It looks like this topic is related to both my planetary geology topic, and my world map topic.
I would like to suggest a reason why these things weren’t defined-- to give DMs the space to do whatever they want in uncharted regions. As it stands now, at least half the planet is not defined at all, and about 80% of what has been drawn has been left intentionally vague for DM’s benefit.
Also, this brings me to another related topic-- non-canon creations.
Maybe before we start defining any more of the world, we agree to have a separate section for non-canon creations. @Grummore - how about your new website?