Oil shale is a term for oil trapped in rock, rather than existing in liquid form. Check out this HowStuffWorks podcast to learn more about the nature of oil shale.
Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

Selects: How Narcolepsy Works
52:41

Rope, yeah ROPE!
43:31

Short Stuff: Did a shipwreck double the size of the United States?
11:46