Unit 3 Lesson 8 - Reconstructing Earth's History

What does the geologic time scale help scientists understand?

• Future weather patterns

• Exact temperature of ancient oceans

• Age and sequence of Earth's history

Why are fossils important?

• Predict future earthquakes

• Help scientists learn about Earth’s past

• Form new rock layers

What is relative dating?

• It tells the exact age of a rock

• It compares the age of rocks without giving exact dates

• It uses fossils to predict future species

Radioactive dating is also called:

• Relative dating

• Absolute dating

• Fossil dating

Which element is used in radioactive dating?

• Hydrogen

• Carbon-14

• Oxygen

What are the four main eons in Earth’s history, from oldest to youngest?

• Phanerozoic, Proterozoic, Archaean, Hadean

• Hadean, Archaean, Proterozoic, Phanerozoic

• Mesozoic, Cenozoic, Paleozoic, Phanerozoic

Which era is called the “Age of Dinosaurs”?

• Cenozoic

• Paleozoic

• Mesozoic

What is an extinction event?

• When a new species evolves

• When many species die out quickly

• When an earthquake splits a continent

The movement of tectonic plates causes:

• Changes in weather only

• Earth’s magnetic field to disappear

• Earthquakes, mountain formation, and volcanic activity

Which eon do we currently live in?

• Phanerozoic

• Archaean

• Proterozoic