Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits.
Earliest signs of life on land preserved in ca. 3.5 Ga hot spring deposits.
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DOI：
10.1038/ncomms15263
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发表时间：
2017-05-09
影响因子：
16.6
通讯作者：
Ward CR
中科院分区：
文献类型：
--
作者：
Djokic T;Van Kranendonk MJ;Campbell KA;Walter MR;Ward CR
CA。3.48位于西澳大利亚皮尔巴拉的Ga梳妆台组是地球上最早的生命证据（叠层石、分馏硫/碳同位素、微体化石）的所在地，该火山口是一个动态的、低喷发的火山口，受大量热液循环的影响。然而，火山口模型中缺少火山热液系统（温泉，间歇泉）的表面表现及其与生命的明确联系。在这里，我们提出了新发现的温泉矿床，包括硅灰岩，烧结阶地和温泉池/喷口的矿化遗迹，所有这些都保存了一套微生物生物特征，表明陆地上最早的生命。这些包括叠层石，新观察到的微生物栅栏织物和气泡保存在推断矿化，外聚合物物质。这些发现将地球上有人居住的陆地温泉的已知地质记录延长了230亿年，并为在古代火星温泉中寻找潜在的化石生命提供了类似物。地球上一些最早的生命在陆地温泉中繁衍生息。在这里，作者提出的证据CA。3.5 Ga温泉沉积物来自澳大利亚皮尔巴拉县的梳妆台组，那里有一些已知的最早的生命，以叠层生物和其他微生物生物特征的形式存在。
The ca. 3.48 Ga Dresser Formation, Pilbara Craton, Western Australia, is well known for hosting some of Earth’s earliest convincing evidence of life (stromatolites, fractionated sulfur/carbon isotopes, microfossils) within a dynamic, low-eruptive volcanic caldera affected by voluminous hydrothermal fluid circulation. However, missing from the caldera model were surface manifestations of the volcanic-hydrothermal system (hot springs, geysers) and their unequivocal link with life. Here we present new discoveries of hot spring deposits including geyserite, sinter terracettes and mineralized remnants of hot spring pools/vents, all of which preserve a suite of microbial biosignatures indicative of the earliest life on land. These include stromatolites, newly observed microbial palisade fabric and gas bubbles preserved in inferred mineralized, exopolymeric substance. These findings extend the known geological record of inhabited terrestrial hot springs on Earth by ∼3 billion years and offer an analogue in the search for potential fossil life in ancient Martian hot springs. Some of the earliest life on Earth flourished in terrestrial hot springs. Here, the authors present evidence for ca. 3.5 Ga hot spring deposits from the Dresser Formation, Pilbara Craton, Australia, that host some of the earliest known life in the form of stromatolites and other microbial biosignatures.