Abstract and keywords
Abstract (English):
To confirm the presence of geophysical anomaly the isotopic composition of uranium has been studied from the samples extracted from the exploration wells drilled in different years in the territory of the Zolotitskoye ore field of the Arkhangelsk diamondiferous province (ADP). The study was based on the heterochronous deposits of the geologic profile and managed to obtain data on isotopic composition of uranium. For the quaternary deposits and coal formations, which are overburden ones in the Zolotitskoye ore field kimberlites, and in the Vendian rocks, which enclose kimberlites, the average values of isotopic ratio $^{234}$U/$^{238}$U did not exceed~1. Most samples from the near-contact zone, which are represented by the upper Vendian deposits and by the peripheral part of crater facies of pipes, contained excessive amounts of the daughter isotope $^{234}$U. The generation of high $\gamma = ^{234}$U/$^{238}$U values is explained as being related to the geologic structure of the near-contact zone. The particular features of the $^{234}$U isotope distribution are consistent with the tectonic and substantial changes in the rocks within the near-contact zone. This phenomenon has also been evidenced by several other investigators. The generation mode of non-equlibrium uranium with the excessive $^{234}$U content is explained by the dynamics and circulation of underground waters along the tectonic fractures bounding the pipes. The empirical data obtained in the course of the laboratory tests allow to conclude with a certain degree of scepticism that non-equilibrium uranium in enclosing rocks relates to kimberlite magmatism in the ADP territory. In turn, non-equilibrium uranium with the excessive content of $^{234}$U, which was discovered in the geologic profile of enclosing Vendian deposits, may be considered as the local indirect evidence of ADP kimberlite bodies. However, when estimating the prospecting areas for availability of the kimberlite magmatism in the geologic profiles of exploration wells, the non-equilibrium state of uranium should be considered only in conjunction with the kimberlite signs.

Non-equilibrium uranium, kimberlites, alpha-activity, isotope fractionation, geochemical indicators
Publication text (PDF): Read Download

1. Androsov, E. A., et al. On structural control of the location of kimberlite bodies on the example of the Arkhangelsk kimberlite province // Efficiency of Forecasting and Prospecting for Diamond Deposits: Past, Present and Future (Diamonds-50) - Saint Petersburg: FGUP VSEGEI., 2004. - p. 9.

2. Antonov, Yu. V., Zhavoronkin, V. I., Slyusarev, S. V., Klyuchnikov, V. I., Slyusarev, A. N. Possibilities of the method of vertical gradient of gravity in the case of a sorting of magnetic anomalies of the tube type, // Bulletin of Voronezh University. Geology, 2004. - no. 1 - p. 153.

3. Arbuzov, S. I., Rihvanov, L. P. Geochemistry of Radioactive Elements. Tutorial - Tomsk: Publishing house of Tomsk Polytechnic Institute., 2009. - 315 pp.

4. Bogatikov, O. A., et al. Arkhangelsk Diamondiferous Province (Geology, Petrography, Geochemistry and Mineralogy) - Moscow: Publishing house of the Moscow State University., 1999. - 524 pp.

5. Chalov, P. I., et al. On the spatial correlation of the anomalous excess of $^{234}$U in groundwater and mercury-antimony mineralization of the telethermal type, // Dokl. AN SSSR, 1990. - v. 312 - no. 3 - p. 580.

6. Chalov, P. I. (Ed.) Methodical guide on uranium-isotopic modeling of groundwater dynamics in conditions of active water exchange - Bishkek: Ilim., 1991. - 88 pp.

7. Cyganov, V. A., et al. Modern aerogeophysical technologies - as a basis for geological and prognostic-mineragenic maps of the new generation // Collection of scientific works ``Congress of graduates of the Geological Faculty of the Moscow State University on May 26, 2004'', edited by Khmelevsky V. K. - Moscow: MSU., 2004. - p. 151.

8. Frolov, A. A., et al. Carbonatites and Kimberlites (Mutual Relations, Mineralogy, Forecast) - Moscow: NIA-Priroda., 2005. - 540 pp.

9. Glavatskih, S. P. Geochemical criteria and methods for prospecting diamondiferous kimberlites (on the example of the Arkhangelsk kimberlite prov.) - Moscow: IMGRE., 1992.

10. Gubajdullin, M. G. Geoenvironmental Conditions for the Development of Mineral Resources in the European North of Russia - Arkhangelsk: M. V. Lomonosov PSU., 2002. - 310 pp.

11. Har'kiv, A. D., Zinchuk, N. N., Kryuchkov, A. I. Native Diamond Deposits of the World - Moscow: Nedra., 1998. - 555 pp.

12. Ignatov, P. A., et al. Paleotectonic structures of the Zimneberegov Diamond Area of the Arkhangelsk Region, // Bull. MOIP. Otd. Geol., 2008. - no. 3 - p. 13.

13. Ignatov, P. A., et al. Reconstruction of kinematics of faults in closed areas according to the analysis of micro-faults in the core, // Izvestiya VUZov, Geology and Exploration, 2011. - no. 3 - p. 55.

14. Ignatov, P. A., et al. Fold and ruptural deformations in the host and overlying strata in the open-pit mining of the Arkhangelsk kimberlite pipe, // Rudy i Metally, 2012. - no. 1 - p. 42.

15. Ignatov, P. A., et al. Types of clarified reddish kimberlites of the Vendian-Cambrian species of the Zimneberegov area of the Arkhangelsk Region, // Izvestiya VUZov, Geology and Exploration, 2015. - no. 2 - p. 15.

16. Kiselev, G. P. Even Uranium Isotopes in the Geosphere - Ekaterinburg: UB RAS., 1999. - 220 pp.

17. Kiselev, G. P. The forecast of mineral deposits and contamination of the geological environment by the uranium-isotope methods - Arkhangelsk: IEEP UB RAS., 2005.

18. Kiselev, G. P., et al. Nonequilibrium uranium in the rocks of the Mezen syneclise // Materials of the IV Youth Scientific Conference ECOLOGY - Arkhangelsk: IEEP UB RAS., 2011. - p. 29.

19. Kiselev, G. P., Yakovlev, E. Yu., Druzhinin, S. V., Zykov, S. B., Bykov, V. M., Ocheretenko, A. A. Uranium isotope composition of kimberlites, the enclosing and overburden deposits of the Zolotitskoye ore field - Moscow: GS RAS., 2018.

20. Kontarovich, R. S., Cyganov, V. A. Problems and Prospects for the Development of Geophysical Technologies in the Arrivals of Diamond Core Areas, // Geophysics, 2000. - no. 4 - p. 52.

21. Korotkov, Yu. V. On the issue of the allocation and tracing of discontinuous violations by the characteristic changes in conductivity in the sedimentary strata, // Geophysical Research, 2011. - v. 12 - no. 4 - p. 81.

22. Kutinov, Yu. G., Chistova, Z. B. Hierarchical Series of Manifestations of Alkaline-Ultrabasic Magmatism in the Arkhangelsk Diamondiferous Prov., Their Reflection in Geological and Geophysical Materials - Arkhangelsk: IEEP UB RAS. IPP ``Pravda Severa''., 2004. - 281 pp.

23. Lapin, A. V., Tolstov, A. V. Geochemical types of kimberlites // Alkaline Magmatism and its Ore Content - Kiev: Logos., 2007. - p. 139.

24. Lutts, B. G., Mineeva, I. G. Uranium and thorium in Kimberlites of Siberia, // Geochemistry International, 1973. - no. 11 - p. 1721.

25. Magomedova, A. Sh., Udoratin, V. V. Bulk activity of radon explosion tubes and magnetic anomalies of Middle Timan // Materials of the XVII Ural Youth Scientific School on Geophysics - Ekaterinburg: IHF UB RAS., 2016. - p. 110.

26. Magomedova, A. Sh., Udoratin, V. V., Ezimova, Yu. E. Reflection of fault zones and blast tubes of Middle Timan in geophysical fields, // Bulletin of the IG Komi Scientific Center UB RAS, 2015. - no. 10 - p. 28.

27. Malyshev, V. I. (Ed.) The method for measuring the specific activity of uranium isotopes ($^{238}$U, $^{234}$U, $^{235}$U) in samples of soils, soils, bottom sediments, rocks and building materials based on them using an alpha-spectrometric method with radiochemical preparation - Moscow: VIMS., 2013. - 18 pp.

28. McDowall, G., Koketso, H. Radon emanometry over some kimberlites and lamproites in Southern and Western Botswana // 53rd EAEG Meeting, , 1991.

29. Mwenifumbo, C. J., Kjarsgaard, B. A. Gamma-ray logging and radioelement distribution in the Fort de la corne kimberlite pipe 169, // Exploration and Mining Geology, 1999. - v. 8 - no. 12 - p. 137.

30. Paul, D. K., Gale, N. H., Harris, P. G. Uranium and thorium abundances in Indian kimberlites, // Geochimica et Cosmochimica Acta, 1977. - v. 41 - no. 2 - p. 335.

31. Ramadass, G., SubhashBabu, A., Udaya Laxmi, G. Structural analysis of airborne radiometric data for identification of kimberlites in parts of Eastern Dharwar Craton, // International Journal of Science and Research, 2015. - v. 4 - no. 4 - p. 2375.

32. Sablukov, S. M. Some Features of the Internal Structure of Kimberlite Pipes - Moscow: TsNIGRI., 1987. - 37-41 pp.

33. Shirobokov, V. N. Some features of the deep structure of the Zimneberezhny diamondiferous region, // Exploration and Protection of Mineral Resources, 1997. - no. 5 - p. 21.

34. Smyslov, A. A. Uranium and Thorium in the Earth's Crust - Leningrad: Nedra., 1974. - 231 pp.

35. Stankovskij, A. F. Wend of the South-Eastern White Sea, // Exploration and Protection of Mineral Resources, 1997. - no. 5 - p. 4.

36. Stognij, V. V., Korotkov, Yu. V. Search for Kimberlite Bodies by the Method of Transient Processes - Novosibirsk: Malotirazhnaya tipografiya 2D., 2010. - 121 pp.

37. Titaeva, N. A. Geochemistry of Natural Radioactive Decay Series - Moscow: GEOS., 2005. - 328 pp.

38. Tihonov, A. I. Nonequilibrium Uranium in Conditions of Active Water Exchange and its Use in Geology and Hydrogeology - Cheboksary: Publishing house L. A. Naumova., 2009. - 458 pp.

39. Vasil'ev, I. D. The geological structures in the contact zone of the Arkhangelsk pipe and their use for prospecting of primary diamond deposits in the Zimneberezhnoy district - Moscow: MGRI-RGGRU., 2010.

40. Verzhak, V. V., et al. The experience in diamond deposits searching in the Arkhangelsk diamond province and adjacent areas or the north of the East European Platform // Problems of Forecasting and Searching of Diamond Deposits in Covered Spaces: Proc. Conf. Devoted to the 40th Anniversary of the Yakut Research Geological Exploration Company of Central Research Institute of Geological Survey ALROSA - Yakutsk: JSC., 2008. - p. 308.

41. Yakovlev, E. Yu., Kiselev, G. P., Druzhinin, S. V. Nonequilibrium uranium in kimberlites and host rocks of the Pionerskaya deposit M. V. Lomonossov, // Bulletin NArFU. Series of Natural Sciences, 2016. - no. 1 - p. 19.

42. Zaripov, N. R. Clarification of the red-colored rocks of the Zimneberezhny diamondiferous region of the Arkhangelsk province and the Nakynsky diamondiferous field of the Yakut province, its connection with the kimberlite control structures - Arkhangelsk: MGRI-RGGRU., 2017.

43. Zaripov, N. R. The first data on radiation defects in sedimentary rocks in the Zimneberegov district of the Arkhangelsk region Earth sciences. Current status // Materials of the II All-Russian Youth Scientific-Practical School-Conference - Novosibirsk: NGU., 2014. - p. 106.

44. Zverev, V. L., et al. Uranium Isotopes in Kimberlite Magmatism in the Eastern Siberia, // Report of the Academy of Science of the USSR, 1979. - v. 245 - no. 4 - p. 946.

45. Zverev, V. L., et al. The Separation of Uranium Isotopes in the Process of Kimberlite Magmatism, // Geochemistry International, 1976. - no. 12 - p. 1884.

Login or Create
* Forgot password?