The Hadean-Archaean Environment
The Hadean-Archaean Environment
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DOI：
10.1101/cshperspect.a002527
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发表时间：
2010-06-01
影响因子：
7.2
通讯作者：
Sleep, Norman H.
中科院分区：
文献类型：
--
作者：
Sleep, Norman H.
稀疏的地质记录结合物理学和分子生物学限制了早期地球的环境条件。地球在月球形成的撞击后开始变热，并在大约1000万年后冷却到液态水存在的程度。随后，一些小行星的撞击可能会短暂地加热表面环境，只在更深的岩石中留下嗜热生物的幸存者。一个温暖的500 K，100巴的CO2温室持续存在，直到俯冲洋壳封存到地幔中的CO2。目前还不知道地球表面是否徘徊在一个类似70摄氏度的嗜热环境中，一直到冥古宙，或者在冥古宙冷却到零度或冰点。最近在哈德逊湾附近发现的类似于4.3 Ga的岩石可能是在温暖的温室中形成的。印度的碱性岩表明碳酸盐俯冲作用发生在4.26 Ga。格陵兰岛3.8 Ga黑色页岩的存在表明，海洋中的硫基光合作用已经进化，陆地上的铁基光合作用和有效的化学风化也可能进化。总的来说，地幔衍生的岩石，特别是金伯利岩和类似的富含二氧化碳的岩浆，保存了俯冲的上洋壳，古老的地表环境和光合作用的生物特征的证据。
A sparse geological record combined with physics and molecular phylogeny constrains the environmental conditions on the early Earth. The Earth began hot after the moon-forming impact and cooled to the point where liquid water was present in similar to 10 million years Subsequently, a few asteroid impacts may have briefly heated surface environments, leaving only thermophile survivors in kilometer-deep rocks. A warm 500 K, 100 bar CO2 greenhouse persisted until subducted oceanic crust sequestered CO2 into the mantle. It is not known whether the Earth's surface lingered in a similar to 70 degrees C thermophile environment well into the Archaean or cooled to clement or freezing conditions in the Hadean. Recently discovered similar to 4.3 Ga rocks near Hudson Bay may have formed during the warm greenhouse. Alkalic rocks in India indicate carbonate subduction by 4.26 Ga. The presence of 3.8 Ga black shales in Greenland indicates that S-based photosynthesis had evolved in the oceans and likely Fe-based photosynthesis and efficient chemical weathering on land. Overall, mantle derived rocks, especially kimberlites and similar CO2-rich magmas, preserve evidence of subducted upper oceanic crust, ancient surface environments, and biosignatures of photosynthesis.