How did an ancient meteor impact help America spread westward?
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- Опубликовано: 6 окт 2024
- The Appalachian Mountains aren't the largest mountains in the United States, but they still present lots of rugged topography which can present an obstacle to travel. Native peoples and even wildlife learned to make use natural gaps and other landforms that made travel practical. European settlers followed suit, and the famous Cumberland Gap was one of the most significant landforms that allowed reasonable passage across some of Appalachia's roughest topography. Interestingly, Cumberland Gap was only good because it opened onto the Middlesboro Impact Structure, the product of an ancient meteor impact. The Middlesboro Structure, in turn, is located next to Rocky Face, a conveniently placed ridge on a minor fault line. Together, these geologic features created a unique path through an otherwise nearly impassable area. This video explains their development with lots of map images and diagrams.
Hello from Poland! Very happy I was reccomended your channel! The Appalachians remind me alot of the Carpathians here in Europe. Mountains covered in a sea of endless forest.
Glad you liked it! There is a huge amount of similarity to Carpathian structure. particularly the Carpathians in southern Poland. I like watching any television shows that show their landscapes. They are sort of like a less eroded Appalachia, where the limestone still makes big mountains! Thanks for the watch and comment.
Shhhhhhh!!! The lumber companies might here you
I don’t get it
As someone who was born and raised in Appalachia, I love every one of these videos
Outstanding! I'm trying to put it out there. Colorado, Wyoming, and Idaho seem to get most of the geology vid traffic.
@@TheGeoModels I’ve always loved the cut through Sidling Hill on I68 in Maryland. Could be an interesting video idea! Thanks for the content
We learned about the Cumberland Gap in Elementary School, but never knew an impact helped create it. Fascinating
Thank you! I live in Middleboro and really wanted to know more about our geology. I'm still watching, but I wanted to say that off the start. 🙏
Just drove through here yesterday. We stopped in Middlesboro, and I was excitedly explaining to my wife how we were in the middle of a meteor crater that formed millions of years ago, etc. She was less excited.
geologist here, 20+ years experience. Love your videos.
Flattered, for sure! I really enjoy trying to illustrate the ideas.
Haha if you only know what you’ve learned from other geologists, you know nothing. The west coast is a giant mermaid and the east coast is a dragon. 🐉 It’s all in the Aztec and Mezoamerican tribes’ legends.
The most important gap for migration of animals and human from the East to the West, I have always considered the Pineville Gap where the Cumberland River cut through the Pine Mountain faulk. Indeed the Northwest face of Pine Mountain is a sheer cliff. The Gap at Pennignton, VA leads into the Cumberland River drainage and if followed, leads to the Pineville Gap. There is another Gap at Pound, VA where it is possible to gain access to the Cumberland River drainage. Also one can find passage though the Breaks of the Mountains at the northeast terminus of the Pine Mountain fault. Or one can go the southwest terminus and find a reasonable track to the Cumberland River near Williamsburg, KY
I have considered that the impart make have weaken the Pine Mountain fault allowing the Cumberland river to cut the Pineville Gap? If so there would have been a lake backed up by Pine Mountain. As a Civil Engineer by education I have often considered Pineville to a an excellent location for a Dam.
By the way I was born raised at the foot of Black Mountain and travel through those gaps to many times to count, following the Cumberland River.
Great video. Keep up the good work.
I've heard that the Green Bank Radio Telescope site is possible due to some unique geography. It would be cool to hear how the geology of the area contributes to a place that is perfect for listening to radio signals from outer space :)
@@nanettenyce4167 near Woodbury GA is a place called The Cove. It is an almost perfect circle of quartzite that is the erosional remains of an impact structure. GA Tech uses it for SETI research as the surrounding rim of quartzite blocks radio wave interference. AT&T used the site with GA Tech taking it over. It was used in filming the Walking Dead too. I would bet the area you are asking about is used for the same reason, the surrounding crest acting as a block on interference.
Greetings from germany, really appreciate your work here. your paint drawings combined with very thorough explanations bring these processes to life. hope to see more, and wish you all the best!
Thank you so much! You will see more, for sure. Exciting to see this stuff reach Germany!
I’m in Logan County, southwestern WVa. I would love to go on a geology field trip. Ive seen Myron Cook’s video about how this area was formed… and that’s rare, like this video… because all of the geology pourn on America is on the West. Typically there’s not much geology to watch about this part of Appalachia. Thanks !!!
you ever go over to Breaks Park? It's a pretty dang good geology field trip! It basically takes my ancient river to nowhere video (Ohio River forming and making its tributaries carve up the landscape) and this Pine Mountain video and mixes them together. The Russell Fork Gorge is as deep as it is today because the river cut deeper after formation of the Ohio River. I think they have a hike where you can essentially see the Pine Mountain thrust fault. You definitely can see it down on the river in the gorge--it's exposed by the last big rapid on the whitewater run. I don't know how long it takes from Logan to get over threre (Plateau travel can be slow!) but it's as good as you'll get in the southeast. If it was closer to a big city it would be one of the most famous parks in America, easily.
@@TheGeoModels that’s the first time I’ve ever heard of that park. I definitely need to check it out 😁
I love the Appalachian content. Keep it coming!
Will do. got a bit of apps vs Rockies coming up.
One of my favorite things to do in the evening is crack open a tasty beverage and relax on the couch with some GeoModels' ms paint diagrams. Thanks for the fascinating knowledge. If you have a chance, I'd love a New England video or two.
I grew up in Middlesboro and I'm glad to see videos like this.
Would you consider a video on Fort Valley (within Shenandoah Valley)? It's fascinated me since a randomly looked out an airplane window and saw this amazing structure framed by two meandering rivers. Thanks! Love your videos.
It might make a good one! The meanders are quite nice and have a good geologic story. Thanks for the watch and comment, and glad you like the videos!
APPALACHIA FTW
LOL
Can I ask you why you put the FTW in your comment? The reason why I ask is bc I live in east TN and I have seen it a lot just wondering if you mean it the same way it's meant here. I'm not judging or saying anything about it so don't think I'm just trying to be bitchy 😂. I'm only being nosey 😅
@@bobbiejothomas681Appalachia "for the win"
@@bobbiejothomas681 search engines are super useful.
@@bobbiejothomas681 FTW is internet slang from like 2005. Meaning “for the win”
Geologist. Did a masters thesis mapping in Hardy and Hampshire counties WVA. Worked the Appalachian’s when Amoco had 2,000,000 federal acres under lease. Driled the discovery well in Swan Creek Field, Hancock County, Tennessee. Enjoy your videos. Bring back many fond memories!
Honored, to say the least! Hope to bring back a few more memories down the road here. You mess around at Bergton any?
Try to get a Ray Sponaugle video going too.
Never fails to amaze me how much detail you create with just a few hash lines
I have made a few of them over the years!
An impact damaging the rock that deep could certainly have cracked Cumberland and Pine mountains enough to cause the faster erosion making the passes possible.
Excellent video! According to the Earth Impact Database, the Middlesboro meteor landed around 300 million years ago, leaving plenty of time for erosion to lead to today's topography. I find it interesting that Virginia's southern border has an impact structure at each end. About 32 million years ago a much larger meteor landed on what is now the mouth of the Chesapeake Bay. It is mostly obscured by erosion and being mostly under water, but a bit of its circularity can be seen along the northern bay shorelines of Virginia Beach and Norfolk.
There is another gap but a little smaller is in Lafollette, TN. US 25W goes through it.
Driving down 41 or 73 in southern Ohio takes you into Serpent Mound outside of Peebles Ohio, which is supposedly an ancient impact crater. I drive through it whenever I go up north to see my family and it's a unique drive.
A lot of the conventional geologists tend to overlook that there is faulting that originates from from the impact, so those effects of the impact probably goes right by them.
Impact events create some radial faulting in multiple directions from the center, and it's likely that one of them went through the rocks over what is now the Gap, and toward Pine Mountain. Those cracks made the areas the easiest for erosion to affect.
BUT...
Most of rock disturbed in that manner would have been in the top one thousand meters of the SURFACE rock layers AS THEY existed at the time of impact. Over the following hundred+ million years, the damaged areas would have been preferentially eroded away, down to where the only rock exposed would be in the impact structure itself (and that there has been coal found and mined IN the structure that formed in the accumulated sedimentary rock, means it probably caught a lot of the drainage, burying its remnants).
But because of that preferential erosion in the cracked areas, the solid rocks that were beneath those areas were probably exposed more quickly than the areas below that did not suffer the fracturing, leading to their faster weathering, and creating the gaps as the areas weathered at similar rates after the radial fault-damaged areas were gone.
This paper agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2008JE003115 discusses the fracturing at Meteor Crater in AZ, and how even the crater sides, and even the bowl itself, have impact created faults in them (and you can see in the pictures in the paper that some of those faults are showing more weathering than the rest of the wall on either side, from providing a steeper path for groundwater (like after a rain).
The road cuts in Powell Valley are really neat in some areas! There are areas that show massive caves collapsed, making a landscape that doesn't match with the bending theory.
This is an awesome video. I live on the Cumberland Plateau and had no idea this was here.
I would like to know how the geography of the NC mountains has a lot of precious gems and the rest of the mountains none have been found. Maybe a video about the area and its gems?
This is great! I grew up in that area and never realized.
I was expecting the crater to not actually be a crater based on the Carolina Bay Video Bay clickbait. But that's no ordinary crater! Love the theory
It's just about all clickbait these days! I am proud to say I have not used the words "undocumented" and "wall" in a geology video yet, though it has brought great success elsewhere. This one is a real-deal impact structure. It has all the high pressure/shock features, etc. etc.
@@TheGeoModelsWhen I was growing up there in the 70's the USGS had an office in the Middlesboro Mall, and on the wall outside they had a huge map of Middlesboro and surroundings. It showed the kinds of rock and had an insert explaining the different theories about the valley and why they determined it was formed by an impact. They showed where the shocked rocks and shatter cones are and gave an approximate age. I think they mentioned there was a small lake for a time that eventually flowed out forming Yellow Creek. The valley definitely has a really thick layer of clay, under a thick layer of rich topsoil. I've had to dig into it when I was helping my Dad dig out the back yard.
Masterful MS Paint skills! Thanks for sharing the geologic features and history of the area.
Enjoyed it! Glad you liked the Paint.
JacksboroTennessee! My dad's from there. Going to visit family in Tennessee, seeing the road cuts and the beautiful mountains started my interest in geology. As a child, when all the kids were playing on the playground equipment, I was looking at the rocks.
Fascinating. Thank you for all the work you put into this!
Enjoyed doing it. Thanks for watching.
I love learning about the Appalachians, but wondered if you had any interest in exploring the geological history of the Great Lakes? I live on the southern shore of Lake Ontario, and I always love hearing about this area including the Finger Lakes of NY.
some of the glacial landforms north of finger lakes are really great in lidar. MIght have to think on that one!
Note that the European immigrants in 1774 were going down the Ohio River from Pennsylvania to start Harrodsburg, and also going through the Cumberland Gap to the south to start Boonesboro. It is interesting how close these first two towns in Kentucky are to each other, one from rivers and creeks to the north for canoes, and one from a Bison and Native trail to the south. Europeans did not build a road, they likely had native guides that showed them where it was, with a few days worth of trail widening in spots so their horse drawn wagons would fit on the trail.
Very interesting stuff!
Middlesboro Kentucky impact creator was one of my bucket lists. ✅ A fantastic place to visit...😎
Alas, I’ve only visited it through google street view, where I’ve taken many a trip.
I was fortunate enough to visit it but I didn't actually know it was there. I was looking at the landscape and told my husband it looked like a crater. I looked it up and turns out I was right.
Middlesboro, home of Lee Majors.
As an amateur fan of geology (in fact got hooked on it thanks to Nick Zentner), I really enjoyed the analysis and explanation. It's not that far to drive from NoVA, I might have to go see the area for myself - knowing what I know now, I'll be able to look at it in a very different light. Thank you!
It's pretty cool to check out. If you haven't driven around in the Appalachian Plateau before, it's worth doing. One-of-a-kind place. The structure and exposure around Cumberland Gap is also legendary.
It was fun to see the geology of this region! I grew up in ridge and valley Pennsylvania, and as a kid I used to wonder why it was so hard to find a way across Cumberland Mountain. Fast forward a couple decades and I drove southwest through Lee County for the first time. That's when I finally understood. Cumberland Mountain has steep sandstone all along the ridge, literally miles and miles. It's not even walking terrain. I get it now.
yep, it's not high, but it's just too rough to do much with.
When I was in school, they made it sound like America would just be 13 States, if it weren't for the Cumberland Gap. Watching this, I realize it pretty much only mattered to Virginia Farmers and quickened the creation of Kentucky, because it was faster than going around the top or bottom of the Appalachians.
It's great to watch this explanation. My ancestors likely came through Cumberland Gap on their way from Maryland by way of North Carolina to Indiana
Thanks! It's a great area. Fun for a geologist to draw up the ramp anticline.
I enjoy watching you showing us the Eastern part of the US geology and Myron Cook showing the Western US development. Both are so interesting.
Trying to boost up the Appalachian side of things. There's lots to see here!
Excellent video Sir, after 70 odd years the song makes sense now! Also, it is good to see the French and us Brits appeared to get on not too badly so named their settlements after their origins - like I used to live in Abingdon UK, once home to the famous MG ( if you are a car nerd )company!!
Interesting! I pass through Abingdon, Virginia quite regularly. Had a fellow comment about Darlington, South Carolina on one of the Carolina Bays videos.
Fascinating!
Awesome video!
Thanks!
Instantly recognizable to a Kentuckian! I live near Jephtha Knob in Shelby County, another astrobleme.
Right on!
I have been part of the Mammoth Cave survey and my opinion is that Kentucky has fine geology, bow to stern.
Cool video man. Good job!
Thanks!
Wow, great video. Thank you brother.
Glad you liked it!
Bravo!
Imagine the forces involved across a heck of a large area and long time, accented by a relatively minor event.
You should make a video just about Jacksboro Tennessee! It’s a really interesting place to look at!
It its. I'm going to see if I can work on it somehow
Yall dranking that dr enuf?
Pibb country I think
It's commonly sold around here in Johnson City, Jonesborough, Elizabethton, Bristol (TN & VA) and in Kingsport. I've never tried it because I'd rather have lemonaide or sweet tea.
Ale8
@@Glaudge This is the way!
@tobiasdogford222 coca-cola bottling plant in Middlesboro. Not as many folks around here drinking dr. Enuff or mtn holler. The name brand stuff is just as cheap.
Love the animations this time!
Used to do tons of them in Va Tech lectures. Spent hours drawing the various frames!
@@TheGeoModels that's a lot of work!
My family crossed the gap and pushed 14.5 miles to Flat Lick and settled there.
Mr Prince, appreciate greatly your videos. Quickly skyrocketed to one of my favorite channels, always a pleasant watch.
Can you clear up for me a puzzle...it seems like sandstone is talked about as resistant to erosion but up here you can erode it with your finger! What am i missing?
On that note maybe you'd like to come check out saint Anthony falls on the Mississippi in Minneapolis. Weve got tunnels, caves, and drama. There's a cutoff wall beneath the river bed and no one knows its condition. Could be interesting fodder for you!
Thanks again. You seem like a swell bloke 🫡
Thanks! Sandstones can vary in their properties, particularly due to the material that cements the sand grains together, as well as the composition of the sand grains and how deeply it was all buried. Here in Appalachia, we have lots of sandstones that are nearly pure quartz sand, cemented with silica (more quartz), and were once buried literally miles deep, almost to the point of the grains fusing to produce quartzite. With that composition and burial history, it's almost like porcelain or tempered glass in layers 10 or 15 feet thick, comprising a few hundred feet of overall stratigraphy. It's physically and chemically the toughest stuff around, and it doesn't take much (relatively speaking) to support a mountain ridge. Now, if the quartz sand grains are cemented together by calcite (mineral which makes limestone), they weather easily and are very crumbly and won't hold up topography. Iron oxide-cemented sandstones also exist, and they are a little better at resisting weathering/erosion than calcite-cemented sandstones, but not by too much. If the sand grains in the sandtone aren't quartz, they are almost certain to be a more weatherable mineral, and the stuff won't be as tough. If it doesnt' get buried very far before being re-exposed by erosion, it also won't be as tough....so there are plenty of possibilities. In the Valley and Ridge, though, the sandstone is by far the toughest stuff around due to its composition, cement, and burial depth!
Even though i love huge impressive mountains, it's just so interesting to see these ancient, eroded landscapes. There are some very interesting really eroded volcanoes here in croatia (psunj, moslavačka gora, gaveznica). I'd love to look at those places in lidar, but its pretty complicated to get you hands on it here
I've heard that from other folks on the euro side. We're actually quite lucky with lidar availability here in the US. It's amazing to be able to view most of the country at 1 meter resolution just from a web browser!
Sooooo totally COOL! I Live in Jeptha Knob ( east of Shelbyville, Ky.) Similar stuff... would love to talk more! REX FREW
Thought about a Jeptha and Wells Creek video for the future.
@@TheGeoModels We live right at the top of crater 1 ... whole set up appears to be a complex crater ... one and 2 to form the whole thing ... I have combed the whole place ... numerous pseudo shatter cones ... lots of iridium. Iridium conformation goes back to previous studies...This state officially labeled the formation volcanic on origin 🤗😁 The song remains the same
@@rexfrew5392 Interesting. I heard you could get shatter cones from the golf course. When I cruised around out there you could definitely find damaged rock and some very odd, messed up materials, but I never found a convincing shatter cone. I thought it was "officially" recorded as an impact structure with central uplift, but maybe folks are a bit behind!
Ben Schwartz paper on Mississippian Hydrology of scarp slope cave development using Omega in the Greenbrier as a model is super interesting. I bet folks would dig your take on that.
Yeah some folded Greenbrier needs to show up here eventually. I was in ole Ben's office area for a while back at Va Tech in 2006-2007 or so--5050/5051 Derring Hall. We wound up on a field trip up in Bath for Devonian karst with a seminar class around that time. Very good memory.
Thanks man!! You are awesome 🤘💪❤️
Enjoyed doing it. Bless up.
I spent about a week in a very secluded cabin in NW Arkansas and unless you followed the ridge we drove in on you couldn`t hike very far before the hills became steeper and steeper until it looked too dangerous to continue. At least that`s how it was in the area I was in. I never saw a squirrel there but hickory trees were everywhere. Deer would stand in the road looking at you like they were playing a joke or just being jerks. But no squirrels. That was odd.
Burke's garden, between tazewell and bland Va. Is very similar to middlesbouro . While I was an evil wicked strip miner drilling a shot near alley (no longer a town) near McClure I noticed everything on the bench was all tree fossils laid down striped for all branches packed tightly like matches in a box oriented away from Burke's garden. It was on the splashdam coal seam. Having a keen interest in geology and paleontology I would be interested in knowing if this was a result of the impact.
Hello, I have a video request on the formation of the devil's marbleyard. I love learning about the geology of a region I spent a lot of time around. Thankyou for the wonderous content
My 4th great-grandfather kept a "memorandum book" of his family's journey from North Carolina to Indiana in 1830. He described how awful it was crossing the mountains in late fall/early winter.
I bet it was very bad.
I don't know where you are from but I keep hearing this place that you always talk about in your videos. Hope you and your family are alright
Is there a way to ask questions more direct? Do you have a direct site or website? Love the channel as a armature!
I grew up on the "back side" of rocky face, right on the creek. Used to race each other to the top when we were kids.
That would get a feller fit for duty!
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Great video! Why does the area near Jacksboro look so suspiciously round?
Your skepticism is valid. No prof would have brought up a different idea if they wanted to keep their job.....
It's an interesting question. I'm curious if anyone has revisited it in recent years.
1980 I took motorcycle vacation with my wife and another couple, we rode to the top where cannon had been dragged to the top overlooking the only pass through! My Harley was top heavy and overloaded and the switch backs up the same access road that the cannon used and I can’t imagine competing that task, tactically it was beyond value
It's a rough as can be place!
You are right about road cuts. Driving along, come around a curve, go into a cut and try not to wreck the car while rubber necking a holy cow mother of God structure. How do geologists rate on the driving off the road scale?
Usually quite high. Been a passenger on several close calls myself. I'm more of a map-scale feature kind of guy so I like to think I'm not as bad about it!
Great videos. I am in East TN. Do you do field trips?
@@jdst1042 great question! I would be there
This answered a question I've had since I was a teen more than 60 years ago. Why did most explorers/settlers leave the East Coast and go to Kentucky ? Just about everything I read said they went to Kentucky, and years later scattered out from there. Granted, not everyone took that route, but a goodly percentage did.
I presume it represented new opportunity, and the limestone country is nice. A lot of early forays out there were to get salt, interestingly enough. Brine springs are/were more numerous, and folks would go all the way from coastal virginia to boil salt. Journal of Daniel Trabue is an interesting read.
I love your videos but you have gotten me to the point of writers block when it comes to making maps for my RPGs. Know I find myself thinking what would cause this land mass to look like this. Absolutely fascinating.
I would say I have done my job, but apologies for the inconvenience. The "why does it look this way" question is what I'm after!
Fascinating geo story, well explained 👏👍 The gap is surely within the zone of impact damage..? Faulting induced/triggered by the impact along preexisting geo tension zones. These are the main ingredients in the mix, aren't they?
Because the of the Rocky Face fault and the assocciated irregularities, there would be a gap in Cumberland and Pine Mountain based on structural geology and erodibility alone...the gaps are in classic Appalachian Gap positions, based on existing geology. I would agree that the impact probably enhanced damage and erodibility, but the rock itself in the vicinity of the gaps is not unusually displaced, etc., in ways that could be seen by lidar. The gaps themselves don't look any different from other Appalachian Gaps, and Cumberland Gap isn't even that "low" by comparison, in the sense that there isn't a large stream flowing through it. It's an interesting questions, and one would have to look very closely at the rocks themselves to really answer it I'd say.
Came here for the geology, staying for the mad MS Paint skills.
Thanks! Trying to keep it alive.
I'm kind of surprised that an impact structure in that location didn't become a lake of some sort since it was lower than the surrounding landscape.
It's flatter, but still higher than the streams. Because all of the land here is entirely erosional, everything is in some sort of slope (unless it's a sinkhole). It's an indicator of the great age of the landscape and how much rock has been removed to expose what we see today.
I grew up in the Powell valley down in Tennessee and I never knew any of this! Can you tell me, though, why it abruptly ends in a 90 degree angle down by Caryville? I'm understanding structural geology so much better thanks to your videos, and am I'm starting to see it, but I still don't quite get it. It seems like the mountains at Frozen Head and the Cumberland mountains here should be made of the same stuff, but the dividing sandstone ridges don't quite make sense to me. In addition, would you be up to explain some igneous stuff soon? I'm feeling so much more comfortable with sedimentary landscapes, but still feel totally at a loss with anything granitic. Maybe you could start with Looking Glass if you want to stick to Appalachia? Many thanks from a theoretical physicist. I can't shut up about geology since finding your videos.
If anyone in here is ever looking for a tour of the area. Holler at me. My family has been here on the backside if rocky face since the 1700s.
I’m with you on the crater structure.. I don’t believe in coincidence
Great video! If you ever want to do a video on this area and need video/photos, let us know. We live at the White Rocks in Ewing, VA 12 miles east of Cumberland Gap.
I'd love to get back up there and see more of the sights! One of these days...
Happenstance and... there is no end to coincidence.
"right place right time" is subjective.
I had no idea there was an ancient impact crater involved in the Cumberland gap, neat
Excellent video and explanation. Really good story. I wonder if you would cover the formation of the right angle in the same area where I-75 follows the escarpment into Kentucky from Rocky Top TN. As far as I can find it’s about the only right angle in the entire Appalachian Plateau.
I'll work on that. Others have asked. Try to see how to illustrate it. In short, the Pine Mountain Thrust Sheet broke loose on an existing fault on that side.
@@TheGeoModels thanks, I will be really interested in that one. BTW, thanks to you I now am completed engrossed in LIDAR greyshade imagery looking for landslides. Lot of fun!
Should talk about chained rock above Pineville, why folks freaked over it and why Geologists think the massive chain on it isn't necessary
Old maps called it a "crypto explosive structure"
I think they do that for Jeptha as well, which (to my knowledge) has been given astrobleme status.
As always, thank you for your fun Appalachia video.
(1) American expansion was likely a piggy-back off of the Ancients and their trails. Or game trails. If the area would have been impassable, game would not have traveled there nor the local citizenry before. Did not the Cherokee/Shawnee fight over this important location (bottle neck)?
(2) If a mile of sediment melted away to form the modern landscape, where did all the sediment go? Was it blown away (wind)? Or down existing rivers to the Gulf of Mexico or Samtee or Savanah? Where did it go and how?
Gulf of Mexico, or most of the way there and now in the Coastal Plain type of deposits, by rivers
A lot of the limestone on cumberland mountain was blasted into Powell Valley, evident in their soil. The gap was a well worn Buffalo trail that eventually followed yellow creek out of the valley and to the Cumberland River. Thomas walkers journals describe the area as they found it. Mounds, native long houses, and bear attacks. I know where a few nice petroglyphs are located in the area.
What are some of the websites you use for viewing maps?
Live in Harlan Co right at thr foot of Pine Mountain, and I work in Bell county...I'm in that crater everyday.
Awesome vid...and thanks for posting this. This area is so beautiful and has such potential for a go-to spot for nature lovers.
It does. Incredible place with incredible geology!
Can you do a video on Fort Valley?
That should’ve been an Ale8.
Any reason you didn’t use “fault” to describe the Rocky Face feature?
That timeline has been interesting to me since sitting in Driese’s Strat/sed class in the 90s.
Enuf was available in places i passed through recently!
Didn't intentionally avoid fault; seems like I would have said it in there somewhere. I was mostly referring to the topography, though, which is associated with a big dip change along the fault. It's drawn as a tear fault, but it's sort of an oblique structure, I'd think. I wouldn't be surprised if it relates to stratigraphic changes in that area...you could see certain beds disappear to the southwest with lidar.
Has Burkes Garden been evaluated as part of an impact zone? I’ve always looked at it on a map and it just looks so out of place.
Do Wolf Creek crater!! Middle TN!!
Was the Cumberland River superimposed on the current topography by downcutting and forming the gaps?
Possibly, at least to some extent. It could also have eroded headwardly and breached into the Middlesboro Syncline as more and more rock eroded away over geologic time. Whether Appalachian Rivers that cut ridges were superimposed or reflect headward erosion breaching ridges and linking up valleys has always been a big point of debate!
Can this be related to the Carolina Bay countless poc marks in timing? 😊
The meteor hit a mountain. Is there a video illustrating the impact dynamics that transpired here.
Not sure...have to be some sort of numerical model!
Eager, not anxious, to get across.
you should probly watch the very unique island video if you haven’t
though I must express appreciation for the close listen that deep in the video!
I'd have appreciated more specific time frames for mountain building and impact. Just saying hundreds of millions of years doesn't pin it down much.
More about the material movement and associated patterns in this one. Thanks for watching and the comment!
What is the general idea as to when the impact happened? I had always assumed that the impact modified existing geology and that the gaps were the result of more erosion due to fractured rock caused by the impact.
Just due to the fold-thrust structures (rocky face fault, changes in local stratigraphy, etc), there would be gaps at cumberland gap and pineville. The impact structure helps to link them, and it probably did enhance fracturing/rock damage to make the gaps even better. That said, Cumberland Gap isn't the greatest gap around and is still a drainage divide, so the rock can't be in that bad of shape. What rock one can see in the middle of the impact structure is, by comparison, an absolute mess.
I had not realized that it was a drainage divide. I assumed that the route followed a river valley
Where would people travel without the Cumberland Gap?
Look at the major transportation hubs north and south of the mountain ranges.
North: New York City > Hudson River > Mohawk River > Erie Canal > Great Lakes. Other canals inland, such as the one connecting Chicago to the larger Mississippi River network, proves that the early construction of canals in the US is what allowed inland transportation.
The South is more straightforward but required some technology: Atlanta.
Atlanta is a city built on a railroad intersection, which at the time was a modern marvel, the fact a city developed as such was proof of the power of railroads.
Both paths avoid the roughest terrain created by these mountain ranges and both represent the peak technology of their time.
So canals and railroads opened up most of the United States.
Take a look at that city that controls the major inland waterway's exit to the larger world: New Orleans.
That's the reason New York and New Orleans were such major ports, they were opposite ends of a major transportation network.
What did Louisiana need to make itself traversable?
Bridges.
Because Louisiana has so many rivers and swamps it needed to build bridges to advance, but that need was neglected all the way until Huey Long in the 1930s. It's why the rest of the state just didn't develop despite its largest city being so nationally important.
Well, the universe had really good aim when it came to the Chicxulub crater, so i guess anytime is possible.
It does seem that way. This one is particularly curious because the rock layers involved in the faulting/folding are changing a bit right in the gap area, which is also a good way to produce a bit of structural irregularity. I had not contemplated the coincidental side of it until a few weeks ago, but it's worth a second thought! Almost like someone is aiming at us...
Somewhere, perhaps here on RUclips, I’ve heard it said that crossing the Appalachians was much harder than crossing the Rockies. I know that sounds counterintuitive. Have you ever heard this? Do you concur? If so, why? What makes the one that is much lower more dangerous than the other that is much more sheer and taller.
Interesting thought. I'd believe it in terms of ruggedness or topographic wavelength...no huge slopes, but tons of little ones and no way to make a good grade on them. On top of that, the river networks in Plateau appalachia are tough to work with as well. If you can find where you heard it, I'd be curious. I think it's a plausible statement that is a product of how the Appalachian landscape is entirely adjusted to what type of rock is exposed where, while the Rockies still reflect the formative tectonic processes that give bigger mountains but longer slopes.
Just curious, why the hesitation to refer to the Middlesboro site as a "crater"? Is it not confirmed that this structure is the result of an extraterrestrial impact? What is the difference between an impact "structure" and an impact "crater"?
Think it's mentioned in the video. "Structure" refers to the area of damaged rock resulting from the impact that is at the land surface today. This damaged rock was thousands of feet underground at the time of impact. It has been exhumed (unburied) by erosion, and produces the round shape because the damage zone is itself round. In other words, the flat circular area is entirely due to erosion interacting with the zone of rock damaged by the impact. Calling it a "crater" would imply that the topography itself was produced by the impact, like the meteor crater in Arizona. I guess calling it a crater just gives the wrong idea about its age and the age/evolution of the landscape. It's definitely the result of an impact. The high pressure materials and associated structure confirm that. It's just that the actual crater gouged out by the impact was on a land surface eroded away long ago.