What are these geologic formations

[masraum]

What are the curved lines, moraines from the last ice age? They seem to run from Scranton, PA down to Birmingham, AL.

[jjone20]

That would be the Appalchian Mountain chain. Formerly mountains as high or higher than the Rockies. Formed by continental drift millenia ago, and since eroded to their current form. The curve is caused by the distortion of colliding plates and different rock composition. In a nutshell...

[J P Stein]

That topography looks similar to the scab lands in Eastern Washington.
Monster flooding drained Lake Missoula multiple times at the end of the last ice age as a result from a broken ice dam. An estimated 500 cubic miles of water draining out in a week or 2 will ruin your day.

Bretz's Flood by John Soennichsen is a pretty good read.

[imcarthur]

jj got it. A terminal moraine is a much smaller geological/geographic formation & it wouldn't be visible from high altitudes. Typically a jumbled ridge line with frequent kettle lakes formed by melting ice boulders. Great places to get gravel btw.

Ian

[89911]

Living in this area, the Appalachian chain was formed with a colliding land mass from the east millions of years ago. The collision resulted in the rich, organic surfaces of the land getting in-turned with the advancing eastern land mass. This all resulted in one of the most abundant coal producing locations in the US. Apparently lots of natural gas also with Marcellus Shale invading the area.

[NYPorsche]

Yep - a result of a series of orogenies (most notably the Taconic, Acadian and Alleghanian) resulting from North America and other continents colliding.


Hate to cite wikipedia, but these cover it pretty well.

Geology of the Appalachians - Wikipedia, the free encyclopedia

Alleghanian orogeny - Wikipedia, the free encyclopedia

Acadian orogeny - Wikipedia, the free encyclopedia

Taconic orogeny - Wikipedia, the free encyclopedia


Driving through Pennsylvania - take a look at the rock cuts along the roadside. Going from southeast to northwest - you'll see the rocks are tilted and deformed due to the continental collision. Continuing west, the deformation will decrease until the bedding will be nearly horizontal.

If you have a long car trip through PA (or just want to bore your kids, as I often do) - check out the Roadside Geology series.

http://www.amazon.com/Roadside-Geology-Pennsylvania/dp/0878422277

[NYPorsche]

Originally Posted by J P Stein

That topography looks similar to the scab lands in Eastern Washington.
Monster flooding drained Lake Missoula multiple times at the end of the last ice age as a result from a broken ice dam. An estimated 500 cubic miles of water draining out in a week or 2 will ruin your day.

Bretz's Flood by John Soennichsen is a pretty good read.

This is a much more localized feature- somewhat similar though to why the Mohawk River in upstate NY is where it is - the St. Lawrence was blocked by glaciation, causing the Great Lakes to drain through the Mohawk. Hence the Mohawk cutting through the Appalachian chain. With this being the only major water route cutting through the mountains, it was later used as a major water route to the west in the 1800's. The river breaking through the mountains is the reason the Erie Canal was able to be routed as it was.

If you are ever around Little Falls, NY, check out Moss Island near Erie Canal Lock 17. There are potholes big enough for a school bus to drive through caused by the rushing water through this break in the mountains. The rush of water caused harder boulders within the river to bore themselves down into the bedrock.

[89911]

Now you now why Brad Penn oil is so coveted

[Flieger]

Cool. I always like learning about geology and natural wonders.

[J P Stein]

Here's a 4 part video by Nova on the Megaflood. This is part 1. You'll have to find & click on the other 3 parts if you want the whole enchilada. I found it fascinating....my geek side came out. Of course these *floods* (see the last vid) would have put my house about 100 feet under water....Mega means MEGA.

NOVA Mystery of the MEGAFLOOD (1/4) - YouTube

[RWebb]

Support the Laramide Revolution!

[VaSteve]

I can't inBed with the iPad, but here's a lik to google photos where you can see they cut up the mountain....pretty cool...

sideling hill cut - Google Search


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[szyzygy]

how can they be millions of years old when the earth is only 6000 years old....

[Por_sha911]

Originally Posted by szyzygy

how can they be millions of years old when the earth is only 6000 years old....

Since you asked, the same way a turtle ends up on a fence post. Someone put it there. All it would take is a supreme supernatural being called God to set it up that way. I guess your question & my answer will get this thread kicked to PARF.

[masraum]

Hopefully not, at least, not as long as we don't have a dozen more folks come in with PARFy comments. The geology stuff is too interesting.

Wow, I had noticed that what I was seeing in the photos seemed to be in the right place for the Appalachians. I've even camped and driven through them when I was younger. But the birds eye view doesn't look as mountainy as I would have expected.

The glacial potholes are interesting. I did a google image search for them and found many very cool pics of the same stuff from other locations.

[ckissick]

Originally Posted by jjone20

That would be the Appalchian Mountain chain. Formerly mountains as high or higher than the Rockies. Formed by continental drift millenia ago, and since eroded to their current form. The curve is caused by the distortion of colliding plates and different rock composition. In a nutshell...

I can expand on this.

This question would have been right out of one of my geology midterms back in the early Holocene at UCSB. The essay answer would be longer than what I will bore you with here.

When the early Appalachians were formed during the collision between Africa and North America, the sedimentary rocks were folded and uplifted to mountains that would have looked a lot like the Alps today. Then the two continents moved apart, ending the episode of uplift.

The large mountain chain then eroded. The contorted layers of sedimentary rock eroded at different rates. Harder sandstone layers stand out. The folding created plunging anticlines and synclines. A plunging fold is a fold whose fold-axis is not horizontal. When you erode plunging folds, you end up with U-shaped features in map view. This is what you've got here.

[IROC]

I work on top of one those ridges here in East TN. I can see the Smoky Mountains off in the distance right now... Those ridges also make it almost impossible to get to North Carolina from here even though I can almost see North Carolina from my desk.

[widebody911]

Originally Posted by IROC

Those ridges also make it almost impossible to get to North Carolina from here even though

So, if you think about it, those ridges are sorta doing you a favor.

[VaSteve]

Quote de IROC

Those ridges also make it almost impossible to get to North Carolina from here even though

So, if you think about it, those ridges are sorta doing you a favor.

I guess that all depends on which side you're on.

[IROC]

Originally Posted by widebody911

So, if you think about it, those ridges are sorta doing you a favor.

I've said it before, but hands down you're the funniest guy on Pelican.