[WIP] Unnamed

[davoush]

Well, I decided to take a break from the artistic side of my map, and took a leaf out of Deoridhe's book. I have made a very simplistic tectonic plates map, but as I know where I want the main mountain ranges to be it's more of a retrospective exercise. Please do tell me if any parts seem completely implausible, though! It has also helped decide where to place rift valleys, which I was a bit stuck on.

Edit: Images removed as not up to date.

[Deoridhe]

Love it! I have no practical commentary except to share one of the things Pixie taught me - large bays need plate tectonics to justify them. You did that most places, but the top right continent could have pulled and India and have the middle triangular chunk of it go smoosh into the continent itself to justify the two bays there while also giving you a higher mountain range if you want (the epic mountain range in Asia owes a lot to India going crash into the rest of it). I spent a while looking at the Earth tectonics and identifying areas that did what I wanted to mimic, then trying to apply them; that might help!

[davoush]

Thanks Deoridhe - your thread and Pixie's advice elsewhere has been very helpful. I've redone some parts of the coastline and the tectonics have been updated accordingly. I think I have continental shelves about right, although I seem to have quite a lot of big continental shelves. I'm unsure how these behave at continental-oceanic divergent boundaries. The south-eastern part is also troubling me a bit because there is a lot going on, and a 'bay within a bay' (around 30 latitude).

Edit: See next post for map.

[davoush]

So, after reading through a lot of Pixie's advice and other threads on creating a map using plausible (or at least semi-plausible) tectonic processes, I have decided to also try this. This has led to a complete reworking of the map, but I actually prefer this map now. It seems organic and nice to look at. I opened a separate thread about tectonics, but as I plan to also make a climate map I will use this thread. I hope there are no glaring errors...! (I realise the movement of the plates looks quite simplistic, but at this stage I am happy just see what is happening 'beneath the surface'...)

Here is the tectonic map (plate names are still a WIP):
Erkalla.png

[Mouse]

I don't know anything about all this virtual tectonics, but I agree with you that the land shape is better than before

[Pixie]

It seems organic and nice to look at.

It really does. And it features some "ok" understanding of tectonics, including some really sweet looking areas, where everything falls into place. Congrats on the major improvement (from the scientic-nerd-wants-it-all-plausible point of view).

Still, there's a lot to more to it, if you want to keep improving. Here's a bunch of comments, based on your map, which I made into Winkel-Tripel projection (twice), to better show the spherical nature of it all:

davoush_WT(Sitan).jpg

1: Starting with the most important idea in relation to plate movement - plates are pulled towards the area where they are subducted. West Qutrus plate is being subducted at its northeastern boundary, so it will be pushed that way. Being a smallish plate, that pull will effectively produce a change in motion. You may leave the southern boundary as it is, breaking the plate into two, with the southern but remaining in place (slowly creeping southward) and the main part rotating clockwise.

2: This is just a very strange zone in terms of boundaries... There is only a segment of oceanic ridge. Aos plate is moving southward, but there is no piece of continental crust on the opposite side of the boundary. Moreover, there would be newly created crust right next to who-knows-how-old crust on that part of the ****an Ocean Crust. Mark this for revision.

3 & 4: It seems to me that in this area there was a rift between Sitan and Hultuppu that has been reverted. That's cool and plausible. The oceanic crust in the southeastern boundary of Sitan began to be subducted, which is now pulling the entire continent towards this area and it also put a stop to Hultuppu movement eastward. The thing is, while Hultuppu was moving eastward, it was "eating up" oceanic crust and creating an Andes-style volcanic mountain change. Now, as it turned around, volcanoes are no longer fed and the chain at the continent gets battered by erosion. However, what stays behind? Maybe a new oceanic rift as magma rises to occupy the empty space.

5: I like that large, mature, rift. It has all the right characteristics. Initially a triple junction, only two of its branches remain very active once it matures.

6: There is a clear subduction area in the northwest of Qutrus plate. Go back to note (1)... Plates are pulled into the areas where they are subducted. Which means the Ayabba oceanic plate gets pulled eastward. But that plate is also, and mainly, pulled north and west, as you have it depicted with the black arrows. Hence, the plate gets torn apart. In fact, such a huge oceanic plate needs a spreading center anyway, so figure that out...

7: Your north pole needs fixing. It's a typical beginners mistake, having several lines going to the north of the map. Upload your map into g.projector and have a look at an ortographic projection centered in the north pole...

8: I don't understand how these boundaries are... please explain?

davoush_WT(Shilan).jpg

1: Again, the spreading center of the Ayabba Ocean...

2: I really like this detail. The old oceanic crust cracks and starts subducting, pulling part of the main continent back and effectively torning it into smaller pieces. That's awesome tectonics there, but beware of the regional implications, specially since you don't have the Shilan Ocean plate that coherent.

3: Shilan plate is a huge continent, and it has been moving (fast or slow) southward and, apparently, clockwise. That makes the entire region I marked with 3 a passive continental margin. Understanding passive continental margins is a good thing if you want your tectonics right. I don't see how it could be a plate boundary.

4: Just wanted to say I love this "ring of fire" brought to equator and all the way to the south pole - it's going to work great, I think.

5: There isn't a single ocean in your map with a spreading center... Have you noticed that?

6: Again. If the Qutrus oceanic plate is being pulled into the subduction zone to its northwest, then it leaves a gap behind it, in the southeast, which is filled with new magma - and that's a spreading center / oceanic ridge.

--------
And that's all. That took me longer than I thought. I hope you don't take this as me being too nosy (which I normally are in these situations). Please feel free to tell me to back off if it's overkill.

[davoush]

@Mouse: I'm glad you also like the land shapes! I was at first very daunted about figuring out the tectonics, but I love puzzles and can be a perfectionist, so it is quite enjoyable so far.

@Pixie. Many thanks for your detailed comments - the board is very lucky to have someone willing to share such expertise!

I have reworked the map based on your comments. The main points/questions (as noted in pink numbers on the map) are:

1) The Sapun landmass was originally attached to Sitan and has rifted, colliding into Shilan, leading to ocean spreading down the middle. I imagine this to be quite an old split.

2) Similarly, Aos was originally part of Chilean but has split, and has now collided with Sitan. I am trying to decide whether the Sitan-Aos or the Sapun-Shilan collision should be the newest? Do the tectonics give any clue? This will help me decide mountain heights.

3) As you pointed out not much ocean-spreading was happening, the Ayabba plate has split. This is a very ancient ocean, I imagine.

4) The Hutuppu Ocean originally also encompassed the Qutrus ocean, but this has split as part of it is dragged towards Qutrus.

5) There are some minor plates. I wanted a South-American style mountain range, so I created a minor plate which is moving in slightly different direction from Ayabba, colliding more directly with the Shilan Coast. I'm not sure how plausible this is? Minor plate 6 was created so I could include a small island chain somewhere around there.

I am most bothered by the boundary between the Aos Plate and the Hutuppu Ocean Plate: Aos is moving South-East, away from Shilan but Hutuppu is moving North-West so there isn't really a clear ocean-spreading in that area where convergent and divergent boundaries meet.

I am still slightly unsure about the polar ocean plates, but I would like them to not interfere too much with the current set up.

Thanks again!

Untitled map 1.png
Untitled map 2.png

[Pixie]

What a quality revision! This is looking very good, davoush.

Indeed, you have a problem with the Aos plate. And it's showing in several parts, but it's always the same issue:
- the shape of the continental crust and the ocean around it isn't coherent with tectonics, simply put.

The Aos subcontinent fits pretty nicely with Shilan, but a bit to the north of its present location and a bit rotated. So you need to "have the movie go back in time". Imagine (or use g.plates for this, but you need to figure how to use it properly, which is a big learning curve) those continents in the past, close to where the mid-ocean ridge now is.

- Continent Aos rotates clockwise, with the rift starting in the south (note to yourself - this could have been an Ethiopia style area).
- Then, as the rift matures, mostly moves east.
- Then the northern part of Aos ocean ridge speeds up the spreading (this can happen, I'm not making this up ), which makes both continents spread with a twist of rotation (clockwise for Shilan, anti-clockwise for Aos).

This would explain present locations, but you can't have oceanic crust belonging to Aos plate that isn't explained as crust created in the back of the continent's trail. As it is now, you do, both south and north. The problem with Hutuppu Ocean is that strip of ocean crust which shouldn't be part of Aos plate. Also, the triangle of ocean between Sitan, Aos and Hutuppu, belonging to Aos is the least sensible solution.

[davoush]

Thanks for the detailed comments once again, Pixie!

As I am going to be busy for a few days, I have tried to implement this advice (although it may be a bit rushed so I am sure there are more elegant solutions).

With your comments in mind, I envisioned:

(Before Aos split from Shilan) - There was a large north-south mid-oceanic ridge. One side of the ocean was subducting under A, B, C and spreading roughly down the centre.

The messy part is Aos: It was pulled into the movement of the earlier subducting plates (labelled in pink, OLD), splitting from Shilan, but it has cut across the east-west divide leaving a weird mess in its tracks. I just can't quite picture how the lateral movement would turn out in terms of generating oceanic crust and boundaries. I think it would create 'G' in the north, (which Shilan has prevented it from spreading) and the horizontal boundary it creates would be mostly transform.

The old subducting plate is nearly disappeared, but the ocean is spreading in roughly the same directions below Aos/Shilan (D/E). Maybe D/E should be merged into one plate? The whole area seems quite messy and I'm not too sure how to resolve it without doing something drastic to Aos or another part.

Reworked Oceans.png

[davoush]

After letting the map sit for a few days, I have come to the conclusion that the Aos plate had to go. All the solutions were ugly.

Instead, it may have been an earlier plate which collided with Sitan long ago, and has now become fused into the Sitan plate. (I may still place a mountain range where I intended at the old plate boundary).

Plates A, B, C are part of a very old plate which are now in their final stages of subduction along the Sitan coast, Hutuppu and between Qutrus and Hutuppu. The ocean is spreading between Silan and Sitan but I'm not sure how realistic this as, as the subduction of A, B, C implies a similar spreading in the past?

I have also extend the north and south polar plates - this has led to a nice subduction zone in the north creating an island chain. I might also add some islands along the Qutrus subduction zone.

The southern part of Shilan is no longer rifting. I really wanted a rift zone over land, but it looks like there has already been extensive (and complete) rifting in several places, so I guess it's unlikely there'd be another one forming. The rift-like bay at the southern part of Shilan is bothering me, but I suppose it could just be explained by the shape of a previous continental collision?

It looks like the world at this stage is in a game of tug-of-war with the ocean spreading on both sides of Silan and Sitan - Will Shilan eventually be pulled towards Sitan creating a new supercontinent or vice versa?

I am also still unsure where is a reasonable place for inland seas - any suggestions from those more knowledgable would be great.

Untitled map 25.png
Untitled map 26.png
Untitled map 27.png