The Rock CyclePg 268-271

Essential Question

• How do the rock cycle and the principle of Uniformitarianism explain Earth’s landscape and history?

Previously, in life science…

You learned about life’s changes over time. Now, you will learn about the rock cycle as on aspect of Earth’s changes over time.

Section 1 vocabulary (page 268)

• geology• erosion• uniformitarianism• igneous rock• sedimentary rock• metamorphic rock• rock cycle• magma• lava

1. What was Hutton’s Big Idea?

• Uniformitarianism!

Who was James Hutton?

• Almost singlehandedly and quite brilliantly created the science of geology and transformed our understanding of the Earth.

• Among questions that attracted his interest was why ancient clam shells and other marine fossils were so often found on mountain tops. How did they get there?

• It was while pondering this, that Hutton had some amazing insights.

• From looking at his own farmland, he could see that soil was created by the erosion of rocks and that particles of this soil were continually washed away and carried off by streams and rivers and deposited elsewhere.

• There also must be some additional process, to lift and renew hills and mountaintops to keep the cycle going.

• The marine fossils had risen along with the mountains themselves!

Marine fossils in the Himalayas!

The rocks of these giant mountains were once at the bottom of the ocean!

2. What is uniformitarianism?

• The idea that the geological processes that operate today ALSO operated in the past.

• AND slow geological processes have large effects over long periods of time.

Who first proposed the principle of uniformitarianism?

• James Hutton!

3. Why was this important?

• Because we can understand the ancient world by observing present-day processes

• Also, Earth must be very old.

4. What are the 3 main groups of rocks?

• Igneous (volcanic)

• Sedimentary (erosion & deposition)

• Metamorphic (heat & pressure)

5. What is the rock cycle?

• A series of forces inside the Earth and at Earth’s surface that build, change, and destroy rocks.

6. How are sedimentary rocks formed?• By erosion and deposition

(wearing away and piling of sediments)

How does a sedimentary rock form?• Erosion and deposition!

7. How does an igneous rock form?

• Volcanic activity!

8. How does a metamorphic rock form?• Heat and pressure!

Does the rock cycle have a beginning or an end?• No!

http://www.uky.edu/AS/Geology/howell/goodies/elearning/module05swf.swf

Here’s a Rock Cycle animation….