微生物参与前寒武纪条带状铁建造沉积的研究进展

Microbial mineralization in Precambrian banded iron formations

地球演化早期太古代和早元古代大规模的条带状铁建造(BIF)是目前世界上最重要的铁矿资源。已有的稳定同位素组成、分子化石以及岩石磁学性质等证据支持早期微生物广泛参与了BIF的形成。本文评述了微生物参与BIF形成过程中铁搬运和沉淀及其同位素分馏、生物标志物和岩石磁学证据。深入地研究BIF成矿中的微生物矿化贡献,有助于解释BIF形成机制,反演前寒武纪大气—海洋环境演化,以及理解地球早期生命的过程。

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.