Evidence of Earth's History

Which of the following is an example of a geologic process that can be described by the principle of uniformitarianism?

• an asteroid impact
• a mass extinction
• steady erosion
• a large earthquake

Which of the following is a type of event that could cause immediate changes in Earth’s global climate?

• continental drift
• asteroid impact
• fossil formation
• mass extinction

Which of the following types of geologic evidence could result from an asteroid impact on Earth's surface?

• alternating layers of lava and volcanic ash erupted by a volcano
• fossils that show a steady rate of evolution in a certain type of organism
• petrified trees that have tree rings showing several years of stunted growth
• ice cores that show a gradual change in the carbon dioxide content of the atmosphere

The composition of sedimentary rock shows the source of the sediment that makes up the rock. Which of the following would provide the best evidence of how the rock formed?

• the rock’s age
• the rock’s color
• the rock’s texture
• the rock’s fossil content

Sometimes a fossil is formed as a result of the movement of an organism in soft sediment. Which of the following are two kinds of trace fossils?

• shells and bones
• tracks and burrows
• bee and beetle in amber
• petrified and mummified fossils

The figure below shows one type of physical evidence that scientists use to understand Earth’s past. Imagine that you found this evidence on a mountaintop.
What could you conclude from your discovery?

• This organism is now extinct.
• This fossil is older than the mountaintop.
• The mountaintop is made of metamorphic rock.
• The rocks on this mountaintop were once at the bottom of an ocean.

Florida was once part of Gondwanaland, which was a supercontinent that later divided into Africa and South America. Which statement best describes this process?

• A volcanic eruption likely caused Gondwanaland to divide.
• The continents have been moving throughout Earth’s history.
• Weathering and erosion eventually broke Gondwanaland apart.
• Africa and South America go through cycles of dividing and colliding.

A team of scientists is searching for specimens to understand how Earth’s climate has changed in the past. The black boxes in the figure below show where this team has drilled to obtain such specimens.
What were these scientists drilling for?

• ice cores
• surface landforms
• sea-floor sediments
• fossils preserved in amber

In 1897, a British scientist proposed that Earth was between 20 and 400 million years old. Based on radiometric dating, scientists now propose a different age for Earth. Based on the most current radiometric dating data, about how old is Earth?

• 40 billion years old
• 20 billion years old
• 4.6 billion years old
• 4.6 million years old

Florida State University has a large collection of ice cores taken from the Antarctic. What can scientists learn by studying these ice cores?

• history of Earth’s climate
• how continents have moved
• how new species have evolved
• major changes that have taken place on Earth’s surface