Granite origin mystery.

[AlexandrKushnirtshuk]

Granite is found only on Earth. It was not found either in meteorites or on other "planets" of the solar system. Officially it is unknown why. I suppose, it is because the Earth is the largest object in the Universe, with the greatest gravity and pressure in the subsoil.

Quote

The role of granites in the structure of the upper shells of the Earth is enormous, but unlike magmatic rocks of the basic composition (gabbro, basalt, anorthosite, norite, troctolite), analogs of which are common on the Moon and terrestrial planets, this rock is found only on our planet and has not yet been established among meteorites or on other planets of the solar system. Among geologists there is an expression "Granite is the calling card of the Earth".

Links to quote in russian (did not find the same in english):

1) https://beversmarmyr.com.ua/articles/istoriya-formirovaniya-granita

2) https://ru.wikipedia.org/wiki/Гранит#Проблема_происхождения_гранитов

[Bufofrog]

11 minutes ago, AlexandrKushnirtshuk said:

I suppose, it is because the Earth is the largest object in the Universe,

The earth is not the largest object in the universe. There are 5 objects larger than the earth in our own solar system.

[AlexandrKushnirtshuk]

13 minutes ago, Bufofrog said:

The earth is not the largest object in the universe. There are 5 objects larger than the earth in our own solar system.

Even officially the solid cores of gas giant planets are smaller than the Earth. Gas shells of that planets is like an atmosphere on Earth. Do we measure earth's size including its atmosphere? I suppose that so called "gas giant planets" are just huge comets, the absence of a tail in which can be explained by the great distance from the Sun and the relatively low speed of movement in their orbits.

Edited March 29, 2021 by AlexandrKushnirtshuk

[John Cuthber]

1 hour ago, AlexandrKushnirtshuk said:

Granite is found only on Earth.

Granite has not been looked for anywhere other than Earth.

If there was granite on the moon, how would we know?

1 hour ago, AlexandrKushnirtshuk said:

I suppose, it is because the Earth is the largest object in the Universe,

No

https://www.nationalgeographic.com/science/article/bizarre-planet-largest-known-rocky-world-40-times-as-massive-as-earth#:~:text=Bizarre new planet is largest,times as massive as Earth&text=The planet TOI-849b is,close to its host star.

[studiot]

1 hour ago, AlexandrKushnirtshuk said:

It was not found either in meteorites or on other "planets" of the solar system

 

Starting your speculation with a false premise is unlikely to allow arrival at a true conclusion.

Quote

Wiki

Lunar granites are relatively rare rocks that include diorites, monzodiorites, and granophyres. They consist of quartz, plagioclase, orthoclase or alkali feldspar, rare mafics (pyroxene), and rare zircon.

https://en.wikipedia.org/wiki/Moon_rock

 

We have no samples from Mercury, Venus, Mars or other Moons or the OOrt.

[Bufofrog]

I see from your graphic that you are showing that the gas giant planets are in fact larger than the earth, so that is good.

Was your OP actually trying to say the earth is the largest solid body in the solar system?

[Sensei]

1 hour ago, AlexandrKushnirtshuk said:

It was not found either in meteorites or on other "planets" of the solar system.

Meteorites and other solid planets (at the moment, we can discuss only about two: Mercury and Mars) have none or too little volcanic activity.

You should start from reading the English version of Granite article on Wikipedia. Always start with the English version, because the local language versions are usually very poor in detail (except articles about the history of the country etc. local things)

https://en.wikipedia.org/wiki/Granite

It explains why granite can't be (easily) found in cosmic space in the first paragraph "It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground.". Without volcanoes, without volcanic activity, there is no granite as well.

[studiot]

1 hour ago, Sensei said:

It explains why granite can't be (easily) found in cosmic space in the first paragraph "It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground.". Without volcanoes, without volcanic activity, there is no granite as well.

In all fairness that description is self contradictory.

No volcanoes are necessary for the formation of granite.

The part about slow cooling is iffy at best since the cooling rate determines the grain size so the actual rock formed does indeed depend upon the cooling rate as noted, but if the composition of the magma is not correct then basaltic group rocks will be formed instead instead of the granitic group.
The 'liquid' granitic magma is much more viscous than the basaltic group so tends not flow out in great lava flows but remains underground and cools.
Outcropping solid granite is then exposed by weathering/duenudation processes.