Constraining the Timing and Nature of Life's Emergence in Extrema: the Geology and Geochemistry of Akilia Island, West Greenland

史蒂芬·J·莫伊齐斯、T·马克·哈里森、克雷格·E·曼宁地球上第一个生命的出现可以被视为发生在全球范围内极端环境的背景下。通过详细的野外考察和年代学研究，结合稳定同位素(碳、氮、S)研究，探索了西格陵兰岛南部已知的最古老的海相沉积岩，其中包含了这些最早的时代的记录。这些岩石的年龄在37亿到39亿年之间。采取双管齐下的方法来研究地球上最早的极端环境的沉积记录。首先，P.是。通过野外研究、变质岩石学观察和锆石U-Pb年代学研究，揭示了与岩石成因和随后的长期变质作用有关的岩石的地质背景和历史。其次，他们的研究寻找碳、氮和S分馏形式的同位素示踪剂，这些分馏是由生命诱导并保存在最古老的沉积物中的。还有就是。有观点认为，这两种方法结合在一起，将在理解地球上生命早期环境的极端方面取得进展。这项研究是利用加州大学洛杉矶分校和项目合作者开发的新的超高分辨率质谱学技术(MC-SIMS，C-GC-IRMS，LEC-SMS)来进行这些测量。有了这项工作，生物地球化学工具的数量将增加，功能和多样性将增加，以探测早期生命的潜在证据和出现的时间，从地球上发现的较老的岩石中发现，最终在其他星球的样本中，如火星和欧罗巴。

Stephen J. Mojzsis, T. Mark Harrison, Craig E. ManningThe emergence of the first life on Earth can be viewed as having occurred in the context of an extreme environment at the global scale. A detailed program of fieldwork and geochronological studies coupled with stable isotopic (C, N, S) investigations is used to explore the oldest known marine sedimentary rocks, from southern West Greenland, that contain a record of these earliest times. These rocks are between 3.7 and 3.9 billion years old. A two-pronged approach is taken to study the sedimentary record of Earth's earliest extreme environments. First, P. Is.' are revealing the geological context and history of the rocks related to petrogenesis and subsequent protracted metamorphism from field studies, metamorphic petrologic observations, and U-Pb zircon geochronological investigations. Second, their study searches for isotopic tracers in the form of C, N, and S fractionations induced by life and preserved in the oldest sediments. P.Is.' view is that these two approaches together will lead the advance in understanding the extremes of early environments for life on Earth. This research is utilizing new ultra-high resolution mass spectrometric techniques (MC-SIMS, C-GC-IRMS, LEC-SMS) developed by UCLA and project collaborators to make these measurements. With this work, the number of biogeochemical tools will increase in power and diversity for detecting potential evidence for early life and the timing of its appearance, in older rocks from Earth when they are found, and eventually in samples from other worlds, like Mars, and Europa.