An alternative hypothesis for the origin of the banded iron formations and the synthesis of prebiotic molecules is presented here. I show the importance of considering water near its supercritical point and at alkaline pH. It is based on the chemical equation for the anoxic oxidation of ferrous iron into ferric iron at high-subcritical conditions of water and high pH, that I extract from E-pH diagrams drawn for corrosion purposes (Geophysical Research Abstracts Vol 15, EGU2013-22 Bassez 2013, Orig Life Evol Biosph 45(1):5-13, Bassez 2015, Procedia Earth Planet Sci 17, 492-495, Bassez 2017a, Orig Life Evol Biosph 47:453-480, Bassez 2017b). The sudden change in solubility of silica, SiO2, at the critical point of water is also considered. It is shown that under these temperatures and pressures, ferric oxides and ferric silicates can form in anoxic terrains. No FeII oxidation by UV light, neither by oxygen is needed to explain the minerals of the Banded Iron Formations. The intervention of any kind of microorganisms, either sulfate-reducing, or FeII-oxidizing or O2-producing, is not required. The chemical equation for the anoxic oxidation of ferrous iron is applied to the hydrolyses of fayalite, Fe2SiO4 and ferrosilite, FeSiO3. It is shown that the BIF minerals of the Hamersley Group, Western Australia, and the Transvaal Supergroup, South Africa, are those of fayalite and ferrosilite hydrolyses and carbonations. The dissolution of crustal fayalite and ferrosilite during water-rock interaction needs to occur at T&P just below the critical point of water and in a rising water which is undersaturated in SiO2. Minerals of BIFs which can then be ejected at the surface from venting arcs are ferric oxide hydroxides, hematite, FeIII-greenalite, siderite. The greenalite dehydrated product minnesotaite forms when rising water becomes supersaturated in SiO2, as also riebeckite and stilpnomelane. Long lengths of siderite without ferric oxides neither ferric silicates can occur since the exothermic siderite formation is not so much dependent in T&P. It is also shown that the H2 which is released during hydrolysis/oxidation of fayalite/ferrosilite can lead to components of life, such as macromolecules of amino acids which are synthesized from mixtures of (CO, N2, H2O) in Sabatier-Senderens/Fischer-Tropsch & Haber-Bosch reactions or microwave or gamma-ray excitation reactions. I propose that such geobiotropic synthesis may occur inside fluid inclusions of BIFs, in the silica chert, hematite, FeIII-greenalite or siderite. Therefore, the combination of high-subcritical conditions of water, high solubility of SiO2 at these T&P values, formation of CO also at these T&P, high pH and anoxic water, leads to the formation of ferric minerals and prebiotic molecules in the process of geobiotropy.

中文翻译：

---

接近超临界点和碱性 pH 值的水，用于在缺氧条件下生产氧化铁和硅酸盐。关于带状铁地层中观察到的矿物合成和流体包裹体内相关地生物化学的新假设。


这里提出了带状铁形成的起源和益生元分子合成的另一种假设。我展示了考虑水接近超临界点和碱性 pH 值的重要性。它基于在高亚临界水和高 pH 条件下将二价铁缺氧氧化成三价铁的化学方程式，我从为腐蚀目的绘制的 E-pH 图中提取了该方程式（地球物理研究摘要第 15 卷，EGU2013-22） Bassez 2013，Orig Life Evol Biosph 45(1):5-13，Bassez 2015，Procedia Earth Planet Sci 17, 492-495，Bassez 2017a，Orig Life Evol Biosph 47:453-480，Bassez 2017b)。还考虑了二氧化硅 (SiO2) 在水临界点溶解度的突然变化。结果表明，在这些温度和压力下，缺氧地区可以形成氧化铁和硅酸铁。不需要紫外线或氧气氧化二价铁来解释带状铁地层的矿物。不需要任何种类的微生物的干预，无论是硫酸盐还原、FeII氧化还是产O2。二价铁缺氧氧化的化学方程式适用于铁橄榄石 Fe2SiO4 和硅铁矿 FeSiO3 的水解。结果表明，西澳大利亚哈默斯利群和南非德兰士瓦超群的BIF矿物为铁橄榄石和硅铁矿水解和碳化矿物。在水-岩石相互作用过程中，地壳铁橄榄石和铁硅岩的溶解需要在水的临界点以下的 T&P 处以及 SiO2 不饱和的上升水中发生。然后可以从排气弧喷射到表面的 BIF 矿物是氢氧化铁、赤铁矿、FeIII-绿铁矿、菱铁矿。 当上升的水在 SiO2 中变得过饱和时，会形成绿钠石脱水产物明尼苏打石，以及利贝克石和硅锰矿。没有氧化铁的长菱铁矿不会出现硅酸铁，因为放热菱铁矿的形成不太依赖于 T&P。还表明，铁橄榄石/铁硅石水解/氧化过程中释放的 H2 可以产生生命成分，例如在 Sabatier-Senderens/Fischer 中由（CO、N2、H2O）混合物合成的氨基酸大分子-Tropsch & Haber-Bosch 反应或微波或伽马射线激发反应。我认为这种向地生物合成可能发生在 BIF 的流体包裹体内部，即硅燧石、赤铁矿、FeIII-绿铁矿或菱铁矿中。因此，水的高亚临界条件、在这些 T&P 值下 SiO2 的高溶解度、在这些 T&P 值下形成 CO、高 pH 值和缺氧水的组合，导致在向地生物性过程中形成铁矿物质和益生元分子。 。