system
Given the following post, respond as if you're commenting on Reddit:
human
Vast swathes of North America used to be an ocean, the Western Interior Seaway. If this is true, why are those lands not salted and inhospitable like other dried saltwater bodies that have left behind only barren salt pans?
gpt
They are! Almost all North American halite (rock salt) mines rely on the salt deposited during this period.

It's just that there has been fifty million years of deposition since then, meaning the salt is quite far below the present surface.