为什么地壳中有铀?和为什么铀只在地壳中，真的吗?铀的化学性质似乎是这样的，它与较轻的元素一起被带到地表，但金的化学性质不是更不利于这种过程吗?这就是为什么在地壳中黄金比铀少500倍吗?< / p >

是that "almost nothing"不是什么都没有吗?< / p >

It's obviously "almost nothing" because there still is gold in the Earth's crust. That said, while gold is 20 times more abundant in the solar system than is uranium, it is 600 times less abundant than uranium in the Earth's crust. That's a close to a perfect differentiation. No chemical process is perfect. After all, there is still a good amount of iron and nickel in the Earth's crust and mantle. Not as much as in the core, but still a good amount.

Whether the gold that remains in the crust is primordial or came from late bombardment asteroids remains highly debated.

enter image description here

因此，来自地核的元素可能通过上图中上升的黑色羽流被带到上地幔和地壳。以这种方式从地核升起的物质数量当然是很少的，所以只有少量的亲铁元素，如金，以这种方式出现在地表/地壳。对氧反应更强的嗜铁生物，如铁，可以直接进入地幔，从而更有效地对流进入地壳。

参考

M.J.Hoggard等人(2016)“全球动态地形观测揭示大尺度地幔流的有限影响”;自然地球科学9,456-463。https:// doi.org/10.1038/ngeo2709

https://www.geologyin.com/2016/05/map-of-flow-within-earths-mantle-finds.html