Evidence for early life in Earth's oldest hydrothermal vent precipitates
Evidence for early life in Earth's oldest hydrothermal vent precipitates
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DOI：
10.1038/nature21377
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发表时间：
2017-03-02
期刊：
影响因子：
64.8
通讯作者：
Little, Crispin T. S.
中科院分区：
文献类型：
--
作者：
Dodd, Matthew S.;Papineau, Dominic;Little, Crispin T. S.
虽然不知道地球上的生命何时何地开始，但一些最早的可居住环境可能是海底热液喷口。在这里，我们描述了推定的微生物，至少有37.7亿，可能42.8亿年的含铁沉积岩，解释为海底热液喷口相关的沉淀物，从Nuvvuagittuq带在魁北克，加拿大。这些结构出现微米级的赤铁矿管和细丝的形态和矿物组合类似的丝状微生物从现代热液喷口沉淀物和类似的微体化石在年轻的岩石。Nuvvuagittuq岩石在碳酸盐和碳质物质中含有同位素轻碳，这些碳质物质以成岩碳酸盐岩中的石墨包裹体、碳酸盐岩和磁铁矿-赤铁矿颗粒之间共生的磷灰石叶片的形式出现，并与碳酸盐直接接触，与推定的微体化石有关。总的来说，这些观测结果与氧化生物量一致，并为37.7亿多年前海底热液环境中的生物活动提供了证据。
Although it is not known when or where life on Earth began, some of the earliest habitable environments may have been submarine-hydrothermal vents. Here we describe putative fossilized microorganisms that are at least 3,770 million and possibly 4,280 million years old in ferruginous sedimentary rocks, interpreted as seafloor-hydrothermal vent-related precipitates, from the Nuvvuagittuq belt in Quebec, Canada. These structures occur as micrometre-scale haematite tubes and filaments with morphologies and mineral assemblages similar to those of filamentous microorganisms from modern hydrothermal vent precipitates and analogous microfossils in younger rocks. The Nuvvuagittuq rocks contain isotopically light carbon in carbonate and carbonaceous material, which occurs as graphitic inclusions in diagenetic carbonate rosettes, apatite blades intergrown among carbonate rosettes and magnetite-haematite granules, and is associated with carbonate in direct contact with the putative microfossils. Collectively, these observations are consistent with an oxidized biomass and provide evidence for biological activity in submarine-hydrothermal environments more than 3,770 million years ago.