[whirring]
(Describer) A machine burns lines into wood, drawing rectangles that form the letters MIT.
(Describer) Different rocks sit in a line.
(female narrator)
I bet you thought rocks
are just rocks, right?
(Describer) Three people are dressed as rocks.
Nope. There are three
major types of rocks:
sedimentary, igneous,
and metamorphic.
The coolest thing
is that each one
has the ability to change
into the other kind.
(Describer) They shake their heads.
Huh?
How is that
possible?
[rock guitar plays]
(Describer) In fast-motion, someone writes on a whiteboard the title: The Rock Cycle. Drawings of lightning, stars and a rock are added.
[record scratch]
(male narrator)
Sedimentary, metamorphic,
and igneous rocks
change into each other
in a process we call...
(Describer) The people dressed as rocks pretend to play instruments.
[rock music]
No, not that kind of rock.
This kind of rock.
[rock music]
(Describer) They hold actual rocks and shake them.
Yeah, that's more like it.
The first type of rock we'll
talk about is sedimentary.
On the Earth's surface,
wind and water break down
rock into tiny pieces.
Those pieces might collect in
a riverbed, on a flood plain,
in sand dunes,
or collect on the ground.
Over time, layers of
these fragments build up
and weigh down on one another.
Eventually,
they get fused together
to form sedimentary rocks.
If you look closely,
you can still see pieces
of the original rocks
or sediment
that were
bound together.
(female narrator)
Let's do a demo.
We'll use jelly beans.
Each flavor of jelly bean
represents a rock or mineral
broken down by wind and water
through erosion.
We'll add jelly beans
to some honey and corn starch.
They're the bonding agents
to hold pieces together,
like glue for rocks.
A little time and pressure
turns our jelly bean
pieces of sediment
into a brand-new rock.
(male narrator)
If you apply heat
and pressure,
it becomes
a metamorphic rock.
Metamorphic rock
may form by friction
of the Earth's
shifting crust,
pressure deep within the Earth,
or even radioactive decay.
The heat and pressure cause
the rock structure to change,
taking on a new form.
Though it's changed,
you can see
structures of its
original components.
(female narrator)
Let's turn our sedimentary
jelly bean rock
into a metamorphic one
with heat and pressure.
(Describer) It’s wrapped in foil.
To add pressure, we'll put
this heavy pot on top.
For heat, we'll bake it
for 30 minutes.
After it's cooled,
our jelly bean rock
has formed a more solid unit.
You can still see the
individual pieces of candy,
but the structure has
fundamentally changed.
(male narrator)
The third type of rock
is igneous.
When rocks get superheated
deep within the Earth,
they melt and form
a liquid called magma.
If magma moves up
in the Earth's crust,
it begins to cool.
Igneous rocks have
a uniform structure,
but different properties,
depending on
whether they cooled
on the Earth's surface
or within the crust.
(female narrator)
To turn our metamorphic rock
into igneous rock,
we're going to melt it
in boiling water.
When our rock has cooled,
you can see the pieces combined
to make an igneous rock
with uniform structure.
(Describer) It’s black.
Pretty cool, huh?
(male narrator)
This is part of the story.
We showed one path
through the rock cycle,
but any rock can go
from one type to another.
For example,
igneous rocks can turn
into either metamorphic
or sedimentary.
And metamorphic rocks don't
have to become igneous rocks.
They can be broken down
again and become sedimentary.
Or sedimentary rocks can
get pushed within the Earth
to form igneous.
See? All of the rock types
are connected,
making a cycle
that never ends.
[rock music]
(Describer) The woman dressed as sedimentary rock sings while the men dressed as metamorphic and igneous rocks pretend to play guitar and drums.
Titles: Made by Allie Anderson, Rita Domingues, Brad Holschuh, Aaron Johnson, Justin Kaderka.
Music by Zep Herme, Luffy (under Creative Commons).
Except where otherwise noted, this work is licensed under Creative Commons: Attribution, Non-Commercial, Share-Alike.
Accessibility provided by the U.S. Department of Education.
♪ We are the rocks
of the world ♪
♪ Whoa-ho-ho
Rocking ♪
♪ We are rocking so much ♪
♪ Until tonight ♪
♪ Rockin', baby ♪
♪ Whoo-hoo
Rockin' to the beat ♪
♪ Rockin', baby ♪
♪ Whoo-hoo, whoo-hoo ♪
♪ Rocking until
the sun comes up ♪♪
Accessibility provided by the
U.S. Department of Education.
