Step 2 - Drawing the Continental Crust
It is now time to decide where the continents will be and give them their shapes.
When I did this, I made a few copies of the tectonic plate sketch on which to draw my continents and landmasses.
But where to start?
One good place would be to find your divergent boundaries. This is a possible location for an oceanic ridge/crust formation point. This is also a possible location for two continents that were one time joined together, but are now separated, like South America and Africa. So you might want these two continents to have coastlines that would mostly "fit together", but separated by a body of water.
Once you have those coastlines drawn, think about the rest of the continent. The shape can be entirely up to you and can have a lot of randomness.
Next, think about your Oceanic Plates. When looking at the Earth's plates, you will notice that only two major plates have no continental crust at all: the Pacific Plate and the Nazca Plate. One of your large plates could be entirely oceanic, and would therefore be a location for one of your oceans, if not the largest. It would also be a good location for a "Pacific Ring/Ring of Fire" type scenario, where most of the plate's boundaries have a lot of volcanic and seismic activity, not to mention some of the deepest trenches where there is the most subduction.
Then look at your convergent boundaries. They will be the locations of either Himalaya type mountain ranges, Andes or Cascade volcanic mountain ranges, or volcanic island arcs. Decide what you would like to have and where. This can help you decide where your oceanic and continental crusts will be.
Finally, think about whether or not you want any continental divergent boundaries, where there may be a large rift in the continent (and a new plate boundary forming).
Most of this step is up to you, but is also largely determined by how you drew your tectonic plates and what direction they are moving. Take some time with this step and make it your own.
Here is what my map looked like after adding the continents (it's not the finished product):
Continents A and B are separated by an ocean created by a divergent plate boundary. They were once together and as such, they would "fit" if placed side by side. Both would also fit with the southern continent, which I forgot to label, as that is also a divergent boundary.
A<->G, E<->B, F<->D and C<->D are all continental convergent boundaries and are creating large mountain ranges.
Notice the island arcs between all of the oceanic convergent boundaries.
All the way to the north is a continental rift caused by a continental divergent boundary. (x) will one day be its own landmass and tectonic plate.
The island between G and (x) has a ridge of mountains caused by a convergent boundary and subduction. B has one as well, but that's from a very old subduction that is not current.
Now, I'm sure a legitimate geologist would look at this and tell me a thousand little things I did wrong, but it has enough scientific base for me, and it has resulted in a realistic looking map. And what's more is that there was enough randomness involved that I didn't know exactly what it was going to look like in the end, so it was just a bit of a surprise.
I still have some more work and detailing to do before going on to editing this in the GIMP according to RobA's excellent guide.
Anyway, even if you don't use this whole method to create world maps, I do hope that there is information here that could be helpful in determining at least some of the terrain on your maps or help shape continents.
Thanks for reading!
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