330.0 g 25.4 g Carbon silicide - rare part., chromium-diopside - single part., zircon - 1.3 %, rutile - 0.5 %, ilmenite - 1.6 % Right river bed Alluvial-fluvial 125 kg, washed to gray sand, sieved Diamond, accessories, gold, zircon, rutile, ilmenite 220.0 g 22.8 g Diamond - single part., carbon silicide - tens of part., chromium spinellid - single part., chromium diopside - single part., zircon - 1.5 %, rutile - 1 %, ilmenite - 2.8 % Right coast Alluvial- coastal 250 kg, washed to gray sand, sieved Diamond, accessories, gold, zircon, rutile, ilmenite 350.0 g 26.0 g Carbon silicide - tens of part., chromium dioside - single part., zircon - 2.2 %, rutile - 0.3 % ilmenite - 1 % Conclusion Our research has indicated diamond placers and associated minerals in Riphean sedimentary suites on the Rybachy and Sredny Peninsulas. We have not studied magmatic explosion pipes of kimberlitic composition. Thus, we may conclude that this region lacks profound geophysical research and requires close attention in this respect. We take into account that (a) Riphean sedimentary complexes of the Rybachy and Sredny Peninsulas are formations of the passive continental margin of that time, and (b) the watershed of the Musta-Tunturi Range is close to the study area. Based on that, we suggest that the matter transfer was not significant, just first km or, probably, first tens of km. We believe that bedrocks of diamond-bearing explosion pipes should be prospected for close to the location of the diamond find. Acknowledgments The study has been carried out in the framework of the state orders No. 0149-2019-0005 and No. 0226­ 2019-0053. References 1. Gavrilenko B. V. Minerageny of precious metals and diamonds in the north-eastern Baltic Shield : Synopsis of Dr Thesis. М., 2003. 58 p. 2. Gavrilenko B. V., Mitrofanov F. P., Zozulya D. R., Chikirev I. V., Sorokhtin N. O. [et al.]. Prospective diamond placer in the Kola region // Vestnik MSTU. 2000. V. 3, N 2. P. 235-244. 3. Evdokimov А. N. On possible diamond-bearing content of bottom sediments in the White Sea Throat // Arctic: ecology and economics. 2016. N 2 (22). P. 35-39. 4. Polyakov I. V., Kalinkin М. М. Diamonds and associated minerals in kimberlites and loose deposits on the Tersky coast of the Kola Peninsula. Zapiski RMO (Proceedings of the Russian Mineralogical Society). 1993. V. 122, N 1. P. 96-101. 5. Sorokhtin О. G., Mitrofanov F. P., Sorokhtin N. О. Origin of diamonds and prospective diamond content in the eastern Baltic Shield / ed. A. O. Bogatikov. Apatity : ^ С RAS, 1996. 146 p. 45