Understanding Geologic Time

The video tutorial explains how geologists measure the age of Earth using geologic time, which is divided into relative and absolute time. Relative time involves comparing the age of rocks and events, while absolute time provides specific ages in years. The law of superposition helps determine the relative age of rock layers. Modern techniques allow geologists to accurately date rocks and fossils, providing absolute ages. Examples include dating a cinder cone volcano and fossilized trees.

How do geologists describe the age of Earth compared to how we describe our age?

• In terms of centuries

• In terms of millions or billions of years

• In terms of decades

• In terms of days and months

What does the law of superposition state about sedimentary rock layers?

• All rocks are the same age

• Older rocks are found at the top

• Younger rocks are found at the bottom

• Younger rocks are found at the top

Which analogy is used to explain the concept of relative time in geology?

• A stack of books

• A stack of pancakes

• A stack of plates

• A stack of cards

What is an example of an absolute geologic age given in the video?

• A desert estimated to be 200 years old

• A cinder cone volcano estimated to be 900 years old

• A river estimated to be 1000 years old

• A mountain estimated to be 500 years old

How do modern geologists determine the age of rocks and fossils?

• By guessing based on appearance

• Using a variety of techniques for accurate dating

• By comparing them to modern objects

• By asking local historians