* (tl;低于博士)*首先,出现回调。亲铁元素是“iron-loving”元素,那些Fe-Ni液体的核心。铀是*亲石元素*,或者“rock-loving”。它分区硅酸盐岩石物质(如地幔和地壳)相对于核心。其次,>,但[这][1]的答案,铀的溶解度在地球> 2 ppm和6之间的核心是ppm。你必须明白这是来自哪里。答案是基于[这][2],实验测量了多少你的铁阶段,共存与橄榄岩组成的硅酸盐阶段(这是一个近似的地幔组成)。如果你看看他们的表3(14页)和图8(17页)可以看到,rm D_ \{你}值美元几乎范围从0到0.03左右。这个值意味着U在金属相的比例相对于硅酸盐相。所以即使在最极端的情况下,你将会有30倍U地幔的核心。 And in their experimental setup they used wt % amounts of U in the starting material, much much more than exists in the Earth, so you eventually get a considerable amount in the Fe-metal phase. This does not mean that this is the amount that is present there now, inside the Earth. The truth is, we do not know how much U is there in the core. And this research papers shows that whatever amount there is, there will be more in the mantle. There will be even more in the crust, because U is an incompatible element in partial melting of the mantle. See this Q&A for more information about that: //www.hoelymoley.com/q/2950/725 Also related, also read the comments: //www.hoelymoley.com/q/4798/725 > Second, what I think: trying to mix unmixable liquids they we will > have separate phases of solutions in the order of their density... You have to differentiate solubility from partitioning. Solubility is how much of x (let's say U) you can put in y (let's say Fe) before you saturate a separate phase instead of one. Partitioning is when you have two phases x and y (let's say Fe-liquid and silicate), how much a third component z (let's say U) will dissolve in each. The paper linked to before was discussing partitioning. In terms of solubility, there is a complete solution of liquid U and Fe when the temperature is high enough (such as in the Earth's core). Even if there's not, a ppm amount of U in liquid Fe is *not* enough to saturate a separate liquid U phase, so density doesn't matter. If it's all one phase, density plays no role. If you have a solution of NaCl and KCl in water, it's all homogeneous. The K doesn't sink because it's denser. **tl;dr** We do not know how much U is in the core. We do know that whatever amount of U goes in the core, more U will be in the silicate mantle. When you melt the mantle to produce magmas that form the crust, it concentrates U even more, and depletes the mantle of U. [1]: http://chemistry.stackexchange.com/a/51798/8083 [2]: https://arxiv.org/ftp/astro-ph/papers/0606/0606614.pdf