Is this meme true (age of the Appalachian Mountains)

Factual Questions
21

It just means not all of the range is 400 million+ years old. The parts with the coal are younger.

  • The Appalachian coalfields were formed from swamps that, 310 million years ago, covered the region. Some quarter of a billon years ago, tectonic forces thrust the region upward to form a plateau, which has been since shaped mainly by erosion. Accordingly, it is a land of waterways. Its place-names reflect this: Alum Lick, Barren Creek, Frozen Run, Left Hand, Stone Branch.*
    The Violent Remaking of Appalachia - The Atlantic
22

Even today, the places where coal is being formed, or at least proto-coal, aren’t forests, but bogs. Give those peat bogs another few million years, and they’d be coal.

23

Is it true that the Appalachian Mountains used to be joined with the Scottish Highland Mountains before the continents divided? I seem to have heard that somewhere, but now I can’t find a cite.

24

Yes, that’s mentioned in the link from @k9bfriender , up above. And also the mountains in northern Africa.

25

They were also once connected to the Ouachita Mountains across the Mississippi near the Ozarks. It is thought that a hotspot heated up the mountains between them, causing them to expand and thus erode quicker, but then the hotspot moved on and the already-eroded land sank even further, forming the Mississippi Embayment.

26

Lots of places are older - there are several locales of Archæan age, the Canadian Shield gneiss exposures are the oldest (although that’s a tricky assessment). This is the oldest large area we know of, and this is the second oldest (been there).

27

And IIRC, also to the Atlas Mountains in Morocco, the Marathon moutains in the Big Bend in Texas, and the mountains in Scotland as well. At one point they were all part of an ancient Pangaean mountain range, but over the intervening 480 million years, plate tectonics has pulled them far apart, or erosion/deposition has obscured the connecting mountains.

28

I’ve read somewhere that coal will never again be produced on the same scale as in the carboniferous. For a long time after the appearance of true wood, there were no organisms yet evolved that could digest it. So trees and other woody plants just piled up in massive quantities and became coal. Is this true?

29

They are older than tress, not ferns, horsetails, scrambling plants…

Not really trees:

Early Carboniferous land plants, some of which were preserved in coal balls, were very similar to those of the preceding Late Devonian, but new groups also appeared at this time. The main Early Carboniferous plants were the Equisetales (horse-tails), Sphenophyllales (scrambling plants), Lycopodiales (club mosses), Lepidodendrales (scale trees), Filicales (ferns), Medullosales (informally included in the “seed ferns”, an assemblage of a number of early gymnosperm groups) and the Cordaitales. These continued to dominate throughout the period, but during late Carboniferous, several other groups, Cycadophyta (cycads), the Callistophytales (another group of “seed ferns”), and the Voltziales (related to and sometimes included under the conifers), appeared.

OK, conifers are trees. Late Carboniferous. No flowers at all.

30

A study just published in Science postulates that one of Saturn’s moons disintegrated about 100 million years ago, after slowing drifting in.

31

Like Pardel-lux said, mostly not woody plants. Overwhelmingly tree ferns, horsetails and club mosses and the like account for the Carboniferous peak of coal deposition. I don’t doubt that inability to digest newly-evolved materials accounts for some of the peak, but the other factors, like higher CO2 fuelling growth, higher O2 feeding fires, the greater prevalence of wetlands. the Pangaean topography creating very wet climate zones… it all adds up.

32

The “should be regarded with pure terror” part doesn’t sound true. Having hiked up some of them, I think “informed apprehension” is more accurate.

33

Yeah I don’t understand the terror part unless someone’s mind boggles at how old the mountains are. They aren’t really scary when you’re near/on/under them.

34

Well if you start hearing banjo music…