Many of you have been out to the Black Hills. If you haven't (or if you can't remember what it is like), visualize the following scenario:
As you drive west from Rapid City, you notice a jagged stretch of sandstone peaks called the Hogback Ridge. After a short descent from those sandtone peaks, you come to an area comprised of another sedimentary rock, red shale, which makes a "Racetrack" around the Black Hills. If you keep driving west, there is a gradual incline made of limestone. This limestone formed 100-500 million years ago, from the shells of ancient marine animals. (Yes, we are still in the Black Hills of South Dakota.) Keep driving still, past this limestone plateau, and you will see the Central Crystalline Core of the Black Hills. This area is made of schist (a metamorphic rock) and granite (an intrusive igneous rock) that have aged for up to 2.5 billion years. The apparent color of this Central Core and the groves of Ponderosa Pine gave this area its name, the Black Hills. You might want to get out of the car and take a hike up to Harney Peak, the highest peak in between the Rocky Mountains and the Alps of Switzerland.
What are the events that led to the formation of these Black Hills? Why does it look the way it does? Like geologists, we will explore these questions today.
If you were not in class for the presentation (or if you could use it to review), here is a video:
Here is a link to the presentation (without sound): Formation of the Black Hills
- Write a summary of how the Black Hills formed. What are the events that led to their formation?
- Would the Badlands exist if weathering/erosion had not taken place? Why/Why not?
- The major uplift of the Black Hills occurred 70 million years ago. What do you think that area of South Dakota looked like 40 million years ago? What do you think the Black Hills and Badlands will look like in another 40 million years?
51 comments:
1.Metamorphic rock.. turns to schist,,,, Igenous... which makes Mount Rushmore.. at one time SD was the bottom of the ocean, shells fell to the bottom when the animal living inside dies, makes sediment. Schist and Granite on the bottom; Limestone on top.. then Red Shale; then Sandstone on top of the red shale. Black Hills began to uplift; was 15,000 feet at one point.. 70 Mil. years ago. Highest now 7,244 feet (harney peak) Highest points now Granite and Schist. The uplift of the schist and then granite caused the sandstone and red shale and limestone to be at top; which was weathered and eroded. The limestone, redshale, and sandstone were eroded and weatheredddd....... :)it didn't get eroded like the others (granite and schist) because its more resistant.
2.No, because they were formed by the weathering and erosion, and if it hadn't happened, then there wouldn't be the formation because it would have just stayed the same over time.
3.I think it was about even for all of these, because the rocks were weathered, but it was probably just evening the whole thing out; and in 40 million more years, it'll probably be wayy lower, and the red shale might be almost completely gone, with the other two nearing the same thing (being gone) idk hah(:
1. By Schist and Granite on the bottome. Then Limestone. Then Red Shale Then Sandstone. After that there was an up lift about 70 million years ago! All of the parts are still there. the highest peak used to be sandstone. And now the highest peak is schist and granite. which used to be on the bottom. That is on top now becasue it is more resistant than weathering and erosion.
2. No, becasue if the sediment never got taken away without having the up lift and the erosion taking away the sediment. They wouldn't be there.
3. I think that the Black Hills looked really flat because all of the sandstone red shale limestone granite and schist were all on top of eachother. Now they turned into beautiful mountains!! (: In 40 million years I would guess that all that would be left is granite and schist because they are the only ones who are resistant from weathering.
1. Granite and Schist formed the bottem layer of the Black Hills. When marine organisms died and fell to the bottem of the ocean floor, Limestone formed the second layer. Red Shale formed the third layer and Sandstone formed the forth layer. There was an uplift, causing the layers to rise up to great hights, forming the Black Hills. Weathering and erosion caused Schist and Granite to become the highest part of the Black Hills because they are the most resiliant, making the other layers more weathered than them.
2. No, because without weathering and erosion, the Badlands would have been just a strip of normal land.
3. 40 million years ago, the Black Hills would have been very tall with Sandstone as the tallest layer. In another 40 million years, the Badlands will have been more weathered, but Granite and Schist will still be the tallest layer because they are the most resilliant.
1) They were layers and layers of rock, that slowly eroded away, spreading the varies layers around the base of it.
2)No, because erosion is waht created them.
3)I think that they could have looked like a huge mountain almost, but in 40 million years, the Badlands will only look like a tiny little hill...they would be almost completey eroded away, maybe even gone completely.
The Black Hills: the one that was at the highest peek is now at te bottom cuz of the breaking down and rising beteen the 70 million yrs.. caused bby erosion and weathering.. schist is resistant to weathering and sandston shake and limestone don't like weathering so they are at the lower parts of the mountians all the sediment ges to the ground ue to weathering and erosion.
The Badlands wouldn't exsist if weathering a erosinon didn't happen beacause the badland were formed by erioson and the rocks all stettled to the bottom and the weathering has cause the rock to break down even more.
the area of the black hills and badlands 40 million years ago look like a big pile of rocks and and the rocks did weather too fast then.
the area of the balands and black hill 40 million years from now will look differant becuz of all the erosion and weathering happening it probably will be twice the amount of it happening.
at first, granit and schist 1.6 milion years ago. The next layers were layers of Limestone and Red Shale that weathers quickly. The last layer was a course cut grained Sandstone.Over time, uplift (still going on)
lifting crystaline core and eroding it. Highest points of black hills are the core granite and schist (as of now) because of uplift and age of the rock allows it to be more restistant.The sediment that was eroded
eventually settled in the Badlands (which is now being weathered away)
2. No. Since the Badlands are made of sediment, there is not enough sediment that could have made them without the help of weathering and erosion of the Black Hills
3. I believe that there will be more flat land, more plants, and more animals as the Hills wear away
1.The black hill are from limestone that is from sea shells from millons of years ago.The black hills start as granite and schist. Then came along limestone. After that limestone came along the red shale. The last thing that come along was the sandstone. It was flat millons of years ago know because of all the weathering that it has had it has gone up and now the granite and schist are the tallest thing on the black hills and befor it was the lowest thing on the black hills. 2. The badlands would not exist because it would be a flat lsnd or some land that has some hills to it that are not that big. 3. The blacks hills would start to work it way up as a hills. What is would look like in another 40 million years is that it would be taller now then it would be before it might be 28,534 is what i think that it would be in 40 million of years.
1. the black hills were formed by limestone wich was formed 100-500 million years ago by shells of ancient marine animals. limestone was formed above or on top of he shist and granite. than red shale layered on top of limestone. and last the sandstone layer formed on top of the limestone. than instead of being flat it had an uplift about 7 million years ago. the elivation was 15,000 feet with the highest peek but now the highest peek is around 7,000 ft. sandstone used to be at the top but now the shist and granite wich used to be at the bottum is now at the top because of weathering and erosion.
2. the badlands would probably not of existed if weathering and erosion hadn't taken place because that is what made them. if weathering and erosion wouldnt of accured they would of never become mountains and they would just probably be flat ground.
3. probably in another 40 million years i think south dakota will either be all mountains or it will eventually all erode away because of all the weathering and erosion. if there will be alot of weathering and erosion than i think in 40 million years the badlands and black holls will be all eroded away and there will either be nothing left or just a little bit left.
1)The Black Hills were formed by granite and schist. They were the first layer of rock. Then the second layer, limestone, was deposited. Then came the third layer,red shale, was deposited. Finally the fourth layer, sandstone, was depostied. seventy million years ago, the black hills began to uplift. At that point, the elevation was 15,000ft. Now, the black hills are uneven becasue the oldest layer(granite and Schist) are ontop. The reason is that the oldest layer is first becasue it can resist weathering. Now the Black Hills are 7244ft in elevation.
2)I think the badlands would not exist without weathering and erosion because, the rock needs to break down and needs erosion to carry on layers.
3)I think 40 million years ago, the rock would have barely gotten smaller because, it takes time for weathering and erosion to occur. I think in another 40 million years from now, it would get bigger, but just a little.
1. The Black Hills started out as sedimentary rock because it used to on the ocean shore line. Then it became igneous rock which formed inside the hills. Differnt types of sedimentary rock like shist, granite, and limestone began to pile up and the Black Hills began to uplift.
2. No, the badlands would not exist if weathering/erosion had not taken place because that is the only way they could have formed.
3. I think it looked much like it did today. It might be a little higher today though. I think the Badlands will weather and erode away more and the Black Hills will get taller in the next 40 million years.
1. It started with granite and schist and then layers of other rocks piled on then there was a random uplift to form the black hills.
2.yes but I think they would look very different. and have greater elevation
3.I think it looked like a bunch of random rock formations. i think they will looke kind of the same except mt. rushmore and those monuments will be seriously eroded. and not look anything like faces.
1) Rocks gather from erosion and weathering and build up in layers. Than one day they had a they had an uplift from the tectonic plates that pushed them up to 15,000 feet and now it is at around 7000 feet. It shrunk because of weathering and erosion.
2) No. Because that's how all the rock got there from other rocks weathering and erosion.
3) I think it was a very tropical mountinous region. In 40 million years i think the mountains will be almost gone dew to weathering and erosion.
1. The black hills started forming as sediments because it use to be on the ocean shore line. Then turned in to a ignoeous rock that formed the inside of the black hills, Layers of granite, shist, and limestone. More sendimentary rocks were added called red very weak, then sandstone went on top of red shale. then black hills begain to uplift and rise.
2.No the badland would not exsit if weather and ersion hadn't taken place, because the badlands were made from weathering a ersion.
3. I think the Black Hills looked Similar to what it looks like to day but the shape might be different. In 40 million years I think the Black Hills will be small because the rocks are being weathered and eroded away. I think the Badlands will be very smooth and short, because of all the weathering a erosion.
1. There is a layer of schist and granite, then a layer of limestone, then a layer of red shale, then a layer of sandstone, Then the area started to uplift and the layers started to erode away, it is still, slowly, uplifting. It started out at 1500feet for the elevation, now it is7244 feet. Now the schist and granite is the highest, then limestone, then red shale, then sandstone. This happened because the top rocks started weathering and eroding away.
2. No, because all of the rock from the Black Hills is, and was, eroding away to the Badlands, and the Badlands are eroding away now.
3. I think that South Dakota was a huge hill or small mountain, do to the eroding rock. I think the Black Hills will be flat land, mabey with a little hill, and the Badlands will look kind of the same but shorter peaks.
1.Sediment toppled on top of each other, which eventually got uplifted to form the Black Hills, but over a lot of time, the seperate layers get weathered and eroded and the order of when it first formed changed because of the weather-resistant rocks, some are stronger than others distorting the order of the Black Hills' rocks today.
2.No because it would've never been able to form because it formed from sediment, nor would anything be able to be deposited because nothing would have been eroded because nothing was weathered. Also, weathering caused it to look like what it is now, so without it, it wouldn't look like that.
3.It was probably very tall, around 10,000 feet tall 40 million years ago. But in 40 million more years, it would probably be very small, maybe just 3,500 feet tall from weathering and erosion.(Black Hills). In 40 million years the Badlands will probably be very jagged and sharp(more than it is now), maybe look like a spiked death trap by then, maybe it might even be gone in 40 million years due to weathering and erosion.
1.the black hills is formed by weathering and erosion because the limestone, shist, red shale, granite they got layered and then they uplift.
2.no because the the sediments need to get there some how and they dont move on there own and weathering and erosion move those sediments.
3. i think they will look like more jagged and highe in elevation. south datoka would look like more space would be taken up by the badlands and black hills because the weathering and erosion would take place again the the whole process would take over again
1. they were formed by the ocean that was once there. when marine creatures went to the bottom of the ocean. also the rock layers of the black hills are granite, shist, limestone, red shale, and sandstone. then the rocks uplift and the rocks eleveated. which eventually formed thee black hills.
2. no, because weathering from other rocks helped make and build the badlands. from piling all the sediment on top of eachother.
3. i think that the black hills used to be huge, before all the erosion and weathering i think it used to be like twice as tall as it is now. in fourty million years from now i think its going to be very small or hardly even mountains because most of it will just be eroeded awayy.
1 the formation of the balck hills happened 70million years ago when a huge uplift happende but b4 thts theres was schist and granite which was piled on by limestone then red shale and finally sandstone
2.if weathering and erosion had never happened then we would have never seen the badlands since the bad lands is made up of weathered sediment from the balck hills then with the help of erosion the sediment ended up building up creating the badlands
3.40 million years ago i belive that the area of south dakota was barren until the huge uplift even the it must have been empty until plants started growing alternatively though it may have been covered by water until the black hills came up
1. Layers of rock built up over time. and about 70 million years ago they started to uplift and created hills. after awhile the shcist and granite rose to the top and became the victors even though they started at the bottom(just kidding) but they did come from the bottom to the top
2.No because rock just doesnt make itself in one spot...it has to be eroded to another spot and deposited
3.Probably had the same features just different rock on top, and badlands and the black hills will continue to weather and erode but still will be pretty high just not as tall
3. I think that fourty million years ago the mountains/hills weren't very weathered away. since the uplift didn't happen to long ago. but fourty years from now I think the hills will very weared down.
1. first, there was some schist and granite, then some limestone on top of that, then red shale, then sandstone. then, at one point, there was an uplift in these layers of rock. this created the black hills. over millions of years however, the outer layers of rock weathered and eroded away, making the hardest rock, the schist and granite that was on the bottom is now at the highest point of the black hills.
2. the badlands would not exist if the weathering and erosion of the black hills hadn't happened, mainly because the badlands are the deposit of sediment that was eroded away from the black hills.
3. 40 million years ago, the black hills hadn't eroded as much yet, so the limestone might have still been on top of the schist and granite, and the badlands would have had little limestone and no schist or granite. in another 40 million years, i think that the black hills will be smaller, and some of the layers of minerals might have completely eroded away to the badlands, making them larger and of higher elevation.
1)They are made up of layers of granite and schist, limestone, red shale, and sandstone. All of these layers appeared with thousands of years between them. Then, about 70 million years ago, the black hills was uplifted. As they rised, the core began to crack/erode, making the granite and schist layer the highest, with an elevation of about 15000 feet. All of the sediment that eroded away is now the badlands.
2)The badlands would not exist without weathering and erosion. If weathering and erosion wouldn't have happenned, sandstone would still be the highest in the black hills, and the sedimentary rock wouldn't have been transported to form the badlands.
3)I think south dakota almost looked the same, the badlands would have been smaller, and the black hills still would have been forming. In 40 million years, I think the black hills may have more layers added, there might be another uprising, causing a new badlands. However, I will be dead, so this will probably not effect me, unless the new badlands are formed on my grave.
-Sarah Quatier
1. First, in the precambrian period, the area now known as western South Dakota was on the edge of the sea and large amounts of sand clay were washed into the sea. They eventually became sandstone and shale. Then molten rock rose from within the earth's crust and cooled, forming granite which is now the core of the Black Hills. This made up the bottom layer of the hills. Limestone then covered the bottom layer of shist and granite. Next, red shale was deposited to create another layer. The next rock deposited was sandstone. An uplift of the land then occured, creating hills. Finally the sedimentary rock began to crack and erode away, exposing the lower layers.
2. If weathering and erosion had not taken place the Badlands would not exist. This is beacuse without these procceses the land would not gain new rock and would just remain flat.
3. I think that 40 million years ago the black hills looked similar in landscape, however the exposed rocks would be different.
1. This happend when the crust cooled underground and unevenly which caused the sparp peaks. Then a layer of shist and granite. Also these racks have been eroded away. Most of the rocks are limestone. During the nest several millions of years it are acculating of layers of sediment. About 70 million years started to uplift and rise the sedimentary rock started to crack and erode.
2. I dont think the Badlands would have not exsited because without all of the weathering and erison it would not be there becasue to form it needs all the cycles of weathering and erison.
3. I think it looked taller more pointed becasue back then the Badlands probably had alot of sediment and over the years it has lost alot of that sediment. I think in another 40 million years the bad lands will reapat the cycle and will be really tall and then loose sediment and will be small again.
1. They started out as metamorphic rock. Sedimentsbeing carried and then deposited. And since there was no plant life the erosion happened faster. Most of the rocks were limestone. Many of the animals died and fell to the bottom to soon become sedimentary rock.
2. NO! Because if erosion didn't happen then the sediment never would've rested there.
3. I think it was a ocean since it says that it was formed from shells of ancient marine animals.
I think they will still be there but it will be smaller or reduce in sizes because of erosion.
helloo!
1- the black hills started as precambrian sediments. since there were no plan life to hold erosion they acted faster than usual. the molten rock began to rise from the earths crust. it cooled unevenly causing them to be uneven. most rocks have been completely eroded away . most of these rocks were limestone (they are deposited in shallow seas.) so the layers are granite and shist with limestone ontop then red shale ontop of them all. the last layer was sand stone . they are all still present but not as easy to find. the uplift was about 70 million years ago. as they rose the sedimentary rocks cracked forming the hills & or peaks. it is now half as high as it started 15,000 to 7,000 (approximtly.) the lowest shist and granit are now the highest point. the layers went through weathering and erosion. granit and shist are more resisitant than others like sandstone. so everything affects them less than red shale, lime stone, and sandstone. woah this is a long comment.
the sediment broke down and was eroded away.
2-no they wouldn't because all the sediment from the black hills that were the highest peaks were washed away from the badlands. and now the badlands are eroding away just as the black hills were.
3-i think after the huge uplift they were starting to erode and be lowered . in 40 million years i think the black hills are going to keep eroding to the badlands. the badlands will erode too but not as fast since not all the sediment have been washed away to the badlands.
woah long comment..
my hands are tired.
okay bye. (:
1. The black hills used to be the edge of the continent. There was a great amount of granite that cooled deep within the earth's surface which is now the top of mount rushmore. There are limestone rocks along the way to the black hills. Millions of marine organisms dies and fell to the bottom of the ocean. The next rock was red shale. The last layer of rock was sandstone. The area of the black hills began to uplift. The layers became a mountain.
2. No, because none of the layers would have eroded away. When the layers uplifted it would they wouldn't have eroded away and created the badlands.
3. I think that the badlands would have been about 13000 feet high. The other 2000 feet eroded away. In another 40 million years, there will probably be about 3000 feet high because the black hills will keep getting eroded.
1. Metamorphic rocks formed at teh bottom of sea. magma deep unter the earth's crust cooled (deep within the eairth) cooled and formed granite. it cooled unevenlying forming fined grained and coarse grained granite. limestone was above the granite. Then Red Shale formed on top of the limestone. The next rock deposited was sandstone. 70 million years ago the area of the black hills uplifted. elevation was 15,000 ft. The hieght of the tallest peak today is 7,244.
2. No because even after the uplift they still wouldn't look similar to today.
3. the black hill would be smaller than they started, but taller than they are today. The Granite still might not be the tallest peak, but like i said the rest would be smaller.
In another 40 million years, i think they'll be even smaller.
Question: What'll happen to Mt. Rushmore? How will they (future people) maintain it???
1. a bunch of rocks deposited into the earth and then they slowly started to uplift and now the are eroding away.
2. No, all of the weathering and erosion made the badlands.
3. The mountains were taller than they are today. 40 million years ago they were probably still higher than they are now. in another 40 million years they will be eroded more than they are now.
1. Erosion took place because there was no plant life during the Precambrian era. Granite was formed but cooled unevenly, forming different areas in the Black Hills. Different kinds of Metamorphic and Sedimentary rocks were deposited. An uplift happened making the highest peak 15,000 feet. The highest peak today is 7,244 feet high.
2. No because without weathering and erosion there wouldn't be the Black Hills. When the Black Hills were weathered away all of the sediment went to the Bandlands.
3. The Black Hills were probably really tall because and uplift occured 30 million years before but they weren't as tall as they were when the uplift first occured. The Black Hills would still be weathering away and so will the Badlands but all the broken down sediment would be making the Badlands grow taller.
1.sediments near the edge of the sea, there was no plant life to keep erosion from happening, molten rock began to rise and it cooled unevenly, granite was formed. limestone was left there from the organic material left from the bottom of the ocean. Red shale was deposited at sometime after the limesotme. Sandstone also formed. There was an uplift and these layers were effected. It was about 3miles high. Today it is only about half that high. The schist and granite are more resistant to the erosion and weathering. The limestone red shale and sandstone has weathered and eroided away down the rivers and have deposited to other places.
2. the badlands would not exist if the weathering and eroison of the limestone, red shale and sandstone had not happened, they formed the badlands.
3.40 million years ago I think the hills were hight than they are today and the plant life was just starting to grow. Since there probably wasn't much plant life, that is why the hills are not as high today as 40 million years agot. the weather and erosion washed amounts of that away.
In 40 million years from now, I think the hills will be smaller yet. The weathering erosion will still break it down and move it. The way trees and plants are being cut down for development the vegitation will not be as strong.
It started as sediment at the bottom of the sea which eventually became metamorphic rock(schist)... then Magma began to rise up to the earths crust it cooled underground (granite)... then the layer of shist and granite was covered by a layer of limestone... then red shale formed on top of the limestone... then sandstone was formed at the top... then the black hills began an uplift making the black hills 3 miles high... then the central core (schist & Granite) rose to the top after the other layers eroded... now the black hills are only half as high as it was 70 million years ago... the eroded parts were eroded to the Badlands...
2. No the Badlands would not exist because they would not have gotten the sediment needed to form if the black hills wouldn't have eroded.
3. I think that South Dakota was a much different place than it is today. I think it would have had mountains instead of flat land. I think that the black hills and the badlands will be much smaller due to erosion... I think that the sediment from the erosion will form another landmark.
*)JaKeC(*
1. The black hills were formed when sediment layered and compacted then they were uplifted. the shist and granite became the highest point because it was the strongest and resisted to weathering.
2. No because the badlands were formed from the deposition of sediment, which was formed from weathering of other rocks.
3. I think that the black hills, 40 million years ago, must've been huge since the uplift was 70 million years ago. and in 40 million years i think they will have weathered more, and will become less elevated.
-->Christa*
1.Black hills formed by sedmimentary rocks pile on top of eachoter.With Granite & Schist on the inside, then limestone, redshale, with sandstone at the outside.This started about 70 million years ago.
2.no, because weathering woulnt have changed certain rocks into others,and the erosion wouldnt have carried it to the place to start the bad lands.
3.40millon years ago the blac hills and badlands wouldnt have been there much because it takse awhile to form. In another 40million years it will probably be very tall.
1)a metamorphic rock called schist and an intrustiv igneous rock called granite, have been here for about 2.5 million years. but also limestone that was formed 100-500 million years ago. so then if formed the Black hills by the limestones and granit and schist.
then came the upleft. the plates would eroide and make layers in a mountain.
2)no. because then the land wouldnt of depsotived the water and dirt and rocks.
3)it was a flat baren land. more mountains and lots more water and more animals and more metamorphic rock and more igneous rock also. more housing too not much but by chance there may be a couple tents or houses or indians.
1. many layers of rock formed on top of eachother in this order:
granite & schist, limestone, red shale, then sandstone. uplift happened and the order stayed the same but, the layers of different rock elevated to 15,000 feet since then, the layers of rock have moved due to weathering and erosion
2. no, because if there wasn't erosion, you wouldn't see the different level of the hills and there would be no difference in height and elevation. the badlands would just be one large plane.
3. the black hills were more organized in how they were formed before, and today, the weathering and erosion has moved the layers of rock down the hills and the the layers of rock have moved drastically. i think in 40 million years that granite and schist will be yet higher than the others and the other layers of rock that were on top before will be weathered so much they will not be there.
Schist and granite have been around for a very long time, and over time limestone that was formed about 50-100 million years and then Red Shale build up on top of each other and form many layers. Then Sandstone is desposited on top of the Red Shale. An uplift cause the layers of rock formed it into the hill and even throughout the movement the layers stayed in the same order. But overtime weathering and erosion wore away the rock on top and deposited it into smaller hills around the Shist and
Granite.
2. I don't think so because the badlands wouldn't have formed at all if there had not been uplift.
3. I think the area where the badlands is now would have bem plains. In another 40 million years the badlands will be not as tall and have more foothills due to the weathering and erosion.
1) Moltan rock cooled and became igneous rock, making the core of the Black Hills. Next,schist, granite, limestone, red shale, and sandstone were deposited and layered. There was a big uplift that made the rock move upward.
2) No it would not exist, because none of the rock would have been eroded away and then deposited in another place.
3) I think that the black hills would have been higher up then it is today but it would have been shorter than when it was formed. In forty million years, I think that the badlands will be shorter or closer to the ground due to erosion.
1-Molten rock cooled to become igneous rock, making up the core of the black hills.Schist,granite, limestone,red shale, and sandstone were deposited and layered. Lastly, there was an unplift that caused all of these layers of rocks to rise up, forming the black hills.
2-No, becuase none of the rock would have been deposited due to erosion.
3-Like it said in the slide, maybe it did look a lot taller than it does now. And in another bunch of years, i bet that we might not have the black hills. I think we wont because of weathering and erosion, but with the trees and stuff,it can still last a while and prevent some erosion and weathering.They wont be the same as they are now obviously, because the land is always changing.
1. Weathering and erosion caused the weaker rocks to erode away, leaving the harder rock, granite and schist (the central core) the top of the Black Hills.
2. They wouldn't have existed because they formed from weathering and erosion.
3. Before - One large slab of rock, with the Sandstone on top.
Later - It depends: more rock deposited on the surface means it will get taller/ if no rock gets deposited, it will be smaller.
1.) At the bottom is schist and granite, which have been there for over 2.5 billion years. Then, there is mainly limestone, which has been there for about 100-500 million years. After that, came red shale. The fourth layer is sandstone. 70 milllion years ago, there was an uplift. The layers are the same, it just has a higher elevation. Today, if you were to drive there, the red shale would be the lowest rock, and schist and granite are the highest. Sandstone and limestone are now in the middle, rather than be closer to the top. Weathering and erosion have forced some rocks down. The oldest layers were the most resistent, and the newest layers were the least resistent.
2.) No, they probably wouldn't exist. Without having the sediments that had been washed away from the Black Hills, the Badlands wouldn't have been able to form.
3.) I think that while the sandstone, red shale, and limestone would no longer be quite as high, they would still be above the granite and schist. The red shale, I suppose, might be a lower, but I don't think it would have been weathered and eroded quite that much yet. In 40 million years, I think the red shale will be pretty much gone, and the limestone and sandstone, while still there, much less than right now. I think that even the granite and schist will have been weathered and eroded down a bit.
1. There was a huge mass of molten rock that cooled to become igneous rock(along with schist) that formed the core of the black hills. Then limestone was eroded and deposited onto the igneous rock. Next, red shale was deposited and then sandstone last. Then the Black Hills began to uplift. Now, due to erosion/weathering, the center is now taller because it is more resistant then the other rocks.
2. No because they formed from the sediment that was eroded from the Black Hills.
3. I think the rocks were layered on top of eachother but the land was flat. In 40 million years, I think they will keep eroding so they will get smaller and smaller.
1.Erosin, weathering, and that the lowest part of the balck hills is now the highest peak of the black hills.
2.No because the Colorado River was the weathering/erosin that formed the Badlands.
3. 40 million years ago South Dakota was just a great big grass land and a lot of hills. The Black Hills in 40 million years will be just schisc and granite left of the Black Hills.
1 layers of different rocks piled up, then uplift occured causing the layers to rise, then weathering and erosion occured and now what was on the bottem was on top
2 no, because it would probably be flat
3 more of the weaker rocks would be gone
1. First the Schist and granite formed the first layer of rock. Then,on top op that formed limestone. Followed by red shale. And the last layer of rock formed on top was the sandstone. They then experienced an uplift. Then, they were eroded. The rocks eroded at different rates, so the sandstone,red shale, and limestone eroded away at the peak leaving only the schist and granite.
2. Not in the form that they are in now, because the rocks on top of the schist and granite would still be there.
3. 40 million years ago, i think that the black hills would have a layer of red shale and limestone on them that had not yet been eroded away. In 40 million years i think that the black hills will be alot lower and some of the granite and schist will have been eroded away.
1. The Schist and granite were depositied where the black hills are, then the Limestone was depositied on that then red shale on that and finally sandstone on top of that. Then because of uplift, the black hills rose up to 15000 feet a long time ago. Soon it began to weather down into what it looks like today.
2. No, because the reason the badlands formed is because of the black hills weathering away creating the badlands. So without weathering and erosion, the black hills would still be at 15000 feet where the badlands are today.
3. It was probably at a lower elevation than 70 million years ago but the red shale wasnt the lowest, but i do think it began to lower and all of the rock be in the order it is today. 40 million years from now it will be at a lower elevation than now, but the rock order wont change with red shale at the lowest and granite and schist at the highest.
1. About seventy millinon years ago the area of the black hills began to uplift with sandstone on the top, red shale, limestone, granite, and then schist. Today granite and schist are the tallest part of the Black Hills because of erosion.
2.The Badlands would not exist if weathering hadn't taken place because to get the different layers of rock you need weathering to compact sediment into the Badlands, which aren't that resistant to weathering.
3. I think that 40 million years ago the granite and schist were just starting to uplift, because the other layers like the sandstone, red shale, and limestone were also starting to erode. In the next 40 million years I think that the schist and granite will be quite a bit taller than the rest.
1. A metamorphic rock called schist and an intrusive igneous rock called granite have aged there over 2 million years. Along with limestone, red shale and sandstone. An uplift of 15,000 ft accured and created mountains. The different types of rocks risisted in defferent ways to weathering, which caused the mountains to differ in size.
2. No, the weathering from the mountains that are now the Black Hills is the rock that made the Badlands and obviously the rock would have no way to get there without erosion.
3. 40 million years ago the Black Hills were probablly almost as tall as they were at the end of thier 15,000 ft uplift. The Badlands were probablly in the middle stage of thier formation. In 40 million years the Black Hills and Badlands will probablly be weathered away then that rock will be forming new mountains.
1.) 2.5 million years ago.. Granite and Schist formed unevenly to create the core of the Black Hills. The flanks of the Black Hills are covered with rocks that formed between 500 and 100 million years ago.. since then they have been completely eroded away.. alot of them were limestone and organic sedimentary rocks. During the next several million years.. other sedimentary rocks were deposited on the land. The next type of sedimentary rock to be deposited was Red Shale. The next sedimentary rock to be deposited was sandstone. So all of these layers of rock were piled all on top of one another.. (in order of course from oldest to newest deposited rock.) About 70 million years ago the area began to uplift.. which by the way.. is still happening... As the Black Hills began to rise, the sedimentary rocks began to crack above the core and then erode away.. so they started to look a little "mountainy" as I like to say... they are just sorta like elevated.
2.) No because all of the weathered and eroded sediment would not have formed to make the Badlands... therefore, they would not be there.
3.) I think that all of the layers were probably in the same order that they formed 40 million years ago.. But in another 40 million years.. I think that all of the layers except for maybe granite and schist, (the first formed layer) will be completely, if not, maybe just eroded and weathered away alot, so just the first layer or part of the first layer is elevated high above the others because it is the most resistant to erosion and weathering.
okay. sorry my comment didn't send when we were in class, it was really weird, because i sent it.. and it said error, and i clicked back.. and it said that it was sent.. so idk what happened there.. so heres my completed blog response for you mr hoegh. thank you very much and have a nice day.
1. The black hills were made by different rocks, layers by layers of rocks were piled on top of eachother and then weathering and erosion took place to form the black hills.
2. No because weathering and erosion created the badlands.
3. 40 million years ago black hills probably was bigger and taller. 40 million years from now it will probably be very worn down and not much of "black hills" anymore.
1.The Black Hills were formed when an wide scale uplift pushed igneous and metamorphic rock through overlying sedimetary rocks. Then it formed a oval-shaped dome made of granites and metamorphic materials. Sedimentary lies at high elevation around the black hills. The geology is very complex and parent materials of soils change rapidly within short distances.
2.No, because if that wouldnt have happened it would just be a huge rock and it would look the way it is either.
3.I think that it wouldnt be as high as it is now and it wouldnt be the highest peak between the Rocky Mountains and The Alps at fifteen thousand feet. I think that it will be i little shorter when weathering takes place and wears it down a little.
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