Abstract The composition of the Earth's core and mantle is set by the chemical equilibrium between metals and silicates during core/mantle segregation. The metallic core separated from the mantle by gravitational descent in the form of diapirs in a magma ocean, and therefore the dynamics of the diapir's downward movement has an influence on the chemical equilibrium. In this study, we characterize the descent of metallic droplets into a molten silicate using numerical models. By varying the silicate and metal viscosities (between 0.1 and 1000 Pa·s for each phase) as well as the partition coefficient between metal and silicate (Dmet/sil, varying between 1 and 1000), we obtained quantifying parametrizing equations for the degree of equilibrium between molten metal and molten silicate, in a regime characterized by low We (We Canup, 2004 ) of the Moon–forming impact, we showed that the Moon formation had an effect on the current Ni/Co ratio. Depending on the radius of Theia's core and the viscosity of the magma ocean produced after the impact between the proto-Earth and Theia, the Moon formation could account for 0.45% to 3% of the current Ni/Co ratio for magma ocean viscosities of 0.1 to 100 Pa·s, respectively.

中文翻译：

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核幔分离动力学：粘度对比和金属/硅酸盐分配系数对化学平衡的影响

摘要 地核和地幔的组成是由地核/地幔分离过程中金属和硅酸盐之间的化学平衡决定的。金属核在岩浆海洋中以底辟的形式通过重力下降与地幔分离，因此底辟向下运动的动力学对化学平衡有影响。在这项研究中，我们使用数值模型表征金属液滴下降到熔融硅酸盐中。通过改变硅酸盐和金属的粘度（每相在 0.1 到 1000 Pa·s 之间）以及金属和硅酸盐之间的分配系数（Dmet/sil，在 1 到 1000 之间变化），我们获得了量化参数化方程熔融金属和熔融硅酸盐之间的平衡，以低 We (We Canup, 2004 年）的月球形成影响，我们表明月球形成对当前的 Ni/Co 比率有影响。根据 Theia 核的半径和原地球与 Theia 碰撞后产生的岩浆海洋的粘度，月球形成可能占当前岩浆海洋粘度为 0.1 的 Ni/Co 比率的 0.45% 至 3%分别为 100 Pa·s。