Comments | jrittenhouse: Timeline on Paleoclimate #0:

jrittenhouse

Timeline on Paleoclimate #0:

Jul 28, 2008 17:14

This is the waaaay early part of my timeline; edits or comments welcome. It’s going from 35.7 mya to .5 mya, with special note to the major level 8 eruptions, big impacts, and a smattering of human development events thrown in. There are different colors for events - orange for impacts, red for eruptions.

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paleoclimatology, paleogeography, prehistory, paleobiology, anthropology

Comments 10

mactavish July 28 2008, 22:25:24 UTC

A subject line and lj-cut tag like that attracts me like "schoolgirls in uniform" or "free candy behind the link" attracts some other people. :)

I can toss this at geographile if you want, folks there might have ideas. (Or you could.)

jrittenhouse July 28 2008, 22:43:21 UTC

Oh, I can. Didn't think about that!

mactavish July 28 2008, 22:52:55 UTC

Though not as massive as these, many people don't realize that the massive granite Sierra Nevada were volcanic first, back when this particular continental edge had a thrust fault under it. (Now it's a strike-slip fault most of the way up California, thrust above that, above Point Arena, up to Canada and Alaska.) But the Sierra used to be a chain of volcanos, and the entire geology of the area is surrounded by huge lava flows. After things shifted and the volcanos stopped, the Sierra batholith rose, shoving through the lava caps. Now there are tilted slopes of lava up to a certain point, where the granite (tops eroded off) has become exposed above it. The buttes of the foothills of the northern Sierra are thick flows that used to lie in riverbeds, but are resistant to erosion, so where there were ridges, the land has now eroded down into canyons, and the former river beds are lava-topped buttes. The lava caps make excellent wine on them, too. :D Then of course, there are the buried/lost streambeds, which have a lot of gold in them ( ... )

jrittenhouse July 28 2008, 23:06:58 UTC

It's these other western Level 8 areas that are just amazing - I've seen some ash-dispersal maps recently from the last three Yellowstone BOOMS, and Ashfall, but I'd love to see how these others all laid down their stuff...

Cripes, it's really a wonder that much fauna lasted through this. Erupt today, no erupt tomorrow.

Thread 6

beamjockey July 28 2008, 23:26:56 UTC

Are you listing eruptions and impacts because you are interested in eruptions and impacts, or because it is easy to get dates for such events?

Small request: If in your researches, you find out what Chicago was like 280 MY ago, or you find out how to find it out, I would appreciate knowing. I would like to flesh out my undestanding of the Des Plaines Disturbance.

jrittenhouse July 29 2008, 04:05:38 UTC

The specific ones that I'm listing were major events, the sort that would have climatic effect.

I'm curious about the Des Plaines Disturbance myself!

marklafon July 29 2008, 15:19:22 UTC

Des Plaines is just plain disturbing no matter when.

What I find interesting is the impact event south of what is now Serpent Mound about 300MYA. Less than 200 miles and 300MYA is too close to my house.! And don't forget the effects of the Appalachian range on climate and such. At one time they were the tallest mountains around. (See what happens when you leave your mountain range out in the weather for a few hundred million years?)

jrittenhouse July 29 2008, 15:38:50 UTC

Good point on that impact, and I don't know beans about it.

*chuckle* on the rest.