Geological Map

[Michi il Disperso]

Hi everyone,
i'm trying to find a praticable but still guesscientific method to make a geological map of my world-in-progress.
I've simulated plate tectonic to develop the actual continents and i've quite a good idea of where the faults are (and were); i've made a proto-height map, mostly to have a placeholder and to find climatic zones.
Now, before moving to more precise (and time consuming) realistic DEM heightmap, i really want to have a geological map to guide the erosion, the age of the mountains, and the placement of natural wonders in my world.
Anyone that have done this before can give me some tips?

I attach a really nice geological map of Earth i found, in my dream i will produce a thing similar to this, more realistically it will be far more semplified, for now at least.

[Bindusara]

I thought about the same thing last week : how doing that?
As far as I know of geology, you have 3 kind of rocks :
- rocks coming from sedimentation
- rocks coming from lavas
- rocks coming from the first two types, transformed by physical processes (pressure and temperature)

My thinking of how doing that was the following :
1 - you start with a "granitic planet" : all plates are granite on the top, meaning magma which have slowly cool down on the top of a core of liquid magma
when going down in the earth, before reaching the mantle, the granite become a metamorphic rock. The layers of types of rocks depend of the temperature and pression. Then you have the liquid magma, but you don't care about it for your work.

At this moment, one question seems important : are there any moutains, seas, from events before you start your planet? Or is your earth flat, a perfect ball of granit, with no erosion?
If yoy have some relief, you can start some erosion there : you have rocks from sedimentation, and you have to decide if your world is with or without life
- without means only sedimentation from rocks erosion
- with means sedimentation from life remains (forming limestone)
I don't know what are the times recquired for forming rocks from sedimentation. You have to find some rule :
- for the seas with life, for knowing the height of limestone that can be formed for example (as long as there is a sea ... of course ...). Forests can become carbonatd rocks like coal, or petroleum.
- for the sedimentation from rocks, you have to simulate erosion, main rivers, sediment deposit
That's mean you have layers of rocks coming atop your granitic planet.


2 - plates start moving
then I think everything becomes very very complicated
plate moving away from each other : at the junction, basalt (volcanoes) come to the top, meaning layers of basalt at surface
plate with friction : the plates are pleated, meaning that your different layers of rocks make waves. Furthermore, there is a another metamorphic transformation due to the pressure. And magmas makes it ways to the surface (volcanos) meaning basaltic rocks.
The erosion still goes on, and sedimentation too, meaning that you have layers of rocks coming atop of what was before, and at a same time, the rocks under your surface become apparent (in mountains, meanings layers of differents kind of rocks for example)

My conclusion is that making a whole simulator is far away from my geological knowledges, and that the simulator should be very consuming in CPU time

[Michi il Disperso]

Thank you for the info!
I think too that a fully working simulator would be really too much for my (scarce) competence.
I'm approaching this from the things i know for "sure", the main fault lines, divergent plates and subduction zones. I think i'm gonna try to find a more "visually pleasing" result that a strictly scientific accurate one; also because i'm beginning to think it's almost unreachable...
However, looking at the reference map of Earth, seems a patchwork of rock type and ages with more randomness and less logical placement; obviously it's only an impression, but i think it means that trying to replicate the Earth past in another world it's simply too difficult. So i'm unsure between start from a sedimentary base everywhere (the rock type that appear on Earth surface) and then slowly add other types based on where the faults and volcanoes are or were, or start from a granitic planet and then recall the major movements of plates and transform the granite in what it will be now...

I think i'm going through the fast one!

I just wanna ask, if someone knows, is there something forbitten? Like "Oh, this kind of rock should never appear near this fault!" or "If the Volcano was here it is not possible that is covered by metamorphic rock now".
Looking at the Earth it seems that almost everything is possible XD