Unnamed Tectonic Start

[kirkspencer]

Hi Pixie,

Thank you, and yep, I've been welcomed. But I figure each new person's going to bring their own special sauce to that welcome.

I honestly had not considered the yellow lines to be sutures. I'd thought of them as guidelines for the fracture lines of the upcoming plates. Your identification of them as sutures... that could make some very interesting terrain down the road. Especially if I actually crack a bit off the line.

That bit about 11 is close to what I was pondering. Despite my clumsy phrasing above I'm not going to actually use the hot spots to drive the split (though i know that's what some theories think). Instead I planned to lay down subduction zones more-or-less based on the fracture guidelines, so they follow the eukler circles. That said if I make a grievous error I hope for correction.

As to gplates, I've looked at it off and on for a couple of years - in ignorance, mostly, but enough to know some of these things. It's actually a peculiarity of the program that's led me to pre-note these fractures. Basically, the fact that before you can split off the new continental plate you have to draw it.

One last point though you did not mention it. The current continental form is intentionally 'blobby' and smooth at this time. It will allow me the ability to adjust actual coastlines as I progress. Or so I hope.

[Charerg]

Actually it might not be a bad idea to take Pixie's suggestions a bit further and roughly split your supercontinent into cratons, and decide which blocks were already sutured together during the assembly of the supercontinent. I see you already did a fairly good start along these lines with the orogens, but it can be worth it to develop it a little further. This will also be helpful in deciding the direction of Debfurkhin's movement. For example, block 2 seems to be made up of three cratons (at least), since it's cross-cut by several orogens. So it seems logical that the tectonic pieces "within" the two orogens formed the core of the supercontinent, and the other blocks were gradually amalgated around it.

This is all well and logical, although I'd make the two orogens less linear, since like Pixie said, continents tend to move towards subduction zones ("slab pull" if being subducted, or "slab suction" if subducting). So, having two orogens exactly opposite one another seems just a touch unlikely, unless the continent reversed direction at some point.

Having an idea about the formation of Debfurkhin (just a vague idea should be enough, no need to model everything in detail ) will also become extremely helpful in the future, because a single cycle of supercontinental breakup won't probably be enough to produce interesting (and realistic) topography everywhere. But if you have some idea about the formation of Debfurkhin and the associated orogens, you can "spice things up" by adding some ancient mountain ranges.

If one were an utter perfectionist, I'd actually say that about three cycles of supercontinent formation and breakup are necessary in order to generate a sufficient amount of geological history for a truly interesting topography, but since it's a bit too much effort to model all that, I recommend only actually modelling the one cycle, and using intuition to determine the effects of the others on the present-day topography of the planet.

[kirkspencer]

Actually it might not be a bad idea to take Pixie's suggestions a bit further and roughly split your supercontinent into cratons, and decide which blocks were already sutured together during the assembly of the supercontinent. I see you already did a fairly good start along these lines with the orogens, but it can be worth it to develop it a little further. This will also be helpful in deciding the direction of Debfurkhin's movement. For example, block 2 seems to be made up of three cratons (at least), since it's cross-cut by several orogens. So it seems logical that the tectonic pieces "within" the two orogens formed the core of the supercontinent, and the other blocks were gradually amalgated around it.

First, to demonstrate ignorance, I had to look up "craton". Second, that's a neat idea.

This is all well and logical, although I'd make the two orogens less linear, since like Pixie said, continents tend to move towards subduction zones ("slab pull" if being subducted, or "slab suction" if subducting). So, having two orogens exactly opposite one another seems just a touch unlikely, unless the continent reversed direction at some point.

While I just whimsically drew both, after they were done I figured they were the result of two previous cycles. That said there's a major flaw I see related to what you said - and I'll discuss further down this message

Having an idea about the formation of Debfurkhin (just a vague idea should be enough, no need to model everything in detail ) will also become extremely helpful in the future, because a single cycle of supercontinental breakup won't probably be enough to produce interesting (and realistic) topography everywhere. But if you have some idea about the formation of Debfurkhin and the associated orogens, you can "spice things up" by adding some ancient mountain ranges.

Having an idea about the formation of Debfurkhin (just a vague idea should be enough, no need to model everything in detail ) will also become extremely helpful in the future, because a single cycle of supercontinental breakup are necessary in order to generate a sufficient amount of geological history for a truly interesting topography, but since it's a bit too much effort to model all that, I recommend only actually modelling the one cycle, and using intuition to determine the effects of the others on the present-day topography of the planet.

Yeah, I'm not doing multiple cycles, sorry (grin). But I do like the idea of putting in previous things, and that brings the major flaw I see to the fore. I envision two block being the first/major split. Yet the parallel orogenical ranges from two previous reassemblies run into it from the east semi-supercontinent.

I'm going to have to go back and repaint these a bit, I think. Not least the big line down the 2-block eastern edge.

FWIW I can already see a nice advantage of GIMP for part of this. Use the 'tracing' selection tool, copy that to a new layer, and rotate and move to my heart's content based on the outline brought back from gplates.

It's a good thing this is a solo vacation week. I may need the time just to get all the "before" steps done. (grin)

[kirkspencer]

Three images, intentionally small, from the lessons of gplates.

This is the map of originally anticipated plates, just for orientation.
plate_IDs.jpg

Same image using Gplates color pattern.
Start.jpg

180 Ma later, gross level movement of plates.
endmap.jpg

Not shown are rifts and spreading oceans and subduction zones and mountains and rivers and, well, you get the idea. I want to get mountains determined so I can work in climates. But i've got a couple of places for a trail of islands (Patagonia like) and quite possibly an indonesia-like zone.

I've got a couple of what I'm going to call 'odd' pieces that may make me go back to the drawing board. Basically, as plate 2 (the big one on the left) hinges out and drops south it interrupts the movement of a couple of other plates. As in they just flat run into it. I see three ways to work them.
1) slow them down.
2) Just meld them to what is becoming the south pole's land base.
3) hit, then separate under a newly developed subduction zone.

In both the latter, one bonus option is to allow one of the impacts to be a subducted continent and make some himalayan mountains.

Anyone wants to throw ideas, I'm open for now.

[Deoridhe]

The idea of an enormous landmass centering on the south pole seems pretty cool to me - something plausible but not found on Earth.

[kirkspencer]

Bubble bursting. That's going to be the north pole. (just felt right). There's still land at the south, it's just not as large.

So now the quadrilateral looks like:
Debfurkhin2.png

So one of the earlier steps I plan to do is change the break so the long skinny continent isn't split across both sides of the map.

While I have not drawn subduction and convergence zones, most of them are pretty easy to guess because of the extra lines. Please note that at this instant all lines are approximates. There are some neat possibilities down in the details that I haven't cracked, it being early on this and all. Still, I wanted to start getting roughs for climate, too. Again, after I get the basic, my first focus for high detail will be where I'm running games in a few short months.

Darker brown is old mountains/high ground from previous cycles. They might be appalachians, they might be urals, they might be alps/Rockies (all of which qualify).

I know you can't see it clearly but I've got a medium and a light yellow. Medium is the inevitable mountainous build-up on the leading edge of continental plates. Just where that is will depend on where the actual continent line goes (one of those details I mentioned a moment ago). I've also got two or three what I can only call catastrophically high mountain areas. For a couple they're basically continental convergences. There's one, though - I'm going to be taking off a chunk of the trailing end of that long split continent. I'm saying it rammed under a piece of what has become the arctic, and I've got himalayan sized mountains. I grabbed it rather than modify because now I've got "the mountains at the top of the world." It may be players never see it, but my imagination is sparked.

[kirkspencer]

Question for admins/experienced members. I appear to have stumbled backward into doing a WIP thread on DebFurkhin (tectonic build).

Should I just keep stumbling along? Should I start a new thread appropriately named and identified? Are there other alternatives you recommend?

(And is "tectonic build" what I really want to call this?)

[Charerg]

Question for admins/experienced members. I appear to have stumbled backward into doing a WIP thread on DebFurkhin (tectonic build).

Should I just keep stumbling along? Should I start a new thread appropriately named and identified? Are there other alternatives you recommend?

(And is "tectonic build" what I really want to call this?)

Well, you did title the thread "Unnamed Tectonic Start", and since you're still dealing with tectonics, that certainly remains descriptive. I don't think there's any need to start a new thread, since all this stuff is related to the present-day tectonics of your world.

[kirkspencer]

Well, you did title the thread "Unnamed Tectonic Start", and since you're still dealing with tectonics, that certainly remains descriptive. I don't think there's any need to start a new thread, since all this stuff is related to the present-day tectonics of your world.

So let it be done.

DebfurkhinBW.png

Though it's a few hours of work as I tried, backed up, and tried again, I'm satisfied with the progress to this point.

Killed two birds with one stone, here. I've got a coarse manual height map in grey tones, which will both let me begin the first pass of climate AND let me take it to Wilbur for terrain work. I should note that I'm considering one or two more 'lower elevation' gray tones between the plateau as it exists and the sea - I've got the grey tones in pattern, it's just a question of whether it's worth the effort.

Bonus, I've got latitude lines for the climate work. 0, 30, 45, and 70 N and S.

[The_Sleeping_Dragon]

I like the concept and have only two observations

1) your original map is based on existing latitude being in straight lines rather than curved so will distort any attempt to then map to a globe particularly creating massive conflux at the poles both of which are much huge on most 2D maps than their actual land mass (have you ever compared actual land mass maps to the usual maps we use?)
2) might the concept be easier if you use an imaginary world as then you can create areas unaffected by tectonic movement or massive tectonic movement in a single direction ie you control the physics of such movement; you can also move the poles to east west if you wish but it gives you more mapping options

Best wishes

The Sleeping Dragon