摘要
作者采用洋底水-岩-微生物相互作用系统的观点首次对太平洋中部洋底多金属结核开展了微生物成矿作用的研究。通过洋底各介质中微生物活动与多金属结核生成机制、成矿物质转化的微生物作用及化学作用对比模拟实验研究、观察和测定系统中成矿物质浓度及环境参数的变化,揭示了成矿组分由微生物活动引起的反应速度和演变方向;从微生物地球化学作用的观点,论证了多金属结核微生物成矿机制和成矿模式;提出了多金属结核微生物成矿阶段和成矿理论。
The ocean floor is a complicated material system, in which there are numerous microbial remains. Some bioclastic remains have evidently participated in the material transformations in the water-rock system of ocean floor. This system is called the interactive water-rock-microbe system, and the polymetallic nodules were formed in the system by the integrated action of factors such as physiochemical and biochemical and other processes.1. The water-rock-microbe system of ocean floor in the central Pacific Ocean lies below the carbonate compensation depth in the northern part of the equatorial zone. The authors make a scientific research on environmental parameters that comprise floor-layer water, sediments and pore-water, on microbial activity and on hydrogen and oxygen isotopes in water of each layer. It has been shown that the study area is in a low-temperature, weakly alkaline oxidizing environment, where floor-layer oceanic currents and violent microbial activities occur, and is an interactive water-rock-microbe system in which the environment is obviously advantageous to sedimentation and enrichment of mineralizing metallic elements. 2. Iron bacteria from the ocean-floor media accelerate the precipitation of mineralizing elements of iron and manganese in the liqud phase. The metabolism of sulphate-reducing bacteria in submarine sediments and pore-water accelerates the sulphate reduction of the media, thus bringing about the dissolution of iron and manganese and other mineralizing components on the surfaces of the sediments and concretions. The authors make a quantitative assessment on varied microbial activities, expound adequately the evolutional tendency and laws of microbial effect on the transformation and enrichment of mineralizing elements in the water-rock system of ocean floor, and give a convincing proof that microbial effect on mineralizing element sedimentation is in excess of chemical sedimentary process (microbial transformation rate is by far greater than chemical transformation rate; their ratio is>90％:<10％).3. Intense activities of iron bacteria afford abundant evidence for maintaining an ongoing oxidizing environment in the water-rock-microbe system of ocean floor: On these grounds, the authors have reasoned out that the occurrence of microbial minerogenesis of polymetallic nodules is continuous on the contemporary ocean floor.4. The evolution and alternation on the aerobic and anaerobic ecosystems may occur on the ocean floor. Just the alternation and evolution can promote the chemical reactions of the matter successfully in the water-rock-microbe system and speed up the transformation from mineralizing element oxidizing sedimentation to reducing dissolution and again to oxidizing sedimentation.In a word, the theory of interactive water-rock-microbe system is an important proof for the study of microbial mineralzation.
出处
《地质学报》
EI
CAS
CSCD
北大核心
1992年第2期122-134,共13页
Acta Geologica Sinica
关键词
太平洋
微生物
成矿
多金属
结核
The Central Pacific Ocean water-rock, microbe system, microbial mineralizing element transformation rate, microbialgeochemical process.
