Joint International Research Project on Free Oxygen and Biomarker on the Early Earth

本研究的目的是了解太古宙微生物在空间和时间上的分布，了解微生物生活在什么地球化学环境中，并研究生命与环境共同演化的地球物理控制因素。2004年，我们又钻了一个洞来收集穿过图姆比亚纳组的岩芯(2.76Ga)。在2003年的钻井项目中，我们未能获得这一地层。在今年的项目中，美国研究小组(深度时间钻井项目)与西澳大利亚大学NASA天体生物研究所和西澳大利亚地质调查局的合作小组合作。在光学和电子显微镜下观察后，对这些岩心进行了硫和碳的同位素组成检测，并提取了有机化合物来研究微生物的化学化石。根据地球化学资料讨论了太古宙的大气和海洋环境。We…更多的研究集中在古地磁学方面，认为地磁场对生物活动具有重要作用。所取得的成果已在国际和国内会议上发表。从2002年到现在，国际会议的发言次数为21次，其中包括ABSCHCON(旧金山)、IGC(费伦泽)和AGU(旧金山)，18次为国内会议。该项目的主要贡献之一可能有助于揭示微生物的发展历史。结果表明，在3.46Ga附近可能以产铁细菌和产甲烷菌为主，在2.77Ga附近可能出现产甲烷菌、产甲烷菌、硫酸盐还原细菌和蓝藻的多样性。第二个是地球上3.46 Ga的迪纳摩发现了最古老的地磁场。2.77Ga前附近的微生物多样性可能与地磁场的增强有很强的关系。较少

The objectives of this research are to understand the distributions of Archean microbes in space and in time, to understand in what geochemical environment the microbes inhabited, and to study the geophysical controlling factors on the co-evolution of life and environmenta. In 2004, we drilled another hole to collect the core which cuts through the Tumbiana Formation (2.76Ga). We had failed to obtain this formation in the 2003 drilling project. The American research group (Deep Time Drilling Project) collaborated us in this year's project, along with our collaboration groups of NASA Astrobiology Institute, University of Western Australia and Geological Survey of Western Australia.After the observation under optic and electron microscope, these cores were examined for the isotopic compositions of sulfur and carbon, and were extracted the organic compounds to examine the chemical fossils of microbes. Archean atmospheric and oceanic environment were discussed from the geochemical data. We … More also focused into paleomagnetism, assumed that geomagnetic field should play an important role to bio-activity.The obtained results have been presented at international conferences as well as domestic conferences. The number of presentation from 2002 to present have been 21 for international conferences including AbSciCon (San Francisco), IGC (Firenze) and AGU (San Francisco), and 18 for domestic conferences.One of the chief contribution of this project might shedding light on the history of development of microbes. Out results suggest that iron-bacteria and methanogen might be the dominant microbes around 3.46Ga, and the microbes might become diversified around 2.77 Ga including methanogen, methanotroph, sulfate-reducing bacteria and cyanobacteria. It also suggests that eukaryote inhabited at that era.The second is the discovery of the oldest geomagnetic field by the Earth's dinamo at 3.46 Ga.. The microbial diversity around 2.77 Ga ago could strongly relates to the increasing geomagnetic field. Less