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 more easily preserved than other kinds of rock.
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.
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.