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The Huoqiu iron ore field in north-west Anhui province is located in the south-east margin of the North China Craton and hosts large iron resources. Orebodies are hosted in Neoarchean amphibolite facies metamorphic rocks, forming silicon-iron bands from north to south. The area is dominated by an Early Precambrian basement consisting of Neoarchean grey gneisses, amphibolites and metasediments. The gneisses are similar with assemblages of Trondhjemite-Tonalite-Granodiorite in compositions and intercalated with amphibolites. Igneous zircons from gneisses and amphibolites have U-Pb ages of 2.86 and 2.75 Ga respectively, which are interpreted as the crystallisation ages of their protolith. Zircons from amphibolite and gneiss have Hf(t) values of 2.4-15.5 and -3.0-1.5 respectively. The tDM2(Hf) model ages of the gneiss range from 2.87 to 3.14 Ga, which is consistent with tDM1(Hf) ages of amphibolite (2.84-3.16 Ga). The U-Pb-Hf isotopes thus confirm that the gneisses were generated by partial melting of amphibolite. Two granites produce two group Hf isotopic compositions. The older one (1916_x000D_
42 Ma) has Hf(t) values and tDM1(Hf) ages of -9.4-3.4 and 2.24-2.71 Ga respectively, whereas the younger one (1823_x000D_
41 Ma) shows a large variation in Hf(t) values of -18.1-12.5 and tDM1(Hf) model ages of 1.73-2.92 Ga. Geological and geochemical characteristics indicate that the Huoqiu banded iron formations are a Superior-type iron formation rather than an Algoma-type as previously considered.CITATION:Yang, X, Liu, L and Wang, B, 2015._x000D_
Study on the Huoqiu banded iron formation, West Anhui Province, East China , in Proceedings PACRIM 2015 Congress, pp 649-656 (The Australasian Institute of Mining and Metallurgy: Melbourne).