• teyrnon@sh.itjust.works
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    17 hours ago

    They are separate tectonic plates, the two continents only crashed together relatively recently, the “columbian exchange” that saw wildlife mix between the continents. South America was near Africa at one point, North America more with Europe as I understand it.

    • Jack@lemmy.ca
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      2 hours ago
      1. Scotia plate (bits of Patagonia),
      2. South American plate,
      3. Altiplano plate,
      4. North Andes plate,
      5. Panama plate,
      6. Caribbean plate,
      7. North America plate,
      8. Pacific plate (Baja California peninsula, southern California).
      • teyrnon@sh.itjust.works
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        17 hours ago

        When I was on the Appalachian trail they had a placard that explained it and said it’s also the oldest mountain range in the world, and used to be like 4x the size of the himalayans (which is the youngest.) Others have disputed that, but just internet randos with no sources, I trust the NPS placard.

          • Zombie@feddit.uk
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            15 hours ago

            Hills near me (northern Scotland) were once magma chambers underneath volcanoes! That’s how worn down they are. Wild to think about, and makes some lovely granite.