Upside-Down Mountain Found Inside Earth

That's to counteract all the upside down houses on the surface of the Earth.

Interesting, and makes sense.

Just as an iceberg is about 1/8 above water and 7/8 below, a floating tectonic plate could be expected to be similar.

I'm having trouble coming to grips with this. Ice floats because it is less dense than water. It is also universally unique in that is expands when changing from a liquid to a solid.

Why do solid rocks float on liquid rocks? And shouldn't there be a "transition zone" where everything is flattened out by the pressure from above?

Lyn, most of the Earths crust is made up of lighter rocks than the mantle, the crust is mainly the lighter silicates like quartz and the feldspars, while the mantle is made up of mainly Fe and Mg silicates with some olivine (FE, Mg)2 SiO4 which are heavy rocks.

So, at one time when everything was liquid, we had stratification of these different density materials? I'm good with that.

Since we seem to understand how mountains are formed on the surface of earth (which has nothing to do with cooling, but uplifting and erosion) how did these features come to be formed, upside down in a more dense liquid? Shouldn't the bottoms be flat, relatively?

This isn't really news, we geologists new this quite some time ago, it is just like an iceberg that floats in the sea, the Earths crust is floating on the upper mantle, and the continental land masses are where the crust is deepest, and there is no reason to believe that the underside of this crust is flat, in fact it is very hilly or even mountainous, with most of this continental crust sunk into the upper mantle!

It wasn't really new news to me either. I had several Geology classes back in the early 00's and that concept was already known and being taught back then.

It would appear that once again the only thing that California educational system and sciences have proven is that they are, as usual, about ten years late to the party but still very proud of it.