The occurrences and geochemical characteristics of thorium in iron ore in the Bayan Obo deposit, Northern China

Abstract

The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit. The occurrences, and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analysis, field emission scanning electron microscopy, energy dispersive spectrometer, and automatic mineral analysis software. Results identified that 91.69% of ThO2 in the combined samples was mainly distributed in rare earth minerals (bastnaesite, huanghoite, monazite; 56.43% abundance in the samples), iron minerals (magnetite, hematite, pyrite; 20.97%), niobium minerals (aeschynite; 14.29%), and gangue minerals (aegirine, riebeckite, mica, dolomite, apatite, fluorite; 4.22%). An unidentified portion (4.09%) of ThO2 may occur in other niobium minerals (niobite, ilmenorutile, pyrochlore). Only a few independent minerals of thorium occur in the iron ore samples. Thorium mainly occurs in rare earth minerals in the form of isomorphic substitution. Analyses of the geochemical characteristics of the major elements indicate that thorium mineralization in the Main Ore Body was related to alkali metasomatism, which provided source material and favorable porosity for hydrothermal mineralization. Trace elements such as Sc, Nb, Zr, and Ta have higher correlation coefficients with thorium, which resulted from being related to the relevant minerals formed during thorium mineralization. In addition, correlation analysis of ThO2 and TFe, and REO and TFe in the six types of iron ore samples showed that ThO2 did not always account for the highest distribution rate in rare earth minerals, and the main occurrence minerals of ThO2 were closely related to iron ore types.

This is a preview of subscription content, log in to check access.

Fig. 1

(modified after Fan et al. 2016)

Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

References

  1. Bai G, Yuan ZX, Wu CY, Zhang ZQ, Zheng LX (1996) Demonstration on the geological features and genesis of the Bayan Obo ore deposit. Geological Publishing House, Beijing, pp 24–46

    Google Scholar 

  2. Cantrell KJ, Bryne RH (1987) Rare-earth element complexation by carbonate and oxalate ions. Geochim Cosmochim Acta 51:597–605

    Google Scholar 

  3. Cao RL, Zhu SH, Wang JW (1994) Source materials for the Bayan Obo Fe–REE–Nb ore deposit and problems of the genetic theory. Sci China (Ser B) 24:1298–1307 (in Chinese with English abstract)

    Google Scholar 

  4. Chao ECT, Back JM, Minkin JA, Tatsumoto M, Wang JW, Conrad JE, Mckee EH, Hou ZL, Meng QR, Huang SG (1997) The sedimentary carbonate-hosted Giant Bayan Obo REE–Fe–Nb ore deposit of Inner Mongolia, China: a cornerstone example for giant polymetallic ore deposit of hydrothermal origin. USGS Bull 2143:1

    Google Scholar 

  5. Drew LJ, Meng QR, Sun WJ (1990) The Bayan Obo iron-rare earth-niobium deposit, Inner Mongolia, China. Lithos 26(1):43–65

    Google Scholar 

  6. Du LT (1996) The relationship between crust fluids and mantle fluids. Geosci Front 3:172–180 (in Chinese with English abstract)

    Google Scholar 

  7. Du LT (2000) Outgassing of the earth is a key link for the framework of the whole earth science. Geosci Front 7(2):381–390 (in Chinese with English abstract)

    Google Scholar 

  8. Du LT (2002) The important significance of alkali-metasomatic rock studies. Miner Depos 21:953–958 (in Chinese)

    Google Scholar 

  9. Fan HR, Yang KF, Hu FF, Wang KY, Zhai MG (2010) Zircon geochronology of basement rocks from the Bayan Obo area, Inner Mongolia, and tectonic impications. Acta Pet Sin 26(5):1342–1350

    Google Scholar 

  10. Fan HR, Hu FF, Yang KF, Pirajno F, Liu X, Wang KY (2015) Integrated U–Pb and Sm–Nd geochronology for a REE-rich carbonatite dyke at the giant Bayan Obo REE deposit, Northern China. Ore Geol Rev 63(2):510–519

    Google Scholar 

  11. Fan HR, Yang KF, Hu FF, Liu S, Wang KY (2016) The giant Bayan Obo REE–Nb–Fe deposit, China: controversy and ore genesis. Geosci Front 7(3):335–344

    Google Scholar 

  12. Hanson GN (1980) Rare earth elements in petrogenetic studies of igneous systems. Ann Rev Earth Planet Sci 8:371–406

    Google Scholar 

  13. Hou XZ, Yang ZF, Wang ZJ, Wang WC (2018) Occurrence and distribution of thorium in fluorite-type iron ore in Bayan Obo mine. J Chin Rare Earth Soc 36(3):365–371 (in Chinese with English abstract)

    Google Scholar 

  14. Huang GL, Yin ZP, Ling HF, Deng P, Zhu B, Shen WZ (2010) Formation age, geochemical characteristics and genesis of pitchblende from no. 302 uranium deposit in northern Guangdong. Miner Depos 29(2):352–360 (in Chinese with English abstract)

    Google Scholar 

  15. Institute of Geochemistry, Chinese Academy of Sciences (1988) The geochemical of Bayan Obo deposit. Science Press, Beijing, pp 333–343

    Google Scholar 

  16. Kazimi M (2003) Thorium fuel for nuclear energy. Am Sci 5:408–415

    Google Scholar 

  17. Kynicky J, Smith MP, Xu C (2012) Diversity of rare earth deposits: the key example of China. Elements 8(5):361–367

    Google Scholar 

  18. Lai XD, Yang XY (2013) Geochemical characteristics of the Bayan Obo giant REE–Nb–Fe deposit: constraints on its genesis. J S Am Earth Sci 41:99–112

    Google Scholar 

  19. Lai XD, Yang XY, Liu JY (2012a) Geochemical features and its genesis of the Bayan Obo Fe–REE–Nb formation: new evidence from elements and isotopes. Acta Geol Eng 86(5):801–818

    Google Scholar 

  20. Lai XD, Yang XY, Sun WD (2012b) Geochemical constraints on genesis of dolomite marble in the Bayan Obo REE–Nb–Fe deposit, Inner Mongolia: implications for REE mineralization. J Asian Earth Sci 57(57):90–102

    Google Scholar 

  21. Lai XD, Yang XM, Santosh M, Liu YL, Ling MX (2015) New data of the Bayan Obo Fe–REE–Nb deposit, Inner Mongolia: implications for ore genesis. Precambrian Res 263:108–122

    Google Scholar 

  22. Lai XD, Yang XY, Liu YL, Yan ZQ (2016) Genesis of the Bayan Obo Fe–REE–Nb deposit: evidences from Pb–Pb age and microanalysis of the H8 formation in Inner Mongolia, North China Craton. J Asian Earth Sci 120:87–99

    Google Scholar 

  23. Li T (1976) Chemical element abundances in the earth and it’s major shells. Geochim 3:167–174 (in Chinese with English abstract)

    Google Scholar 

  24. Liu YJ, Cao LM (1987) Introduction to elemental geochemistry. Geological Publishing House, Beijing, pp 81–97

    Google Scholar 

  25. Liu YL, Yang G, Chen JF, Du AD, Xie Z (2004) Re–Os dating of pyrite from Giant Bayan Obo REE–Nb–Fe deposit. Chin Sci Bull 49(24):2627–2631

    Google Scholar 

  26. Liu ZY, Li XD, Meng YN, Wang MT, Huang SH, Han XZ, Zhang B (2016) The style of thorium ore and its control factors in Bayan Obo deposit. J East Chin Univ Technol 39(3):201–209 (in Chinese with English abstract)

    Google Scholar 

  27. Luo MB, Guo GL, Guo GL, Liu CZ (2010) Occurrence state of thorium in Baotou rare earth concentrate. Rare Met 34(3):471–474 (in Chinese with English abstract)

    Google Scholar 

  28. Masuda A, Nakamura N, Tanaka T (1973) Fine structures of mutually normalized rare-earth patterns of chondrites. Geochim Cosmochim Acta 37:239–248

    Google Scholar 

  29. Meng YN, Fan HH (2013) Research on geochemical characteristics of thorium for Julong’an deposit, Xiangshan ore field. Geol J Chin Univ 19(1):148–158 (in Chinese with English abstract)

    Google Scholar 

  30. Smith MP, Campbell LS, Kynicky J (2015) A review of the genesis of the world class Bayan Obo Fe–Ree–Nb deposits, Inner Mongolia, China: multistage processes and outstanding questions. Ore Geol Rev 64(1):459–476

    Google Scholar 

  31. Su WQ, He HJ, Song HF, Li ZH (2005) Research status of recovery of thorium resource of Baotou Bayan Obo ore and application of thorium in nuclear power fuels. Rare Met 29(6):914–918 (in Chinese with English abstract)

    Google Scholar 

  32. Sun SS, McDonough WF (1989) Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders AD, Norry MJ (eds) Magmatism in ocean basins. Geological Society of London, Special Publications, London, pp 313–345

    Google Scholar 

  33. Taylor SR (1964) Abundance of chemical elements in the continental crust: a new table. Geochim Cosmochim Acta 28:1273–1285

    Google Scholar 

  34. Tu GZ (1998) The unique nature in ore composition, geological background and metallogenic mechanism of non-conventional superlarge ore deposits: a preliminary discussion. Sci China (Ser D) S2:1–6

    Google Scholar 

  35. Wu JH, Liu S, Yu DG, Zhang BT (2005) Mantle geofluid and uranium ore-formation model. Uran Geol 4:196–203 (in Chinese with English abstract)

    Google Scholar 

  36. Xiao WJ, Kusky T (2009) Geodynamic processes and metallogenesis of the Central Asian and related orogenic belts: introduction. Gondwana Res 16(2):167–169

    Google Scholar 

  37. Xu GX, Shi CX, Wang DZ, Zhao ZX, Wang DZ, He ZX, Wang NY, Fang SX, Guo MS, Ou YY, Fei WY, Liu YF, Yang YC, Li DY, Tang XY, Gu ZM (2005) Protection of thorium and rare earths in Bayan Obo and avoidance of radioactive pollution of the Yellow River and Baotou. Bull Chin Acad Sci 20(6):448–450 (in Chinese)

    Google Scholar 

  38. Yang XM, Yang XY, Chen TH, Zhang PS, Tao KJ, Le BMJ, Henderson P (2000) Geochemical characteristics of a carbonatite dyke rich in rare earths from Bayan Obo, China. J Rare Earths 18(1):1–8

    Google Scholar 

  39. Yang XY, Sun WD, Zhang YX, Zheng YF (2009) Geochemical constraints on the genesis of the Bayan Obo Fe–Nb–REE deposit in Inner Mongolia, China. Geochim Cosmochim Acta 73(5):1417–1435

    Google Scholar 

  40. Yang XY, Lai XD, Pirajno F, Liu YL, Ling MX, Sun WD (2014) Formation of the super-large Bayan Obo Fe–REE–Nb deposit, Inner Mongolia. Acta Geol Sin Eng 88(S2):478–479

    Google Scholar 

  41. Yang XY, Lai XD, Ren YS, Ling MX, Liu YL, Liu JY (2015) Geological characteristics and their scientific problems of the Bayan Obo Fe–REE–Nb deposit: discussion on the origin of Bayan Obo super-large deposit. Acta Geol Sin 89(12):2323–2350 (in Chinese with English abstract)

    Google Scholar 

  42. Yang XY, Lai XD, Pirajno F, Liu YL, Ling MX, Sun WD (2017) Genesis of the Bayan Obo Fe–Ree–Nb formation in Inner Mongolia, North China Craton: a perspective review. Precambrian Res 288:39–44

    Google Scholar 

  43. Yuan ZX, Bai G, Wu CY, Zhang ZQ, Ye XJ (1992) Geological features and genesis of the Bayan Obo REE ore deposit, Inner Mongolia, China. Appl Geochem 7(5):429–442

    Google Scholar 

  44. Zhang RH (1995) Genetic mineralogy of metasomatism and metallogenesis in Bayan Obo ore area. Earth Sci 20(2):231–236 (in Chinese with English abstract)

    Google Scholar 

  45. Zhang ZQ, Tang SH, Yuan ZX, Bai G, Wang JH (2001) The Sm–Nd and Rb–Sr isotopic systems of the dolomites in the Bayan Obo ore deposit, Inner Mongolia, China. Acta Pet Sin 17(4):637–642

    Google Scholar 

  46. Zhang PS, Tao KJ, Yang ZM, Yang XM, Song RK (2002) Rare earths, niobium and tantalum minerals in Bayan Obo ore deposit and discussion on their genesis. J Rare Earths 20(2):81–86

    Google Scholar 

  47. Zhang YX, Lv HB, Wang J, Liu JY, Meng QW, Huang M (2012) Analysis of ore-forming tectonic settings of the Bayan Obo REE deposit. Acta Geol Sin Eng 86(5):767–770

    Google Scholar 

  48. Zhu XK, Sun J, Pan CX (2015) Sm–Nd isotopic constrains on rare-earth mineralization in the Bayan Obo ore deposit, Inner Mongolia, China. Ore Geol Rev 64(64):543–553

    Google Scholar 

Download references

Acknowledgements

This study was supported by the National Basic Research Program of China (973 Program) (2012CBA01200) and Northern Rare Earth Science and Technology Project (BFXT-2015-D-0002) and (2016H1928).

Author information

Affiliations

Authors

Corresponding author

Correspondence to Xiaozhi Hou.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Hou, X., Yang, Z., Wang, Z. et al. The occurrences and geochemical characteristics of thorium in iron ore in the Bayan Obo deposit, Northern China. Acta Geochim 39, 139–154 (2020). https://doi.org/10.1007/s11631-019-00331-3

Download citation

Keywords

  • Thorium
  • Occurrence state
  • Distribution law
  • Geochemical characteristics
  • Iron ore
  • Bayan Obo deposit