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Vocabulary
Fossils
Geologic Time
Miscellaneous
EMPTY
100
The idea that geologic processes occurring now are the same as those in the past.
What is uniformitarianism
100
If a trilobite were buried by ocean sediment, it would leave a cavity, or a(n )___________.
Mold
100
What is the largest division of geologic time?
Eon
100
The phrase "younger over older" could be used to remember the principle of
superposition
200
The idea that geologic change happens suddenly.
What is catastrophism
200
A fossil used to date surrounding rock layers is called a(n)
index fossil
200
How many years of the history of Earth do geologists study?
4.6 billion years
200
Which era ended with the largest mass extinction in Earth's history?
Paleozoic
300
The study of past life
What is paleontology
300
Give an example of a trace fossil.
foot prints, tail tracks
300
What process always occurs at a steady rate?
Radioactive decay
300
What happens during radioactive decay?
Radioactive isotopes break down into stable isotopes of other elements
400
A science that combines uniformitarianism and catastrophism
What is modern geology
400
What can scientists learn from studying the relationships between fossils?
How life has changed
400
How do geologists use the geologic time scale?
To divide Earth's history into manageable parts
400
What can animal tracks tell about the animal that left them?
How big it was
500
What process involves the comparison of rock layers with others in a sequence to determine its age?
What is relative dating
500
What does a scientist need to know to figure out the absolute age of a rock?
The rate of decay for a radioactive element in the rock
500
What word describes the geologic column?
ideal
500
Erosion is one of the major causes of the missing rock layers known as
unconformities