Earth Science 13th Edition solutions

Earth Science 13
Refer to the geologic time scale in Figure 12.3. The Precambrian accounts for nearly 90 percent of geologic time. Why do you think it has fewer divisions than the rest of the time scale?

Earth Science 13
Referring to Figure 12.4, list the major events that led to the formation of Earth.

Earth Science 13
What does the existence of iron-rich rocks during the Precambrian indicate about the evolution of Earths atmosphere?

Earth Science 13
What are two ways that the appearance of a significant amount of oxygen in the atmosphere relates to life?

Earth Science 13
Presently, about 71 percent of Earths surface is ocean covered. This percentage was much higher early in Earth history. Explain.

Earth Science 13
Refer to Figure 12.12. Explain why there are so few rocks older than 3,500 million years old on Earth.

Earth Science 13
Contrast the eastern and western margins of North America during the Cenozoic era in terms of their relationships to plate boundaries.

Earth Science 13
Why do you think plants moved onto land before animals?

Earth Science 13
Refer to Figure 12.21. How has biodiversity changed with time? How did mass extinctions contribute to this trend?

Earth Science 13
Some scientists have proposed that the environments around black smokers may be similar to the extreme conditions that existed early in Earth history. Therefore, they look to the unusual life that exists around black smokers for clues about how earliest life may have survived. Compare and contrast th