Superlarge polygenic REE-Fe-Nb deposit (Bayan-Obo type) with reserves of more than 40 million tonnes REE minerals (grading at 3-5.4% REE), 1 million tonnes Nb2O5 and 470 million tonnes Fe. World's largest REE deposit with 120-174 minerals.
The deposit occurs in an east-west trending Mesoproterozoic rift zone along the northern margin of the Sino-Korean Craton. Host strata are quartzite, slate, limestone, and dolomite. The latter is also the main host rock. The orebodies are stratiform and lenticular, with masses, bands, layers, veins, and disseminations. Besides clear features of hot water sedimentation, the deposit also exhibits Mg, Fe, Na and F metasomatism. Sm-Nd monazite isochron age for bastnaesite and riebeckite is 1200 to 1300 Ma, whereas Th-Pb and Sm-Nd age of Ba-REE-F carbonates and aeschynite is 474 to 402 Ma.
References:- Ren Yingchen, Ximen Lulu, and Peng Zhizhong (1983): Daqingshanite: A new mineral recently discovered in China. Geochemistry 2(2), 180-84 (in English).
- Le Bas, M.J., Kellere, J., Tao Kejie, Wall, F., William, C.T., and Zhang Peishan (1992): Carbonatite dykes at Bayan Obo, inner Mongolia, China. Mineralogy and Petrology 46(3), 195-228.
- Zhang Peishan, Yang Zhuming, Tao Kejie, and Yang Xueming (1996): "Mineralogy and Geology of Rare Earths in China", Science Press (Beijing), 226 pp.
- Chao, E.C.T., Back, J.M., Minkin, J.A., Tatsumoto, M., Wang Junwen, Conrad, J.E., McKee, E.H., Hou Zonglin, Meng Qingrun, and Huang Shengguang (1997): The Sedimentary Carbonate-Hosted Giant Bayan Obo REE-Fe-Nb Ore Deposit of Inner Mongolia, China: A Cornerstone Example for Giant Polymetallic Ore Deposits of Hydrothermal Origin. USGS Bulletin 2143. (also at
http://pubs.usgs.gov/bul/b2143/intro.html)
- Smith, M.P., Henderson, P., and Peishan, Z. (1999): Reaction relationships in the Bayan Obo Fe-REE-Nb deposit Inner Mongolia, China: implications for the relative stability of rare-earth element phosphates and fluorocarbonates. Contributions to Mineralogy and Petrology 134, 294-310.
- Smith, M.P., Henderson, P., and Campbell, L.S. (2000): Fractionation of the REE during hydrothermal processes: constraints from the Bayan Obo Fe-REE-Nb deposit, Inner Mongolia, China. Geochimica et Cosmochimica Acta 64(18), 3141-1360.
- Orris, G.J., and Grauch, R.I. (2002): USGS Open-File Report 02-189.
- Hongrui Fan, Yihan Xie, Kaiyi Wang, and Wilde, S.A. (2004): Methane-rich fluid inclusions in skarn near the giant REE–Nb–Fe deposit at Bayan Obo, Northern China. Ore Geology Reviews 25, 301-309.
- Gupta, C.K., and Krishnamurthy, N. (2005): Extractive Metallurgy of Rare Earths. CRC Press (Boca Raton), 484 pp.
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http://wrgis.wr.usgs.gov/open-file/of03-220/DATABASE/lode_deposits.txt
125 entries listed. 80 valid minerals. 12 type localities (valid minerals).
