How can there be gold in the upper layers of the earth crust?

If the early Earth were moilten for a long time AND made of sufficiently fluid materials, you would be right to expect the denser materials to be at the bottom. Gold is fairly dense. But the truth is that the materials that make up the earth have an overall high viscosity, which means they resist flow. There is just alot of stuff between the surface and the center and you have to be able to push that stuff out of the way.

While we are on the topic, there is also alot of other stuff moving around. You cannot effectively sink if other stuff is heading towards the surface at your location. The current would drive you up even if you were dense enough to sink.

Last, even dense things can rise in a molten early earth. The density of a material depends also on it's temperature. Hot things can rise when they are made hot.

The intense pressures in the interior of the Earth cause the material to behave more solid than it really is. Things don't just sink to the bottom. The further down you go, the harder it is to go down. Unless I'm mistaken.

plate tectonics... it got pushed up over time... gold may be dense, but not compared to other materials that earth is made up of.

there are even materials denser than gold .. don't you remember?

hmmm