A Realistic World Map WIP. Is everything geologically plausible? Critique!

[QuietlyConfident]

I've been into worldbuilding for a long while, but I've never properly dove in because I would always get bogged down by the details: star size, planet size, mass, gravity, geology. As I'm not fantastic at science, this would quickly overwhelm me and I'd just give up and forget about ever finishing it.
This time, I'm not planning on doing that.

So, here is the WIP of my first world map. I'm going for an Earth-like world; much less water (only 54% or so coverage), which is slightly larger and slightly older than our planet. Water is black, landmasses are grey.



Stupidly, I created the map before even thinking about tectonics, because I wanted to dive into actual worldbuilding before getting bogged down like I usually do. So I had to try and work around it and make up a hopefully realistic (though still very rough) guide as to where the plate boundaries are. Note: I'm not a good geologist, and the most I know of tectonics is gleaned from the Internet and my dull memory. Nevertheless, I hope I've done okay.


Mustard shading is continental plates, blue shading is oceanic plates. Red arrows are directional movements, green highlights are mid-oceanic rifts and brown highlights are mountainous areas. How's that look?

Please, do critique it. I'm very very very open to suggestions. If I have gotten something totally wrong, I want to change it.

Thank you!


EDIT: Actually I do have a couple of questions before we even begin. There are quite a few inland seas. How are they created in the first place? Again, I suck at geology and should really have thought that up before I drew it in.
Secondly; is it realistic for almost all the land to be in the top half of the planet? I tried to work through this by having the oceanic plates in the middle between two continental plates, as if its been recently formed due to a vast split between the Northern and Southern plates. Is that realistic?

[Hai-Etlik]

First, you need to be aware of directions being on a globe. You can't have a plate expanding or contracting in all directions away/toward a pole. Remember that a continental craton is going to stay roughly the same size. If you have one at a pole and it is moving, it will be going north on one side, and south on the other. The ratio of continental to oceanic crust stays pretty much constant.

If it helps, don't think in terms of linear movement, think in terms of plates rotating about the centre of the planet as that's a more accurate view of "strait line" movement on the surface of a sphere.

So you can't have an all land planet which ruptures open a ring shaped ocean around the equator. A supercontinent at a pole, does work if you want it, and it would likely result in severe cooling and sea level drop IIRC.

Also, your coastlines look far too 'rough' and 'fractaly'. If you look at a map of Earth you'll see it tends to have a much lower fractal dimension with just a few 'rough spots' like South East Asia. Large rough spots like that tend to be shallow continental seas. If you look at it more zoomed in, you see more variation in roughness, but not so much with continents.

[Ascension]

Hai's pretty much our expert on these things, along with a few others, so what he/they say I'd take heed. What I see are 2 super continents - the bottom one is solid but apparently shrinking in on itself; the top one is expanding outward toward the equator; the wrap-around one (on both sides of the image) is moving northward; middle left plate is moving south; central plate is moving north; the wrap-around ocean plate is moving south; left ocean plate is moving north; central ocean plate is moving south; and bottom ocean plate is moving north. 2 land plates and 2 ocean plates move north while everything else moves south, where the south pole plate shrinks in on itself. You have some basics here to work with but maybe a redraw might be in order to refine some things.

[Hai-Etlik]

Hai's pretty much our expert on these things, along with a few others

Actually, I just have a basic layman's understanding of Geophysics from reading some intro textbooks on physical geography and Wikipedia. (And the background in GIS and Non-Euclidean Geometry to help me put it in context) So I certainly wouldn't call myself an expert, at least not in this field.