My name is Chris Anderson, and this is granite.

It's an igneous rock, and it was formed when magma cooled inside a giant volcano.

But I don't see any volcanoes.

I'm in Acadia National Park, and all I see is the beautiful Atlantic coast of Maine.

So how did a rock that formed inside a magma chamber get here?

And what other rocks can we find?

Let's learn today on OutSCider Classroom!

[Intro music] [Music] The geologic history of Acadia National Park is both legendary and explosive.

420 million years ago, this area was taking a geologic butt kicking.

The North American and European tectonic plates began smashing into each other.

And all that bumping and grinding generated a ton of pressure under the surface.

Eventually, an underground chamber of magma formed, kind of like a really big, really hot zit in the Earth's crust.

As the continents continue to push together, more magma filled the chamber.

It got to untold amounts of pressure, and eventually the magma chamber blew its top.

[Chris making explosion noises with his mouth] That explosion caused a volcanic hole in the earth called a caldera, nearly ten miles wide.

And today, you can stand right at the edge of that ancient caldera here in Arcadia.

Check out this formation.

This is the shatter zone.

[slow motion and guitar riff] The shatter zone.

And it's the edge of the caldera.

Here you can see rock that was broken and blasted away when the caldera blew its top.

These shards of rock are suspended in granite as the magma from the eruption cooled.

This granite is a really awesome example of igneous rock, a type of rock that's formed when magma cools and crystallizes.

And you can find that rock all over Acadia.

In fact, when you're standing on Cadillac Mountain, known the world over for its granite formations, you're standing on a giant mass of cooled magma at the bottom of that ancient caldera.

To help teach us more about the different types of rocks and how they form, it's my friend and structural geologist, Doctor Folarin Kolawole.

Hey guys, my name is Doctor Folarin Kolawole and I am a structural geologist at Columbia University.

Sedimentary rocks is the rock type that forms due to the weathering and laying down of weathered materials in different layers.

So metamorphic rocks form when, sedimentary rocks that were laid down in layers on the Earth's surface, or igneous rocks that either make it up to the surface, as you know, volcanic igneous rocks or solidifies within the Earth, as intrusive igneous rocks.

When these two types of rocks are buried deep into the earth, and are subjected to high temperatures and pressures, the minerals would change their form.

And, they form what we call metamorphic rocks.

So plate tectonics is the grand process that actually drives the cycling of Earth's rocks from sedimentary rocks to igneous rocks into metamorphic rocks.

This process primarily involves the burial or exposure of rocks.

So while sedimentary rocks are laid down on the surface, you need to bury them deep down to subject them to metamorphism and to melting to create magma.

Right.

And after igneous rocks are being formed within the earth, say by through, as intrusions or, during metamorphism, if tectonic forces bring those rocks up to the surface, they get subjected to weathering processes like, you know, from rainfalls and from heating and cooling due to different seasons.

This makes the rocks that have been exposed to the surface break down, in the process called weathering.

And they get washed down through rivers and glaciers and wind, and they get deposited within basins in layers.

This is a really good, place to look at rock cycling, simply because we are within a mountain, an area where rocks that were buried deep down has been brought up to the surface.

And if you look at these rocks, you would see evidence that suggests that they've been subjected to high pressure and temperatures.

You can see the minerals in this rock.

So these are gneisses, and you can see that they've been subjected to, high pressures and temperatures because the minerals align really well.

Check out this rock.

It's mudstone, and it's a sedimentary rock.

It was formed on a seafloor 470 million years ago.

Now, check out this rock.

It used to be mudstone, but got transformed into schist, a metamorphic rock.

Back when the tectonic plates were converging here.

They exerted a ton of heat and pressure on this rock, turning it from mudstone into schist.

New rock, new properties.

And check out the lines here.

All these waves are a sign of the immense forces that were at work here.

Eventually, this rock will be weathered, eroded, and deposited somewhere else as a sedimentary rock, or it'll find its way below the Earth's surface, melt and cool into an igneous rock.

Guess that's why they call it the rock cycle.

Hey, the only thing that's better than the Earth recycling rocks is me recycling geology puns.

[Music] By knowing what type of rock you're looking at you can really understand a lot about what was happening on Earth when that rock was formed.

Igneous rocks are formed when magma is cooled.

Sedimentary rocks are formed by sediments like sand or mud or corals.

And metamorphic rocks are formed when the other two types of rocks are subject to really intense heat and pressure.

Rocks really are the best evidence we have for understanding our planet's history, and we should never take them for "granite."

[drum beat] [crickets] Okay.

Okay, I'll stop "talc-ing."

[drum beat] [crickets] Hey, I love a good geology pun.

We all have our "faults."

BOOOOO!!

Okay.

I'm done.

[Music] My name is Doctor Folarin Kolawole, and I'm a structural geologist.

I study how rocks break and why they break.

[Woosh, pops] [Ding] Structural geology is the study of the Earth's structure.

And primarily, we care about how rocks break and how they slide along those breaks, and the implications of this processes such as earthquakes, particularly earthquakes that are being created by human activities, like when we push water into the ground because we don't want the water at the surface because it's too contaminated and we want to keep them down there so that they don't come up to the surface.

Those activities can change the stresses and the rocks and make previous, cracks or faults, you know, slide.

And that creates earthquakes.

So, I grew up in southwest Nigeria in a small town, called Akure, and this town is surrounded by beautiful, granite hills.

And, you know, growing up every day and seeing those beautiful hills just fascinated me.

And, I learned that I could study how these rocks form and make money in the process.

So I'm like, yeah, I think I can spend my life doing that.

When I was in high school, my geography teacher played a very critical role in helping me discover that I really loved geography and particularly, more specifically the, physical aspect of it, physical geography.

And I was so fascinated about that part of the course that I knew I could, I could actually do that stuff.

He presented it in such a way that was it was inspiring.

It basically made me imagine what those things look like, like mountains.

Of course, I had hills around the town I grew up in, but there were not mountains.

But, you know, learning about, you know, Mount Kilimanjaro in East Africa and Mount Everest, as you know, highest point on Earth, and the ability to imagine what those, those features look like and you can do with the spark of imagination and adventure, in my mind.

The best part of my job is exploring questions that are yet to be answered.

You know, the fact that after all these years of studying this same process, there are still certain questions that we cannot answer, will not be able to answer that, that excites me.

It makes me feel like I could make important contributions to advance the society.

Yeah, that I think that that's the most exciting part of my job.

And I guess another part I can mention is working with students.

It's amazing to pass that knowledge across and inspire beautiful minds, you know, creative minds.

[Music] Acadia National Park is one of the most beautiful places in the northeastern United States.

There's rolling hills and some of the oldest trees east of the Mississippi River.

So how do you make it easy for people to drive through the park on their visit without bulldozing everything?

The answer?

You don't.

Back in the early 20th century, oil tycoon John D Rockefeller wanted to give his favorite national park a present for being so awesome.

45 miles of carriage roads.

What's a carriage road?

Well, it's a road for carriages, of course.

Rockefeller wanted visitors of Acadia to be able to get around the park motor free, wandering through the mountains and the forest, taking in the scenery and enjoying themselves.

So how do you build one of these things?

I'm here with my friend Gail Gladstone, who's a park ranger at Acadia and knows a thing or two about these here carriage roads.

So, Gail, how are these things built?

Well, they are built with three layers of gravel, granite, gravel.

The first layer, called the base, is large chunks.

The second layer is more medium sized chunks, and those are used to fill in the spaces in the big chunks.

And the third layer, known as the top coarse, is the finer stuff.

Tiny one inch dust.

And what that does is that fills in those spaces.

And it kind of.

And as it gets wet and used, it locks it all in.

Very cool.

So where was this rock from?

Was it, is it granite from around here?

Originally, most of it was probably was quarried on the island.

Most of it probably right nearby.

How did they decide the kind of the paths that, that the roads would go along?

So there they had, John D Rockefeller Jr.

Who's vision, this was his dream, his vision was these roads.

He had his own set of engineers and road foreman who worked for him.

And what they would do is they'd come out and site the route using, you know, survey techniques, figuring out they knew they wanted this view or they knew they wanted to get to the top of this mountain or to go around this mountain.

And so using the survey techniques, figuring out the best way to do that, these roads are built mostly on the sides of the mountains, and they take you around or they go, in this case where we're close to Eagle Lake, they go around the lake and, yeah.

So what are some of the challenges, like engineering wise, of building roads in and around the mountains without trying to disturb too much of the, of the ecosystem?

Yeah.

So a big issue on the Mount Desert Island is the water, getting the water from the mountains down to the lakes, which is where the water wants to go.

So when you have a carriage road that kind of cuts right through the path of that water on the side of a mountain, you have to get the water under it so that it can get to the lake.

If it goes over it, then there's a big chance that you're going to get washed out is when water goes over it, you're going to lose all this fine stuff is going to get washed away.

So along all the roads, you'll see these ditches which collect the water as it comes down the mountain, and it runs it into the culverts, which go under the road and take it down to the pond.

What else did they build?

They built bridges.

- Okay.

And, back drains.

They're part of that infrastructure where it's often times there are stone lined drains that go up the slope a little bit.

And what it will do is catch the water as it's coming down the slope and funnel it into one spot on the culvert.

A culver.

[buzzer] -Yes.

Culver?

[Buzzer] Culvert.

Culver?

[Buzzer] -Culvert -What or how or what is that?

A culvert is a pipe that goes under the road.

It's the it's the plumbing of the system, part of the plumbing of the system.

And it's just an 18 inch pipe or 24 inch pipe.

Takes, collects the water, takes it under the road and out the other side.

What are what some of your favorite ways to enjoy the carriage roads?

I like biking on the carriage roads.

I bet that is a cool way to get around.

It's a great way to get around.

Well Gail, thanks for teaching me about these carriage roads and how they were built.

This is great.

You're welcome.

[Music] Over there is Little Moose Island.

[Footsteps get increasingly quicker] This is Little Moose Island, and you get here by hiking across the land bridge.

But, I'd say more, but it's lunchtime and, Chris is getting a little hungry.

Go grab a little bite to eat.

[Clock ticking] Dude, where's my land bridge?

Tides are the daily rise and fall of sea levels.

And in Acadia, those sea levels go up and down anywhere between 10 and 12ft.

That's why this land bridge will disappear underwater, only to reemerge a few hours later.

So how come I can hike out to Little Moose Island instead of put on a pair of swim trunks and goggles and go for what I imagine to be a very cold swim?

For that answer, we look up.

The moon.

Beautiful.

Serious.

Definitely landed on.

The Earth's gravity pulls on the moon, keeping in orbit around us.

But the moon also pulls on the Earth.

But since the moon's mass is much smaller than the Earth, its gravitational pull is much weaker.

It's just a little tug.

Not really enough to change the Earth's orbital path, but enough to make our sea levels go up and down.

The moon pulls on the land, too, but it's a lot harder for anybody to notice.

Water has a much easier time getting around.

It's the gravitational pull of the moon that causes our oceanic tides.

And depending on your local geography, causes land bridges like the one I'm currently standing on to dip below water for part of the day.

But that's just part of the story.

When we get high and low tides depends not just on the moon, but the position of the earth and sun as well.

And for that we need to talk to an astronomer.

Hello, my name is Kiersten Boley and I am an astronomer at The Ohio State University.

The position of the moon has a pretty big impact and the biggest impact on Earth, because its position influences tides.

So when we think about the moon, and Earth, and how the tides relate to all of this, you'll have the moon and basically all the water will kind of drain from the sides that the moon is not facing.

And then you'll get these two bulges on the sides, both facing the of the earth that's facing the moon, and the side that's opposite of the moon as well.

When we think about these bulges, the bulges stay the same relative to the moon.

But as you know, the Earth has a 24 hour day.

And so that means that basically you've got this, you can almost think about it as like this bubble of bulged water that we're rotating under, almost.

And so that's why you'll get times of day where you'll have high tide and low tide.

And it's, that's mostly due to the Earth's rotation as opposed to the moon moving around and changing where it's at.

It's the fact that the Earth is moving underneath this water, if you want to think about it like that.

So the sun in this whole system actually does one really, really cool thing in that it can kind of it creates its own bulge that is a little bit weaker than the moon's.

It ends up counteracting the moon, the bulge, the water bulge that the moon is creating in some instances, but also sometimes it will help get an even larger, an even higher high tide.

So an even larger water bulge then you would normally have.

So this would be in a situation where you have the Earth, the moon, and then the sun basically in alignment.

And then you would get these really, really high tides, like extremely high tides.

And that only happens occasionally.

At other points when the moon is, say, is perpendicular.

So you have like the, the moon, the Earth and the sun, you know, you'll have your regular high tides.

But then sometimes when it's facing the other way, you'll end up having it interfere with the tides.

And so the high tides won't be as high.

And it's probably a little bit safer if you want to go surfing or something.

There's a couple other factors that determine how high and how low a tide gets at a given location.

The Earth doesn't have a global ocean.

We've got seven continents kind of scattered across the surface of the planet, so the water can't perfectly follow the moon's gravitational pull.

Also, the ocean isn't at an even depth.

At some places the difference between high and low tide is barely noticeable, others, it's quite drastic.

When you do visit Acadia, pay attention to when the tide rolls in and out.

Otherwise, you can get stuck on an island for six hours or more.

Check in with the visitor center to see when high and low tide is for that day.

If the tide is out, you can hike out to Little Moose or the Bar Islands.

Just make sure you get back for the tide rolls in.

[Music] [Speaking in native language] Greetings.

My name is Nolan Atlvater.

And I'm a Passamaquoddy citizen from Sipayik, which is located in what is now eastern Maine.

As east as you can go in the United States near Eastport.

The Passamaquoddy is one of the four tribes, or five tribes of the Wabanaki Confederacy.

The word Wabanaki is actually the English version of it.

We pronounce it as, Wobonaki.

And that comes from the word Ckuwaponahkiyik, which roughly translates to "Land of the Dawn."

And as Wabanaki people, we see ourselves coming directly from this land.

And so that word actually refers to us as well as, Wabanaki people, as people of the dawn.

You know, archeological records tell us that we've been here for over 13,000 years.

However, our oral histories teach us that we've been here since time immemorial.

So this land has always been ours, but not ours in a possessive type of way.

Ours in a relational type of way.

Our, the Passamaquoddy word for Earth is "skitkomiq," which I was taught to translate it as "our mother."

And with that relationship comes accountability and responsibility.

So we can see that this area was a place for our ancestors to come seasonally for hunting, for harvesting sweet grass, which were actually in a sweet grass, a salt marsh right now where, we harvest sweet grass today and we use sweet grass for our baskets.

And it's also a culturally significant material for us as part of our creation stories.

So another cultural practice that I think the Wabanaki people are known for is our skills in basketry.

And I think that starts with the material that we use, which is the black or brown ash tree.

And that is much more than just material to us for our baskets.

The ash tree is part of our creation story where Gluskap, who is a significant cultural figure for us, he shot an arrow through the ash tree and out walked the [native language] or the first native people from that tree.

So it's much more than a resource to us.

It's very spiritually significant.

Over time, we've developed a lot of means for weaving baskets from your traditional pack baskets for carrying materials, or for harvesting potato or corn, to your contemporary fancy baskets that a lot of native artists beautifully design, through their imaginations and their own creativity.

It's very important to realize that wherever you may call home, there are in fact, indigenous people to that land.

Each indigenous tribe or nation is distinct in their own languages, their own cultures, their own traditions and histories.

So with that, wherever you call home, there are in fact, indigenous people.

So I think it's just important to not only recognize that you are on indigenous land and that there are present tense indigenous people that still hold connections to the land and to their cultures, but to try and take the responsibility to build an understanding of those people and relationship with those people to work towards, repatriations for those communities who face a lot of significant injustice in a lot of, in a lot of areas, I think that's very important.

Not just for society overall, but also for the sustainability of the planet.

Well, that's our show.

Thanks for watching.

Now, if you'll excuse me, I have some title amplitudes to quantify.

We'll see you next time on OutSCider Classroom!

[Music] Major funding is provided by the National Geographic Foundation.

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