1. Inside the Restless Earth Chapter 3 Section 5
Time Marches On
Inside the Restless Earth
Chapter 3 Section 5

2. Q: What is the rock record and geologic time?
A: The rock layers (strata) in the Grand Canyon represent about 2 billion years of Earth’s history.
D:The Colorado River has cut (weathering and erosion) the canyon in as much as 2km is some areas.
D: The river has been at work for almost 6 million years.

3. Q: What is the fossil record and the geologic time scale?
A: Fossils of plants and animals are common in the sedimentary rock structures of the Green river in Colorado, Utah, and Wyoming.
D: The rocks were part of a system of lakes for millions of years.
D: Fine-grain sediment preserved delicate structures

4. Q: What is the fossil record and the geologic time scale?

5. Q: How is time divided?
A: The geologic time scale in divided into eons, eras, periods, epochs.
D: eon
Hadean (4.6 billion – 3.8 billion year ago)
Archean (3.8 billion – 2.5 billion years ago)
Proterozoic (2.5 billion million years ago)
Phanerozoic (543 million – present time)
D: Panerozoic eon is divided into three eras
Cenozoic
Mesozoic
Paleozoic

6. Q: How is time divided?

7. Q: What does the appearance or disappearance of species mean?
A: Throughout history the number of different species either increased or decreased.
Hallucigenia appeared in the Cambrian period
Other organisms disappeared
Extinction-the death of every member of a species (ex. Dinosaurs)

8. Q: What is the Paleozoic Era? (543-248 million years ago) Old Life
A: This is the first era represented by fossils and is known as the old life era.
D: Marine (ocean) life flourished
D: Near the end of the era-reptiles began to live on land
D: This era ended with a mass extinction. 90% of all species were killed

9. Q: What is the Mesozoic Era? (248 years ago) The age of Reptiles
A: This is called the age of reptiles because dinosaurs roamed the land during this time.
Birds and mammals began to evolve
15%-20% of species went extinct
Climate change or an asteroid caused the extinction

10. Q: What is the Cenozoic era? (65 million years ago) The Age of Mammals
A: This era is known as the Age of Mammals.
D: Mammals flourished
Regulate body temperature