中文摘要：

根据形貌识别以及分子生物学最新研究结果,包括Gallionella ferruginea,Leptothrix ochracea和Mariprofundus ferrooxydans在内的嗜中性Fe氧化菌在现代甚至古代热液喷口系统的Fe氧化物沉积体的形成中起到了重要作用。对于现代热液喷口系统而言,还原性羽流进入氧化性海水时形成的氧化还原过渡带是嗜中性Fe氧化菌最重要的生存环境,它们能在此环境中与Fe的无机氧化机制展开有效竞争,藉此获取生存所必须的能量。此外,通过静电吸引和表面活性基团的键合作用,细胞能在其表面和附属器官形成Fe氧化物壳层,从而形成与细胞自身相态相似的各种丝缕状结构。丝缕状结构生长到一定程度,就会阻滞热液流体和海水混合,进而在丝缕体交织成的网络内发生传导性热冷却,使流体中的Si达到饱和,在Fe氧化物表面沉淀下来,形成现代热液喷口系统的Fe-Si＂二期次＂复合生长结构。与现代Fe-Si沉淀类似的古代条带状Fe建造（B IF）沉积体的近期研究成果显示,Fe的来源很可能是前寒武纪时的热液喷口系统。由于B IF形成的海洋环境处于整体缺氧状态,早期营光合作用的微生物以及与现代类似的嗜中性Fe氧化菌很可能都参与了这个过程。

英文摘要：

Hydrothermal Fe-Si oxide deposits are ubiquitous in the hydrothermal vent sites at mid-ocean ridge and back-arc seafloor spreading centers.According to the recognitions of micron-scale filamentous textures and the results of molecular biology,neutrophilic Fe-oxidizing bacteria including Gallionella ferruginea,Leptothrix ochracea and the novel Mariprofundus ferrooxydans（PV-1 Strain） are considered to have a significant role in the formations of Fe-Si oxides deposits of the hydrothermal systems.These bacteria are capable of autotrophic metabolism with Fe2＋ as the sole electron donor,increas the rate of Fe2＋ oxidation,and then get energy for their growth.Electrostatic attraction along with the organic functional groups lead to the precipitations of iron oxides on the surface of abundant filamentous microbial structure that closely resemble the morphology of the Fe-oxidizing bacteria.Then the filaments were combined together to form a three-dimensional network.Novel observations were made of the Fe-Si framework of the network revealing the composite structure of Fe-rich filamentous in the core and the pure opal crust in the outer to form the ＂two-generation structure＂.This indicates that the large-scale silica precipitation caused by conductive cooling often takes place after the construction of the network.Recent studies about the Banded Iron Formations（BIF） considered to be the analog of modern hydrothermal Fe-Si deposits indicate an ancient hydrothermal origin for the iron.Moreover,owing to the pervasive anoxic state when the BIFs formed,the photosynthetic organisms for instance,cyanobacteria and the neutrophilic Fe-oxidizing bacteria are proposed to be involved in the ancient BIFs formations.