Biological activities at the Archean submarine hydrothermal environments

太古宙海底生命热液起源论正在成为一种流行的理论，除了认为早期生物群的演化发生在海底热液环境之外，在太古宙地层中发现了丰富的海底热液沉积物，这些沉积物中仍有可能保存着早期生物群的遗迹及其生态系统的化学化石。本研究的主要目的是利用地质和地球化学方法识别早期生物群及其生态系统的残余。本研究对澳大利亚2.7 Ga Abitibi绿岩带和3.2 Ga Pilbara地块进行了详细的地质调查。本研究还对太古宙海底热液活动和现代热液活动相关的其他样品进行了化学分析。本研究的主要发现包括：富二氧化碳流体的特定热液改变和海洋地壳中磷的动员，甲烷相关生物群的特定年龄活动及其与岩浆活动和热液反应中有机质中金属富集的关联。在现代热液沉积物中发现了新的生态能量交换系统，并提出了其与太古宙生态系统的联系。这些成果已在若干国际和国内刊物上发表，并在国际会议上作为特邀发言进行报道。本研究还提出了与当代岩浆活动有关的生物进化新理论。

Hydrothermal origin of life on the Archean seafloor is becoming a popular theory, besides the idea that the evolution of early biota took place at the submarine hydrothermal environments Abundant submarine hydrothermal sediments have been found in the Archean strata and there exists possibility that remnants of early biota and chemical fossils of their ecosystem were still preserved in these sediments. The main purpose of this study is to identify the remnants of early biota and their ecosystem based on the geological and geochemical ways. In this study, detailed geological surveys were conducted in two areas : the 2.7 Ga Abitibi Greenstone Belt and 3.2 Ga Pilbara Blocks in Australia. Other samples related to Archean submarine hydrothermal activities and modern hydrothermal activities were also subjects for the chemical analyses in this study. The followings are the notable findings from this study : specific hydrothermal alterations by carbon dioxide-rich fluids and mobilization of phosphorous from oceanic crust, age specific activity of methane-related biota and their association with magmatic activity and metal enrichments in organic matter by hydrothermal reaction. New ecological energy exchange system was also found in the modern hydrothermal sediments and its links to Archean ecosystem was also proposed. These achievements were already published in the several international and domestic journals, and also reported at international conferences as invited talks. New theory of biological evolution associated with the contemporary magmatic activity is also proposed from this study.