Decoding Earth Evolution Program : development of effecient methods for data aquisition and decoding the Earth's environmental history

本研究的目的是发展高效数据采集的分析方法，建立岩石样品和分析数据的数据库，并通过多学科方法解码4.0 Ga以来的地球环境历史。本研究的主要结果如下：(1)研制并运行了几台“5点后机器”，对所获得的样品进行一级化学分析。我们的样品在尺寸为400x200x30mm或200x200x30mm的板材中加工。x射线分析显微镜是五台仪器中最有用的仪器之一，它获得了样品的化学图像，经过图像处理后表示为与层序相对应的化学剖面。(2)数据库包括(1)西格陵兰岛Isua的燧石岩和带状铁组（3.8Ga）， (2) Pilbara地块3.4 Ga的燧石岩和BIF， (3) Hamersley BIF (2.4Ga),(4)加拿大Yellowknife Superg…More群Bell和Dwyer Lake BIF (2.8Ga),(5)加拿大Hearne叠层岩（1.9 Ga），(6)纳米比亚Rastof盖层碳酸盐岩（约0.7 Ga）。在加拿大和纳米比亚的采样中，我们使用了发动机切割机和一个方便的盖子来进行薄片的节奏和事件分析所需的完全连续采样。(3)在格陵兰岛Isua的带状铁地层中发现了富cr层。为了探讨其成因，应用了锰铬同位素系统学。一个标本被送到澳大利亚的地球化学家那里，以启动国际合作。(4)作为早期陆地生态系统的模型，我们对温泉微生物垫产生了兴趣，并开始与微生物学家进行联合研究。最近，我们开发了一种方便的光谱仪，可以在野外识别光合微生物。此外，对微生物垫的温度和RGB颜色分布进行了图像分析，以表征微生物垫的生态特性。另一方面，我们提出了“地球与生命共同进化”的地球历史观，认为地球与陆地生命的进化是紧密相关的。特别关注光合作用、真核生物和后生动物的起源以及大气含氧量的演变。少

The purpose of this research is to develop analytical methods for efficient data aquisition, to make data base of rock samples and analytical data, and to decode the Earth's environmental history dating back to 4.0 Ga through multidisciplinary approaches. The major results of this study are as follows.(1) Several "after 5 O'clock machines" has been developed and operated for first order chemical analysis of the obtained samples. Our samples were processed in plates with 400x200x30 mm or 200x200x30 mm in dimension. X-ray analytical microscope, one of the most useful after 5 machines, aquired chemical images of the samples, which were after image processing represented as chemical profiles corresponding to the stratigraphic sequence.(2) The database we obtained includes (1) chert and banded iron-formation from Isua, West Greenland (3.8Ga), (2) chert and BIFs from Pilbara Blocks with 3.4 Ga in age, (3) the Hamersley BIF (2.4Ga), (4) Bell and Dwyer Lake BIFs (2.8Ga) from Yellowknife Superg … More roup, Canada, (5) the Hearne stromatolites (1.9 Ga) from Canada, and (6) Rastof cap carbonate (ca. 0.7 Ga) from Namibia. In sampling in Canada and Namibia, we used an engine cutter and a handy corer for completely continuous sampling required for the rhythm and event analysis of laminations.(3) The Cr-enriched layer has been found in banded-iron formation from Isua, Greenland. In order to discuss its origin, the Mn-Cr isotope systematics is applied. A specimen was sent to geochemists in Australia to initiate international colaborations.(4) As a model for early terrestrial ecosystem, we have been interested in hotspring microbial mats and started joint study with microbiologists. Recently we developed a handy spectrometer, which enabled indentification of photosynthetic microbes in the field. Further, image analysis of temperature and RGB color distribution was performed for an ecological characterization of microbial mats. On the other hand, we proposed a new view of Earth history, "co-evolution of the Earth and life", which argues that the evolution of Earth and terrestrial life is tightly related each other. Special attension has been paid for the origins of photosynthesis, eukaryotes and metazoa and evolution of atmospheric oxygen level. Less