Modern mining is a red queen's race. As we exhaust the ore/oil/coal/whatever in mines we switch to others. But this is only possible because our technology keeps improving so mining that was impossible becomes possible. If our society falls then our successors won't have much to mine (other than our ruins) because they won't have the technology to mine the places that haven't been exhausted.
How does this relate to Cidri?
- Theory 1: Dwarvish mining technology keeps improving just like ours and they'll be able to mine deeper and less accessible places. Well, why not? Our society did.
- Theory 1A: This will allow them to collect the ore they need and continue their business model. It's possible. If Cidri was assembled from basically normal chunks of planet then this would make sense.
- Theory 1B: But they'll find no ore. If Cidri was built to have deposits of ore that dwarves could mine then this would make sense. Why would the Mnoren have bothered to create ore deposits their dwarven pets couldn't reach?
- Theory 2: Dwarvish mining technology won't progress. I find this easy to believe. Cidri doesn't generally seem to be a progressive place.
- Theory 2A: They will run out of ore. Dwarvish mining in Cidri is doomed, followed by the entire Cidri metallurgy industry. Depressingly believable.
- Theory 2B: Mnoren machinery will make replacement deposits. The Mnoren would not have wanted their pet dwarves to run out of diggables, so maybe they set machinery in motion that would do this.
- Theory 2C: Theory 2B until the machinery wears out and then Theory 2A. Yeah.
Have I missed any possibilities?