Isotope and trace element geochemistry of Archean chert : Deciphering the ancient oceanic environment and biological activity

通过使用3.46Ga硅质岩和3.2Ga硅质岩/BIF/黑色页岩的新钻芯样品进行的多学科地球化学研究，获得了以下令人兴奋的结果。在受热液活动影响的3.46Ga深海热液中，来自热液喷发的亚铁被氧化，很可能是被溶解氧氧化。在3.2Ga海洋中，我们的研究表明与3.46Ga海洋非常相似，微生物的反硝化作用、氧合光合作用和硫酸盐还原都很活跃。我们的主要结论是，中太古代海洋总体上是氧化的，局部和暂时存在缺氧水体。这项研究对地球微生物生物圈和地表环境的早期共同进化具有深远的影响。

From multidisciplinary geochemical studies using the fresh drillcore samples of 3.46 Ga chert and 3.2 Ga chert/BIF/black shales, the following exciting results are obtained. Ferrous iron from hydrothermal venting was oxidized, most likely by dissolved oxygen, in the 3.46 Ga deep hot ocean that was influenced by hydrothermal activity. In the 3.2 Ga ocean, that was shown from our studies to have been very similar to the 3.46 Ga ocean, microbial denitrification, oxygenic photosynthesis, and sulfate reduction were all active. Our major conclusion is that the Mesoarchean ocean was generally oxic with local and temporal existence of anoxic water bodies. This study has far-reaching implications for the early co-evolution of microbial biosphere and surface environments of the Earth.