论文标题
Oldhamite：C-O-S-CA周期的地幔中的新链接和行星可居住性指标
Oldhamite: a new link in mantle for C-O-S-Ca cycles and an indicator for planetary habitability
论文作者
论文摘要
在太阳系中，通常认为Oldhamite（CAS）是由太阳星云气体的凝结形成的。 Enstatite软管是Oldhamite最重要的存储库之一，被认为是形成地球材料的代表。因此，Oldhamite的形成机理和演变过程对对太阳星云，陨石，地球的起源以及地球的C-O-S-CA周期的深入了解具有重要意义。迄今为止，尚无关于地幔中奥尔德汉特的报告。但是，在这里，我们通过1.5 GPA/1510 K和0.5 GPA/1320 K的含硫化物邻苯二酚和熔融方解石之间的反应来显示Oldhamite的形成。令人惊讶的是，我们实验中的氧散发性在地幔条件范围内，比Solar Nebula Nebula机制高6个。奥尔德汉特很容易氧化为硫酸钙。岩浆的低氧赋形性和大气中极低的氧气含量对于在行星表面上存在奥尔德汉特都是必要的。否则，硬石石或石膏将大量存在。奥尔德汉特在地球表面上的广泛存在表明，由于氧气稀缺，地球绝对不可居住。 Oldhamite的形成和氧化伴随着二氧化碳的产生和氧气的消耗，氧气的消耗可能会在大氧化事件和二叠纪三叠纪边界之前对地球大气产生影响。
In the solar system, oldhamite (CaS) is generally considered to be formed by the condensation of solar nebula gas. Enstatite chondrites, one of the most important repositories of oldhamite, are believed to be the representative of the material which formed Earth. Thus, the formation mechanism and the evolution process of oldhamite are of great significance to the deeply understanding about the solar nebula, meteorites, the origin of Earth, and the C-O-S-Ca cycles of Earth. To date, no report about the oldhamite in the mantle exists. However, here we show the formation of oldhamite through the reaction between sulfide-bearing orthopyroxenite and molten calcite at 1.5 GPa/1510 K and 0.5 GPa/1320 K. Surprisingly the oxygen fugacities in our experiments are within the range of mantle conditions, which is 6 orders of magnitude higher than that of the solar nebula mechanism. Oldhamite is easily oxidized to calcium sulfate. Both low oxygen fugacity of magma and extreme low oxygen content of atmosphere are necessary for existence of oldhamite on the surface of a planet; otherwise, anhydrite or gypsum will exist in large quantities. The widespread existence of oldhamite on the planet surface indicates the planet is definitely not habitable because of the scarcity of oxygen. The formation and oxidation of oldhamite are accompanied by the production of carbon dioxide and the consumption of oxygen, which may have an impact on the Earth atmosphere before the Great Oxidation Event and during the Permian-Triassic Boundary.
