硅酸盐熔体中Fe2+和Fe3+的结构性质以及Fe3+/ΣFe比值在至少30年以来受到广泛关注。这是因为Fe3+/ΣFe不仅可以反映，而且在许多情况下可以建立硅酸盐熔体的氧逸度（fO2）。由于压力对硅酸盐熔体中Fe2+和Fe3+的配位结构以及体积性质方面的影响会存在差异，因此压力也会影响硅酸盐熔体中的Fe3+/ΣFe，并进一步影响氧逸度。对早期类地行星岩浆洋的氧化还原环境的研究需要人们了解压力对硅酸盐熔体中Fe3+/ΣFe，以及氧逸度的影响。目前前人的实验研究最高只到7GPa，而对于火星和地球而言，早期核幔分异的压力分别为~14GPa和>25GPa。因此本项目拟结合实验岩石学，微区测量手段和热力学模拟，测定25-80GPa下硅酸盐熔体中Fe3+/ΣFe比值。研究结果将进一步理解高压下硅酸盐熔体中Fe2+和Fe3+的结构性质，并为早期岩浆洋氧化还原梯度以及延缓提供重要制约。

In natural and synthetic silicate melt, the structural properties of Fe2+ and Fe3+ and the Fe3+/ΣFe ratio have been received broad attention for at least 30 years, because the Fe3+/ΣFe ratio not only reflects, but also in many cases can establish the oxygen fugacity (fO2). Due to the different pressure effects on the coordination structure and volume properties of Fe2+ and Fe3+ in silicate melts, pressure will also affect the Fe3+/ΣFe ratios in silicate melts, further, the oxygen fugacity(fO2). The effect of pressure on the Fe3+/ΣFe ratio in silicate melts is necessary to understand the redox environment of the early terrestrial planet magma ocean. So far, the highest pressure of experimental studies is only 7GPa, but for Mars and Earth, the core formation pressure is ~14 GPa and >25 GPa, respectively. Therefore, this project is going to determine the Fe3+/ΣFe ratio in silicate melts under 25-80 GPa with experimental apparatus combining micro measurements. The results will help people further understand the structure properties of Fe2+ and Fe3+ in silicate melts at high pressure, and provide important constraints for early magma ocean redox gradients and evolution.