# Presentation: 363830

## Today, you are going meet a rock band to help explain about the changing earth—but not the kind of rock band you might expect.  These are the rocks that make up the Central Appalachian Mountains, and they are going to tell you their story. 

- The oldest member of the band is Granny Gneiss.

- When you look** **at the land around you—the rocks, mountains, streams, and other features, you may think they have always been the way they look now.  But the entire Earth is changing all the time  in ways that might surprise you.

## GRANNY GNEISS:

**GRANNY GNEISS:**
- Hello!  My real name is* ****Granite***
- Gneiss, but you can call me Granny.  My name is **not **spelled N-I-C-E like it sounds.  It’s G-N-E-I-S-S.
- I have seen a lot of changes since
- I was formed over a billion years
- ago. **  **Continents have moved around and have collided with each other. Mountains have grown, then eroded or worn down into tiny pieces of sand, then formed again. I’ve seen dinosaurs come and go, and volcanoes erupt.  I’ve seen it all, I tell you.   In fact, I’m one of the oldest things on Earth.   Nothing you can see around you is nearly as old!

## When I was born, all the continents of the world had collided to form one giant continent.  During the collision I was pushed and squeezed until my minerals flattened and some look like eyes.

## Then,  I noticed that it was getting awfully hot underneath me, and suddenly— 

- Then,  I noticed that it was getting awfully hot underneath me, and suddenly—

## there were volcanoes erupting all over the place. 

- there were volcanoes erupting all over the place.

## FLO:

**FLO:**
- Hello.  I came from one of those volcanoes, and you can call me Flo.  A lot of people think that I am hot stuff.  Maybe that’s because when I formed, my temperature was about 2000 degrees Fahrenheit. That’s a lot hotter than an oven.  It’s  hot enough to melt rock!  But I flow slowly—kind of like a thick, hot fudge topping. When I cooled off,  I became a black rock with crystals too tiny to see with your eye.  But if you think I was hot stuff, you should meet Tuffy.

## TUFFY:

**TUFFY:**
- Hi! Yes, indeed, I was not only
- hot, I was explosive!  Do you
- know what will happen if you
- shake a can of soda for a long
- time and then open it?  Gases in the soda make it explode out of the top.

## Well, that’s how I came out of the volcano—gases in the lava carried me out of the top and I exploded.  I thought I was Rocket Rock! It was really exciting when I shot through the air.  Then I fell to the ground and cooled off.

## FLO: Do you know what group of rocks Tuffy and I belong to?

## We are igneous. That means we were totally melted when we formed!

## TUFFY: The eruptions were exciting, but when they ended,  I was out in the open.  

**TUFFY: **The eruptions were exciting, but when they ended,  I was out in the open.

## It rained and snowed on me. Water froze in cracks and wedged me into pieces, and bit by bit I started to break up into tiny pieces of sand and clay.

## SANDY:

- Hey Tuffy! Do you have a problem with sand and clay?  Just remember that we’re the ones who have all the fun!
- Hi.  My name is sandstone, but my friends call me Sandy.  When Tuffy broke up or eroded into sand and clay, I was formed.  I’m made of sand, and my brother, Shay, is made of clay.

## Have you ever gone river rafting? Well, that’s what we did, only we didn’t ride on top of the river, we rode in it— washed downstream by the water!

- Have you ever gone river rafting? Well, that’s what we did, only we didn’t ride on top of the river, we rode **in** it— washed downstream by the water!

## After we rode in the river for a long time we got to the seashore. My pieces of sand were heavier than Shay’s tiny pieces of clay.  When the river finally carried me to the ocean I was too heavy to be moved by the water any more. I stayed where I fell along the seashore and formed a beach.  My brother Shay was lighter and floated out to sea before settling to the bottom. 

## SHAY:

**SHAY:**
- Hi.  I’m shale, but you can call me Shay. I form in deep water where it’s quiet and calm. There is another rock that forms as far out in the ocean as I do.

## SHAY:

**SHAY:**
- Her name is Limey and she is very useful to people. After all of the continents were together, they drifted apart, and for a long time most of what is now the United States was covered by a huge, shallow sea.  That’s where I met Limey.

## LIMEY: 

**LIMEY:**
- Thank you, Shay. Yes, I was born in the sea.  Sometimes I’m made of seashells or corals that turn into fossils.  I like warm, shallow water.

## SANDY: Limey, Shay, and I are all part of the same group of rocks.  Can you guess which group?

**SANDY: **Limey, Shay, and I are all part of the same group of rocks.  Can you guess which group?

## LIMEY:If you guessed sedimentary, you were right. The word “sediment”  means “to settle” because we settle out into flat layers, usually underwater. 

**LIMEY:**If you guessed sedimentary, you were right. The word “sediment”  means “to settle” because we settle out into flat layers, usually underwater.

## SHAY: People like Limey because she does a lot to help them.

**SHAY: **People like Limey because she does a lot to help them.

## Yes, lime in soil helps plants like apple trees grow. 

## LIMEY:  People also dig me up to make roads and concrete.  

## When I change to marble it is easy to cut big strong blocks for making buildings. Did you know that the Washington Monument is made of marble that used to be limestone?

- I also help teach your class at school. The chalk your teacher uses is made of a very pure form of limestone.

## Sometimes, when water dissolves me underground, I make caves.  People like to visit caves because many are so beautiful inside.  Caves also provide homes for bats, which eat lots of mosquitoes and flies every day. 

- Sometimes, when water dissolves me underground, I make caves.  People like to visit caves because many are so beautiful inside.  Caves also provide homes for bats, which eat lots of mosquitoes and flies every day.

## When I was forming, there was a much larger and deeper ocean to the east. The ocean was a lot like the Atlantic Ocean of today, but it  was different, too. 

## FLO:

**FLO:**
- Yes, there were islands and volcanoes in the ocean.  When I erupted out of a volcano, I flowed right out under the ocean water onto the sea floor just like lava does today in Hawaii and Iceland. Talk about cold water! I turned rock hard in seconds.

## Since Granny first formed life had been slowly developing on Earth.  By this time, about 400 million years ago, plants and animals had come out of the oceans and were adapted to life on land. This was a long, long time ago, even before age of dinosaurs, and the plants and animals looked a lot different than the ones you see today. 

- Since Granny first formed life had been slowly developing on Earth.  By this time, about 400 million years ago, plants and animals had come out of the oceans and were adapted to life on land. This was a long, long time ago, even before age of dinosaurs, and the plants and animals looked a lot different than the ones you see today.

## SHAY:

**SHAY:**
- The *really *big change was deep
- within the earth.  The continents
- started moving closer together again. The ocean that was between them got squeezed smaller and smaller, including the layers of rock that were under the ocean. Then some of the volcanic islands ran right over the top of me. Now that’s a lot of pressure!

## Finally, the continents collided.  It was like a big truck running into a giant snow bank.  Huge layers of rock slid across each other like they were nothing but a deck of cards. 

- Finally, the continents collided.  It was like a big truck running into a giant snow bank.  Huge layers of rock slid across each other like they were nothing but a deck of cards.

## SANDY: We were buried under tons of  rock, and it was hot, too. 

**SANDY: **We were buried under tons of  rock, and it was hot, too.

## SHAY:

**SHAY:**
- Yes, but the collision pushed us
- right back up into the mountains,
- so we could ride rivers again.
- With the first hard rain, I’m ready
- to travel back to the ocean again.

## SANDY:

**SANDY:**
- I’m harder than Shay, and I like being up high on the ridges and cliffs. But I’ve been here for a few million years and I am ready to go for a ride.  Let’s go!

## GLOMMY:

**Hey! Wait for me!**
**I want to go, too!**

## SANDY:

**Look out!**
- Here comes Glommy!

## SHAY:

- Glommy is made of pebbles that are so big it takes a flood to get her moving.

## SHAY: When water slows down, the pebbles fall straight to the bottom, because they are so heavy.  When pebbles get cemented together they make a rock called conglomerate.  That’s Glommy!

## SANDY:

- After Glommy settled down, I enjoyed the ride. The lake we were washing into formed when the continent started to pull apart again, and water filled low areas.  One of those areas was in what is now northern Virginia  between Reston and Leesburg.

## There was lots of oxygen in the air and bits of iron in me rusted or turned red, and soon I had a new red outfit.

## But then melted rock came up along cracks, and I got roasted.  When the melted rock cooled, it got solid and hard and it’s used on a lot of roads now.  

- But then melted rock came up along cracks, and I got roasted.  When the melted rock cooled, it got solid and hard and it’s used on a lot of roads now.

## SHAY:

**SHAY:**
- Roasted feet wasn’t the only thing that happened to  Sandy though—no indeed!  One day the water in the lake was so low that she was at the surface.  She was just lying there in the sun minding her own business when she felt something ***very*** heavy walking on her.

## Here’s a closer look at the lake and there it is.  

## A dinosaur walked right across Sandy’s new red outfit.

## SANDY:

** **

**SANDY:**
- That dinosaur’s big old feet sank right in and made footprints all over me.  Then, about 200 million years later, people found the dinosaur’s footprints in a quarry.  They got excited and called in scientists from the USGS.  They all made a big exciting fuss about it.

## They cut out a  big block of me to display the footprints. I loved being noticed by all those people. If you visit the USGS and see the dinosaur footprints, I hope you will notice me, too. 

## SHAY:

**SHAY:**
- With the water drying up and land rising, it was time to move on.  The new Atlantic Ocean was right nearby and since it was downhill from us, off we went on another river ride.

## FLO:

**FLO:**
- Well, Tuffy and I are still in the mountains, but we cooled off a long time ago. We changed even more when the continents collided.  I used to be jet black, but I’m dark green now.  Some rocks changed so much that you can hardly tell what used to be—like my friend, Shifty Schist.

## SHIFTY SCHIST:

**SHIFTY SCHIST:**
- Hi everybody!  It’s about time I
- got to meet you!  I guess they
- saved the best for last.  I used to be a volcanic rock, but I am completely changed.  Yes, indeed, heat and pressure made a new rock of me.  High temperatures and pressures deep in the earth let new minerals grow and pushed them into shiny layers that are neatly folded.
- Do you know what kind of rock
- I am?

## I am metamorphic (that means changed), and like all rocks, I just keep on changing.  As a matter of fact, just like all my rock band friends in the hills and mountains around here,  I’m about  to go on another river ride. 

## GRANNY GNEISS:

**GRANNY GNEISS:**
- Hey Shifty, that sounds like fun.  I’d like to go, too.

## GLOMMY:

**GLOMMY:**
**Hey! Wait for me!**
**I want to go!**

## SHIFTY:  Look out!  Here comes Glommy!  OK, Glommy, hurry up!

## GRANNY GNEISS:

- Now you have met the members
- of the rock band.  We belong to
- three groups, but we are all related,
- and one thing that we all do is
- change.  So the next time you see
- us, stop and look closely to get
- to know us better.
- So all together—What is your favorite rock?

## Slide 54

## Slide 55