Download Rick Crosslin: On this earth science edition of Indiana

Presented By:
Episode Two 202 – Forces That Shaped Indiana
(Earth Science)
>> Rick Crosslin: On this earth science edition of Indiana Expeditions, we’ll be taking a
look at some science that rocks. We’ll travel the path of ancient glaciers; we’ll go 520
feet underground to dig up important Indiana resources; and we’ll get a firsthand look at
one of the longest manmade structures in existence, all in the name of earth science.
(Music)
>> Rick Crosslin: Try it yourself! Let’s go check it out. Come on!
>> Announcer: Indiana Expeditions with Rick Crosslin is made possible through the
generous support of the Dr. Laura Hare Charitable Trust: enhancing Indiana’s natural
environment through preservation and protection of ecologically significant natural areas
and promoting environmental education, stewardship, and awareness. The Center for
Student Learning, Indiana Department of Education. And Veolia Water Indianapolis: As
the operator of Indianapolis water, Veolia is dedicated to providing billions of gallons of
clean, safe, drinking water to nearly one million customers in central Indiana every year.
>> Rick Crosslin: Welcome to another episode of Indiana Expeditions. I’m Rick
Crosslin, and I’m standing here in Lake Michigan, and today’s story is about forces that
shaped the earth. This is Science! Try it yourself!
(Music)
>> Rick Crosslin: I’m here on the shore of Lake
Michigan in the Indiana Dunes State Park. Lake
Michigan is a huge body of water, and what’s
cool about Lake Michigan is it was originally
formed by glaciers that came into the state. And
this large body of water is affected by our
weather and our wind. The wind makes the waves that come in. And when you get wind
and waves, you have two forces of erosion that helped shape the state. For example,
right now this wind is coming in off and pushing this water into these waves. It doesn’t
seem to be doing much harm until it hits the beach. And as you see here at my feet, all
this sand and gravel is being washed ashore, washed in, washed out, moved down the
beach. And so this is a dynamic force that’s constantly shaping Indiana, at least in this
part of Indiana. Now imagine over time, over thousands of years, you’re going to get a
lot of movement of Indiana. But that’s not the full story. As this wind comes into shore,
it starts to pick up this sand, dry it out, and pile it up, and that’s when you get an Indiana
sand dune.
And today, I found the expert here at the Indiana Dunes State Park. This is Brandt
Baughman, our property manager. Brandt, nice to meet you. Thanks for taking time to
come with us today.
>> Brandt Baughman: No problem, Rick. Thanks for coming.
>> Rick Crosslin: Now this is a beautiful place, but it also has a lot of science that we
can learn about here. These dunes behind me, they kind of look like big hills. Can you
tell us a little bit about the dunes?
>> Brandt Baughman: Well, the dunes are actually a very rare ecosystem. This is one of
the only places in the world that you’re going to find this kind of plant diversity, and
most certainly one of the only places in Indiana.
>> Rick Crosslin: Brandt, most people when they think of a sand dune, like in Egypt or
in other parts of Africa, they think of miles of just sand and wind and no vegetation.
How come it’s different here?
>> Brandt Baughman: Well, for the most part that is a correct perception, but the
nature of sand dunes is that they’re typically in arid areas. Here we’re in a temperate
area that gets lots of rainfall. We’re right next to a freshwater lake. So it’s a different set
of circumstances. The sand dunes, being at the bottom of a freshwater lake with the
rainfall we get, creates a great environment for these plants to grow.
>> Rick Crosslin: Brandt, thanks a lot for taking time and allowing us to see this
beautiful example of forces in Indiana.
>> Brandt Baughman: Absolutely.
>> Rick Crosslin: I don’t know about you, but seeing this water, it’s a little bit easier to
understand the power of ice and water as a force that shapes Indiana.
I’m here in a really flat part of Indiana, in fact, I’m out in a field that’s been plowed. Now
another name for plowing is till. In fact, this is the Central Till Plain. And it was made flat
by a geological force, a giant glacier that pushed down through the state and pushed all
the debris and sediments ahead of it. In fact, it plowed the northern part of our state
completely flat.
>> Announcer: Did you know the tallest building in Indiana is 811 feet tall. Glaciers
were over 9,000 feet tall.
>> Rick Crosslin: Here is a huge rock out in the
middle of this cornfield, a rock that’s not
supposed to be here, a rock that came all the
way from Canada and was pushed down with the
glaciers.
Okay, I’m on top of this rock, and I believe two
thirds of it is still buried underground. But this is
a huge example of a rock that was brought down here. This rock didn’t originate from
here, but it’s here now, and it would take a huge geological rock to move this rock. But
it’s cool. From my viewpoint up here, everywhere I look is nice and flat. Those
tremendous geological forces that push rocks and gravel and large metamorphic rocks
from far north stopped here. But that is not the end of the story. Because as those
glaciers melted, the water continued to carve and shape Indiana.
The beautiful hills of southern Indiana are not really hills at all. Over time, water has
eroded the valleys around them, exposing the bedrock.
Indiana is famous for a very dramatic feature where the land seems to drop away.
400 steps. Wow! Anyone who said Indiana was flat has never climbed up Knobstone
Hill. I’m standing on the top of Knobstone Escarpment, a high area between some
Indiana lowlands down here in southern Indiana. And I’m telling you, the view is
spectacular. This Knobstone ridge was formed when the glaciers stopped, melted, sent
all of that water down to southern Indiana, cutting out and carrying away the sediments
to make these beautiful, beautiful ridges and these wonderful valleys and vistas. This is
worth the climb.
Well, I’d like to stay here longer and admire this beautiful vista, but now it’s time to go
down the other side of the Knobstone Escarpment.
So most people when they think of Indiana, they think of a flat land. But I have proof
that in Indiana, it’s not flat everywhere you look. In fact, behind me is one of the largest
canyons in Indiana. In fact, everything you see down there is a remnant of a force in
nature called glacial melt.
I’m here at the top of the Pine Hills Nature
Preserve. Let’s see what it’s like at the bottom. I
can tell you it’s a lot cooler here. And there’s
evidence of it being cool with these beautiful
hemlock trees that are here from the glaciers
that helped carve this beautiful canyon. I’m also
standing on a force that is still present today.
This creek is actually still cutting through this sandstone. It’s cutting and depositing
debris like you see right here. So these forces are not forces from long ago, they’re
actually forces that are continuing today here in Indiana. And we’re getting ready to go
to a very, very deep and perfectly cut place called the Devil’s Backbone.
And this part of the sandstone is very, very soft. As a matter of fact, it turns back into
sand sediments just almost by the touch. But higher up is a hard layer of sandstone
that’s acting as a capstone to hold this whole unique structure in place. And that’s why it
gets its name the Devil’s Backbone. But let’s really go take a look at it up top.
Well, I’m finally up at the top of Devil’s Backbone. But by the looks of things, don’t you
think it’d be better if we called it Devil’s Sidewalk?
But this is a spectacular view.
Okay, so I’ve got a little bit of a mystery here: I’m surrounded by sedimentary rock,
sandstone and shale, but this rock is neither one of those. I think I’m going to have to
do some more investigation and talk to some experts to find out how this rock came to
Indiana which is filled with sedimentary rocks, and it’s not a sedimentary rock.
In order to find out, I need to take this to my friend, Nelson.
Ahh, Nelson. Long time, no see.
>> Nelson Shaffer: Rick! What do you have there?
>> Rick Crosslin: Well, Nelson, I’ve been across Indiana trying to solve a mystery, and I
think this is a piece of granite, but I’m not sure. So the best thing to do about science is
when you’re not sure to ask an expert. So I thought I’d come to the Indiana Geological
Survey, and this is the first time I’ve been here. This is a pretty cool entranceway.
>> Nelson Shaffer: We’ve been studying the minerals, and rocks, and fossils of Indiana
since 1837. In fact the United States Geological Survey grew out of some of our early
work. So we look at a lot of these from citizens from all over the state. Be glad to take
a look at it. Let’s go see what’s inside.
>> Rick Crosslin: Okay. Cool.
>> Nelson Shaffer: Before we talk about what’s inside that rock, let’s see how a rock of
that sort got here.
>> Rick Crosslin: From as little as ten thousand years ago, glaciers spread through
North America. Nelson explained that our rock was probably pushed down from its
native home in Canada by glaciers that, when melted, not only pushed our rock down
waterways with melt water, but created our Great Lakes. But Nelson explained there’s
only one way to be sure of its origin.
>> Nelson Shaffer: So let’s take this and do what
geologists like to do best: we’ll hit it with a
hammer.
>> Rick Crosslin: Let’s do it. That’s awesome.
Awesome. Wow, that’s actually got all kinds of
sparkling pieces just like those minerals you
showed me upstairs. So we’ve helped uncover
the mystery of how this Canadian igneous rock
got down to Indiana, a state known for sediments and sedimentary rocks, rocks that
were deposited many years ago and forces like glaciers that have shaped Indiana and
made it what it is today. And thanks to Nelson, I know a little bit more about Indiana
rocks and this rock right here. Nelson, thanks.
After talking to Nelson, I wanted to share my new-found knowledge with my friend
Chuck Cowley from Chapel Glen Elementary. When I arrived, Chuck was already doing
a cool experiment controlling run-off water.
>> Chuck Cowley: What we have is three control groups to where we have the same
composition in each creek bed. So we had rock, sand, and they actually measured it out
in volume what materials they were going to add to the riverbed. And then the variable
group, they were charged the task of stopping erosion. So I showed them some
examples that scientists are currently using through images I captured on the internet,
and they came up with, okay, we’re going to put cloth down on top of the soil, use big
rocks or we’re going to build a clay wall. And so we’re testing which one of these three
variables will control erosion the best.
Right now we’re doing science. We have controls. We have variables. We’re measuring
the data we collected. We’re analyzing the data. And this is doing science.
>> Rick Crosslin: Do you know how it’s going to turn out?
>> Chuck Cowley: No. I have no idea, so we’ll see.
>> Rick Crosslin: Chuck was using a model to
explain how water can shape Indiana. A model is
used in science to explain something that is not
easy to reproduce. A big part of teaching science
correctly is not giving the answers to your
students. Better yet, let them find out and find
out what might happen.
>> Chuck Cowley: If you didn’t want your pond to be filled up with sediments, what
would you use?
>> Rick Crosslin: Chuck’s class found that the clay wall was most effective in stopping
erosion.
>> Class: This is science! Try it yourself!
>> Rick Crosslin: This last summer, you didn’t need a model of eroding water. Record
rainfall caused massive flooding in Indiana. So much water rushed through the state that
manmade and natural features were changed.
All of this water, powered by gravity, created new features on the land, like this new
channel and island in the Wabash River.
>> Kevin Collier: Maybe I’m the fortunate one. I still have property, but it’s all on an
island now.
>> Rick Crosslin: This farmer used to farm this land, but the flooding was so powerful
that it changed this peninsula into an island.
>> Bill Norfleet: We’re located in southern Posey County right near the confluence of
the Wabash and the Ohio Rivers, and we’re standing right here at the new cut that has
been created by the floods back in mid-June. As you can see behind me is the new
channel. The Wabash still has its existing channel, but then also there’s a new channel
that’s cut through behind me that cuts all the way across this peninsula, and then
reconnects with the Wabash on the other side.
>> Rick Crosslin: The floods washed away
millions of tons of earth, rock and gravel. Indiana
exported a lot of sediments into the Ohio River.
Indiana’s sedimentary rocks provide a window
into the lives of plants and animals of prehistoric
time. Fossils are found in sedimentary rocks. The
more there are sediments, the greater the chance
for fossils. Since Indiana is covered with
sedimentary rocks, we are also covered with fossils: marine fossils from ancient sea beds
and plant fossils from swamps turned into stone. Many fossils are deep underground in
sedimentary layers waiting to be discovered. However, in some places, natural forces
like water erosion or manmade forces like mining cause these fossils to be uncovered.
In places like these, you may not even need to dig for fossils, because most of the work
has already been done for us.
Indiana is famous for ironstone plant fossils, and the best time to look for these fossils is
right after a rain.
Here’s a cool nodule, Indiana ironstone nodule, kind of an oddity. There’s a little
brachiopod fossil right there, a little piece of pyrite there. But who knows, inside of this
could be a shrimp, a leaf, a crab, don’t know until you crack it open.
Coal is a fossil fuel that comes from, what else, ancient plants that turned to fossils.
Getting the coal out of the ground takes manmade forces like this huge dragline in
southern Indiana.
We’re getting ready to go inside the inside of this huge dragline here in Indiana. This is
the money-maker that pulls away the overburden, and gets it ready for the coal to be
eventually taken out.
(Music)
>> Rick Crosslin: Check out the links in this chain.
>> Miners: This is science! Try it yourself!
>> Rick Crosslin: We’ve talked a lot about forces, but this is human force that helps
shape the earth. Here’s one of the largest draglines scooping up this overburden,
moving it out of the way so they can get at the coal. But the great thing is this giant hole
will be filled back in and reclaimed. This is human forces shaping Indiana.
Coal mining today has stiff regulations on what happens to the land after the mining.
Bruce, you’re telling me this used to be a mined area right here where we’re standing.
>> Bruce Stevens: Absolutely. It’s just the new age of coal mining reclamation.
>> Rick Crosslin: Before the laws like the Surface Reclamation Act were put in place,
miners in the past would just dump the refuse, and scenes like this were commonplace.
>> Bruce Stevens: This is not natural at all. This
is what was described earlier as being before
inception of the Surface Mining Act, prior to May
3, 1977 at which time, coal companies did not
have the understanding or the requirements to
put back the land into a useful state.
>> Rick Crosslin: Due to how easily refuse
erodes, water erodes this barren land much
quicker than in nature. And it washes poisons into our waterways. However, there is
still hope for this desolate environment. Dedicated people like Bruce, and
environmentally-conscious Indiana coal mining operations work together to turn around
the damage done over fifty years ago.
>> Bruce Stevens: In the old days, there was quite a bit of coal which did remain. And
you can see some of that coal in the walls of this little valley. And those areas can be
picked back up and sorted and actually sold. So a form of recycling of what was left can
occur. A year from now, this area will have clover or alfalfa growing on it, and will be
cut for hay, and will be able to be utilized by the landowner.
>> Announcer: Did you know the Great Wall of China is made of earth, stone and
manmade bricks and stretches over 58,326 football fields?
>> Rick Crosslin: We’ve been talking about forces that shape the earth, and I’m standing
on one that is a manmade force that has helped shape this part of the earth. I’m standing
on the Great Wall outside of Beijing in China. I’m standing on stone that has been
carved and placed here, and the sides of the wall are made of bricks. These are definitely
earth’s resources that have been used for one purpose, and it has actually helped shape
this part of the countryside. As far as you can see, this mountain pass has this manmade
structure on top of it to help block invading armies that came this way. See you at the
top.
Over time, the study of minerals has led to some amazing discoveries. Here on the
campus of Rose-Hulman, teachers and geologists come to study at the DNR mineral
workshop.
Here teachers can learn the best ways to teach their students about minerals. To get an
up close and personal look at one of Indiana’s most famous minerals, I traveled to
Shoals, where a mineral called gypsum is turned into something that almost everyone
has in their home: drywall.
Well, we’ve been studying how forces shape Indiana and the sediments they leave
behind. And I’m here today at a pretty special place in Indiana, National Gypsum.
Before we head down, is there anything special we need to do? I’ve got my helmet, but
is that it?
>> Brent Baker: It’s actually pretty dark down there, so we’ll get you guys a mine light
and a self-rescuer.
>> Rick Crosslin: In case of an emergency, this is the thing that will keep us alive.
520 feet deep.
Man goes down, gypsum comes up.
(Music)
>> Rick Crosslin: This is not your grandpa’s mine. I’m going to tell you that right now.
(Music)
>> Rick Crosslin: Keeping a city beneath the
earth is not an easy task. Before new gypsum can
be blasted, great care must be taken to secure
the rock above. A giant pick machine knocks off potentially loose rocks on the ceiling.
Then bolts mixed with resin are used to strengthen the ceiling.
>> Brent Baker: This is a two-part apoxy is all this is. You’ll load the tube into the
machine. Once he gets the hole drilled, you’ll see the head transfer over, air pressure
will shoot this resin up in the hole. This little plastic piece right here helps sustain it in
the hole until the rod comes around, and the rod will be shoved up in and bust the
lining here. Turn it for eight or ten seconds, and it will set up, and the plate will help
support the top.
>> Rick Crosslin: Okay, I’m right here in the face of the gypsum. And Jeff, I noticed that
we just watched the driller, and why is he putting all these holes here?
>> Jeff Hawks: Well, he’s drilling these holes in the face. These are about a two inch
diameter hole, and he’s going in about fourteen and a half feet deep, and once he gets a
series of these holes drilled on a certain pattern, we’ll have some blasters come in here,
fill these holes with explosives, and they’ll blast this rock out for us to load to the
crusher.
>> Rick Crosslin: After blasting the gypsum
loose, the front-end loader gets to work
moving the gypsum to the crusher.
(Music)
>> Rick Crosslin: We’re right here by the
crusher where all the gypsum gets brought by
these loaders and trucks and is dumped in the crusher, because it’s too big to go to the
surface. So here it’s crushed and put on conveyer belts, and remember: man down,
gypsum up. This is where it starts its trail back up to the top.
(Music)
>> Rick Crosslin: While underground, I couldn’t help but add a rock or two to my
collection.
Let’s take a look up close at some of these. Where’s the gypsum we’ve been mining? Do
you have a sample of that?
>> Jeff Hawks: This right here is the gypsum we’ve been mining. This is almost 100
percent calcium sulfate. And it has two water molecules on its molecular structure. This
right here is another type of gypsum. And you can see a big difference in the color. This
one here is blue. This is calcium sulfate, but it doesn’t have any water on its molecular
structure. And just by changing those two molecules, there’s a big difference in the
density of the rock, the color of the rock, and the hardness.
>> Rick Crosslin: And you call that anhydrite?
>> Jeff Hawks: Anhydrite.
>> Rick Crosslin: Which is Greek for?
>> Jeff Hawks: Without water.
>> Rick Crosslin: An: Without. Hydrite: Water.
And now, I always have my pocket knife with me,
and this seems really quite hard.
>> Jeff Hawks: It’s quite a bit harder.
>> Rick Crosslin: And this is a lot softer. I could almost carve this. I can’t scratch-well
wait-I can actually scratch it with my fingernail. So on the Mohs Hardness Scale, that’s
about a>> Jeff Hawks: It’s about a 2.
>> Rick Crosslin: So this is what we’re after, but I see some other stuff. I saw a layer up
in the rocks here. This was up in the ceiling here. What is that?
>> Jeff Hawks: This white layer in here, this is also gypsum. And this is actually a crystal
form of gypsum called satin spar.
>> Rick Crosslin: If I’m starting a rock collection, this would be the number one place
to start it. Hey thanks. Let’s go take a look at what’s going on upstairs, okay.
(Music)
>> Announcer: Did you know gypsum can also be used to create plaster? In 1666, the
King of France ordered all buildings to be covered with plaster for fire protection. So
much gypsum was mined around Paris that it became known as Plaster of Paris.
>> Rick Crosslin: We’ve been learning about the natural geologic forces that help shape
our state, and you know it’s about time I think that we put this piece of red granite, that
came all the way from Canada, back into the rock cycle. Join us on the next Indiana
Expedition. I’m Rick Crosslin. And remember, science is for everyone.
Now this rock can continue its journey on downstream.
(Music)
>> Announcer: Indiana Expeditions with Rick Crosslin is made possible through the
generous support of the Dr. Laura Hare Charitable Trust: enhancing Indiana’s natural
environment through preservation and protection of ecologically significant natural areas
and promoting environmental education, stewardship, and awareness. The Center for
Student Learning, Indiana Department of Education. And Veolia Water Indianapolis: As
the operator of Indianapolis water, Veolia is dedicated to providing billions of gallons of
clean, safe, drinking water to nearly one million customers in central Indiana every year.