Tectonics

[davoush]

Hello,

After reading other people's inspirational threads about how they worked out the plate tectonics, I decided I would also have a try. I am quite attached to where I had already decided long ago to place the mountains etc. so this is more of a retrospective 'fit'. I know some members are very knowledgable about tectonics and other processes, so please don't hold back on criticism. There are a few areas that I think might defy any tectonic based stuff, in which case it'll just have to be ~unexplained~ or ~mystical~.

I imagine the Western continent (middle section) was originally two plates which fused, with a mountain range in the centre. These are now pulling apart, and a big rift valley is occurring right down the middle. The eastern coast is having a massive mountain range being created, and the western side has an older mountain range a bit further inland. I don't really want to add any more island chains, but I would like to know where I should place volcanoes. I also don't know how to best explain the equatorial island chain: erosion from an older larger landmass, or oceanic plates colliding? Either way, the southern half of these isles is mountainous.

Edit: Green = old mountain ranges
Edit: Added updated map

Any comments/criticism (please be as harsh as you like) more than welcome.

Thanks!

Edit 2: I've decided to explain some mountain ranges just as 'old' ranges from previously fused plates. This makes it a bit easer.

Updated: Attachment 96860

[Deoridhe]

Oh the 15 and 16 plates - those could be block mountains caused by the continent being dragged apart. They're away from a subduction zone, so it could work.

[Pixie]

Hi there. "Retrofitting" tectonics into a given conworld design is much harder than creating from scratch, and that's already pretty hard. If you had a look at recent (or not so recent) threads you realize that by now. Furthermore, your original land/ocean design looks awesome, but it would be a nightmare for tectonics... I mean, there's a couple of sweet spots to start, but then you'd need to delete/add landmasses.

Are you sure you want to go up this road?

If so, here's a couple of ideas:
- draw on a sphere - you won't get proper shape and movement direction unless you think of this as a sphere, and, because of that, learn how to use g.plates.
- read about and truly understand the Wilson Cycle, that's the basic tectonics you want to master.
- everytime you make a decision concerning present tectonics, think about what that entails backwards (for example, if you have one continent moving in one direction, where's the other part of the continent which separated and moved in the opposite direction?)
- most of the movement is towards subduction zones, so that's something you need to establish, more importantly than mid-ocean ridges or continental himalaya-style mountains.

I hope this helps,
good luck

[davoush]

Hi Pixie, thanks for your comments. I have actually just been reading through a good load of recent (and older) threads where other posters have gone down the tectonic road, with your excellent advice. I am slowly getting a clearer picture of how things work, and so I have adjusted my map somewhat. (I tend to use G. Projector as I draw so I am used to thinking in a globe.)

I think one main issue was the chain of large islands across the middle - they were too big and were interfering with every attempt I made. My basic (and probably mistaken) intentions for this updated version were:

The Zam and Ea plates were originally connected, and have rifted, leaving a mid-oceanic ridge. Zam collided with Sapun to the East, and with Sitan to the South.
Sitan and Shilan were a large continent, possibly from an earlier collision of two continents. This is now rifting down the middle as Shilan is pulled towards the big subduction in the East, and Sitan to the West. (I really want to keep this rift, so I may have to give it a magical explanation if it can't be plausible).

The Shupal plate is moving northwards, colliding into the Sitan and Shiilean plates, forming a mountain range and area of subduction. The South polar plate is then rifting away. (Maybe I should have this moving towards the Oceanic plate as that subduction pulls it, and also a South polar subduction?)

Across the water...

Ea has rifted from Zam, as mentioned, and is now colliding with Onaxa which is moving north-west, creating a Himalaya-type range. The Eastern part of Onaxa was originally part of Sapun, but rifted along ago and 'fused' to Onaxa, leaving a mid-oceanic ridge between Sapun and Onaxa.

Traqos has rifted from Onaxa, moving south, possibly pulled by the Ayabba plate. I think there should be some subduction of either Traqos or Ayabba here but I am not sure which one would get subducted under the other.

As Onaxa moves north to collide with Ea, it has pulled up Kurnugi which has now become attached by a thin strip of land (this part will probably be messy in tectonic terms). Kurnugi was once perhaps attached to Shilan, but if it was, it split a long time ago.

The oceanic plate is moving away from Kurnugi and subjecting under the Shilan plate, causing an island chain.

Now, the other island chains I am not so sure about. I imagined the Ayabba plate was moving north-west, colliding with Zam. Then a few minor plates allow me to keep an island chain which more-or-less connects the two main landmasses.


Anyway, I think I have tried to use what I have learnt, but a lot of it still may not make sense. I am quite enjoying the learning process and the 'puzzle', so I am quite keen to get the tectonics fitting correctly. I don't mind moving/deleting/adding landmasses too much.

Attachment 97008

[Pixie]

Just a quick reply, I need some rest now, but I wanted to leave you with "food for thought"...

Have a look at this map:


Do you think you could do a similar one based on your current understanding of your tectonics?

If you can, then you aced it!

[Naima]

Hello,

After reading other people's inspirational threads about how they worked out the plate tectonics, I decided I would also have a try. I am quite attached to where I had already decided long ago to place the mountains etc. so this is more of a retrospective 'fit'. I know some members are very knowledgable about tectonics and other processes, so please don't hold back on criticism. There are a few areas that I think might defy any tectonic based stuff, in which case it'll just have to be ~unexplained~ or ~mystical~.

I imagine the Western continent (middle section) was originally two plates which fused, with a mountain range in the centre. These are now pulling apart, and a big rift valley is occurring right down the middle. The eastern coast is having a massive mountain range being created, and the western side has an older mountain range a bit further inland. I don't really want to add any more island chains, but I would like to know where I should place volcanoes. I also don't know how to best explain the equatorial island chain: erosion from an older larger landmass, or oceanic plates colliding? Either way, the southern half of these isles is mountainous.

Edit: Green = old mountain ranges
Edit: Added updated map

Any comments/criticism (please be as harsh as you like) more than welcome.

Thanks!

Edit 2: I've decided to explain some mountain ranges just as 'old' ranges from previously fused plates. This makes it a bit easer.

Updated: Attachment 96860

Looking good, and as others are advicing on plaques I do not have much else to add , only eventually that the coastlines look a bit too spikey and a little unnatural but I guess this can be refined later on and it depends on the drawing tool used . Keep up the great work .

[davoush]

Thanks Pixie and Naima. @Naima, I agree they were too jagged - I have actually updated the coasts quite a bit, my second post (and this post) shows them now.

@Pixie, I have seen those maps showing the age of the oceanic lithosphere, but I never thought to make one myself. I have made a very rough attempt.
light blue = youngest,
purple = intermediate,
dark blue = oldest.
I have not coloured the polar plates. In fact, I might make the northern plates extend a bit further north to reduce the polar plates size as I don't want them to interfere too much. Or even just connect, like the North American and Eurasian plates.

I am unsure about the large oceanic plate with the very ancient ocean in it (in the South). There is subduction happening on most sides, but I feel like this would have split, as it looks like a very old and large plate.

Attachment 97028

[davoush]

I have reworked a few areas. Mainly: the northern pole plate has disappeared. Instead are the large continental and oceanic plates, and I added in an extra minor plate because I needed an island chain there to balance things out visually. I think this is a more elegant solution. The south polar plate has been reduced.

I am unsure about: I added a small island on the plate which contains the big northern continent. I don't know how realistic it is for a large plate to have a landmass so far away from the mainland. I can't justify it having its own plate there, but I think it looks better with it.

In the large Eastern plate which contains a previously fused plate, I added an island arc from the earlier collision. Would these islands still be there given that the collision happened long ago and the plates are now fused? I also need to work out the island arc coming off the large southern island.

I feel like there are a lot of island arcs, but they help balance the two halves nicely - maybe I should reduce a few? Or is this amount plausible?

I also want to decide on 1 or 2 inland seas, I know these are likely to form where an older sea has been closed by surrounding land, but I just can't quite picture it yet.

Attachment 97036

[Naima]

I don't think the Archipelagos are too many and look good.