All language subtitles for Making North America Series 1 NOVA 1of3 Origins 1080p

KIRK JOHNSON: North America,
the land that we love.

It looks pretty familiar,
don't you think?

Well, think again!

The ground we walk on
is full of surprises

if you know where to look.

As a geologist,

the Grand Canyon is perhaps
the best place in the world.

Every single one of these layers
tells its own story

about what North America
was like

when that layer was deposited.

Are you ready for a little
time travelling?

I'm Kirk Johnson,

the director
of the Smithsonian

National Museum
of Natural History,

and I'm taking offon the field trip of a lifetime.

Wow, look at that rock
right there.

That is crazy!

To find out how did
our amazing continent

get to be the way it is?

EMILY WOLIN:
Underneath Lake Superior,

that's about 30 milesof volcanic rock.

30 miles of volcanic rock?

How did the landscape
shape the creatures

who lived and died here?

14-foot-long fish in Kansas?

MAN:
That's what I'm telling you!

JOHNSON: And how did we turn
the rocks of our homeland...

Oh, man!

...into riches?

This thing is phenomenal.

In this episode,
we hunt down the clues

to our continent's epic past.

You can see new land
being formed

right in front of your eyes.

Why does this golf course
hold the secret

to the rise and fall
of the Rockies?

What forces nearly cracked
North America in half?

And is it possible that
the New York City skyline...

I've always wanted to do this.

...was once dominated
not by skyscrapers,

but by towering mountains?

We're uncovering secrets
hiding in our own backyard.

Peel it back.

Whoa, that is unbelievable!

"Making North America: Origins,"
right now on
NOVA.

MajoKIRK JOHNSON:
NOVA North America, our continent. c

Filled with all these
spectacular landscapes.

They look like they've
been here forever,

but they are anything
but permanent.

The truth is, our continent
has had its ups and downs--

literally!

It's an epic tale
of creation and destruction

playing out over thousands,
millions,

even billions of years.

Wow.

We're going to trace
this story

back to the very beginning,

to the origins
of North America.

(tail rattling)

Our journey starts here
in the American Southwest.

This place is a paradise
for geologists

and one of our
national treasures.

It is, of course,
the Grand Canyon.

That is a big hole!

And it gets me every time.

Wow, this is absolutely awesome!

The landscape is breathtaking,
and so much more.

As a geologist,
the Grand Canyon

is perhaps the best place
in the world.

It's this incredible
300-mile-long slice

through the earth,

and you can see layer
after layer after layer

after layer of sedimentary rock.

Each layer is a time capsule

with a slice of our continent's
epic history locked inside,

stretching hundreds of millions
of years into the past.

Every single one of these layers
tells its own story

about what North America
was like

when that layer was deposited.

So here in one place,

you have this incredible story
of our continent

laid out
for your viewing pleasure.

But to really tell that story,

I've got to step out
of my comfort zone.

Are you ready
for a little time travelling?

I'm going to rappel
down the cliff

to get up close and personal
with these rocks.

Looks like I'm good to step off
the edge of the Grand Canyon.

I can't believe I'm doing this.

I really don't like the factyou've put a cactus right here.

This is the moment of truth.

Oh, baby!

This is not
the easiest thing to do,

especially in 100-degree heat,
but it's worth it.

Every foot I descend takes me
further back in time.

The first layer you come to
in this part of the canyon

is this pinkish rock
I'm hanging next to right now.

It's called the Esplanade Layer,

and like all the rocks
in the Grand Canyon,

it's an ancient landscape
frozen in time.

300 million years ago,

this place, and all
of the American Southwest,

was a vast sea of sand.

Hot, dry winds sculpted
an immense desert landscape

of endless dunes.

Over time,
the sand compressed

and transformed
into the sandstone

that forms the top ledgeof the Grand Canyon here today.

Further down, there's evidence
of a very different landscape.

About 1,000 feet below the rim
of the canyon,

the rock changes to limestone
loaded with fossils.

I've got a little fossil coral
in my hand.

It's fossils like this
that tell us

that this whole landscape
was once underwater.

340 million years ago,

a warm, shallow sea covered
all of the American Southwest.

Its waters were teeming

with trillions of microscopic
marine organisms.

When they died, their skeletons
piled up on the seafloor

and compressed into limestone,

forming layers that are hundreds
of feet thick.

And so it goes,
layer after layer of rock

telling us the story
of long-lost landscapes,

each one once the surface
of our continent.

And right at the bottom,

you find the granddaddy
of Grand Canyon rocks:

Granodiorite.

This rock is more than
4,000 feet

below the rim of the canyon,

and it's one of the oldest rocks
of them all.

By measuring the radioactive
elements in this granodiorite,

the rock here at the bottom,

geologists have figured out thatit formed 1.7 billion years ago.

Old for sure, but not the oldest
rock on our continent.

In fact, not even close.

The first rocks
on our planet formed

over four billion years ago.

Back then, the whole thing
was a lump of molten rock

under constant fire
from asteroids.

Eventually, the bombardment
slowed and the earth cooled.

It formed a hard, rocky crust,

and as water seeped
from the rocks,

oceans soon covered
almost the entire planet.

Under an orange methane
atmosphere,

there was hardly any land
in sight.

So, how did North America
and its fellow continents

get started?

To see what the very first land
might have looked like,

I'm heading to a place
far from our continent,

right in the middle
of the Pacific ocean:

Hawaii.

Here, you can witness
a force of nature

that creates land from scratch.

From up here,
it looks like paradise,

but there's an inferno
bubbling under the surface.

Just below us, lava is pouring
right out of the mountainside.

I'm flying over Mount Kilauea,

one of the most active volcanoes
on earth.

Erupting since 1983,

Mount Kilauea has spewed out
ten billion tons of lava

and resurfaced
50 square miles of land.

All land on our planet
started out like this,

as lava cooling and turninginto dark, heavy volcanic rock.

It would take a dramatic
transformation

to turn volcanic islands
like this

into the first continents.

I've got two kinds
of rocks here.

The first one is this dark,
heavy stuff called basalt.

This is the kind of rock
you find on ocean floors

and ocean crust
and ocean islands like Hawaii.

The second kind of rock
is lighter in color

and it's lighter in weight.

It's called granite,

and rocks like this form
the stuff of our continents.

You can find granite all over
the place in North America,

from the Appalachians
on the East Coast

to the sheer rock faces
of Yosemite

and the towering peaks
of the Rockies.

Without granite
and other light rocks,

there might not even be
any continents.

Because at one time,

the only rock
on the face of the Earth

was volcanic rock like basalt.

The trick is, how do you get
the granite in the first place

if you start out
with only basalt?

Under the ancient oceans,

our whole planet
was covered in basalt,

broken into large chunks
called plates.

Deep beneath them,

the heat of the earth
softens the rocks

and moves them
like a giant conveyor belt.

This pushes and pulls the plates
of basalt along the surface

and sometimes
even drags them down,

triggering a reaction
in the red hot rocks below.

The lighter stuff melts,
floats upwards,

and cools into granite,
gradually building up

a thick layer
of light, buoyant rock.

And this is how you turn
heavy volcanic rocks

into the rocks that make
continents, including our own.

In southern Canada,
just north of Lake Superior,

I'm on the hunt

for some of the oldest rocks
on our continent.

I'm Kirk Johnson,
here to see Cameron McLean.

Okay, on you go.

Thanks very much.

This is Lac des Iles,a mine in Thunder Bay, Ontario.

This huge open pitis just the tip of the iceberg.

I'll be going way deeper.

How deep are we goingright now?

We're going to get off
at the 740 level.

That's 740 meters
below the surface.

So over 2,000 feet,something like that.

We're going down!

Way down.

Way down!

At the bottom,
nearly half a mile down,

I realize the full scale
of the mining operation.

(explosion)

Every day, they blast out
3,000 tons of rocks

to find a treasure that formed
a long time ago.

McLEAN:
Here, we've got a pile of ore

that was just blasted
this morning.

We're in the ore now?
Yup.

JOHNSON:
You basically shovel it out,

grind it up, process it,
and what do you get?

We get this.

Palladium.

JOHNSON:Every day, miners extract nearly
$400,000 worth of palladium

from these rocks.

This silvery metal

makes our cars'
catalytic converters function.

Palladium is 35 times more rare
than gold.

But to me, the most
valuable thing down here

is the rock
the miners throw away.

Geologists have dated the rock
here in Lac des Iles

and figured out that it formednearly three billion years ago,

which is just mind-blowing.

That's almost
a billion years older

than the oldest rock atthe bottom of the Grand Canyon.

Lac des Iles sits in an ancient
chunk of continental crust,

one of the oldest building
blocks of North America.

Cooked up nearly
three billion years ago,

it merged with other chunks
about 1.7 billion years ago

to build the very first version
of our continent:

Laurentia.

To this day, the ancient rocks
of Laurentia

form a solid foundation

reaching about 100 miles deeper
into the Earth

than the rest of North America.

Building Laurentia
was a huge step forward

in the making of North America.

But there was some trouble
ahead.

150 miles farther south,

the peaceful shores
of Lake Superior

hold traces
of a cataclysmic event

that very nearly ripped
Laurentia apart.

I've always loved beachcombing.

You find amazing things
on beaches.

And one thing as a geologist
you learn very quickly

is that every single pebble
tells a story.

And on this beach,

I'm looking for a very
particular kind of pebble.

Oh, here's one,
that's excellent.

It doesn't look like much
on the backside of it,

but if you turn it over,
you can actually see

this incredible
banded structure.

This is a classic beautiful
Lake Superior agate.

Agates form in cavities in rocks
made by gas bubbles,

and the result
is this incredible banded

semi-precious gemstone.

Where you find agates,

volcanoes, the source
of the gas bubbles,

are usually not far away.

And just a stone's throw from
the beach at Gooseberry Falls,

I find a landscape made
of nothing but volcanic rock.

That tells me that this place

was not always as serene
as it looks today.

A billion years ago,
it was a hellish scene.

And geophysicist Emily Wolin
has the evidence.

These falls are the record
of a series

of volcanic eruptions
that happened in this area.

So we have five steps
in these falls,

and you can think
of each of those steps,

each of these layers
as another volcanic eruption.

We have flow after flow of lava
coming out,

and believe it or not,
what we're seeing here--

this huge stack of basalt--
is really only the tip.

So it goes deep into the ground
below us.

It goes much deeperinto the ground.

So just how deep
does this volcanic rock go?

Emily has brought
a piece of equipment

that can help us see
below the surface.

It's an array of seismic sensors

that you simply pin
into the ground.

Emily is part of a team

that has deployed
similar sensors

all around Lake Superior.

Should we test this now?

WOLIN:
Absolutely, go for it.

JOHNSON:
All right.

I'm setting off
little earthquakes!

This is great!

Did that work?

WOLIN:
Looks good.

The key to this
is that seismic waves

travel at different speedsthrough different kinds of rock.

The waves travel
at different speeds

through soil and granite
and basalt?

Exactly, yeah.

We've put seismometers
all around Lake Superior,

and that tells us
the kind of material

that's far,
far below our feet

without actually
having to drill down.

How much basalt
is actually down there?

Underneath Lake Superior,

this basalt and other volcanic
rocks associated with it

stretch 55 kilometers
into the crust.

That's about 30 miles
of volcanic rock.

30 miles of volcanic rock
straight down.

That's a lot of volcanic rock.

That is a huge pile
of volcanic rock.

This rock is what remains

from one of the biggest
volcanic eruptions

in the history of our planet.

Where the water runs today,there once flowed a sea of fire.

A little more than
a billion years ago,

Gooseberry Falls was the scene

of one of the most
violent events

in North America's history.

Huge torrents of lavapoured from the earth off and on

for about 20 million years.

And it wasn't just burning up
what's now Minnesota;

the devastation spread
much farther.

Evidence of the immense scale
comes from surveys

like the ambitious project
called the USArray.

It's a huge networkof 400 movable seismic sensors.

In the last eight years,

scientists have deployed these
across the United States.

It's providing the first
complete picture

of the rocks
that make up our continent,

almost like a 3-D MRI scan
of North America,

revealing an ancient
geological wound.

I'm looking at a map
of the midwest United States.

What I'm seeing is
the distribution

of these basalt flows.

They stretch
all the way through Iowa

up into Minnesota,
to Lake Superior,

and then back down
to Lake Michigan.

It's a huge area
about 1,000 miles long.

And this map
is really revealing

because it shows
a tremendous scar

across the North American
continent.

The scar is the result
of a huge rift that opened up

in the heart of Laurentia
over one billion years ago.

Torrents of lava poured
from the Earth.

It was a gash
more than 1,000 miles long

that threatened to split
our budding continent apart.

But the rift
mysteriously stopped.

Today, all that's left
of this gaping wound

is the scar tissue,

the basalt we find
under Gooseberry Falls

and right through the Midwest.

What happened that kept
our young continent whole?

What was it
that stopped the rift?

No one knows for sure,

but it could have been
our neighbors.

A billion years ago,

some of the other continents
on Earth

converged on North America

to form a supercontinent
called Rodinia.

It was a titanic group hug,

and when it broke up,
the rift had healed.

North America was safe,
but far from finished.

Our continent
now had a stable core.

But to build its coastlines
east and west,

it would take a beating

that went on for hundreds
of millions of years.

Making the East Coast
we know today

is an epic story
of heat and collisions.

Today, I'm hunting for relics

of this continental makeover
in Manhattan.

Apartment block.

Apartment block...

Apartment block.

Wow.

No apartment block here.

Rock!

All over the city,you can see outcrops of bedrock.

It's called Manhattan schist,and it's a clue to how the city

and the whole East Coast
was made.

These rocky outcrops
in Central Park

don't really show up
in too many guidebooks,

but they're as important
to New York's history

as the Statue of Liberty
or the Empire State Building.

Here in the heart of midtown,
a brand new apartment complex

will soon rise up
from the rocks.

To build the foundation,

the crew has to dig a pitdeep into the Manhattan schist.

So what's the toughest thingabout drilling into this rock?

A.B. OLEVIC:
This rock is very solid.

We've been here for ten weeks,

and so far we went down
about three feet.

Wow, and you're justpounding away

with those rock hammers?

OLEVIC:
Drilling and hammering
away, yeah.

Can I have a try?

Absolutely,
here's your chance.

JOHNSON:
All right, let's go do it.

This is great,
I've always wanted to do this.

Takes a little concentration,but it's pretty straightforward.

Up, down, backwards and then
down, and then, hammer!

This is incredibly hard rock.

I mean, I could sit in this cab
for hours pounding away,

and it would take a long time

to make even a couple of inches
of progress.

It's the tough Manhattan schist

that's allowed the city's
skyscrapers to soar.

And the thing about schist isthat it started its life as mud.

What could have turned mud
into this beast of a rock?

I've found some evidence at thebottom of this construction pit.

You can see the rock
has a particular shine to it.

This is a mineral
called muscovite.

And muscovite forms
in big, platy crystals.

Here's one that's almost
an inch in diameter,

and what's cool about this stuff

is that it forms
in even larger sheets,

and in Moscow, where the word
muscovite comes from,

they used to use sheets
of muscovite as window glass.

Muscovite forms
at over 500 degrees,

and some of
the surrounding schist formed

at even higher temperatures.

That gives me an idea
about what happened

that turned soft mud
into hard rock.

About a half a billion
years ago,

a chain of volcanic islands
headed towards North America.

Riding the Earth's
conveyor belt,

these islands bulldozed mud
from the seafloor,

dumped it onto the East Coast,
and buried it.

Over time, the mud compressedand baked into the hard bedrock,

or schist, that's shaped
the face of New York City.

The skyline of New York City
is so familiar.

It's got this incredible group
of tall buildings

in the midtown,
and then far to the south,

down in downtown Manhattan,

there's a second clump
of skyscrapers.

And in betweenthere's much smaller buildings.

And what's going on here
is that in midtown,

the Manhattan schist
comes near the surface,

and that allows the builders
of the skyscrapers

to attach their foundations
firmly to bedrock.

The same thing happens
to the far south in downtown.

And in between the bedrock
dips deep below the surface

where it's covered
by gravels and sands.

And there's not
so many skyscrapers there--

it's much smaller buildings.

So it's actually
the geology that gives

this very American city
its very particular look.

While other factors
are involved,

today these
steel and concrete giants

dominate New York's skyline.

But 440 million years ago,
they would have been dwarfed

by something else.

The same collision that created
the Manhattan schist

turned a flat coastal plain
into something

that's hard to believe--
a mountain range.

Standing almost ten times taller
than any skyscraper

in New York today:
the Taconic Mountains.

The ancient Taconic Mountains
were really big.

They were the size of the Alps,
maybe 13,000 feet tall.

Today, very little remains.

So where did they go?

In Manhattan, they eroded away,
leaving only bedrock.

And this reveals one
of the great geologic truths:

no landscape is permanent.

The formation of New York
and the East Coast

was just the first in a series

of gigantic continental
collisions

that would transform
not just North America,

but the entire planet.

(beeping)

Evidence of this great clash
of continents is hidden

in one of the most spectacular
vistas of North America.

Over here, Kirk, this is one
of the best spots up here.

Wow, what a spot this is.

This is incredible.

JOHNSON:
This is Zion Canyon.

Its 2,000-foot sandstone cliffs

are among the tallest
of their kind on the planet.

Locked inside them are
the remnants of a lost world.

DAVID LOOPE:
Put yourself
back in the Jurassic.

JOHNSON:
200 million years ago,
these rocks were endless dunes

in a vast desert
covering much of the West.

LOOPE:
So this sandstone means we had
nothing but sand

being blown over
an almost lifeless desert.

And you piled up more and more
and more, dune after dune.

JOHNSON:
So these great cliffs of Zion,

these great sandstone cliffs

are actually the stacked
fossilized ancient sand dunes.

LOOPE:
That's it.

JOHNSON:
The rocks here in Zion bear
witness

to a traumatic phase
in our continent's history.

More than 300 million years ago,
all the continents on Earth

came together into
the biggest landmass ever:

the mega-continent Pangaea.

A towering mountain range
rose in its center,

disrupting the climate

and turning great swaths of
North America parched and dry.

It was a huge desert.

Everything was so far
from a source of moisture

that you couldn't get rainfall.

No moisture in the air.

JOHNSON:
So what happened
to this giant desert?

Why did it disappear?

David has brought me here
to look for clues

in the rocks beneath our feet.

But they're not easy to spot.

LOOPE:
We're getting close here.

JOHNSON:
And they'll be round?

Or are they irregular?

They'll look like circles
on the rock surface.

Always takes me a little while
to get tuned in.

JOHNSON:
Is this one over here?

Like this thing?

LOOPE:
Yup, you got it.

There's that one.

So they're in a row?

You got a scale?

LOOPE:
That's about
as good as it gets, yeah.

JOHNSON:
What we've found
are strangely regular circles

in the sandstone.

Some of them lined up
like a string of pearls.

What could have made them?

LOOPE:
I ruled out tracks,
I ruled out burrows,

and then when I saw
the near perfect alignment

of these in lines
and how they cross cut

several different dune deposits,
the light finally came on

and I realized
it's gotta be earthquakes.

JOHNSON:
Earthquakes?

How could these little circles

have anything to do
with earthquakes?

Turns out the mega-continent
Pangaea was too big

for its own good.

Trapped heat rising fromthe earth caused enormous stress

under the gigantic landmass,

sending earthquakes
shuddering across the land.

When they hit
the deserts of Zion,

streams of groundwater
shot up through the dunes

and erupted in mini volcanoes
of quicksand.

So you're telling me that
there'd be geysers of sand

shooting out of these holes?

(chuckling):
That's what I'm telling you.

JOHNSON: Pangaea ruled the Earth
for 100 million years,

but, finally,
this monster of a continent

couldn't hold it together,
and it cracked apart.

The sea flowed into a rift
between the continents

to form the Atlantic Ocean.

North America drifted northward
and as the climate changed,

it became green again.

Finally, our continent was free.

The break-up of Pangaea
more or less marks the moment

that North America became
a continent in its own right

with the newly formed
Atlantic on one side,

what would become the Pacific
on the other side,

and a shape
we'd recognize today.

Still, one very important thing
was missing:

the Rocky Mountains.

Miles high, stretching all the
way from New Mexico to Canada,

you'd think
they've been here forever.

But you would be wrong.

These majestic mountains have
come and gone several times.

(beeping)

Just outside the Mile High City
of Denver, Colorado,

you can see that
for the Rocky Mountains,

ups and downs
were par for the course.

This is an embarrassingly
manicured landscape

for a geologist,

but I'm heading
to the 14th hole,

where there's some pretty
amazing evidence

for the forces involved in the
uplift of the Rocky Mountains.

Hey Kirk, how are you?

Good to see you.

Drone expert Jon Fredericks
and I are gonna take

his state of the art eye in
the sky for a little spin.

RICHIE:
All right, let's take off.

JOHNSON:
The drone camera reveals
a bizarre landscape.

Jagged slabs of sandstone
jutting out of the ground.

Oh, look at that.

Incredible.

Just a beautiful landscape
there.

This is like being a bird

and that's what geologists
want to do,

they want to get up in the air
and look down on these rocks.

And I can see
just a beautiful perspective.

These are layers of sandstone,
they started off as sand,

which means they were
originally horizontal.

Now they're tilted up.

It's the kind of landscape
you look at and wonder,

what happened here?

If you take a closer look
at the sandstone slabs,

you'll find some clues
to how they got here.

Mixed in with the finer
sand grains are big pebbles

with sharp edges.

These are way too big
to have been blown by wind.

And given the size
of these particles

and how angular they are,
there's probably only one way

to get this kind of sediment
moved along

and that's by a river.

And fast-flowing rivers
begin in big mountains.

So I'm thinking I'm looking
at a sandstone that was formed

near a mountain range.

But what mountains?

It can't be the Rockies.

This sandstone formed
way before they even existed.

So what's the story?

Standing here
300 million years ago,

I'd be witnessing the birth
of a long-lost mountain range.

Called the Ancestral Rockies,

they were nearly as high
as the Rockies we see today.

But over millions of years,

rivers and rain ground down
these ancient mountains

and reduced them
to sand and gravel,

which compressed into sandstone.

So the slabs we see
on the golf course

are all that's left of this
long-forgotten mountain range.

But how come these layers
that were once horizontal

are now standing on their heads?

What was the force
that was strong enough

to push up hundreds of feetof layered rock up into the sky?

70 million years ago, the rock
that makes our modern Rockies

was deep underground and coveredby 10,000 feet of layered rock.

But then something happened
hundreds of miles away,

on the western edge
of North America:

a slab of ocean floor
diving deep into the earth

suddenly starts attacking
our continent,

bulldozing right through
its foundations.

Far inland, this forced up
a massive mountain range--

the Rockies 2.0.

They lifted up the 10,000 feet
of layered rock above them,

tilting that ancient layer
of sandstone,

which erosion then sculpted
into sharp, angled slabs:

the jagged red monoliths

that make this golf course
so special.

The colossal mountains
that created them

eventually eroded down.

But then,
about ten million years ago,

the entire region was lifted
a mile above sea level,

giving us the spectacular
Colorado Rockies we see today,

a true signature landscape
of the American West.

They're still under
construction,

pushing up from below
even as erosion

keeps carving away
at their majestic peaks.

Now there's just one more
big piece to add

to our continental puzzle.

The magnificent landscapes
of the West Coast.

Like Big Sur,

the snow-capped volcanoes
of the Pacific Northwest,

and the fjords and islandsof British Columbia and Alaska.

To find out
what made these landscapes,

I'm gonna have to crack open
a few rocks.

To help me, I've brought a crew
of fossil hunters

to this remote beach.

So what time is it?

MAN:
I think the tide
has probably turned.

MAN:
7:41.

MAN:
So we have about
three hours right?

JOHNSON:
So I'm gonna turn
you guys loose on this outcrop

and just scream if you find
something good, all right?

I've been here before and
I really wanted to come back.

(grunting)

Nothing.

It's just rock.

You gotta break a lot of rock
though to find fossils.

There's nothing quite like
splitting open slabs of rock--

you never know what you will
find hidden inside.

The bigger the slab
you can lift up the better,

because you just can't--
I can't emphasize it enough.

MAN:I think you've been emphasizing
it quite a bit.

(grunting)

JOHNSON:
We've been cracking rocks
for hours

and we're running out of time.

The tide is coming in, guys--
it's about 20 feet behind us.

MAN:There it goes.

JOHNSON:
I have the rock,
you take that rock.

MAN:Peel this one back.

And no fossil.

Big split.

No fossil.

MAN:
Big nothing!

JOHNSON:
With the tide on our heels,

we get one last shot.

You're on it.

My fingers.

Okay, we're... whoa.

Oh, yes!

Okay now, get this edge right
here and just peel it back.

Real slow-- one, two, three.

(cheering)

Look, there it is.

Oh, my God.

We've hit the jackpot:
a fossilized palm frond.

That is unbelievable!

That, my friends,
is a palm frond.

The reason I'm so excited
is we're not on

the sunny shores of
California...

We're in Alaska!

What's a palm leaf
doing so far north?

I'll tell you what.

If you have a palm tree,
the ground doesn't freeze.

This palm grew here
when the climate in Alaska

and the rest of the world
was much warmer.

But there's something else
going on here,

because we've also found
fossilized corals

on a neighboring island.

And they're much older
than the palm frond.

We know these corals
lived near the equator,

so how did their fossils
wind up here in Alaska?

Turns out the corals hitched
a ride on strings of islands

moving up from the Pacific,
smacking into North America

over millions of years.

These travelling landmasses
radically re-shaped

our Pacific coastline.

Imagine an island the size of
Japan and imagine that island

off the coast of North America
drifting towards the coast

at about three inches a year.

Then imagine this field of logs
is like lots of little Japans,

log after log smacking in
and sliding north,

smacking in and sliding north.

And you start to see a model

for how the west coast
of North America grew.

It was a titanic
geological logjam

that grafted thousands of miles
of new coastline

onto our continent
and still had enough power

to push up the spectacular
coastal mountain ranges

of Alaska and British Columbia.

The West coast
is the most recent addition

in the great continental
construction project

that built North America,
but it's far from complete.

On the coast of California,

it's easy to find
the signs of ongoing work.

Just 30 miles
north of San Francisco,

Tomales Bay is one
of the most enigmatic places

on the West Coast,

and a favorite spot
for geologist Lisa White.

Growing up in San Francisco,

I always lovedthis area so much.

It's really a curious situation
here because the rocks

on that side of the bay,
that whole peninsula has been

moving for millions of years
from an area further south.

And part of the puzzle

is we're standing
on the San Andreas fault.

JOHNSON:
Hidden deep under this bay

is an enormous crack
in the earth.

This is the San Andreas fault.

It cuts right through
Tomales Bay

and runs 800 miles
through California,

separating two huge chunks
of the earth's crust--

the Pacific plate
and the North American plate--

which are sliding
in opposite directions.

WHITE:
We're sitting
on the North American plate

and the Pacificplate over there

relative to where we're sittingis moving to the northwest.

So that whole peninsulais moving along.

How fast is it going?

That whole peninsula is moving

about the speed
that our fingernails grow,

so couple of inches
every year.

JOHNSON:
Tension in the San Andreas

can trigger violent earthquakes,
like the one that devastated

San Francisco in 1906
and many others since.

WHITE:
1906, 1989, 1993--

you name them.

Pretty much most decades
we can think of

significant earthquakes
that happened.

JOHNSON:
The power of the moving plates

constantly changes
the face of California,

with surprising
long-term results.

So what this is means is thatsooner or later Los Angeles

is going to pull upright next to San Francisco.

The view from the Hollywood
hills will be very different.

WHITE:
Imagine that.

So two towns that don't even
like each other very much

will be neighbors.

But what understanding
the geology of California

really illustrates is just how
dynamic the state is.

JOHNSON:
California is one
of those places

where the forces under our feet
really make themselves known.

Our wild ride across
North America and back in time

reveals these forces
are relentlessly at work.

Continent building never ends

because we know one thing
for sure in geology--

nothing ever stays the same
for very long.

North America has seen
some amazing transformations.

It took billions of years
to take the shape it is today.

But far from reaching
the end of our story,

we're really just embarking
on the next chapter:

how geology shaped life
on our continent.

(hissing)

The investigation continues
online

Our great continent is split
in half by a giant sea.

How did it shape
the creatures who lived...

A 14-foot long fish, in Kansas.

...and died here?

The amazing connection
between life and our land.

Making North America,
next time on

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NOVA
is provided by the following...

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