Continental Crust Puns

Title.

I'm pretty bad at geochemistry/petrogenesis.

Maybe not a direct answer, but at least pointing me to a chapter of a book or something.

Thanks in advance.

Or is there another reason to explain why only continental crust is above sea level?

I’ve always found the relationship between plates, oceanic crust, continental crust and continents confusing…

My understanding is that plates can include both oceanic and continental crust, and continents are just the portion of continental crust that is above sea level. Is that correct?

...concidering that the density of continental crust is lower than the one of oceanic crust. Is it simply because continental crust is so much thicker, hencer heavier than oceanic crust - even though latter has a higher density?

If yes, what would theoretically happen if their densities where the same?

And why is continental crust so much thicker than oceanic crust in the first place?

Looking forward to your replys : )

Cheers
Diclo

Is a crust with such extreme variation in thickness unique to Earth in the solar system? I know we have found vulcanism on other planets, but do any have continents like ours, or something analogous?

I’ve been wondering about this for a few days and the only thing I’ve come up with is that it could somehow be a result of the collision which formed the moon, but since the whole planet would have been molten I can’t really see how that would work. My best guess is that the fast-spinning Earth concentrated more mass in a band around the equator which ended up going on to form the original continental crust. Obviously things would have moved around a lot since then.

Does this make any sense?

I was also wondering, would it be possible in such a hole to evacuate heat in such a way that it would be liveable for humans at the bottom (solving the problem of the geothermal gradient?)?

I understand that they are different in composition and that continental crust is less dense etc, but why did they both form? Why not just one kind of intermediate crust over the entire planet? I haven’t been able to find any solid answers or resources when I looked online, so I was hoping some of you nice folks could help me out.

I understand the standard explanation on the difference between oceanic and continental crust- their differing densities and average composition (felsic vs mafic). And, if I've understood my reading correctly, I'm made to believe that such a differentiation was achieved slowly through eons of melting and partial-melting which let less dense elements migrate to higher rock, and denser ones stay low.

My question is- is this a process which is still, on the whole, continuing to differentiate these two types of crust today? I.e., is continental crust getting overall lighter and more felsic over time, and oceanic denser and more mafic? Or has the whole system reached an equilibrium, and the only real changes are on a local scale?

Oceanic crust gets subducted and melted in subduction zones and new gets created in mid- ocean ridges but does continental crust have something similar? And how does mountain erosion fit into this?

I was trying to find a ratio of continental to oceanic crust on google, but all I found was that continental crust covers about 40% of the Earth's surface.

Does anyone know the ratio in terms of volume or mass?

Also, if there was a significant change in that ratio since the start of the formation of the first tectonic features that still remain today, what was the ratio back then, and what caused said significant change?

I am not a geologist, so this is probably a dumb question, but I was wondering: let's say Onlong Java plateau was raised above sea level by volcanism or tectonics, something like 30-million years ago. Would it possibly have mineral resources that are commercially viable, meaning they could be explored for a profit? Or dry land created from the sea floor due to volcanism cannot have mineral resources if it does not have parts of continental crust embedded in it?

Any help will be appreciated and let me know if this is not the proper sub to ask this question.

I apologize if this is a noob question.
So continental crust is created as island chains and archipelagos, and is accreted onto existing continents, but never really destroyed. Continents collide and rift, but as far as I know, the crust is never really destroyed like oceanic crust is.
Was the earth, shortly after the differentiation, and the hardening of the crust covered only by mafic, oceanic crust? If so, what caused the creation of the lighter continental crust in the first place? And can we expect the ratio of the earth's surface covered by continental crust to increase with time into the far future until the earth cools to a point where Tectonic processes no longer occur?

The question popped into my brain as I read this article.

http://www.nytimes.com/1987/03/12/us/whale-fossils-high-in-andes-show-how-mountains-rose-from-sea.html

Basically describing how seashells and whale bones have been found high in mountain ranges. And this kind of confused me because I always thought that during subduction, ocean crust was always folded under continental crust. I thought the fate of all ocean crust was to be folded under, super heated, destroyed or created into volcanoes. So my question how is it that bits of the seafloor containing those shells were pushed so high up into the mountains if ocean crust is always folded under?

Thank you so very much for your time.

So continental crust is felsic and oceanic crust is mafic but why the discrepancy? Obviously it's due to the magma that eventually forms the crust but why is it mafic at mid ocean ridges and felsic at continents? How did these two compositions separate during the early stages of Earths formation? Or why do we have two types of crusts rather than one type all of the same composition?

I was under the impression that continental crust would eventually subduct or melt back into the mantle, but that's not the case? Do we know what would happen if eventually all or most of the Earth's surface is covered in continental crust?

I was also wondering, would it be possible in such a hole to evacuate heat in such a way that it would be liveable for humans at the bottom (solving the problem of the geothermal gradient?)?

The question popped into my brain as I read this article.

http://www.nytimes.com/1987/03/12/us/whale-fossils-high-in-andes-show-how-mountains-rose-from-sea.html

Basically describing how seashells and whale bones have been found high in mountain ranges. And this kind of confused me because I always thought that during subduction, ocean crust was always folded under continental crust. I thought the fate of all ocean crust was to be folded under, super heated, destroyed or created into volcanoes. So my question how is it that bits of the seafloor containing those shells were pushed so high up into the mountains if ocean crust is always folded under?

Thank you so very much for your time.