Just about the coolest thing in a really, really, REALLY long time

[maradydd]

In middle school and high school, when we learned about continental drift, we learned that there had been a supercontinent, Pangaea, which broke apart millions of years ago into two smaller supercontinents, Laurasia and Gondwanaland. Gondwanaland comprised South America, Africa, India, Antarctica and Australia, and broke apart first; Laurasia was made up of North America, Greenland, and Eurasia, and separated some 90 million years after Gondwanaland. Presumably, then, plate tectonics working as it does, other supercontinents existed before Pangaea, broke apart, and recombined; and presumably, the continents we know today will one day collide and form a new supercontinent. All pretty straightforward.

Until tonight, however, I had no idea that geologists actually have honest-to-God evidence of where past supercontinents lay. Nor did I have any idea just how many there's evidence for. I mean, really, seriously, wow -- they can identify iron-bearing rock layers that are the same age and have identically aligned magnetic fields, and thus identify regions which used to be adjacent but aren't anymore. How freaking awesome is that?

At first I was annoyed that I hadn't learned about this back when we were studying Pangaea, but then I noticed that the most recent proposed pre-Pangaea supercontinent (as in most recently in existence prior to Pangaea, not most recently proposed), Pannotia, was first described in 1997 -- three years after I graduated, and if memory serves, about the same time I took intro geology along with madandrew. So I guess I don't feel quite so deprived.

Comments

[grimmtooth.livejournal.com]

When I first heard of it, it was called "Continental Drift" and was still considered quite questionable. It's been a wild ride of sorts watching the theory become mainstream and morph into current day "Plate Tectonics". So, my teachers had an excuse for not teaching it. My intro was Wegener's book itself, which I found in the bookmobile when it passed through town.

It's funny you're pointing to wikipedia; I got sucked into it not too long ago when I started looking at how many different plates there are conjectured to be. That, too, is pretty freakin' cool.

[feonixrift.livejournal.com]

I'd love to see someone start publishing catch-up guides. No review, assume people remember what they learned in school, just a summary of "by the way, since decade X we found out and started teaching about these N things which now your kids are going to think you're dumb if you don't know".

[maradydd.livejournal.com]

Hunh. That would be an interesting counterpart to Cliff's Notes.

Magnetic fields

[madandrew.livejournal.com]

I'm pretty sure that was mentioned somewhere. I tend to perk up my ears when I hear the words "magnetic field". It probably wasn't in the text, but it may have been mentioned in class.

[songblaze.livejournal.com]

...I vaugely remember reading about theories about pre-Pangaea supercontinents, but I suspect I read about it in Discover magazine(which was laying around the house when I was in junior high and high school) rather than learning about it in school.

[sclerotic-rings.livejournal.com]

And now you know how I feel when I ask "And why didn't anyone share this with me before now?"