So, I mentioned I would post something about the geologic history of C. Eocidar's western mountain belts (dubbed the "Eocidarian Cordillera" since they're mostly inspired by the real-world mountains of that name). I actually have a fair bit worked out for how various parts of the mountain range formed, ranging from different terranes docking with Eocidar to subduction of submarine plateaus. But since I keep most notes in my head it's all a bit disorganized, and this post ended up being mostly about the history of the C'thuana terrane, so I guess I'll call this post "part one" on this topic.

With the intro out of the way, let's dive in and take a look at Aduhr 200 Mya:
200 Mya.PNG
Needless to say, this is all very WIP still and the further back in time we go, the less detailed things become. But at present the C'thuana terrane is envisioned as originating from the southern margins of Panwara, diverging at about 250 Mya. The main reason for the divergence is the NW movement of Panwara: there is a retreating subduction zone on the southward margin of the continent, and this causes the C'thuana block to break off. Overall, a similar process to what went on with Japan diverging from mainland Asia, or Stikinia from Laurentia for an even better example.

Next up, a few screenshots from the ages 150 and 100 Mya:
150 Mya.PNG100 Mya.PNG

At 150 Mya, it can be seen how Panwara begins to break up, and the subduction zone south of the supercontinent has shifted into rapid advance from its former state. This cause a new subduction zone to form at the southern margins of Nomune (the southernmost piece), subducting the now-quite-aged crust of the "C'thuana Sea". At 100 Mya, the mid-oceanic ridge is subducted and the C'thuana Plate itself falls under slab pull, beginning to once again converge with Eocidar.

Finally, here's a look at Eocidar 50 Mya:
50 Mya.PNG
Here, the C'thuana terrane is on the verge of colliding with Eocidar, a process that will eventually close off the western interior sea. To the north of the continent, the collision between Urgaleon and Eocidar is proceeding, which will result in the opening of the Trans-Eocidarian Rift, breaking the continent in two (the epeirogenic uplift, normal faulting and flood basalts released as part of this process will close off the eastern interior sea). Besides the C'thuana terrane, there are also two smaller terranes (K'wira and T'kalo) that have been accredited to Eocidar at a later date than C'thuana. As their exact movements remain a bit in flux, I decided not to go in too deep about those just yet (maybe in future if I ever complete the tectonic model for that Indonesia-like region SW of Eocidar).

And with that, I think we can close off "part one". The next part will discuss the northern portions of the cordillera and how they acquired their present-day structure.