LAUSR

Abstract The major archive of iron deposits in China occur within Precambrian banded irons formations (BIFs). Here we investigate the Wutai complex that represents an Archean to Paleoproterozoic subduction-related arc system between the Ordos and Qianhuai micro-blocks of the central North China Craton (NCC). We report the carbon and oxygen isotopes of calcites from carbonate-rich BIFs, and in situ trace elements (LA-ICP-MS) and sulfur isotopes (ion probe) of pyrites from sulfidic BIFs and carbonate samples with an aim to characterize the nature and genesis of the iron deposits associated with these rocks. The δ13CV-PDB, δ18OV-PDB and δ18OV-SMOW of calcites range from −2.4‰ to −1.1‰, −20.4‰ to −19.3‰ and 9.9‰ to 11‰ respectively, displaying Archean greenstone belt and marine carbonate settings. Pyrite from the BIFs and carbonates are enriched Ni, As, Se, Te, and Pb. Their δ34SCDT values range from −8.8‰ to 7.9‰ with a peak at 0.0‰, comparing with the features of typical Algoma-type BIFs. Our study provides insights into the depositional environment of the BIFs in the Wutai Complex.