Microbial mineralization in Precambrian banded iron formations
Wu Wenfang1,2, Li Yiliang3, Pan Yongxin1,2
1. Paleomagnetism and Geochronology Laboratory, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029;
2. Franco-Chinese Biomineralization and Nano-Structures Laboratory, Beijing 100029;
3. Department of Earth Sciences, The University of Hong Kong, Pokfulam, Hong Kong
Late Achaean to Palaeoproterozoic deposition of banded iron formations(BIF)is the most important iron ore resource on Earth.As evident by stable isotopes compositions,fossil molecule,rock magnetic properties,microorganisms such as cyanobacteria,iron-oxidizing and iron-reducing bacteria are suggested to have participated in the deposition of BIF.In this review,we briefly introduced the global distribution of BIF and the environments of early Precambrian Earth; then we went through the recent studies on bacterial mineralization related to the deposition of banded iron,including oxygenic/anoxygenic photosynthesis and dissimilatory iron reduction.Finally,we proposed some challenges and prospectives.We suggest three approaches to understand the microbial mediated deposition of BIF: Searching for organic and inorganic signatures of bacterial mineralization,investigating the microbial participation in modern iron deposition in aquatic environments comparable to the microbial process of BIF,and laboratory microbial mineralization simulation,aiming at promoting the research on BIF formation mechanism.