Dr Raoul McLaughlin has some interesting older uploads about ancient Roman contact with China.
Myron Cook (a retired geologist) can be interesting, but has a younger target audiance
Nick Zentner is a geology 101 teacher at the University of Washington and does a lot of interesting content
Parallax Nick does astronomy history content that is really good.
Geology Hub is 5× larger than the limit but is a relatively new, fast rising must watch for what is really happening in geology news like reporting about all active volcanoes and events in short 5 minute vids
Looks like geology is under appreciated IMO/watch list.