geologic time review

Put these amounts of time in order from biggest to smallest.  

• Eon > Era > Period > Epoch
  
• Epoch > Eon > Period > Era
• Period > Eon > Epoch > Era
• Era > Eaon > Epoch > Period

What percent of carbon-14 would be left after 5730 years (one half-life)? 

• 100%
• 75%
• 50%
• 25%

What percent of carbon-14 would be left after 11,460 years (two half-lives)?

• 100%
• 75%
• 50%
• 25%

What is Half-life?

• The amount of time it takes for some of the atoms in a sample of the isotope to decay
• the amount of time it takes to double the atoms in a sample of the isotope to decay
• The amount of time it takes for half the atoms in a sample of the isotope to decay

Use the diagram and the law of superposition to determine what is the oldest layer. 

• The bottom layer will contain the oldest fossils
• The top layer will contain the oldest fossils
• It is impossible to tell which layer contains the oldest fossils with out absolute dating
• Layer A and C contain fossils from the same period

_{Which rock layer in the diagram seems to be the oldest?}

• F
• E
• B
• A

Which of the following is the oldest?

• Layer L
• Intrusion D
• Intrusion H
• Layer E

In this rock layer diagram there are two unconformities, a fault at E and an intrusion at D. Which unconformity occurred first?  How do you know?

• Intrusion D occurred first because the instrusion has been moved by the fault.
• The fault occurred first because it has moved the intrusion D.
• Intrusion D occurred first because it can be seen in all of the rock layers.
• Fault E occurred first because it is a normal fault.

Most events on the geologic timeline happened:

• a long time ago, near the beginning
• more recently, near the modern time
• evenly spread out
• right in the center of the timeline

What type of rock do fossils form in?

• Igneous
• Sedimentary
• Metamorphic
• Classic