I voted for option #3. I'm not a geology expert by any means, but I do expect a fantasy map to at least be believable for a layperson like myself. By believable, I mean that the geology is realistic OR that there's an explicit reason in the source as to why it's not realistic. In general, I (and I think most other people) assume that a fantasy world conforms to the basic physical laws of the real world unless the source material states otherwise. So clearly unnatural geology with no explanation is a little jarring to me.