Geologic Time Goal D Flashcard-Index Fossils

Front

What is an index fossil?

Back

An index fossil is a fossil that is used to define and identify a particular time period in the geologic time scale. It is typically widespread, abundant, and existed for a relatively short duration.

Front

Why are index fossils important in geology?

Back

Index fossils help geologists determine the relative ages of rock layers and correlate them across different geographic locations.

Front

What are the two main traits of a good index fossil?

Back

A good index fossil is widespread geographically and has a short lifespan.

Front

If two rock layers contain the same index fossil, what can be inferred about their ages?

Back

The rock layers are likely to be the same age.

Front

What does relative dating mean in geology?

Back

Relative dating is the method of determining the age of rocks and fossils in relation to one another, without determining their exact age.

Front

What is absolute dating?

Back

Absolute dating is a method used to determine the actual age of a rock or fossil, often through radiometric dating techniques.

Front

Why is fossil #4 not a good index fossil?

Back

Fossil #4 is not a good index fossil because it is not short-lived and does not appear in numerous layers.

Front

What is the significance of widespread distribution in index fossils?

Back

Widespread distribution allows geologists to correlate rock layers across large distances, making it easier to establish a timeline.

Front

How does a short lifespan contribute to the effectiveness of an index fossil?

Back

A short lifespan ensures that the fossil represents a specific time period, making it easier to date the rock layers accurately.

Front

What is the difference between relative and absolute dating?

Back

Relative dating places events in order without exact dates, while absolute dating provides a specific age or date for an event.