Bayan Obo deposit (Bayun-Obo deposit; Baiyunebo deposit), Bayan Obo, Bayan Obo Mining District, Baotou League (Baotou Prefecture), Inner Mongolia Autonomous Region, China
|Latitude & Longitude (WGS84):||41° 47' 44'' North , 109° 58' 9'' East|
|Latitude & Longitude (decimal):||41.79583,109.96944|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
Super large polygenic REE-Fe-Nb deposit (Bayan-Obo type), discovered as an iron deposit in 1927. REE minerals were discovered in 1936, and Nb-bearing ores in the late 1950s. Reserves are estimated at more than 40 million tons of REE minerals grading at 3-5.4% REE (70% of world's known REE reserves), 1 million tons of Nb2O5 and 470 million tons of iron. The deposit also contains a vast amount of fluorite, which is contained in all ore types; reserves are estimated at 130 million tons.
The ore is transported to the industrial city of Baotou for processing (hydrometallurgical leaching). There, liquid waste fills a 10 km2 surface pool (coordinates: 40.65 N, 109.70 E).
Bayon Obo is the world's largest REE deposit. The fluorite content of the ores also makes it the world's largest fluorite deposit.
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.
Aegirine from metamorphic rocks associated with the ore is peculiar in being colourless in thin section, possibly due to the lack of charge transfer transitions.
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded from this region.
Mineral ListMineral list contains entries from the region specified including sub-localities
128 valid minerals. 15 (TL) - type locality of valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
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252.17 - 541 Ma
|Paleozoic intrusive and metamorphic terranes|
Age: Paleozoic (252.17 - 541 Ma)
Comments: Mixtures of metamorphic and intrusive or plutonic rocks, tracts known as crystalline, migmatitic terranes, moderately to highly metamorphosed rocks of unknown origin with or without intrusions. This classification is inherently prone to variable interpretation, as other compilers might distinguish some packages by their metamorphic or gneissic protoliths, and the associated age ranges may be more variable.
Lithology: Intrusive and metamorphic terranes
Reference: Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.