The only thing we know of that can contain amorphia is trellanstone. Perhaps Dragaera has trace amounts of Trellanstone in the soil? Or even a bedrock layer of Trellanstone?
Another theory is that the gods simply intervened to stabilize the expanding chaos, and save Dragaera. This seems more plausible, since Trellanstone is supposed to be quite rare. (A chunk the size of the Orb being thought extremely unusual).
A simple combination of these two possibilities is exceedingly likely. In "Issola" it is mentioned that trellanstone "only appears as a gift from the gods", implying that the gods either have a source or can create trellanstone. Either way, it would seem legitimate that the gods could control the spread of amorphia on dragaera.
Then again, "simply intervening" may not be so simple for the gods. Their intervention has been, in the recorded cases, well within the laws of reality or at least those of sorcery and necromancy. They have intervened to close gates between worlds, enable or disable witchcraft/sorcery, reunite bodies and souls, and likewise well-defined tasks. Making an arbitrary huge area of land immune to the effects of amorphia seems less well-defined perhaps.
Though the Jenoine apparently did so when creating the river of amorphia in Issola (book), and Verra seems to have intervened to stop Vlad's little Elder Sorcery attack from turning into another disaster in Adrilankha. So maybe they can.
Another theory might be that amorphia only expands in response to sentient consciousness. We know that some individuals (descendents of Kieron) possess the power to manipulate amorphia with their mind--perhaps this link can extend both ways?
This might explain why the Lesser Sea of Chaos stopped expanding after consuming Dragaera City and the immediate environs--once there was no longer a concentration of thinking beings to help it expand, it stopped.
This link between consciousness and amorphia might also explain the consciousness of Adron e'Kieron that seems to still be present in the Lesser Sea.
Also, that Vlad can create amorphia is not because he is descended from Kieron. He’s not: Dolivar was Kieron’s brother. They share the same parents. It appears that Kieron’s siblings were also amorphia-makers.
-- Tom Christiansen 02:25, April 4, 2011 (UTC)