Introduction to Physical Geology - Chapter 9

How old do geologists believe the Earth is?

• 2022 years old

• 3.6 billion years old
• 4.6 billion years old
• 4.6 million years old
• 10 Billion years old

The ______________ era covers almost 90% of earth's history.

• Paleozoic 
• Mesozoic 
• Cenozoic
• Precambrian 
• Jurassic

According to the law of superposition, which layer is the youngest?

• A
• B
• C

Scientists chose where units of geologic time began and ended based on major changes in life forms at certain times.

• True
• False

Relative age of a rock is the number of years that have passed since the rock formed?            

• True
• False

Radiometric dating is often referred to as 

• total age.
• absolute dating.
• historic age.
• geologic age.
• none of the above

The Geologic Time Scale is a record of what?

• old geologists
• sweet geology music
• the known history of rocks and fossils
• a list of every living thing ever
• relativity

In which geological era do we currently live?

• Jurassic

• Paleozoic

• Mesozoic

• Cenozoic

• Triassic

What is the difference between relative dating and absolute dating?

• Relative dating provides the exact age of a rock, while absolute dating provides a rough estimate of the rock’s age
• Relative dating can estimate a rock’s age only in relation to other objects or events, while absolute dating can provide an actual age
• Relative dating uses several types of radioactive decay to determine an object’s relative age, while absolute dating only uses the halflife of uranium 235
• Relative dating and absolute dating can only determine the rock’s age in relation to other objects or events