Earth Science 4.09

Which of the following is the primary technique for determining the absolute age of a rock?

• comparing the rock to similar rocks and noting the differences
• measuring radioactive decay of element isotopes
• comparing the rock to other geologic features
• measuring the dimensions of the rock

The disappearance of organisms from the geologic record provides evidence for which of the following events?

• periods of mass extinction
• a change in climate
• a change in sea level
• continental drift

What does the theory of uniformitarianism state?

• Earth has not changed for billions of years.
• Evidence from fossils can give us glimpses into the past.
• Major catastrophic events shaped the earth.
• Geologic processes we see today were also at work in the past.

Geologists frequently look at the relationships among rock layers. Which statement best describes the information geologists get from studying these relationships?

• They get a sense of which rocks are the most valuable.
• They get a sense of the history of the area they are investigating.
• They can tell how dense the rocks are.
• They can tell how old the rocks are.

Which of the following could be used to interpret the geologic history of a location?

• plant life
• human remains
• rock layers
• atmospheric components

Suppose you are hiking in the hills and you come across a wall of rock. You look closely at the rock and you notice a Trilobite fossil embedded in it. What might this fossil suggest to you about the hills you are hiking in?

• The hills used to be volcanic and are now dormant.
• The hills, at one time, were under water.
• The hills were once at a much higher elevation.
• The hills are rich in sandstone.

Volcanic rock has often been found early in the rock record but less frequently in later rock layers. What does this suggest to scientists about early earth?

• Volcanic rock is easier to find.
• Volcanic activity is the same today as it was early in earth's history.
• Volcanic activity was more common in the past than it is today.
• Volcanic rock is more easily preserved than other kinds of rock.

Which of the following events separate geologic time into eras and periods?

• the number of earthquakes occurring at that time
• the appearance and disappearance of volcanoes
• the creation of new ocean ridges
• the appearance and disappearance of groups of organisms

Fossils in Precambian rocks are rare, while there are many fossils in rocks from the Phanerozoic eon. What does this evidence suggest?

• There was no life in the Precambian eon.
• There was a major change in the diversity of life in the Phanerozoic eon.
• The rocks from the Phanerozoic eon are much harder than those from the Precambrian eon.
• There was no change in the diversity of life in the Phanerozoic eon.

Only a small portion of the organisms that lived in the geologic past have been preserved as fossils. Which condition best increases the chance that an organism will become fossilized?

• slow burial and large body size
• slow burial and hard body parts
• rapid burial and large body size
• rapid burial and hard body parts