Banded iron formation recorded volcanic eruption and sedimentary events during the evolution of the North China Craton

Abstract The main global iron ore reserves are found in banded iron formations (BIFs) from the Precambrian age. They have undergone long-term environmental changes since their formation, attracting much research attention. A large, recently discovered mineral deposit is located in the North China Craton called the Lanling BIF. A Neoarchean Taishan Group BIF of the Algoma type. We analysed trace and major rare earth elements in the present study to characterize their mineral sources and formation environments. The major elements indicate that the Lanling BIF is mainly composed of SiO2 + Fe2O3T with small amounts of Al2O3, MnO, K2O, CaO, MgO, Na2O, P2O5 and TiO2. After PAAS standardization, according to REY analyses, light rare earths are depleted, while heavy rare earths are enriched. In addition, La, Eu, and Y are positive anomalies, while Ce is a slightly negative anomaly. According to the trace elements and REY, Seafloor hydrothermal environments and seawater environments contributed to the ore-forming material. Moreover, when the BIF precipitated, very little crustal material was added. Finally, based on negative Ce anomalies and REY characteristics, it is speculated that BIF formed in reducing conditions in Lanling. They recorded the volcanic eruption and sedimentary events during the evolution of the North China Craton.