What is a fossil? Give some examples.

A fossil is an imprint of something that lived a long time ago. I have seen an imprint of a shell on a rock.

What are some things scientists can find out using rocks and rock layers?

Scientists can figure out what the rocks are made of and about different things that used to live there.

What are some organisms that have lived in the past that are now extinct?

Dinosaurs, ferns, raptors, pterodactyls, woolly mammoths, different bug like things.

Give an example of weathering.

Weathering is when rocks are broken down into smaller pieces.

What are examples of erosion?

Erosion happens when wind and water move small pieces of rocks and stuff around and it settles in a new place.

Name some of Earth’s processes that can change what the landscape looks like.

Some processes that can change how the landscape looks are erosion, earthquakes, volcanoes, and landslides.

How old is Earth and what do we use to keep track of major Earth events?

Earth is 4.6 billion years old and the geologic time scale is used to keep track of the events that have happened since Earth was formed.

What caused most of the dinosaurs to go extinct and how do scientists know?

A big meteor hit Earth, and scientists know this because they have found a rock layer they named the K-T boundary that show dinosaurs living before that layer but none after.

Explain how weathering and erosion can lead to creating some of the landforms we see?

Weathering and erosion made things like the Grand Canyon because the river weathered the rocks and erosion moved it down the river.

What can the rock layers tell us about life on Earth?

The rock layers can tell us when different organisms went extinct. They can also tell us when new organisms showed up, like during the Cambrian explosion.

Explain the process that creates sedimentary rocks.

Sedimentary rock is made from sediment that were eroded and deposited in layers. Over time, the weight of the layers on top compact the sediments in the layer below. Sediments are later cemented together by natural processes forming sedimentary rock.

Explain how natural processes, like earthquakes, unearth new rock layers and fossils.

Earthquakes shake Earth, sometimes causing cracks. When Earth shakes, it moves the crust around and this could help expose new rock layers and fossils.

Rock Layers (Geologic Time)

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What you will learn from this videoWhat you will learn

Scientists study rock layers to understand Earth's history.
In a series of rock layers, the oldest ones are the bottom and the newest one are at the top.
Scientists organize Earth's 4.6 billion year history through the geologic time scale.

Discussion Questions
- Before Video
  What is a fossil? Give some examples.ANSWER
  - A fossil is an imprint of something that lived a long time ago. I have seen an imprint of a shell on a rock.
  What are some things scientists can find out using rocks and rock layers?ANSWER
  - Scientists can figure out what the rocks are made of and about different things that used to live there.
  What are some organisms that have lived in the past that are now extinct?ANSWER
  - Dinosaurs, ferns, raptors, pterodactyls, woolly mammoths, different bug like things.
  Give an example of weathering.ANSWER
  - Weathering is when rocks are broken down into smaller pieces.
  What are examples of erosion?ANSWER
  - Erosion happens when wind and water move small pieces of rocks and stuff around and it settles in a new place.
  Name some of Earth’s processes that can change what the landscape looks like.ANSWER
  - Some processes that can change how the landscape looks are erosion, earthquakes, volcanoes, and landslides.
- After Video
  How old is Earth and what do we use to keep track of major Earth events?ANSWER
  - Earth is 4.6 billion years old and the geologic time scale is used to keep track of the events that have happened since Earth was formed.
  What caused most of the dinosaurs to go extinct and how do scientists know? ANSWER
  - A big meteor hit Earth, and scientists know this because they have found a rock layer they named the K-T boundary that show dinosaurs living before that layer but none after.
  Explain how weathering and erosion can lead to creating some of the landforms we see?ANSWER
  - Weathering and erosion made things like the Grand Canyon because the river weathered the rocks and erosion moved it down the river.
  What can the rock layers tell us about life on Earth?ANSWER
  - The rock layers can tell us when different organisms went extinct. They can also tell us when new organisms showed up, like during the Cambrian explosion.
  Explain the process that creates sedimentary rocks.ANSWER
  - Sedimentary rock is made from sediment that were eroded and deposited in layers. Over time, the weight of the layers on top compact the sediments in the layer below. Sediments are later cemented together by natural processes forming sedimentary rock.
  Explain how natural processes, like earthquakes, unearth new rock layers and fossils.ANSWER
  - Earthquakes shake Earth, sometimes causing cracks. When Earth shakes, it moves the crust around and this could help expose new rock layers and fossils.
Vocabulary
- Geologic time scale DEFINE
- Sedimentary rock DEFINE
- Erosion DEFINE
- Deposited DEFINE
- Weathering DEFINE
- Intrusion DEFINE
- Relative dating DEFINE
- Absolute dating DEFINE
- Fossil DEFINE
- Plate tectonics DEFINE
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Assessment
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